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Sample records for rectum volumes cibles

  1. Rectal cancer: The radiation basis of radiotherapy, target volume; Cancers du rectum: volumes cible de la radiotherapie, bases rationnelles

    Energy Technology Data Exchange (ETDEWEB)

    Bosset, J.F.; Servagi-Vernat, S. [Service oncologie-radiotherapie, CHU Jean-Minjoz, 3, boulevard Fleming, 25030 Besancon (France); Crehange, G. [Service oncologie-radiotherapie, centre Georges-Francois-Leclerc, 1, rue du Pr-Marion, 21079 Dijon cedex (France); Azria, D. [Service oncologie-radiotherapie, centre Val-d' Aurelle, rue Croix-Verte, 34298 Montpellier cedex 5 (France); Gerard, J.P. [Service oncologie-radiotherapie, centre Antoine-Lacassagne, 33, avenue Valombrose, 06189 Nice (France); Hennequin, C. [Service oncologie-radiotherapie, hopital Saint-Louis, 1, avenue Claude-Vellefaux, 75475 Paris (France)

    2011-10-15

    Since the implementation of preoperative chemo-radiotherapy and meso-rectal excision, the 5-year rates of locoregional failures in T3-T4 N0-N1M0 rectal cancer fell from 25-30% thirty years ago to 5-8% nowadays. A critical analysis of the locoregional failures sites and mechanisms, as well as the identification of nodal extension, helps the radiation oncologist to optimize the radiotherapy target definition. The upper limit of the clinical target volume is usually set at the top of the third sacral vertebra. The lateral pelvic nodes should be included when the tumor is located in the distal part of the rectum. The anal sphincter and the levator muscles should be spared when a conservative surgery is planned. In case of abdomino-perineal excision, the ischio-rectal fossa and the sphincters should be included in the clinical target volume. A confrontation with radiologist and surgeon is mandatory to improve the definition of the target volumes to be treated. (authors)

  2. Testing the new ICRU 62 'Planning Organ at Risk Volume' concept for the rectum

    International Nuclear Information System (INIS)

    Muren, Ludvig Paul; Karlsdottir, Asa; Kvinnsland, Yngve; Wentzel-Larsen, Tore; Dahl, Olav

    2005-01-01

    Background and purpose: To study the impact of the new ICRU 62 'Planning organ at Risk Volume' (PRV) concept on the relationship between rectum dose-volume histogram (DVH) data and toxicity. Patients and methods: The acute gastro-intestinal (GI) RTOG toxicity in 127 prostate cancer patients prescribed a total dose of 70 Gy with conformal irradiation to either the prostate, the prostate and seminal vesicles or the whole pelvis (initial 50 Gy only) were analysed. DVHs were derived for the rectum only and for rectum extended with six PRV margin sets (narrow/intermediate/wide; anterior/anterior and posterior). The data was analysed using permutation tests, logistic regression and effective uniform dose (EUD) calculations. Results: Acute Grade 2 GI toxicity was seen in 22 of 127 cases (17%). Permutation tests showed that the difference between DVHs for patients with and without Grade 2 effects was significant, both for rectum only and rectum PRVs (P-value range: 0.02-0.04), with generally lower P-values for the PRVs. In the logistic regression, the fractional DVH variables (i.e. volumes) were significantly related to toxicity, with approximately 2-3 times as many significant dose levels for the PRVs as for rectum only. E.g. with wide anterior and posterior margins (16 and 11 mm, respectively) the relation was significant at 26 different dose levels (6-7, 13-14, 35-43, 60-71 and 73 Gy), compared to nine levels (38-40, 43-44 and 71-74 Gy) for rectum only. EUDs were significantly different for patients with and without Grade 2 effects both for rectum only and the PRVs (95% confidence interval for EUD increase with Grade 2 effects: 0.1-3.1 Gy). Conclusions: All statistical methods applied indicated a small, but definite difference in DVH parameters between patients with versus those without Grade 2 effects. The difference was most pronounced when margins of 16 mm anterior and 11 mm posterior were applied

  3. A Monte Carlo study of the impact of the choice of rectum volume definition on estimates of equivalent uniform doses and the volume parameter

    International Nuclear Information System (INIS)

    Kvinnsland, Yngve; Muren, Ludvig Paul; Dahl, Olav

    2004-01-01

    Calculations of normal tissue complication probability (NTCP) values for the rectum are difficult because it is a hollow, non-rigid, organ. Finding the true cumulative dose distribution for a number of treatment fractions requires a CT scan before each treatment fraction. This is labour intensive, and several surrogate distributions have therefore been suggested, such as dose wall histograms, dose surface histograms and histograms for the solid rectum, with and without margins. In this study, a Monte Carlo method is used to investigate the relationships between the cumulative dose distributions based on all treatment fractions and the above-mentioned histograms that are based on one CT scan only, in terms of equivalent uniform dose. Furthermore, the effect of a specific choice of histogram on estimates of the volume parameter of the probit NTCP model was investigated. It was found that the solid rectum and the rectum wall histograms (without margins) gave equivalent uniform doses with an expected value close to the values calculated from the cumulative dose distributions in the rectum wall. With the number of patients available in this study the standard deviations of the estimates of the volume parameter were large, and it was not possible to decide which volume gave the best estimates of the volume parameter, but there were distinct differences in the mean values of the values obtained

  4. Influence of volumes of prostate, rectum, and bladder on treatment planning CT on interfraction prostate shifts during ultrasound image-guided IMRT

    International Nuclear Information System (INIS)

    Reddy, Nandanuri M. S.; Nori, Dattatreyudu; Sartin, William; Maiorano, Samuel; Modena, Jennifer; Mazur, Andrej; Osian, Adrian; Sood, Brijmohan; Ravi, Akkamma; Sampath, Seshadri; Lange, Christopher S.

    2009-01-01

    Purpose: The purpose of this study was to analyze the relationship between prostate, bladder, and rectum volumes on treatment planning CT day and prostate shifts in the XYZ directions on treatment days. Methods: Prostate, seminal vesicles, bladder, and rectum were contoured on CT images obtained in supine position. Intensity modulated radiation therapy plans was prepared. Contours were exported to BAT-ultrasound imaging system. Patients were positioned on the couch using skin marks. An ultrasound probe was used to obtain ultrasound images of prostate, bladder, and rectum, which were aligned with CT images. Couch shifts in the XYZ directions as recommended by BAT system were made and recorded. 4698 couch shifts for 42 patients were analyzed to study the correlations between interfraction prostate shifts vs bladder, rectum, and prostate volumes on planning CT. Results: Mean and range of volumes (cc): Bladder: 179 (42-582), rectum: 108 (28-223), and prostate: 55 (21-154). Mean systematic prostate shifts were (cm, ±SD) right and left lateral: -0.047±0.16 (-0.361-0.251), anterior and posterior: 0.14±0.3 (-0.466-0.669), and superior and inferior: 0.19±0.26 (-0.342-0.633). Bladder volume was not correlated with lateral, anterior/posterior, and superior/inferior prostate shifts (P>0.2). Rectal volume was correlated with anterior/posterior (P 0.2). The smaller the rectal volume or cross sectional area, the larger was the prostate shift anteriorly and vice versa (P 0.2). The smaller the prostate volume, the larger was prostate shift superiorly and vice versa (P<0.05). Conclusions: Prostate and rectal volumes, but not bladder volumes, on treatment planning CT influenced prostate position on treatment fractions. Daily image-guided adoptive radiotherapy would be required for patients with distended or empty rectum on planning CT to reduce rectal toxicity in the case of empty rectum and to minimize geometric miss of prostate.

  5. An improved distance-to-dose correlation for predicting bladder and rectum dose-volumes in knowledge-based VMAT planning for prostate cancer

    Science.gov (United States)

    Wall, Phillip D. H.; Carver, Robert L.; Fontenot, Jonas D.

    2018-01-01

    The overlap volume histogram (OVH) is an anatomical metric commonly used to quantify the geometric relationship between an organ at risk (OAR) and target volume when predicting expected dose-volumes in knowledge-based planning (KBP). This work investigated the influence of additional variables contributing to variations in the assumed linear DVH-OVH correlation for the bladder and rectum in VMAT plans of prostate patients, with the goal of increasing prediction accuracy and achievability of knowledge-based planning methods. VMAT plans were retrospectively generated for 124 prostate patients using multi-criteria optimization. DVHs quantified patient dosimetric data while OVHs quantified patient anatomical information. The DVH-OVH correlations were calculated for fractional bladder and rectum volumes of 30, 50, 65, and 80%. Correlations between potential influencing factors and dose were quantified using the Pearson product-moment correlation coefficient (R). Factors analyzed included the derivative of the OVH, prescribed dose, PTV volume, bladder volume, rectum volume, and in-field OAR volume. Out of the selected factors, only the in-field bladder volume (mean R  =  0.86) showed a strong correlation with bladder doses. Similarly, only the in-field rectal volume (mean R  =  0.76) showed a strong correlation with rectal doses. Therefore, an OVH formalism accounting for in-field OAR volumes was developed to determine the extent to which it improved the DVH-OVH correlation. Including the in-field factor improved the DVH-OVH correlation, with the mean R values over the fractional volumes studied improving from  -0.79 to  -0.85 and  -0.82 to  -0.86 for the bladder and rectum, respectively. A re-planning study was performed on 31 randomly selected database patients to verify the increased accuracy of KBP dose predictions by accounting for bladder and rectum volume within treatment fields. The in-field OVH led to significantly more precise

  6. A study on planning organ at risk volume for the rectum using cone beam computed tomography in the treatment of prostate cancer

    International Nuclear Information System (INIS)

    Prabhakar, Ramachandran; Oates, Richard; Jones, Daryl; Kron, Tomas; Cramb, Jim; Foroudi, Farshad; Geso, Moshi; Gill, Suki

    2014-01-01

    In this study, we analyzed planning organ at risk volume (PRV) for the rectum using a series of cone beam computed tomographies (CBCTs) acquired during the treatment of prostate cancer and evaluated the dosimetric effect of different PRV definitions. Overall, 21 patients with prostate cancer were treated radically with 78 Gy in 39 fractions had in total 418 CBCTs, each acquired at the end of the first 5 fractions and then every alternate fraction. The PRV was generated from the Boolean sum volume of the rectum obtained from first 5 fractions (PRV-CBCT-5) and from all CBCTs (PRV-CBCT-All). The PRV margin was compared at the superior, middle, and inferior slices of the contoured rectum to compare PRV-CBCT-5 and PRV-CBCT-All. We also compared the dose received by the planned rectum (Rectum-computed tomography [CT]), PRV-CBCT-5, PRV-CBCT-All, and average rectum (CBCT-AV-dose-volume histogram [DVH]) at critical dose levels. The average measured rectal volume for all 21 patients for Rectum-CT, PRV-CBCT-5, and PRV-CBCT-All was 44.3 ± 15.0, 92.8 ± 40.40, and 121.5 ± 36.7 cm 3 , respectively. For PRV-CBCT-All, the mean ± standard deviation displacement in the anterior, posterior, right, and left lateral directions in centimeters was 2.1 ± 1.1, 0.9 ± 0.5, 0.9 ± 0.8, and 1.1 ± 0.7 for the superior rectum; 0.8 ± 0.5, 1.1 ± 0.5, 1.0 ± 0.5, and 1.0 ± 0.5 for the middle rectum; and 0.3 ± 0.3; 0.9 ± 0.5; 0.4 ± 0.2, and 0.5 ± 0.3 for the inferior rectum, respectively. The first 5 CBCTs did not predict the PRV for individual patients. Our study shows that the PRV margin is different for superior, middle, and the inferior parts of the rectum, it is wider superiorly and narrower inferiorly. A uniform PRV margin does not represent the actual rectal variations during treatment for all treatment fractions. The large variation in interpatient rectal size implies a potential role for adaptive radiotherapy for prostate cancer

  7. Liquid hydrogen and deuterium targets; Cibles a hydrogene et deuterium liquides

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    Bougon, M; Marquet, M; Prugne, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1961-07-01

    A description is given of 1) Atmospheric pressure target: liquid hydrogen, 400 mm thickness; thermal insulation: styrofoam; the hydrogen vapors are used to improve the target cooling; Mylar windows. 2) Vacuum target: 12 liter content: hydrogen or deuterium; liquid thickness 400 mm; thermal insulation is afforded by a vacuum vessel and a liquid nitrogen shield. Recovery and liquefaction of deuterium vapors are managed in the vacuum vessel which holds the target. The target emptying system is designed for operating in a few minutes. (author) [French] Description de: 1) Cible a pression atmospherique; hydrogene liquide, 400 mm d'epaisseur; l'isolement thermique: styrofoam; on utilise les vapeurs d'hydrogene pour ameliorer le refroidissement de la cible; hublots en Mylar. 2) Cible sous vide; contenance 12 litres; hydrogene ou deuterium; epaisseur du liquide 400 mm; l'isolement thermique est assure par une cuve a vide et un ecran d'azote liquide. Recuperation et liquefaction des vapeurs de deuterium sont effectuees dans la cuve a vide contenant la cible. Le systeme de vidange pour la cible est concu pour fonctionner en quelques minutes. (auteur)

  8. SU-E-J-83: CBCT Based Rectum and Bladder Dose Tracking in the Prostate Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z; Wang, J; Yang, Z; Hu, W [Fudan University Shanghai Cancer Center, Shanghai (China)

    2015-06-15

    Purpose: The aim of this study is to monitor the volume changes of bladder and rectum and evaluate the dosimetric changes of bladder and rectum using daily cone-beam CT for prostate radiotherapy. Methods: The data of this study were obtained from 12 patients, totally 222 CBCTs. All the volume of the bladder and the rectum on the CBCT were normalized to the bladder and the rectum on their own original CT to monitory the volume changes. To evaluate dose delivered to the OARs, volumes that receive 70Gy (V70Gy), 60Gy, 50Gy, 40Gy and 30Gy are calculated for the bladder and the rectum, V20Gy and V10Gy for rectum additionally. And the deviation of the mean dose to the bladder and the rectum are also chosen as the evaluation parameter. Linear regression analysis was performed to identify the mean dose change of the volume change using SPSS 19. Results: The results show that the variances of the normalize volume of the bladder and the rectum are 0.15–0.58 and 0.13–0.50. The variances of V70Gy, V60Gy, V50Gy, V40Gy and V30Gy of bladder are bigger than rectum for 11 patients. The linear regression analysis indicated a negative correlation between the volume and the mean dose of the bladder (p < 0.05). A 10% increase in bladder volume will cause 5.1% (±4.3%) reduction in mean dose. Conclusion: The bladder volume change is more significant than that for rectum for the prostate cancer patient. The volume changes of rectum are not significant except air gap in the rectum. Bladder volume varies will cause significant dose change. The bladder volume monitoring before fractional treatment delivery would be crucial for accuracy dose delivery.

  9. Dose Volume Histogram analysis for rectum and urethral reaction of prostate cancer

    International Nuclear Information System (INIS)

    Yanagi, Takeshi; Tsuji, Hiroshi; Kamada, Tadashi; Tsujii, Hirohiko

    2005-01-01

    The aim of this study is to evaluate the clinically relevant parameters for rectum and urethral reaction using DVH (dose volume histogram) in carbon ion radiotherapy of prostate cancer. In this year, we studied the urinary reaction mainly. 35 patients with prostate cancer were treated with carbon ion beams between June 1995 and December 1997. The applied dose was escalated from 54.0 GyE to 72.0 GyE in fixed 20 fractions. Clinical urinary reaction and rectum reaction were reviewed using Radiation Therapy Oncology Group (RTOG) scoring system for acute reactions, RTOG/European Organization for Research and Treatment of Cancer (EORTC) scoring system for late reactions. Taking the ROI (region of interest) for DVH of urethra, we used surrogate one that was derived from the observation of MR images. 35 patients were analyzed for acute urinary reaction and 34 for late urinary reaction in the study of this year. DVH analysis suggested difference among the grades for acute and late reactions. These analysis appears to be a useful tool for predicting the urinary reactions. (author)

  10. Normal tissue complication probabilities correlated with late effects in the rectum after prostate conformal radiotherapy

    International Nuclear Information System (INIS)

    Dale, Einar; Olsen, Dag R.; Fossa, Sophie D.

    1999-01-01

    Purpose: Radiation therapy of deep-sited tumours will always result in normal tissue doses to some extent. The aim of this study was to calculate different risk estimates of late effects in the rectum for a group of cancer prostate patients treated with conformal radiation therapy (CRT) and correlate these estimates with the occurrences of late effects. Since the rectum is a hollow organ, several ways of generating dose-volume distributions over the organ are possible, and we wanted to investigate two of them. Methods and Materials: A mathematical model, known as the Lyman-Kutcher model, conventionally used to estimate normal tissue complication probabilities (NTCP) associated with radiation therapy, was applied to a material of 52 cancer prostate patients. The patients were treated with a four field box technique, with the rectum as organ at risk. Dose-volume histograms (DVH) were generated for the whole rectum (including the cavity) and of the rectum wall. One to two years after the treatment, the patients completed a questionnaire concerning bowel (rectum) related morbidity quantifying the extent of late effects. Results: A correlation analysis using Spearman's rank correlation coefficient, for NTCP values calculated from the DVHs and the patients' scores, gave correlation coefficients which were not statistically significant at the p max , of the whole rectum, correlated better to observed late toxicity than D max derived from histograms of the rectum wall. Correlation coefficients from 'high-dose' measures were larger than those calculated from the NTCP values. Accordingly, as the volume parameter of the Lyman-Kutcher model was reduced, raising the impact of small high-dose volumes on the NTCP values, the correlation between observed effects and NTCP values became significant at p < 0.01 level. Conclusions: 1) High-dose levels corresponding to small volume fractions of the cumulative dose-volume histograms were best correlated with the occurrences of late

  11. Rectal compliance as a routine measurement: extreme volumes have direct clinical impact and normal volumes exclude rectum as a problem.

    Science.gov (United States)

    Felt-Bersma, R J; Sloots, C E; Poen, A C; Cuesta, M A; Meuwissen, S G

    2000-12-01

    The clinical impact of rectal compliance and sensitivity measurement is not clear. The aim of this study was to measure the rectal compliance in different patient groups compared with controls and to establish the clinical effect of rectal compliance. Anorectal function tests were performed in 974 consecutive patients (284 men). Normal values were obtained from 24 controls. Rectal compliance measurement was performed by filling a latex rectal balloon with water at a rate of 60 ml per minute. Volume and intraballoon pressure were measured. Volume and pressure at three sensitivity thresholds were recorded for analysis: first sensation, urge, and maximal toleration. At maximal toleration, the rectal compliance (volume/pressure) was calculated. Proctoscopy, anal manometry, anal mucosal sensitivity, and anal endosonography were also performed as part of our anorectal function tests. No effect of age or gender was observed in either controls or patients. Patients with fecal incontinence had a higher volume at first sensation and a higher pressure at maximal toleration (P = 0.03), the presence of a sphincter defect or low or normal anal pressures made no difference. Patients with constipation had a larger volume at first sensation and urge (P 500 ml had complaints of constipation. No correlation between rectal and anal mucosal sensitivity was found. Rectal compliance measurement with a latex balloon is easily feasible. In this series of 974 patients, some patient groups showed an abnormal rectal visceral sensitivity and compliance, but there was an overlap with controls. Rectal compliance measurement gave a good clinical impression about the contribution of the rectum to the anorectal problem. Patients with proctitis and pouchitis had the smallest rectal compliance. A maximal toleration volume 500 ml was only seen in constipated patients, and therapy should be given to prevent further damage to the pelvic floor. Values close to or within the normal range rule out the

  12. Effect of various methods for rectum delineation on relative and absolute dose-volume histograms for prostate IMRT treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Kusumoto, Chiaki [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Ohira, Shingo [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita (Japan); Miyazaki, Masayoshi [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Ueda, Yoshihiro [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Department of Radiation Oncology, Graduate School of Medicine, Osaka University, Suita (Japan); Isono, Masaru [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Teshima, Teruki, E-mail: teshima-te@mc.pref.osaka.jp [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan)

    2016-07-01

    Several reports have dealt with correlations of late rectal toxicity with rectal dose-volume histograms (DVHs) for high dose levels. There are 2 techniques to assess rectal volume for reception of a specific dose: relative-DVH (R-DVH, %) that indicates relative volume for a vertical axis, and absolute-DVH (A-DVH, cc) with its vertical axis showing absolute volume of the rectum. The parameters of DVH vary depending on the rectum delineation method, but the literature does not present any standardization of such methods. The aim of the present study was to evaluate the effects of different delineation methods on rectal DVHs. The enrollment for this study comprised 28 patients with high-risk localized prostate cancer, who had undergone intensity-modulated radiation therapy (IMRT) with the prescription dose of 78 Gy. The rectum was contoured with 4 different methods using 2 lengths, short (Sh) and long (Lg), and 2 cross sections, rectum (Rec) and rectal wall (Rw). Sh means the length from 1 cm above the seminal vesicles to 1 cm below the prostate and Lg the length from the rectosigmoid junction to the anus. Rec represents the entire rectal volume including the rectal contents and Rw the rectal volume of the area with a wall thickness of 4 mm. We compared dose-volume parameters by using 4 rectal contour methods for the same plan with the R-DVHs as well as the A-DVHs. For the high dose levels, the R-DVH parameters varied widely. The mean of V{sub 70} for Sh-Rw was the highest (19.4%) and nearly twice as high as that for Lg-Rec (10.4%). On the contrary, only small variations were observed in the A-DVH parameters (4.3, 4.3, 5.5, and 5.5 cc for Sh-Rw, Lg-Rw, Sh-Rec, and Lg-Rec, respectively). As for R-DVHs, the parameters of V{sub 70} varied depending on the rectal lengths (Sh-Rec vs Lg-Rec: R = 0.76; Sh-Rw vs Lg-Rw: R = 0.85) and cross sections (Sh-Rec vs Sh-Rw: R = 0.49; Lg-Rec vs Lg-Rw: R = 0.65). For A-DVHs, however, the parameters of Sh rectal A-DVHs hardly changed

  13. Modeling volume effects of experimental brachytherapy in the rat rectum: uncovering the limitations of a radiobiologic concept

    International Nuclear Information System (INIS)

    Johannessen, Hans-Olaf; Dale, Einar; Hellebust, Taran P.; Olsen, Dag R.; Nesland, Jahn M.; Giercksky, Karl-Erik

    2002-01-01

    Purpose: To analyze the significance of volume effects in experimental brachytherapy, based on modeling normal tissue complication probability. Methods and Materials: Experimental brachytherapy in the rat rectum was based on an eight-step 2.5-mm step size source configuration for 192 Ir, afterloaded into an unshielded polystyrene applicator. Volume effects were studied using a half-circumferential lead-shielded applicator and a shorter (two-step) source configuration. The main end point was rectal stenosis. Results: Rectal stenosis was always caused by a radiation ulcer. With the shielded configuration, single-dose ED 50 (50% incidence of rectal stenosis) increased from 23 Gy to 36.5 Gy. Single-dose ED 50 for the short configuration was 77.9 Gy. The data showed a reasonable fit to a three-parameter version of the biophysical model described by Jackson et al. (1995). This model assumes that organs consist of a large number of radiobiologically independent subunits and that radiation causes a complication if the fraction of the organ damaged is greater than its functional reserve. The fraction of the organ damaged is calculated summing over fractions of the organ damaged at each dose level. The calculated mean functional reserve (ν 50 ) of the rat rectum, assuming a cumulative functional reserve distribution in the group of experimental rats, was 0.53. Conclusions: The volume effect observed within small brachytherapy volumes agreed well with clinical experience of large tolerance doses in contact X-ray therapy. However, the ν 50 value was comparable to the high functional reserve value reported for liver. Experimental volume effects probably reflect repair processes originating in the areas adjacent to small radiation fields of brachytherapy more than the radiobiologic characteristics of the cells in the irradiated volume

  14. Non-Cooperative Air Target Identification Using Radar (l’Identification radar des cibles aeriennes non cooperatives)

    Science.gov (United States)

    1998-11-01

    des techniques tr~s prometteuse pour la detection longue port~e. Les progr~s escompt ~s dans le domaine des techniques radar devraient amener des...cibles fixes, des cibles mobiles ou du fouillis de sol. Sa vocation Le moyen de mesures comprend un radar premiere est d’enrichir les banques de donn6es

  15. Analysis of motion of the rectum during preoperative intensity modulated radiation therapy for rectal cancer using cone-beam computed tomography

    International Nuclear Information System (INIS)

    Yamashita, Hideomi; Takenaka, Ryousuke; Sakumi, Akira; Haga, Akihiro; Otomo, Kuni; Nakagawa, Keiichi

    2015-01-01

    The purpose of the present study was to quantify the inter-fractional motion of the rectum and the rectal and bladder volumes using CBCT scans taken during chemoradiation therapy (CRT) for rectal cancer. Also, assessment was made for a better margin for simultaneous integrated boost - intensity modulated radiation therapy (SIB-IMRT) for rectal cancer. There were 32 patients in this study undergoing preoperative CRT for rectal cancer. Each rectum and bladder was contoured on all planning CTs and CBCTs (day 1, 7, 13, 19, 25). The target volume was configured by adding margins (0, 3, 5, 7, 10, and 15 mm) to the rectum on planning CT. The respective percentage of rectal volume that exceeds the target volume was calculated for each of these margins. The percentage of bladder volume that exceeds the bladder volume in the planning CT and motion of the center of gravity of rectum were also analyzed. Planning CTs and series of each 5 CBCTs for 32 patients were analyzed in this study. The rectal volume tended to shrink week after week. The mean values (± SD) in the 32 series per patient of the percentage of rectum on the CBCTs exceeding target volume in which the margins of 0, 3, 5, 7, 10, and 15 mm were added to the rectum on planning CT were 20.7 ± 12.5%, 7.2 ± 8.3%, 3.9 ± 5.9%, 2.1 ± 3.9%, 0.7 ± 1.8%, and 0.1 ± 0.3%, respectively. No association was seen between the percentage of changes of bladder volume and motion of rectal centroid. In this study, we estimated the motion of the rectum using planning CT and CBCT. Ten to fifteen mm is a sufficient margin for the rectum during SIB-IMRT for rectal cancer in the supine position

  16. Bladder–Rectum Spacer Balloon in High-Dose-Rate Brachytherapy in Cervix Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Bhavana [Department of Radiotherapy and Oncology, Regional Cancer Centre, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Patel, Firuza D., E-mail: firuzapatel@gmail.com [Department of Radiotherapy and Oncology, Regional Cancer Centre, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Chakraborty, Santam; Sharma, Suresh C.; Kapoor, Rakesh [Department of Radiotherapy and Oncology, Regional Cancer Centre, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Aprem, Abi Santhosh [Corporate R and D Division, HLL Lifecare Limited, Karamana, Trivandrum (India)

    2013-04-01

    Purpose: To compare bladder and rectum doses with the use of a bladder–rectum spacer balloon (BRSB) versus standard gauze packing in the same patient receiving 2 high-dose-rate intracavitary brachytherapy fractions. Methods and Materials: This was a randomized study to compare the reduction in bladder and rectum doses with the use of a BRSB compared with standard gauze packing in patients with carcinoma of the cervix being treated with high-dose-rate intracavitary brachytherapy. The patients were randomized between 2 arms. In arm A, vaginal packing was done with standard gauze packing in the first application, and BRSB was used in the second application. Arm B was the reverse of arm A. The International Commission for Radiation Units and Measurement (ICRU) point doses and doses to 0.1-cm{sup 3}, 1-cm{sup 3}, 2-cm{sup 3}, 5-cm{sup 3}, and 10-cm{sup 3} volumes of bladder and rectum were compared. The patients were also subjectively assessed for the ease of application and the time taken for application. Statistical analysis was done using the paired t test. Results: A total of 43 patients were enrolled; however, 3 patients had to be excluded because the BRSB could not be inserted owing to unfavorable local anatomy. Thus 40 patients (80 plans) were evaluated. The application was difficult in 3 patients with BRSB, and in 2 patients with BRSB the application time was prolonged. There was no significant difference in bladder doses to 0.1 cm{sup 3}, 1 cm{sup 3}, 2 cm{sup 3}, 5 cm{sup 3}, and 10 cm{sup 3} and ICRU bladder point. Statistically significant dose reductions to 0.1-cm{sup 3}, 1-cm{sup 3}, and 2-cm{sup 3} volumes for rectum were observed with the BRSB. No significant differences in 5-cm{sup 3} and 10-cm{sup 3} volumes and ICRU rectum point were observed. Conclusion: A statistically significant dose reduction was observed for small high-dose volumes in rectum with the BRSB. The doses to bladder were comparable for BRSB and gauze packing. Transparent balloons of

  17. Reduction of rectal doses by removal of gas in the rectum during vaginal cuff brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sabater, S.; Sevillano, M.M.; Andres, I.; Berenguer, R. [Complejo Hospitalario Univ. de Albacete (CHUA) (Spain). Dept. of Radiation Oncology; Machin-Hamalainen, S. [C.S. General Ricardos, Madrid (Spain); Mueller, K.; Arenas, M. [Hospital Univ. Sant Joan, Reus (Spain). Dept. of Radiation Oncology

    2013-11-15

    Objective: The goal of this work was to evaluate whether the volume reduction related to removal of gas in the rectum could be translated in lower doses to organs at risk (OAR) during vaginal cuff brachytherapy (VBT). Material and methods: Fourteen pairs of brachytherapy planning CT scans derived from 11 patients were re-segmented and re-planned using the same parameters. The only difference between pairs of CTs was the presence or lack of gas in the rectum. The first CT showed the basal status and the second was carried out after gas removal with a tube. A set of values derived from bladder and rectum dose-volume histograms (DVH) and dose-surface histograms (DSH) were extracted. Moreover the cylinder position related to the patient craniocaudal axis was recorded. Results: Rectum volume decreased significantly from 77.8 {+-} 45 to 55.43 {+-} 17.6 ml (p = 0.0052) after gas removal. Such volume diminution represented a significant reduction on all rectal DVH parameters analyzed except D{sub 25%} and D{sub 50%}. DSH parameter results were similar to previous ones. A nonsignificant increase of the bladder volume was observed and was associated with an increase of the DVH metrics analyzed. Conclusion: Removal of gas pockets is a simple and inexpensive maneuver that decreases rectal dose parameters on VBT, which can be translated as a better therapeutic ratio. It also suggests that other actions directed to empty the rectum could have a similar effect. (orig.)

  18. Inter fraction variations in rectum and bladder volumes and dose distributions during high dose rate brachytherapy treatment of the uterine cervix investigated by repetitive CT-examinations

    International Nuclear Information System (INIS)

    Hellebust, Taran Paulsen; Dale, Einar; Skjoensberg, Ane; Olsen, Dag Rune

    2001-01-01

    Purpose: To evaluate variation of dose to organs at risk for patients receiving fractionated high dose rate gynaecological brachytherapy by using CT-based 3D treatment planning and dose-volume histograms (DVH). Materials and methods: Fourteen patients with cancer of the uterine cervix underwent three to six CT examinations (mean 4.9) during their course of high-dose-rate brachytherapy using radiographically compatible applicators. The rectal and bladder walls were delineated and DVHs were calculated. Results: Inter fraction variation of the bladder volume (CV mean =44.1%) was significantly larger than the inter fraction variation of the mean dose (CV mean =19.9%, P=0.005) and the maximum dose (CV mean =17.5%, P=0.003) of the bladder wall. The same trend was seen for rectum, although the figures were not significantly different. Performing CT examinations at four of seven brachytherapy fractions reduced the uncertainty to 4 and 7% for the bladder and rectal doses, respectively. A linear regression analysis showed a significant, negative relationship between time after treatment start and the whole bladder volume (P=0.018), whereas no correlation was found for the rectum. For both rectum and bladder a linear regression analysis revealed a significant, negative relationship between the whole volume and median dose (P<0.05). Conclusion: Preferably a CT examination should be provided at every fraction. However, this is logistically unfeasible in most institutions. To obtain reliable DVHs the patients will in the future undergo 3-4 CT examinations during the course of brachytherapy at our institution. Since this study showed an association between large bladder volumes and dose reductions, the patients will be treated with a standardized bladder volume

  19. SU-F-J-217: Accurate Dose Volume Parameters Calculation for Revealing Rectum Dose-Toxicity Effect Using Deformable Registration in Cervical Cancer Brachytherapy: A Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Zhen, X; Chen, H; Liao, Y; Zhou, L [Southern Medical University, Guangzhou, Guangdong (China); Hrycushko, B; Albuquerque, K; Gu, X [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: To study the feasibility of employing deformable registration methods for accurate rectum dose volume parameters calculation and their potentials in revealing rectum dose-toxicity between complication and non-complication cervical cancer patients with brachytherapy treatment. Method and Materials: Data from 60 patients treated with BT including planning images, treatment plans, and follow-up clinical exam were retrospectively collected. Among them, 12 patients complained about hematochezia were further examined with colonoscopy and scored as Grade 1–3 complication (CP). Meanwhile, another 12 non-complication (NCP) patients were selected as a reference group. To seek for potential gains in rectum toxicity prediction when fractional anatomical deformations are account for, the rectum dose volume parameters D0.1/1/2cc of the selected patients were retrospectively computed by three different approaches: the simple “worstcase scenario” (WS) addition method, an intensity-based deformable image registration (DIR) algorithm-Demons, and a more accurate, recent developed local topology preserved non-rigid point matching algorithm (TOP). Statistical significance of the differences between rectum doses of the CP group and the NCP group were tested by a two-tailed t-test and results were considered to be statistically significant if p < 0.05. Results: For the D0.1cc, no statistical differences are found between the CP and NCP group in all three methods. For the D1cc, dose difference is not detected by the WS method, however, statistical differences between the two groups are observed by both Demons and TOP, and more evident in TOP. For the D2cc, the CP and NCP cases are statistically significance of the difference for all three methods but more pronounced with TOP. Conclusion: In this study, we calculated the rectum D0.1/1/2cc by simple WS addition and two DIR methods and seek for gains in rectum toxicity prediction. The results favor the claim that accurate dose

  20. Comparison of different contouring definitions of the rectum as organ at risk (OAR) and dose-volume parameters predicting rectal inflammation in radiotherapy of prostate cancer: which definition to use?

    Science.gov (United States)

    Nitsche, Mirko; Brannath, Werner; Brückner, Matthias; Wagner, Dirk; Kaltenborn, Alexander; Temme, Nils; Hermann, Robert M

    2017-02-01

    The objective of this retrospective planning study was to find a contouring definition for the rectum as an organ at risk (OAR) in curative three-dimensional external beam radiotherapy (EBRT) for prostate cancer (PCa) with a predictive correlation between the dose-volume histogram (DVH) and rectal toxicity. In a pre-study, the planning CT scans of 23 patients with PCa receiving definitive EBRT were analyzed. The rectum was contoured according to 13 different definitions, and the dose distribution was correlated with the respective rectal volumes by generating DVH curves. Three definitions were identified to represent the most distinct differences in the shapes of the DVH curves: one anatomical definition recommended by the Radiation Therapy Oncology Group (RTOG) and two functional definitions based on the target volume. In the main study, the correlation between different relative DVH parameters derived from these three contouring definitions and the occurrence of rectal toxicity during and after EBRT was studied in two consecutive collectives. The first cohort consisted of 97 patients receiving primary curative EBRT and the second cohort consisted of 66 patients treated for biochemical recurrence after prostatectomy. Rectal toxicity was investigated by clinical investigation and scored according to the Common Terminology Criteria for Adverse Events. Candidate parameters were the volume of the rectum, mean dose, maximal dose, volume receiving at least 60 Gy (V 60 ), area under the DVH curve up to 25 Gy and area under the DVH curve up to 75 Gy in dependence of each chosen rectum definition. Multivariable logistic regression considered other clinical factors such as pelvine lymphatics vs local target volume, diabetes, prior rectal surgery, anticoagulation or haemorrhoids too. In Cohort 1 (primary EBRT), the mean rectal volumes for definitions "RTOG", planning target volume "(PTV)-based" and "PTV-linked" were 100 cm 3 [standard deviation (SD) 43 cm 3 ], 60

  1. Water enema CT examination of rectum cancer by reduced amount of water

    International Nuclear Information System (INIS)

    Palko, A.; Gyulai, Cs.; Fedinecz, N.; Balogh, A.; Nagy, F.

    2000-01-01

    To define whether volume of water, administered during water enema CT (WE-CT) for local staging of rectal cancer, may be reduced without compromising the diagnostic value of the examination. Materials and Methods: 29 patients with rectum cancer underwent preoperative WE-CT. Contrast-enhanced CT (equilibrium phase) measurements were performed after i.v. injection of smooth muscle relaxant and rectal administration of 400 - 500 ml lukewarm tap water. Quality of the obtained scans was evaluated and the images were analyzed for depth of tumor invasion. Results of the CT examinations were compared to findings at surgery. Results: Despite reduced dose of water enema, 19/29 examinations were of excellent quality, 6/29 good, and 4/29 poor, but still diagnostic. We achieved sensitivity (90.1), specificity (70.1) and accuracy (86.2) in differentiating tumors confined to the bowel wall from those extending beyond it. Conclusion: Large volume of water enema administered during CT examination of the rectum may cause complaints and increases the risk of complications. Our results prove that using lower amount of water does not impair the quality of examination and accuracy of local staging of rectum carcinomas. (orig.) [de

  2. Strategies to reduce the systematic error due to tumor and rectum motion in radiotherapy of prostate cancer

    International Nuclear Information System (INIS)

    Hoogeman, Mischa S.; Herk, Marcel van; Bois, Josien de; Lebesque, Joos V.

    2005-01-01

    Background and purpose: The goal of this work is to develop and evaluate strategies to reduce the uncertainty in the prostate position and rectum shape that arises in the preparation stage of the radiation treatment of prostate cancer. Patients and methods: Nineteen prostate cancer patients, who were treated with 3-dimensional conformal radiotherapy, received each a planning CT scan and 8-13 repeat CT scans during the treatment period. We quantified prostate motion relative to the pelvic bone by first matching the repeat CT scans on the planning CT scan using the bony anatomy. Subsequently, each contoured prostate, including seminal vesicles, was matched on the prostate in the planning CT scan to obtain the translations and rotations. The variation in prostate position was determined in terms of the systematic, random and group mean error. We tested the performance of two correction strategies to reduce the systematic error due to prostate motion. The first strategy, the pre-treatment strategy, used only the initial rectum volume in the planning CT scan to adjust the angle of the prostate with respect to the left-right (LR) axis and the shape and position of the rectum. The second strategy, the adaptive strategy, used the data of repeat CT scans to improve the estimate of the prostate position and rectum shape during the treatment. Results: The largest component of prostate motion was a rotation around the LR axis. The systematic error (1 SD) was 5.1 deg and the random error was 3.6 deg (1 SD). The average LR-axis rotation between the planning and the repeat CT scans correlated significantly with the rectum volume in the planning CT scan (r=0.86, P<0.0001). Correction of the rotational position on the basis of the planning rectum volume alone reduced the systematic error by 28%. A correction, based on the data of the planning CT scan and 4 repeat CT scans reduced the systematic error over the complete treatment period by a factor of 2. When the correction was

  3. Sensitivity of the sigmoid colon and rectum in children treated for chronic constipation.

    Science.gov (United States)

    Loening-Baucke, V A

    1984-06-01

    Sensations in the sigmoid and rectum and the response of the anal canal to balloon distension were measured with a latex balloon and pressure transducer in 15 chronically constipated and 15 healthy control children. The constipated children received milk of magnesia and bowel training. Thirteen constipated children were restudied 7-12 months later and 11 were restudied 3 years later. Although thresholds of transient sensation and of the rectosphincteric reflex were not different in constipated and control children, the threshold of fullness, the critical volume, and the volume for constant relaxation were significantly higher in constipated than in control children (p less than 0.05), and remained higher 1 year and 3 years later, even in the children who recovered. The initial data support the concept of a sigmoid and rectum so enlarged that a normal fecal bolus may not cause a sensation of fullness or a sensory stimulus for defecation. Despite improvement in clinical manifestations and normal rectal size, the abnormalities in sensitivity of the sigmoid and rectum persisted in five of eight recovered children. This may explain why these children are so vulnerable to recurrence of constipation and fecal soiling.

  4. Foreign Objects in the Rectum

    Science.gov (United States)

    ... Abscess Anorectal Fistula Foreign Objects in the Rectum Hemorrhoids Levator Syndrome Pilonidal Disease Proctitis Rectal Prolapse (See ... Abscess Anorectal Fistula Foreign Objects in the Rectum Hemorrhoids Levator Syndrome Pilonidal Disease Proctitis Rectal Prolapse NOTE: ...

  5. Impact of knee support and shape of tabletop on rectum and prostate position

    International Nuclear Information System (INIS)

    Steenbakkers, Roel; Duppen, Joop C.; Betgen, Anja; Lotz, Heidi; Remeijer, Peter; Fitton, Isabelle; Nowak, Peter; Herk, Marcel van; Rasch, Coen

    2004-01-01

    Purpose: To evaluate the impact of different tabletops with or without a knee support on the position of the rectum, prostate, and bulb of the penis; and to evaluate the effect of these patient-positioning devices on treatment planning. Methods and materials: For 10 male volunteers, five MRI scans were made in four different positions: on a flat tabletop with knee support, on a flat tabletop without knee support, on a rounded tabletop with knee support, and on a rounded tabletop without knee support. The fifth scan was in the same position as the first. With image registration, the position differences of the rectum, prostate, and bulb of the penis were measured at several points in a sagittal plane through the central axis of the prostate. A planning target volume was generated from the delineated prostates with a margin of 10 mm in three dimensions. A three-field treatment plan with a prescribed dose of 78 Gy to the International Commission on Radiation Units and Measurements point was automatically generated from each planning target volume. Dose-volume histograms were calculated for all rectal walls. Results: The shape of the tabletop did not affect the rectum and prostate position. Addition of a knee support shifted the anterior and posterior rectal walls dorsally. For the anterior rectal wall, the maximum dorsal shift was 9.9 mm (standard error of the mean [SEM] 1.7 mm) at the top of the prostate. For the posterior rectal wall, the maximum dorsal shift was 10.2 mm (SEM 1.5 mm) at the middle of the prostate. Therefore, the rectal filling was pushed caudally when a knee support was added. The knee support caused a rotation of the prostate around the left-right axis at the apex (i.e., a dorsal rotation) by 5.6 deg (SEM 0.8 deg ) and shifts in the caudal and dorsal directions of 2.6 mm (SEM 0.4 cm) and 1.4 mm (SEM 0.6 mm), respectively. The position of the bulb of the penis was not influenced by the use of a knee support or rounded tabletop. The volume of the

  6. A three-dimensional computed tomography-assisted Monte Carlo evaluation of ovoid shielding on the dose to the bladder and rectum in intracavitary radiotherapy for cervical cancer

    International Nuclear Information System (INIS)

    Gifford, Kent A.; Horton, John L.; Pelloski, Christopher E.; Jhingran, Anuja; Court, Laurence E.; Mourtada, Firas; Eifel, Patricia J.

    2005-01-01

    Purpose: To determine the effects of Fletcher Suit Delclos ovoid shielding on dose to the bladder and rectum during intracavitary radiotherapy for cervical cancer. Methods and Materials: The Monte Carlo method was used to calculate the dose in 12 patients receiving low-dose-rate intracavitary radiotherapy with both shielded and unshielded ovoids. Cumulative dose-difference surface histograms were computed for the bladder and rectum. Doses to the 2-cm 3 and 5-cm 3 volumes of highest dose were computed for the bladder and rectum with and without shielding. Results: Shielding affected dose to the 2-cm 3 and 5-cm 3 volumes of highest dose for the rectum (10.1% and 11.1% differences, respectively). Shielding did not have a major impact on the dose to the 2-cm 3 and 5-cm 3 volumes of highest dose for the bladder. The average dose reduction to 5% of the surface area of the bladder was 53 cGy. Reductions as large as 150 cGy were observed to 5% of the surface area of the bladder. The average dose reduction to 5% of the surface area of the rectum was 195 cGy. Reductions as large as 405 cGy were observed to 5% of the surface area of the rectum. Conclusions: Our data suggest that the ovoid shields can greatly reduce the radiation dose delivered to the rectum. We did not find the same degree of effect on the dose to the bladder. To calculate the dose accurately, however, the ovoid shields must be included in the dose model

  7. Radiotherapy indications - rectum cancer

    International Nuclear Information System (INIS)

    2009-05-01

    This document is addressed to oncologists radiotherapists and to any health professional concerned by rectum cancer treatment. Rectum cancer therapy is based on various technical procedures including surgery, radiotherapy and systemic treatments defined for each patient according to his clinical situation. This document precises the specific situations where radiotherapy can be employed. However, the radiotherapy decision must be taken with respect to other therapeutic alternatives. Such a decision must be validated and must be the object of a discussion in the framework of a pluri-disciplinary consultation. (J.S.)

  8. Villes ciblées - recyclage des déchets et négoce agricole à Kampala ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Journal articles. Kampala Urban Agriculture Team networks, tours project sites during WUF3 [Third World Urban Forum]. Download PDF. Journal articles. Kampala Focus Cities project launched. Download PDF. Journal articles. Lancement du projet de ville ciblée de Kampala. Download PDF. Journal articles. Journalist's ...

  9. Preoperative treatment of rectum cancers; Traitement preoperatoire des cancers du rectum

    Energy Technology Data Exchange (ETDEWEB)

    Mineur, L.; Serin, D.; Chauvet, B.; Reboul, F. [Institut Sainte-Catherine, 84 - Avignon (France); Molinari, N. [Centre Hospitalier Universitaire, 30 - Nimes (France); Guyot, T. [Laboratoire Chugai, 75 - Paris (France); Ciornea, D. [Universite de la Medecine et Pharmacie GR.T.POPA, IASI, Dept. de la Radiotherapie-oncologie (Romania); Leignel, D.L.; Chapet, L.C.; Garaud, P.G.; Calais, G.C. [Centre Hospitalier Universitaire, Service de Radiotherapie, Hopital Bretonneau, 37 - Tours (France); Calan, L.D.C. de [Centre Hospitalier Universitaire, Hopital Trousseau, 37 - Tours (France); Viguier, J.V. [Centre Hospitalier Universitaire, Hopital Trousseau, Service de Gastroenterologie, 37 - Tours (France); Boukerche, A.; Bechekat, C.; Dali-Youcef, A.F. [Service de Radiotherapie, Oran (Algeria); Larbaoui, B.; Djellali, L. [Service d' Oncologie Medicale, Oran (Algeria); Safir, A. [Service de Gastroenterologie, Oran (Algeria); Albarghach, M.N.; Malhaire, J.P.; Bouchekoua, M.; Muller, M.; Metges, J.P.; Pradier, O. [Departement de Cancerologie, 29 - Brest (France); Robaszkiewicz, M. [Departement de Gastroenterologie, 29 - Brest (France)

    2007-11-15

    Five articles treat the question of rectum carcinoma through a combined therapy that associates radiotherapy ( pre or post operative), chemotherapy (concomitant before surgery) and surgery. The local control is also considered. (N.C.)

  10. Strategies for Online Organ Motion Correction for Intensity-Modulated Radiotherapy of Prostate Cancer: Prostate, Rectum, and Bladder Dose Effects

    International Nuclear Information System (INIS)

    Rijkhorst, Erik-Jan; Lakeman, Annemarie; Nijkamp, Jasper; Bois, Josien de; Herk, Marcel van; Lebesque, Joos V.; Sonke, Jan-Jakob

    2009-01-01

    Purpose: To quantify and evaluate the accumulated prostate, rectum, and bladder dose for several strategies including rotational organ motion correction for intensity-modulated radiotherapy (IMRT) of prostate cancer using realistic organ motion data. Methods and Materials: Repeat computed tomography (CT) scans of 19 prostate patients were used. Per patient, two IMRT plans with different uniform margins were created. To quantify prostate and seminal vesicle motion, repeat CT clinical target volumes (CTVs) were matched onto the planning CTV using deformable registration. Four different strategies, from online setup to full motion correction, were simulated. Rotations were corrected for using gantry and collimator angle adjustments. Prostate, rectum, and bladder doses were accumulated for each patient, plan, and strategy. Minimum CTV dose (D min ), rectum equivalent uniform dose (EUD, n = 0.13), and bladder surface receiving ≥78 Gy (S78), were calculated. Results: With online CTV translation correction, a 7-mm margin was sufficient (i.e., D min ≥ 95% of the prescribed dose for all patients). A 4-mm margin required additional rotational correction. Margin reduction lowered the rectum EUD(n = 0.13) by ∼2.6 Gy, and the bladder S78 by ∼1.9%. Conclusions: With online correction of both translations and rotations, a 4-mm margin was sufficient for 15 of 19 patients, whereas the remaining four patients had an underdosed CTV volume <1%. Margin reduction combined with online corrections resulted in a similar or lower dose to the rectum and bladder. The more advanced the correction strategy, the better the planned and accumulated dose agreed.

  11. Dosimetric evaluation of rectum and bladder using image-based CT planning and orthogonal radiographs with ICRU 38 recommendations in intracavitary brachytherapy

    Directory of Open Access Journals (Sweden)

    Jamema Swamidas

    2008-01-01

    Full Text Available The purpose is to compare CT-based dosimetry with International Commission on Radiation Units and Measurements (ICRU 38 bladder and rectum reference points in patients of carcinoma of uterine cervix treated with intracavitary brachytherapy (ICA. Twenty-two consecutive patients were evaluated. Orthogonal radiographs and CT images were acquired and transferred to PLATO planning system. Bladder and rectal reference points were identified according to ICRU 38 recommendations. Dosimetry was carried out based on Manchester system. Patient treatment was done using 192 Iridium high dose rate (HDR remote after-loading machine based on the conventional radiograph-based dosimetry. ICRU rectal and bladder point doses from the radiograph plans were compared with D 2 , dose received by 2 cm 3 of the organ receiving maximum dose from CT plan. V 2 , volume of organ receiving dose more than the ICRU reference point, was evaluated. The mean (±standard deviation volume of rectum and bladder was 60 (±28 cm 3 and 138 (±41 cm 3 respectively. The mean reference volume in radiograph and CT plan was 105 (±7 cm 3 and 107 (±7 cm 3 respectively. It was found that 6 (±4 cm3 of rectum and 16 (±10 cm 3 of bladder received dose more than the prescription dose. V2 of rectum and bladder was 7 (±1.7 cm 3 and 20.8 (±6 cm 3 respectively. Mean D 2 of rectum and bladder was found to be 1.11 (±0.2 and 1.56 (±0.6 times the mean ICRU reference points respectively. This dosimteric study suggests that comparison of orthogonal X-ray-based and CT-based HDR ICA planning is feasible. ICRU rectal point dose correlates well with maximum rectal dose, while ICRU bladder point underestimates the maximum bladder dose.

  12. Concomitant chemo-radiotherapy for the locally advanced rectum cancer; Chimioradiotherapie concomitante dans le cancer du rectum localement evolue

    Energy Technology Data Exchange (ETDEWEB)

    Haoui, M.; Aksil, N.; Boualga, K.; Moussaoui, D.; Ladj, O. [Service de radiotherapie-oncologie, centre anti-cancer, Blida (Algeria)

    2010-10-15

    The authors report a retrospective study which aimed at assessing the use of a concomitant chemo-radiotherapy, its tolerance and its feasibility in the case of a locally advanced rectum cancer. Based on data obtained among 62 patients presenting a rectum cancer, they analyse the results in terms of tolerance (cases of leukopenia, anemia, diarrhea, radiodermatitis), of relapses, and survival. Toxicity is acceptable and the concomitant treatment renders the tumour operable in many cases. Short communication

  13. The rectum: a window to irritable bowel syndrome?

    NARCIS (Netherlands)

    Coremans, G.; Azpiroz, F.; Collins, S.; Dapoigny, M.; Müller-Lissner, S. A.; Pace, F.; Smout, A.; Stockbrügger, R. W.; Whorwell, P. J.

    2002-01-01

    This report summarizes current concepts and information gathered to date about the rectum in the irritable bowel syndrome (IBS) that were presented at the 10th meeting of IBiS Club held in Leuven, Belgium. A working group of experts in the field of IBS discussed whether the rectum or the whole colon

  14. Deep convolutional neural network with transfer learning for rectum toxicity prediction in cervical cancer radiotherapy: a feasibility study

    Science.gov (United States)

    Zhen, Xin; Chen, Jiawei; Zhong, Zichun; Hrycushko, Brian; Zhou, Linghong; Jiang, Steve; Albuquerque, Kevin; Gu, Xuejun

    2017-11-01

    Better understanding of the dose-toxicity relationship is critical for safe dose escalation to improve local control in late-stage cervical cancer radiotherapy. In this study, we introduced a convolutional neural network (CNN) model to analyze rectum dose distribution and predict rectum toxicity. Forty-two cervical cancer patients treated with combined external beam radiotherapy (EBRT) and brachytherapy (BT) were retrospectively collected, including twelve toxicity patients and thirty non-toxicity patients. We adopted a transfer learning strategy to overcome the limited patient data issue. A 16-layers CNN developed by the visual geometry group (VGG-16) of the University of Oxford was pre-trained on a large-scale natural image database, ImageNet, and fine-tuned with patient rectum surface dose maps (RSDMs), which were accumulated EBRT  +  BT doses on the unfolded rectum surface. We used the adaptive synthetic sampling approach and the data augmentation method to address the two challenges, data imbalance and data scarcity. The gradient-weighted class activation maps (Grad-CAM) were also generated to highlight the discriminative regions on the RSDM along with the prediction model. We compare different CNN coefficients fine-tuning strategies, and compare the predictive performance using the traditional dose volume parameters, e.g. D 0.1/1/2cc, and the texture features extracted from the RSDM. Satisfactory prediction performance was achieved with the proposed scheme, and we found that the mean Grad-CAM over the toxicity patient group has geometric consistence of distribution with the statistical analysis result, which indicates possible rectum toxicity location. The evaluation results have demonstrated the feasibility of building a CNN-based rectum dose-toxicity prediction model with transfer learning for cervical cancer radiotherapy.

  15. Dysmenorrhoea is associated with hypersensitivity in the sigmoid colon and rectum

    DEFF Research Database (Denmark)

    Brinkert, Willem; Dimcevski, Georg; Arendt-Nielsen, Lars

    2007-01-01

    if dysmenorrhoea is associated with hypersensitivity in the referred somatic skin area or in the large bowel, i.e., viscero-visceral hyperalgesia. We measured skin sensitivity in the referred area of the sigmoid colon as well as stimulus-response relationships in the sigmoid colon and rectum. The latter were...... measured using mechanical (balloon) distension applied via a Barostat in 11 dysmenorrhoea patients without gastro-intestinal complaints and 10 healthy and age matched women, again without gastrointestinal complaints. We found no skin hypersensitivity in the colonic referred area. In contrast, significantly...... lower distension volumes were seen at each threshold in dysmenorrhoea patients, particularly in the sigmoid colon. The mean reduction in colonic distension volume thresholds for dysmenorrhoea patients vs. controls was 57% at the detection threshold and 39% at the pain threshold. There were...

  16. Preoperative treatment of rectum cancers

    International Nuclear Information System (INIS)

    Mineur, L.; Serin, D.; Chauvet, B.; Reboul, F.; Molinari, N.; Guyot, T.; Ciornea, D.; Leignel, D.L.; Chapet, L.C.; Garaud, P.G.; Calais, G.C.; Calan, L.D.C. de; Viguier, J.V.; Boukerche, A.; Bechekat, C.; Dali-Youcef, A.F.; Larbaoui, B.; Djellali, L.; Safir, A.; Albarghach, M.N.; Malhaire, J.P.; Bouchekoua, M.; Muller, M.; Metges, J.P.; Pradier, O.; Robaszkiewicz, M.

    2007-01-01

    Five articles treat the question of rectum carcinoma through a combined therapy that associates radiotherapy ( pre or post operative), chemotherapy (concomitant before surgery) and surgery. The local control is also considered. (N.C.)

  17. Interposition of Ileal J-Pouch for Rectum Reconstruction in Dog

    Directory of Open Access Journals (Sweden)

    Leila Ghahramani

    2014-03-01

    Full Text Available Background: The gold standard of the management of rectal cancer in the middle and lower parts is low anterior resection with coloanal anastomosis. About 50% of the patients undergoing this procedure might experience some complications because of the low capacity of the neorectum. The aim of this study was to evaluate ileal J-pouch interposition as a neorectum between the anal canal and the remaining colon in comparison to coloanal anastomosis and transverse coloplasty. Methods: Twelve dogs, weighing 23-27 kg, were divided into three groups. After laparotomy, the volume of the primary rectum was measured so that it could be compared with that of the neorectum at the end of the study. After rectal resection in Group A, the colon was directly anastomosed to the anus. In Group B, a 5-cm longitudinal incision was made 2 cm proximal to the anastomosis and was sutured transversely (coloplasty. In Group C, a 5-cm ileal J-pouch was interposed between the colon and anus. After 8 weeks, the neorectum was evaluated for volume, radiology, and pathology. Results: All the samples were alive until the end of the study. The healing of the anastomotic lines was acceptable (pathologically in all. The mean volume expansion was 20.9% in Group A, 21.7% in Group B, and 118.2% in Group C, with the latter being significantly higher than that of the other groups (P=0.03. Colon J-pouch and coloplasty after proctectomy in some situations have not been performable. This study evaluated the performance of ileal J-pouch interposition. Conclusion: This study showed that ileal J-pouch interposition might produce an acceptable reservoir function and that it seems feasible and safe in selected cases. Please cite this article as: Ghahramani L, Yazdani S, Derakhshani S, Rezaianzadeh A, Jalli R, Geramizadeh B, Safarpour AR, Rahimikazerooni S, Hosseini SV. Interposition of Ileal J-Pouch for Rectum Reconstruction in Dog. Iran J Med Sci. 2014;39(2:117-122.

  18. Answer to preoperative chemie radiation in locally advanced rectum cancer

    International Nuclear Information System (INIS)

    Villegas Mendez, Silvia

    2006-01-01

    Study the pre-operative combined therapy effect in the treatment of the rectum cancer cases of the Servicio de Cirugia General 2 of the Hospital Mexico. The study covers since January of 2003 until December of 2005. It has like specific objectives to analyze the effect in the tumour stages, the sphincters preservation and the recurrence. In the conclusions, it notes that the pre-operative chemie-radiation in the rectum cancer is indicated in II and III stages, in which it has showed most advantages for the patient. It describes that the time between the end of pre-operative combined treatment and the surgery must has at least six weeks to guarantee the effect in the tumour and to reduce the treatment toxicity. It concludes besides, that the complication rate after the pre-operative combined therapy and the total meso rectum excision is approximately of 33%; however, the pelvic septic complications can reduce with an ostomy of protection. It focus that the technique of sphincters preservation has showed to be effective and secure if it does a previous selection to the patients in appropriate form. To get an suitable stages must count with trans rectum endoscopic ultrasound and a tomography of suitable quality. It concludes, also, in intervened tumours after of neo-adjuvancy they don't need free distal margins of illness higher to 2 cm. The total meso rectum excision is the updated surgical recommendation in the rectum cancer [es

  19. Interactive and scale invariant segmentation of the rectum/sigmoid via user-defined templates

    Science.gov (United States)

    Lüddemann, Tobias; Egger, Jan

    2016-03-01

    Among all types of cancer, gynecological malignancies belong to the 4th most frequent type of cancer among women. Besides chemotherapy and external beam radiation, brachytherapy is the standard procedure for the treatment of these malignancies. In the progress of treatment planning, localization of the tumor as the target volume and adjacent organs of risks by segmentation is crucial to accomplish an optimal radiation distribution to the tumor while simultaneously preserving healthy tissue. Segmentation is performed manually and represents a time-consuming task in clinical daily routine. This study focuses on the segmentation of the rectum/sigmoid colon as an Organ-At-Risk in gynecological brachytherapy. The proposed segmentation method uses an interactive, graph-based segmentation scheme with a user-defined template. The scheme creates a directed two dimensional graph, followed by the minimal cost closed set computation on the graph, resulting in an outlining of the rectum. The graphs outline is dynamically adapted to the last calculated cut. Evaluation was performed by comparing manual segmentations of the rectum/sigmoid colon to results achieved with the proposed method. The comparison of the algorithmic to manual results yielded to a Dice Similarity Coefficient value of 83.85+/-4.08%, in comparison to 83.97+/-8.08% for the comparison of two manual segmentations of the same physician. Utilizing the proposed methodology resulted in a median time of 128 seconds per dataset, compared to 300 seconds needed for pure manual segmentation.

  20. Gastric heterotopia in rectum: A literature review and its diagnostic pitfall.

    Science.gov (United States)

    Dinarvand, Peyman; Vareedayah, Ashley A; Phillips, Nancy J; Hachem, Christine; Lai, Jinping

    2017-01-01

    The term heterotopia, in pathology, refers to the presence of normal tissues at foreign sites. Gastric heterotopia has been reported anywhere in the gastrointestinal tract. However, the presence of gastric heterotopia in the rectum is very rare. We, here, report a rare case of a localized 2-cm area of cratered mucosa with heaped-up borders in the rectum of a 51-year-old, asymptomatic woman who underwent screening colonoscopy. Histologic examination of the biopsy from the lesional tissue in rectum demonstrated fragments of rectal mucosa co-mingling with oxyntic- and antral-type gastric mucosa. No intestinal metaplasia or Helicobacter pylori is identified. Patients with gastric heterotopia in rectum usually present with bleeding and/or abdominal pain. Definite treatment of choice is surgical or endoscopic resection, although the lesions also respond to histamine-2 receptor blockers. In this article, most recent literature about gastric heterotopia in rectum is reviewed, following a case presentation about it.

  1. Gastric heterotopia in rectum: A literature review and its diagnostic pitfall

    Directory of Open Access Journals (Sweden)

    Peyman Dinarvand

    2017-02-01

    Full Text Available Objectives: The term heterotopia, in pathology, refers to the presence of normal tissues at foreign sites. Gastric heterotopia has been reported anywhere in the gastrointestinal tract. However, the presence of gastric heterotopia in the rectum is very rare. Methods: We, here, report a rare case of a localized 2-cm area of cratered mucosa with heaped-up borders in the rectum of a 51-year-old, asymptomatic woman who underwent screening colonoscopy. Results: Histologic examination of the biopsy from the lesional tissue in rectum demonstrated fragments of rectal mucosa co-mingling with oxyntic- and antral-type gastric mucosa. No intestinal metaplasia or Helicobacter pylori is identified. Conclusion: Patients with gastric heterotopia in rectum usually present with bleeding and/or abdominal pain. Definite treatment of choice is surgical or endoscopic resection, although the lesions also respond to histamine-2 receptor blockers. In this article, most recent literature about gastric heterotopia in rectum is reviewed, following a case presentation about it.

  2. Stimulation of butyrate absorption in the human rectum in vivo

    DEFF Research Database (Denmark)

    Holtug, K; Hove, H; Mortensen, P B

    1995-01-01

    BACKGROUND: Models of short-chain fatty acid absorption have focused on the stimulation of sodium absorption, an effect mainly located in the proximal colon of man. With the present efforts to utilize butyrate enemas as a treatment of ulcerative colitis, it seemed important to assess the transport...... in the rectum. METHODS: Non-equilibrium dialysis of the rectum was applied by placing dialysis bags containing various electrolyte solutions in the rectum of volunteers for 30 min. In this period changes in ion concentrations were linear with time. Net absorption and secretion rates were calculated from...

  3. Target volumes in gastric cancer radiation therapy; Les volumes-cibles de la radiotherapie des adenocarcinomes gastriques

    Energy Technology Data Exchange (ETDEWEB)

    Caudry, M.; Maire, J.P. [Hopital Saint Andre, Service de Cancerologie, 33 - Bordeaux (France); Ratoanina, J.L.; Escarmant, P. [Hopital Clarac, Service de Radiotherapie et de Cancerologie, 97 - Fort de France (France)

    2001-10-01

    The spread of gastric adenocarcinoma may follow three main patterns: hemato-genic, lymphatic and intraperitoneal. A GTV should be considered in preoperative or exclusive radiation therapy. After non-radical surgery, a 'residual GTV' will be defined with the help of the surgeon. The CTV encompasses three intricated volumes. a) A 'tumor bed' volume. After radical surgery, local recurrences appear as frequent as distant metastases. The risk depends upon the depth of parietal invasion and the nodal status. Parietal infiltration may extend beyond macroscopic limits of the tumor, especially in dinitis plastica. Therefore this volume will include: the tumor and the remaining stomach or their 'bed of resection', a part of the transverse colon, the duodenum, the pancreas and the troncus of the portal vein. In postoperative RT, this CTV also includes the jejuno-gastric or jejuno-esophageal anastomosis. b) A peritoneal volume. For practical purposes, two degrees of spread must be considered: (1) contiguous microscopic extension from deeply invasive T3 and T4 tumors, that remain amenable to local sterilization with doses of 45-50 Gy, delivered in a CTV including the peritoneal cavity at the level of the gastric bed, and under the parietal incision; (2) true 'peritoneal carcinomatosis', with widespread seeds, where chemotherapy (systemic or intraperitoneal) is more appropriate. c) A lymphatic volume including the lymph node groups 1 to 16 of the Japanese classification. This volume must encompass the hepatic pedicle and the splenic hilum. In proximal tumors, it is possible to restrict the lover part of the CTV to the lymphatic volume, and therefore to avoid irradiation of large intestinal and renal volumes. In distal and proximal tumors, involvement of resection margins is of poor prognosis -a radiation boost must be delivered at this level. The CTV in tumors of the cardia should encompass the lover part of the thoracic esophagus and the

  4. Diagnostic role of barium enema in carcinoma rectum

    International Nuclear Information System (INIS)

    Asghar, M.

    2003-01-01

    Objective: The main aim of this barium enema study was to evaluate its role in patients suspected to have rectal pathologies with complaints of change in bowel habit, anorexia/weight loss, bleeding per rectum and acute/sub-acute colonic obstruction. Results: barium enema study as screening test for colo-rectal carcinoma was undertaken. Contrast outlined the colonic growth in 35 cases, out of which the cases of carcinoma colon were 24 including 13 patients suffering from carcinoma rectum. The percentage of carcinoma colon to total colonic growth was 68% while, carcinoma rectum to total carcinoma colon was 54%. Conclusion: On the basis of these investigations, it is concluded that patient's compliance is important factor in the early detection of colonic neoplasia. Though results of colonoscopy are more reliable but in practice, barium enema (double contrast) is performed initially to outline the lesion and then colonoscopy for biopsy purpose. (author)

  5. Treatment plan evaluation using dose-volume histogram (DVH) and spatial dose-volume histogram (zDVH)

    International Nuclear Information System (INIS)

    Cheng, C.-W.; Das, Indra J.

    1999-01-01

    Objective: The dose-volume histogram (DVH) has been accepted as a tool for treatment-plan evaluation. However, DVH lacks spatial information. A new concept, the z-dependent dose-volume histogram (zDVH), is presented as a supplement to the DVH in three-dimensional (3D) treatment planning to provide the spatial variation, as well as the size and magnitude of the different dose regions within a region of interest. Materials and Methods: Three-dimensional dose calculations were carried out with various plans for three disease sites: lung, breast, and prostate. DVHs were calculated for the entire volume. A zDVH is defined as a differential dose-volume histogram with respect to a computed tomographic (CT) slice position. In this study, zDVHs were calculated for each CT slice in the treatment field. DVHs and zDVHs were compared. Results: In the irradiation of lung, DVH calculation indicated that the treatment plan satisfied the dose-volume constraint placed on the lung and zDVH of the lung revealed that a sizable fraction of the lung centered about the central axis (CAX) received a significant dose, a situation that warranted a modification of the treatment plan due to the removal of one lung. In the irradiation of breast with tangential fields, the DVH showed that about 7% of the breast volume received at least 110% of the prescribed dose (PD) and about 11% of the breast received less than 98% PD. However, the zDVHs of the breast volume in each of seven planes showed the existence of high-dose regions of 34% and 15%, respectively, of the volume in the two caudal-most planes and cold spots of about 40% in the two cephalic planes. In the treatment planning of prostate, DVHs showed that about 15% of the bladder and 40% of the rectum received 102% PD, whereas about 30% of the bladder and 50% of the rectum received the full dose. Taking into account the hollow structure of both the bladder and the rectum, the dose-surface histograms (DSH) showed larger hot-spot volume, about

  6. Squamous cell carcinoma of the rectum 21 years after radiotherapy for cervical carcinoma

    International Nuclear Information System (INIS)

    Leung, Kevin K; Madan, Anand; Heitzman, Joseph

    2009-01-01

    Squamous cell carcinoma (SCC) of the rectum is an extremely rare malignancy, accounting for 0.1-0.2% of rectal malignancies. It is associated with ulcerative colitis, prior radiation, schistosomiasis, ovarian cancer, endometrial cancer, human papilloma virus, colocutaneous fistulas and colonic duplication. Prior reported cases of SCC of the rectum have involved treatment with brachytherapy and external beam radiation. This case is particularly interesting because of the remote exposure of radiation (21 years previously) and the subsequent development of SCC of the rectum. Although extremely rare, SCC of the rectum can occur decades after radiation exposure. (author)

  7. Gas in the rectum tends to reduce during radical external beam radiotherapy for localised prostate cancer

    International Nuclear Information System (INIS)

    Nakamura, Naoki; Mizuno, Norifumo; Endo, Haruna; Ogita, Mami; Kawamori, Jiro; Sekigucho, Kenji; Hatanaka, Shogo; Takahashi, Osamu; Tamaki, Seiichi; Shikama, Naoto

    2014-01-01

    This study aims to clarify the time-course of gas accumulation in the rectum during treatment as guidance for the management of rectal volumes. We reviewed 2042 sets (35.2 sets per patient) of anteroposterior and right–left mega voltage (MV) images obtained for daily set-up from 58 patients who underwent radical external beam radiotherapy for localised prostate cancer. The patients were instructed to take magnesium oxide tablets during radiotherapy. They were also encouraged to avoid foods that might cause intestinal gas during radiotherapy. Gas accumulation in the rectum was graded into three classes by the same radiation oncologist. If no gas was seen in the rectum, it was classified as grade 0. A small amount of gas was classified as grade 1, whereas a marked amount of gas that required removal was classified as grade 2. Of the 2042 sets of MV images, grades 1 and 2 gas accumulation were seen in 332 (16%) and 156 (8%), respectively. By the trend test, gas accumulation significantly decreased towards the end of treatment (P=0.02 for grade 1 or 2 and P=0.02 for grade 2). On multivariate analysis, we did not identify any significant independent predictors for either baseline gas accumulation or gas reduction. Gas accumulation tended to decrease until the end of treatment. This tendency should be reconfirmed by other institutions.

  8. Toward a definition of a threshold for harmless doses to the anal-sphincter region and the rectum

    International Nuclear Information System (INIS)

    Al-Abany, Massoud; Helgason, Asgeir R.; Agren Cronqvist, Anna-Karin; Lind, Bengt; Mavroidis, Panayiotis; Wersaell, Peter; Lind, Helena; Qvanta, Eva; Steineck, Gunnar

    2005-01-01

    Purpose: To investigate dysfunction caused by unwanted radiation to the anal-sphincter region and the rectum. Methods and materials: A questionnaire assessing bowel symptoms, sexual function, and urinary symptoms was sent to 72 patients with clinically localized prostatic adenocarcinoma treated by external beam radiation therapy at the Radiumhemmet, Karolinska Hospital, in Stockholm, Sweden, 2-4 years after treatment. The mean percentage dose-volume histograms for patients with and without the specific symptom were calculated. Results: Of the 65 patients providing information, 9 reported fecal leakage, 10 blood and mucus in stools, 10 defecation urgency, and 7 diarrhea or loose stools. None of the 19 and 13 patients who received, respectively, a dose of ≥35 Gy to ≤60% or ≥40 Gy to ≤40% of the anal-sphincter region volume reported fecal leakage (p < 0.05). In dose-volume histograms, a statistically significant correlation was found between radiation to the anal-sphincter region and the risk of fecal leakage in the interval 45-55 Gy. There was also a statistically significant correlation between radiation to the rectum and the risk of defecation urgency and diarrhea or loose stools in the interval 25-42 Gy. No relationship was found between anatomic rectal wall volume and the investigated late effects. Conclusions: Although the limited data in this study prevent the definition of a conclusive threshold regarding volume and dose to the anal-sphincter region and untoward morbidity, it seems that careful monitoring of unnecessary irradiation to this area should be done because it can potentially help reduce the risk of adverse effects, such as fecal leakage. Future studies should pay more attention to the anal-sphincter region and help to more rigorously define its radiotherapeutic tolerance

  9. Horizontal cryostat for polarized proton targets; Cryostat horizontal pour cibles de protons polarises

    Energy Technology Data Exchange (ETDEWEB)

    Roubeau, P M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-11-15

    Continuously fed horizontal cryostat to be used for polarized proton targets; includes: 1 standard storage dewar commercially available; 2 shifting of dewar requiring 10 minutes, without any warming of the target; 3 no conventional nitrogen cooled shield but rather taking advantage of the cold helium vapours evaporated in the transfer line and/or the helium evaporated to cool the polarized crystal; 4 a heat exchanger which reduces by a factor of two the consumption of helium lowering in the same ratio the transfer line and/or the helium evaporated to cool the polarized crystal; 5 regulation of the temperature by means of a needle valve included in the superfluid helium line. This cryostat, used in conjunction with a 1000 l/s pump allows one to maintain at 1.06 deg. K a target, in which is dissipated 1 watt hyper frequency power, with an helium consumption of 40 litres/day (measured directly in the storage dewar). (author) [French] Description d'un cryostat horizontal, a alimentation continue, pour cible de protons polarises, presentant les caracteristiques suivantes: 1 utilisation de vases de stockage de modele commercial; 2 echange de vase en 10 minutes sans rechauffement; 3 absence d'azote liquide remplace par les vapeurs froides de l'helium evapore dans la canalisation de transfert et/ou les vapeurs de l'helium evapore pour refroidir le cristal polarise; 4 utilisation d'un echangeur qui aboutit a reduire de moitie la consommation d'helium, donc la pression d'evaporation, et qui permet, pour une pompe donnee, d'abaisser la temperature de fonctionnement de 0.1 degre environ; 5 reglage de la temperature au moyen d'une vanne a aiguille placee sur le circuit d'helium prerefroidi (superfluide). Ce cryostat, utilise avec une pompe de 1000 l/s permet de maintenir a une temperature de 1.06 deg. K une cible dans laquelle est dissipee une puissance d'hyperfrequence de 1 watt, moyennant une consommation d'helium de 40 litres/jour (mesuree dans le vase de stockage). (auteur)

  10. Endometriosis of the rectum: CT findings

    International Nuclear Information System (INIS)

    Guo Yan; Huang Zhaomin; Liu Mingjuan; Zhong Juemin

    2004-01-01

    Objective: To investigate the CT manifestations of recto-endometriosis. Methods: Three pathologically proved cases of recto-endometriosis were reported, the CT features and clinical manifestations were investigated retrospectively with review of literatures. Results: The patients were all menstruating females (28, 34, and 45 years old, respectively), and anal pain emerged during menses in one case. Rectal examination revealed stiff immobile mass along the rectal wall in all three cases. All the cases showed solid masses on CT scan with moderate enhancement after contrast administration. Two of them confined to the rectal walls, another involved the rectum and peri-rectal aspect. One case was misdiagnosed as well-differentiated adenocarcinoma of rectum in frozen section by biopsy specimen. Conclusion: A solid mass was always found in recto-endometriosis. No characteristic CT feature was manifested. Attention should be paid to the differentiation from rectal tumors when making the diagnosis

  11. SU-E-J-103: Propagation of Rectum and Bladder Contours for Tandem and Ring (T&R) HDR Treatment Using Deformable Image Registration

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Y; Chao, M; Sheu, R; Dumane, V; Gupta, V; Lo, Y [Mount Sinai Medical Center, New York, NY (United States)

    2015-06-15

    Purpose: To investigate the feasibility of using DIR to propagate the manually contoured rectum and bladder from the 1st insertion to the new CT images on subsequent insertions and evaluate the segmentation performance. Methods: Ten cervical cancer patients, who were treated by T&R brachytherapy in 3–4 insertions, were retrospectively collected. In each insertion, rectum and bladder were manually delineated on the planning CT by a physicist and verified by a radiation oncologist. Using VelocityAI (Velocity Medical Solutions, Atlanta, GA), a rigid registration was firstly employed to match the bony structures between the first insertion and each of the following insertions, then a multi-pass B-spine DIR was carried out to further map the sub volume that encompasses rectum and bladder. The resultant deformation fields propagated contours, and dice similarity coefficient (DSC) was used to quantitatively evaluate the agreement between the propagated contours and the manually-delineated organs. For the 3rd insertion, we also evaluated if the segmentation performance could be improved by propagating the contours from the most recent insertion, i.e., the 2nd insertion. Results: On average, the contour propagation took about 1 minute. The average and standard deviation of DSC over all insertions and patients was 0.67±0.10 (range: 0.44–0.81) for rectum, and 0.78±0.07 (range: 0.63–0.87) for bladder. For the 3rd insertion, propagating contours from the 2nd insertion could improve the segmentation performance in terms of DSC from 0.63±0.10 to 0.72±0.08 for rectum, and from 0.77±0.07 to 0.79±0.06 for bladder. A Wilcoxon signed rank test indicated that the improvement was statistically significant for rectum (p = 0.004). Conclusion: The preliminary results demonstrate that deformable image registration could efficiently and accurately propagate rectum and bladder contours between CT images in different T&R brachytherapy fractions. We are incorporating the propagated

  12. A predictive model to guide management of the overlap region between target volume and organs at risk in prostate cancer volumetric modulated arc therapy

    International Nuclear Information System (INIS)

    Mattes, Malcolm D.; Lee, Jennifer C.; Einaiem, Sara; Guirguis, Adel; Ikoro, N. C.; Ashamalla Hani

    2013-01-01

    The goal of this study is to determine whether the magnitude of overlap between planning target volume (PTV) and rectum (Rectum overlap ) or PTV and bladder (Bladder overlap ) in prostate cancer volumetric-modulated arc therapy (VMAT) is predictive of the dose-volume relationships achieved after optimization, and to identify predictive equations and cutoff values using these overlap volumes beyond which the Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) dose-volume constraints are unlikely to be met. Fifty-seven patients with prostate cancer underwent VMAT planning using identical optimization conditions and normalization. The PTV (for the 50.4 Gy primary plan and 30.6 Gy boost plan) included 5 to 10 mm margins around the prostate and seminal vesicles. Pearson correlations, linear regression analyses, and receiver operating characteristic (ROC) curves were used to correlate the percentage overlap with dose-volume parameters. The percentage Rectum overlap and Bladder overlap correlated with sparing of that organ but minimally impacted other dose-volume parameters, predicted the primary plan rectum V 45 and bladder V 50 with R 2 = 0.78 and R 2 = 0.83, respectively, and predicted the boost plan rectum V 30 and bladder V 30 with R 2 = 0.53 and R 2 = 0.81, respectively. The optimal cutoff value of boost Rectumoverlap to predict rectum V75 >15% was 3.5% (sensitivity 100%, specificity 94%, p overlap to predict bladder V 80 >10% was 5.0% (sensitivity 83%, specificity 100%, p < 0.01). The degree of overlap between PTV and bladder or rectum can be used to accurately guide physicians on the use of interventions to limit the extent of the overlap region prior to optimization.

  13. Iatrogen perforation of the rectum following barium enema; Iatrogen perforasjon av rectum ved roentgen colon

    Energy Technology Data Exchange (ETDEWEB)

    Eggum, R.; Kressner, U.; Haffner, J. [Buskerud Central Hospital, Drammen (Norway)

    1998-05-01

    Perforation of the rectum following barium enema is relatively rare, occurring in 1 of 3,000 procedures. Colorectal perforation is a serious condition and early diagnosis is of paramount importance in order to avoid any delay in treating the patient. Direct suture of the perforation, lavage, presacral drainage and stomia are the preferred methods of primary surgical treatment. 10 refs., 1 fig.

  14. An adolescent with prolapsed omentum per rectum: Spontaneous rectal perforation managed laparoscopically

    Directory of Open Access Journals (Sweden)

    Ameet Kumar

    2017-01-01

    Full Text Available Spontaneous rupture of the rectum is a rare occurrence. A total laparoscopic approach to rectal perforation has only occasionally been reported. We report an unusual case of a young boy who developed a spontaneous rupture of the rectum following a trivial fall. A magnetic resonance imaging revealed a tear in the rectum at the peritoneal reflection with the omentum plugging it. He denied any history of rectal instrumentation or abnormal sexual activity. He had no history of constipation or rectal prolapse. The tear was repaired laparoscopically and a covering loop sigmoid colostomy was added. He made an uneventful post-operative recovery. Spontaneous rupture of the rectum can occur in younger age groups and even in the absence of significant trauma. One needs to diligently bring out a history of rectal trauma. Equally important is to rule out any underlying pathological condition. A laparoscopic approach is feasible, especially in early cases.

  15. Sphincter-saving procedure for radiation-injuried rectum

    International Nuclear Information System (INIS)

    Moriya, Yoshihiro; Koyama, Yasuo; Hojo, Keiichi

    1982-01-01

    Up to this time the sigmoid colostomy has been widely accepted and conventional treatment for radiation-injured rectum, but patients without residual malignancy strongly desire to live without colostomy. We have tried to remove the involved rectal segments by sphincter-saving procedures. Four patients underwent these procedures, pull-through procedure in three and low anterior resection in one. Among sphincter-saving procedures, pull-through procedure was most adequate. Provided the following five conditions are fulfilled, pull-through procedure should be considered for severe radiation-injured rectum. (1) No recurrence of initial malignancy in the pelvis. (2) More than 2 cm intact rectal segment above dentate line may be preserved. (3) No radiation-injured segment in upper sigmoid. (4) No severe radiation damage in small intestine. (5) Patients under 70 year-old, with normal tonus of anal sphincter. (author)

  16. A predictive model to guide management of the overlap region between target volume and organs at risk in prostate cancer volumetric modulated arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mattes, Malcolm D.; Lee, Jennifer C.; Einaiem, Sara; Guirguis, Adel; Ikoro, N. C.; Ashamalla Hani [Dept. of Radiation Oncology, New York Methodist Hospital, Brooklyn (United States)

    2013-12-15

    The goal of this study is to determine whether the magnitude of overlap between planning target volume (PTV) and rectum (Rectum{sub overlap}) or PTV and bladder (Bladder{sub overlap}) in prostate cancer volumetric-modulated arc therapy (VMAT) is predictive of the dose-volume relationships achieved after optimization, and to identify predictive equations and cutoff values using these overlap volumes beyond which the Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) dose-volume constraints are unlikely to be met. Fifty-seven patients with prostate cancer underwent VMAT planning using identical optimization conditions and normalization. The PTV (for the 50.4 Gy primary plan and 30.6 Gy boost plan) included 5 to 10 mm margins around the prostate and seminal vesicles. Pearson correlations, linear regression analyses, and receiver operating characteristic (ROC) curves were used to correlate the percentage overlap with dose-volume parameters. The percentage Rectum{sub overlap} and Bladder{sub overlap} correlated with sparing of that organ but minimally impacted other dose-volume parameters, predicted the primary plan rectum V{sub 45} and bladder V{sub 50} with R{sup 2} = 0.78 and R{sup 2} = 0.83, respectively, and predicted the boost plan rectum V{sub 30} and bladder V{sub 30} with R{sup 2} = 0.53 and R{sup 2} = 0.81, respectively. The optimal cutoff value of boost Rectumoverlap to predict rectum V75 >15% was 3.5% (sensitivity 100%, specificity 94%, p < 0.01), and the optimal cutoff value of boost Bladder{sub overlap} to predict bladder V{sub 80} >10% was 5.0% (sensitivity 83%, specificity 100%, p < 0.01). The degree of overlap between PTV and bladder or rectum can be used to accurately guide physicians on the use of interventions to limit the extent of the overlap region prior to optimization.

  17. Chronic inflammatory diseases of the rectum and prostate: a review of literature

    Directory of Open Access Journals (Sweden)

    Z. A. Kadyrov

    2016-01-01

    Full Text Available The paper analyzes the Russian and foreign literature on chronic inflammatory diseases of the rectum and chronic prostatitis. The universally known anatomic and vascular relationships of the prostate and rectum indicate that there is a correlation of the development of chronic prostatitis and rectal diseases.

  18. Grading-System-Dependent Volume Effects for Late Radiation-Induced Rectal Toxicity After Curative Radiotherapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Laan, Hans Paul van der; Bergh, Alphons van den; Schilstra, Cornelis; Vlasman, Renske; Meertens, Harm; Langendijk, Johannes A.

    2008-01-01

    Purpose: To assess the association between the dose distributions in the rectum and late Radiation Therapy Oncology Group and the European Organisation for Research and Treatment of Cancer (RTOG/EORTC), Late Effects of Normal Tissue SOMA, and Common Terminology Criteria for Adverse Events (CTCAE) version 3.0 graded rectal toxicity among patients with prostate cancer treated with RT. Methods and Materials: Included in the study were 124 patients who received three-dimensional conformal RT for prostate cancer to a total dose of 70 Gy in 2-Gy fractions. All patients completed questionnaires regarding rectum complaints before RT and during long-term follow-up. Late rectum Grade 2 or worse toxicity, according to RTOG/EORTC, LENT SOMA, and CTCAE v3.0 criteria, was analyzed in relation to rectal dose and volume parameters. Results: Dose-volume thresholds (V40 ≥65%, V50 ≥55%, V65 ≥45%, V70 ≥20%, and a rectum volume ≤140 cm 3 ), significantly discriminated patients with late Grade 0-1 and Grade 2 or worse rectal toxicity, particularly using the LENT SOMA and CTCAE v3.0 systems. The rectum volume receiving ≥70 Gy (V70) was most predictive for late Grade 2 or worse rectal toxicity with each of the grading systems. The associations were strongest, however, with use of the LENT SOMA system. Conclusions: Volume effects for late radiation-induced rectal toxicity are present, but their clinical significance depends on the grading system used. This should be taken into account in the interpretation of studies reporting on radiation-induced rectal toxicity

  19. Asymptomatic gastric heterotopia in the rectum with Helicobacter pylori infection.

    Science.gov (United States)

    Swatek, Jarosław; Wronecki, Lech; Ciechanek, Roman; Szumiło, Justyna

    2015-12-01

    Gastric heterotopia is very rare in the rectum - less than 50 cases have been reported so far. Only in six of them Helicobacter pylori has been observed in heterotopic mucosa. We report a case of a 58-year-old woman with asymptomatic gastric heterotopia in the rectum, incidentally revealed during colonoscopy as a small, sessile polyp. The presence of H. pylori was confirmed by immunohistochemistry. This finding supports the opinion that H. pylori may pass along the gastrointestinal tract in a viable form and that the fecal-oral route of transmission is possible.

  20. Ligation of the Rectum with an Extracorporeal Sliding Knot Facilitating Laparoscopic Cross-Stapling

    DEFF Research Database (Denmark)

    Bulut, Orhan

    2013-01-01

    : The extracorporeal ligation of the rectum just proximal to the cut end of the rectum before applying the linear stapling stapler facilitates the procedure and requires only a few firings of the stapler during the laparoscopic rectal resections. Results: Ten patients with a median age of 72 years underwent rectal...

  1. Mucinous Adenocarcinoma of the Rectum with Breast and Ocular Metastases

    Directory of Open Access Journals (Sweden)

    Raja B. Hisham

    2006-04-01

    Full Text Available We present the case of a 32-year-old woman who, 10 months after abdominoperineal resection and total mesorectal excision for a locally advanced mucinous adenocarcinoma of the rectum, presented with local recurrence and metastases to the breast, spine, the left eye and orbit. Following surgery, due to the patient's personal reasons, adjuvant chemoradiation was not given. The patient died 2 months later, with disseminated cancer. To the best of our knowledge, breast as well as ocular metastasis in a patient with mucinous adenocarcinoma of the rectum has never been reported and, therefore, needs to be documented.

  2. SU-E-T-525: Dose Volume Histograms (DVH) Analysis and Comparison with ICRU Point Doses in MRI Guided HDR Brachytherapy for Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Badkul, R; McClinton, C; Kumar, P; Mitchell, M [University of Kansas Medical Center, Kansas City, KS (United States)

    2014-06-01

    Purpose: Brachytherapy plays a crucial role in management of cervix cancer. MRI compatible applicators have made it possible to accurately delineate gross-target-volume(GTV) and organs-at-risk(OAR) volumes, as well as directly plan, optimize and adapt dose-distribution for each insertion. We sought to compare DVH of tumor-coverage and OARs to traditional Point-A, ICRU-38 bladder and rectum point-doses for four different planning-techniques. Methods: MRI based 3D-planning was performed on Nucletron-Oncentra-TPS for 3 selected patients with varying tumor-sizes and anatomy. GTV,high-risk-clinical-target-volume(HR-CTV), intermediate-risk-clinical-target-volume(IR-CTV) and OARs: rectum, bladder, sigmoid-colon, vaginal-mucosa were delineated. Three conventionally used techniques: mg-Radium-equivalent(RaEq),equal-dwell-weights(EDW), Medical-College-of-Wisconsin proposed points-optimization (MCWO) and a manual-graphical-optimization(MGO) volume-coverage based technique were applied for each patient. Prescription was 6Gy delivered to point-A in Conventional techniques (RaEq, EDW, MCWO). For MGO, goal was to achieve 90%-coverage (D90) to HR-CTV with prescription-dose. ICRU point doses for rectum and bladder, point-A doses, DVH-doses for HR-CTV-D90,0.1cc-volume(D0.1),1ccvolume( D1),2cc-volume(D2) were collected for all plans and analyzed . Results: Mean D90 for HR-CTV normalized to MGO were 0.89,0.84,0.9,1.0 for EDW, RaEq, MCWO, MGO respectively. Mean point-A doses were 21.7% higher for MGO. Conventional techniques with Point-A prescriptions under covered HR-CTV-D90 by average of 12% as compared to MGO. Rectum, bladder and sigmoid doses were highest in MGO-plans for ICRU points as well as D0.1,D1 and D2 doses. Among conventional-techniques, rectum and bladder ICRU and DVH doses(0.1,1,2cc) were not significantly different (within 7%).Rectum D0.1 provided good estimation of ICRU-rectum-point doses (within 3.9%),rectum D0.1 were higher from 0.8 to 3.9% while bladder D0

  3. The action of sennosides and related compounds on human colon and rectum 1

    Science.gov (United States)

    Hardcastle, J. D.; Wilkins, J. L.

    1970-01-01

    The direct action of intraluminal senna and related compounds on the human colon and rectum has been investigated. Motility was recorded by balloon kymography with recording units inserted into well established transverse colostomies or into the rectum. The motility of the colon was not changed by intraluminal senna glycosides but the introduction of senna previously incubated with faeces or Esch. coli stimulated the colon to peristalt. The peristalsis was similar to that stimulated by rheinanthrone, an oxanthrone produced by chemical hydrolysis and reduction of senna. Both activated senna and rheinanthrone appeared to act in the colon by contact stimulation. No peristaltic response was stimulated in the rectum, either with activated senna or with rheinanthrone. PMID:4929273

  4. [Rectal tonsil or lymphoid follicular hyperplasia of the rectum].

    Science.gov (United States)

    Trillo Fandiño, L; Arias González, M; Iglesias Castañón, A; Fernández Eire, M P

    2014-01-01

    The rectal tonsil is a reactive proliferation of lymphoid tissue located in the rectum. The morphology of the lymphoid proliferation of the colon is usually polypoid or, less commonly, nodular. Only in exceptional cases does lymphoid proliferation of the colon present as a mass in the rectum (rectal tonsil), although this is the most common presentation in middle-aged patients. It is important to be familiar with the rectal tonsil because in cases of exuberant growth it can be difficult to distinguish it from other types of masses. We present the case of rectal tonsil in a four-year-old girl. We describe the magnetic resonance imaging findings and review the literature. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

  5. Two patients with rare mixed adenoneuroendocrine carcinomas of the rectum.

    Science.gov (United States)

    Gül-Klein, Safak; Sinn, Marianne; Jurmeister, Philipp Sebastian; Biebl, Matthias; Weiß, Sascha; Rau, Beate; Bläker, Hendrik; Pratschke, Johann; Aigner, Felix

    2018-01-01

    Mixed adenoneuroendocrine carcinomas of the gastrointestinal tract are until today poorly understood and thus very challenging for interdisciplinary therapy. We herewith report the first case series of patients with a primary mixed adenoneuroendocrine carcinoma of the rectum. Both cases were initially diagnosed as adenocarcinoma and only secondarily with mixed adenoneuroendocrine carcinoma and had a poor outcome due to a rapid tumor progression and resistance to chemotherapy. A 65-year-old female presented with local tumor recurrence and hepatopulmonary metastasis 1 year after primary surgery for adenocarcinoma of the rectum and consecutive radiochemotherapy regimen. Fluorouracil (5-FU) was followed by bevacizumab- and capecitabine-based chemotherapy but had to be discontinued due to side effects and progressive disease. Progressive local pain syndrome accompanied by recurrent bleeding episodes led to a local tumor-debulking operation. Afterward, mixed adenoneuroendocrine carcinoma as the underlying diagnosis in the final histopathological examination was detected. The patient died 3 months after the operation in the context of a fulminant tumor progress. A 63-year-old male patient underwent neoadjuvant radiochemotherapy and laparoscopic rectum resection. After 5 months, postoperative oxaliplatin/capecitabine-based adjuvant chemotherapy was switched to carboplatin/etopsid due to a progressive polyneuropathy and biopsy-proven pulmonary metastasis. The patient then had to be switched to local radiation of cerebral metastases and Topotecan due to cerebral bleeding episodes but died 18 months after the initial diagnosis. In conclusion of our case series, mixed adenoneuroendocrine carcinomas of the rectum should be considered as a rare but aggressive tumor entity. An early and detailed histopathological diagnosis is required in order to establish an individual interdisciplinary treatment concept.

  6. [Endoscopic dilatation of benign colon and rectum stenosis].

    Science.gov (United States)

    Rivera Vega, Juan; Frisancho Velarde, Oscar; Cervera, Zenón; Ruiz, Edwin; Yoza, Max; Larrea, Pedro

    2002-01-01

    To determine the usefulness of endoscopic dilatation in dealing with benign stenosis of the anus, rectum and colon. PATIENTS AND METHODS USED: Thirty six (36) patients with stenosis, anus (8), rectum (22) and colon (6) were given endoscopic treatment using hydroneumatic balloons, electro incision (radiated cuts) or a combination of both. Rigid equipment (metal) was used for distal stenosis. Age ranged between 30 and 82 years. Twelve (12) patients were male and 24 female. The diameter of the stenosis was less than 13 mm in 18 of the patients and 11 patients carried colostomy. All 36 patients were subjected to a total of 113 dilatation sessions. The average number of sessions per patient for patients with anal stenosis was 2.5 and for patients with colorectal stenosis, 3.32. One patient with rectal stenosis required 21 sessions to achieve final objective. The result achieved was good in 31 patients, less than satisfactory in 3 patients and bad in one patient, who presented a stenosis which was over 5 cm long. We lost track of a patient in the follow up stage. Success in closing the colostomy was achieved in 9 patients, while one presented a complication due to the procedure (cervical emphysema) which remitted with medical attention. Endoscopic dilatation offers, through its different techniques, a safe and efficient method for the treatment of benign stenosis of the anus, rectum and colon and must be considered as a first class tool for the treatment of this kind of pathologies.

  7. Case of unusual foreign body in the rectum

    International Nuclear Information System (INIS)

    Akhtar, Murtaza A; Arora, Pooja K

    2009-01-01

    A 44-year-old male patient with a foreign body in rectum (beverage bottle), introduced as sexual perversion, is presented with literature review. The management emphasis is on transanal retrieval and ruling out of the rectal and colonic perforation and the requirement for postremoval psychiatric treatment.(author)

  8. Bio-mechanical and morphometric evaluation of late radiation-induced changes in the mouse rectum

    International Nuclear Information System (INIS)

    Lundby, L.

    1998-01-01

    The overall aim of this thesis was to study the development of late radiation induced damage of the rectum and describe the histopathological and morphometric characteristics of the late injury. This required the design of a new, small probe for rectal measurements of cross-sectional area and distension pressure in mice. The impedance planimetric method was developed and validated in vitro and applied in in vivo studies of normal mice. The study of radiation induced damage of the rectum also required a new set-up for selective irradiation of a specific part of the rectum, shielding other organs. Mice were irradiated with varying single doses and followed with impedance planimetric measurements at regular intervals until death of the animals. In order to compare observed changes of the functional properties of the rectum following irradiation, a description of morphometric and morphologic characteristics by a stereolic technique was planned. A simplified stereological method has been applied to this study to describe late morphometric changes in the different intestinal layers after irradiation with varying single doses. (EG)

  9. Definition of the rectum and level of the peritoneal reflection - still a matter of debate?

    Science.gov (United States)

    Kenig, Jakub; Richter, Piotr

    2013-09-01

    Pathological lesions of the rectum are common and their management requires detailed knowledge of pelvic anatomy. There has been considerable debate as to the definition of the rectum and the variability of the level of the peritoneal reflection. The lack of a clear consensus was proven in the research by McCullen et al. regarding the current pattern of practice for the investigation of primary rectal cancer by general surgeons. To carry out bibliographic research on the definition of the rectum and level of the peritoneal reflection. A web-based published literature search of PubMed, Ovid Medline, Science Direct and Springer was made. The paper presents the current definitions of proximal and distal margin of the rectum and level of peritoneal reflection based not only on the results of tests on cadavers but also on living humans. The results of tests on living humans allow more accurate qualification of patients for local excision, which is particularly important for patients with colorectal cancer.

  10. Clinical aspects of forecasting results of treatments of patients with rectum cancer

    International Nuclear Information System (INIS)

    Kas'yanova, T.S.; Rusinovich, V.M.; Mirilenko, L.V.; Kizina, L.I.

    1990-01-01

    To predict the outcome of surgical treatment of patients with rectum cancer and the efficiency of the radiation component of multimodality treatment, some clinical aspects, having the prognostic meaning, are proposed. It is established that the prognostically significant signs for rectum cancer are: the disease stage, the status of the regional lymphatic system, the invasion degree and tumor growth form, tumor differentiation degree, its propagation over the circle, the availability or absence of ileus symptoms, the anamnesis period and some hemogram characters. 8 refs.; 1 tab

  11. Indication for, and valuation of computed tomography following anterior resection of the rectum

    International Nuclear Information System (INIS)

    Bauer, W.M.; Sommer, B.; Rath, M.; Fenzl, G.; Lissner, J.; Wirsching, R.

    1982-01-01

    During a controlled study, 55 patients who had an anterior resection of the rectum were thoroughly examined, including by computed tomography. The results verified the following statements: 1. The use of CT as a screening-method for early detection of local tumour recurrence following anterior resection of the rectum appears not to be justified. 2. CT is indicated: a) if there is a laboratory or clinical suspiciaon of recurrence, despite normal findings on proctoscopy; b) to clarify the question of extramural extension if recurrence has been established by proctoscopy. 3. Following anterior resection of the rectum, CT normally demonstrates no remarkable development of scar tissue, unless the anastomosis is inadequate. 4. Following anterior rectal resection every indefinable tissue thickening in the pelvis must be considered a possible tumour recurrence and must be further investigated by needle biopsy. (orig.)

  12. Indication for, and valuation of computed tomography following anterior resection of the rectum

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, W.M.; Sommer, B.; Rath, M.; Fenzl, G.; Lissner, J.; Wirsching, R.

    1982-02-01

    During a controlled study, 55 patients who had an anterior resection of the rectum were thoroughly examined, including by computed tomography. The results verified the following statements: 1. The use of CT as a screening-method for early detection of local tumour recurrence following anterior resection of the rectum appears not to be justified. 2. CT is indicated: a) if there is a laboratory or clinical suspicion of recurrence, despite normal findings on proctoscopy; b) to clarify the question of extramural extension if recurrence has been established by proctoscopy. 3. Following anterior resection of the rectum, CT normally demonstrates no remarkable development of scar tissue, unless the anastomosis is inadequate. 4. Following anterior rectal resection every indefinable tissue thickening in the pelvis must be considered a possible tumour recurrence and must be further investigated by needle biopsy.

  13. Rare tumors of the rectum. Narrative review.

    Science.gov (United States)

    Errasti Alustiza, José; Espín Basany, Eloy; Reina Duarte, Angel

    2014-11-01

    Most rectal neoplasms are adenocarcinomas, but there is a small percentage of tumors which are of other histological cell lines such as neuroendocrine tumors, sarcomas, lymphomas and squamous cell carcinomas, which have special characteristics and different treatments. We have reviewed these rare tumors of the rectum from a clinical and surgical point of view. Copyright © 2013 AEC. Published by Elsevier Espana. All rights reserved.

  14. Rectum. Strategy for management of cancer of the rectum

    International Nuclear Information System (INIS)

    Rider, W.D.; Chenery, S.A.G.; Hawkins, N.V.; Cummings, B.J.

    1984-01-01

    Cancer of the rectum, with few exceptions, has in the past been treated surgically, with results which are now being questioned and with results which have demonstrated that there has been no improvement in the past 40 years. The concept that curative irradiation might be a real challenge to surgery is of very recent origin. Thus the pattern of referral to the Princess Margaret Hospital (PMH) has, in the past, been restricted to those patients considered unsuitable for surgery for one reason or another. The most common reason for referral to PMH has been ''inoperability''. Patients unfortunate enough to be diagnosed with surgically inoperable cancers are in the main, those with tumours which have already invaded pelvic structures, making surgical excision impossible. Another group of patients are those with associated medical conditions and of an age which would make a very large operation hazardous. These two groups can be considered to be technically inoperable and technically operable; the former group is younger (median age 66) than the latter (median age 72). The prognosis is much better in the older ''technically operable'' group, and it appears from preliminary studies that the results of irradiation are probably as good as surgery

  15. Primært planocellulært karcinom i rectum

    DEFF Research Database (Denmark)

    Matlub, Karam; Qvist, Niels

    2010-01-01

    Primary squamous cell carcinoma of the colon and rectum is rare. It presents clinically as other types of colorectal cancer and the treatment is primarily surgery. The pathogenesis is unclear, but several hypotheses have been suggested, including human papilloma virus infection. Gynaecological...

  16. Mobilization of the rectum: anatomic concepts and the bookshelf revisited.

    Science.gov (United States)

    Chapuis, Pierre; Bokey, Les; Fahrer, Marius; Sinclair, Gael; Bogduk, Nikolai

    2002-01-01

    Sound surgical technique is based on accurate anatomic knowledge. In surgery for cancer, the anatomy of the perirectal fascia and the retrorectal plane is the basis for correct mobilization of the rectum to ensure clear surgical margins and to minimize the risk of local recurrence. This review of the literature on the perirectal fascia is based on a translation of the original description by Thoma Jonnesco and a later account by Wilhelm Waldeyer. The Jonnesco description, first published in 1896 in French, is compared with the German account of 1899. These were critically analyzed in the context of our own and other techniques of mobilizing the rectum. Mobilization of the rectum for cancer can be performed along anatomic planes with minimal blood loss, preservation of the pelvic autonomic nerves and a low prevalence of local recurrence. Different techniques including total mesorectal excision are based on the same anatomic principles, however, popular words have been used to replace accepted, established terminology. In particular, the description of total mesorectal excision has been confusing because of its emphasis on the words "total" and "mesorectum." The use of the word "mesorectum" anatomically is inaccurate and the implication that total excision of all the perirectal fat contained within the perirectal fascia "en bloc" in all patients with rectal cancer will minimize local recurrence remains contentious.

  17. Graphic and haptic simulation system for virtual laparoscopic rectum surgery.

    Science.gov (United States)

    Pan, Jun J; Chang, Jian; Yang, Xiaosong; Zhang, Jian J; Qureshi, Tahseen; Howell, Robert; Hickish, Tamas

    2011-09-01

    Medical simulators with vision and haptic feedback techniques offer a cost-effective and efficient alternative to the traditional medical trainings. They have been used to train doctors in many specialties of medicine, allowing tasks to be practised in a safe and repetitive manner. This paper describes a virtual-reality (VR) system which will help to influence surgeons' learning curves in the technically challenging field of laparoscopic surgery of the rectum. Data from MRI of the rectum and real operation videos are used to construct the virtual models. A haptic force filter based on radial basis functions is designed to offer realistic and smooth force feedback. To handle collision detection efficiently, a hybrid model is presented to compute the deformation of intestines. Finally, a real-time cutting technique based on mesh is employed to represent the incision operation. Despite numerous research efforts, fast and realistic solutions of soft tissues with large deformation, such as intestines, prove extremely challenging. This paper introduces our latest contribution to this endeavour. With this system, the user can haptically operate with the virtual rectum and simultaneously watch the soft tissue deformation. Our system has been tested by colorectal surgeons who believe that the simulated tactile and visual feedbacks are realistic. It could replace the traditional training process and effectively transfer surgical skills to novices. Copyright © 2011 John Wiley & Sons, Ltd.

  18. SU-E-T-284: Dose Plan Optimization When Using Hydrogel Prostate-Rectum Spacer: A Single Institution Experience

    Energy Technology Data Exchange (ETDEWEB)

    Rajecki, M; Thurber, A; Catalfamo, F; Duff, M; Shah, D [Cancer Care of Western New York, Cheektowaga, NY (United States)

    2015-06-15

    Purpose: To describe rectal dose reduction achieved and techniques used to take advantage of the increased peri-rectal spacing provided by injected polyethylene-glycol. Methods: Thirty prostate cancer patents were 2:1 randomized during a clinical trial to evaluate the effectiveness of injected poly-ethylene glycol hydrogel (SpaceOAR System) in creating space between the prostate and the anterior rectal wall. All patients received a baseline CT/MR scan and baseline IMRT treatment plan. Patients were randomized to receive hydrogel injection (n=20) or Control (n=10), followed by another CT/MR scan and treatment plan (single arc VMAT, 6 MV photons, 79.2 Gy, 44 fractions). Additional optimization structures were employed to constrain the dose to the rectum; specifically an avoidance structure to limit V75 <15%, and a control structure to limit the maximum relative dose <105% in the interface region of the anterior rectal wall and the prostate planning target volume. Dose volumetric data was analyzed for rectal volumes receiving 60 through 80 Gy. Results: Rectal dose reduction was observed in all patients who received the hydrogel. Volumetric analysis indicates a median rectal volume and (reduction from baseline plan) following spacer application of 4.9% (8.9%) at V60Gy, 3.8% (8.1%) at V65Gy, 2.5% (7.2%) at V70Gy, 1.6% (5.8%) at V75Gy, and 0.5% (2.5%) at V80Gy. Conclusion: Relative to planning without spacers, rectal dose constraints of 5%, 4%, 3%, 2%, 1% for V60, V65, V70, V75, and V80, should be obtainable when peri-rectal spacers are used. The combined effect of increased peri-rectal space provided by the hydrogel, with strict optimization objectives, resulted in reduced dose to the rectum. To maximize benefit, strict optimization objectives and reduced rectal dose constraints should be employed when creating plans for patients with perirectal spacers. Clinical Trial for SpaceOAR product conducted by Augmenix,Inc. The research site was paid to be a participating site.

  19. SU-E-T-284: Dose Plan Optimization When Using Hydrogel Prostate-Rectum Spacer: A Single Institution Experience

    International Nuclear Information System (INIS)

    Rajecki, M; Thurber, A; Catalfamo, F; Duff, M; Shah, D

    2015-01-01

    Purpose: To describe rectal dose reduction achieved and techniques used to take advantage of the increased peri-rectal spacing provided by injected polyethylene-glycol. Methods: Thirty prostate cancer patents were 2:1 randomized during a clinical trial to evaluate the effectiveness of injected poly-ethylene glycol hydrogel (SpaceOAR System) in creating space between the prostate and the anterior rectal wall. All patients received a baseline CT/MR scan and baseline IMRT treatment plan. Patients were randomized to receive hydrogel injection (n=20) or Control (n=10), followed by another CT/MR scan and treatment plan (single arc VMAT, 6 MV photons, 79.2 Gy, 44 fractions). Additional optimization structures were employed to constrain the dose to the rectum; specifically an avoidance structure to limit V75 <15%, and a control structure to limit the maximum relative dose <105% in the interface region of the anterior rectal wall and the prostate planning target volume. Dose volumetric data was analyzed for rectal volumes receiving 60 through 80 Gy. Results: Rectal dose reduction was observed in all patients who received the hydrogel. Volumetric analysis indicates a median rectal volume and (reduction from baseline plan) following spacer application of 4.9% (8.9%) at V60Gy, 3.8% (8.1%) at V65Gy, 2.5% (7.2%) at V70Gy, 1.6% (5.8%) at V75Gy, and 0.5% (2.5%) at V80Gy. Conclusion: Relative to planning without spacers, rectal dose constraints of 5%, 4%, 3%, 2%, 1% for V60, V65, V70, V75, and V80, should be obtainable when peri-rectal spacers are used. The combined effect of increased peri-rectal space provided by the hydrogel, with strict optimization objectives, resulted in reduced dose to the rectum. To maximize benefit, strict optimization objectives and reduced rectal dose constraints should be employed when creating plans for patients with perirectal spacers. Clinical Trial for SpaceOAR product conducted by Augmenix,Inc. The research site was paid to be a participating site

  20. [Iatrogen perforation of the rectum after colon radiography].

    Science.gov (United States)

    Eggum, R; Kressner, U; Haffner, J

    1998-05-10

    Perforation of the rectum following barium enema is relatively rare, occurring in 1 of 3,000 procedures. Colorectal perforation is a serious condition and early diagnosis is of paramount importance in order to avoid any delay in treating the patient. Direct suture of the perforation, lavage, presacral drainage and stomia are the preferred methods of primary surgical treatment.

  1. Local hyperthermia and artificial hyperglycemia in combined treatment of patients with rectum cancer

    International Nuclear Information System (INIS)

    Bezmen, V.A.; Illarionov, A.A.; Novokhrost, V.I.; Shilov, N.I.; Ospishchev, A.A.; Kejs, G.D.

    1990-01-01

    To study prospects of application of local hyperthermia, artificial hyperglycemia and radiotherapy in a preoperative period, 31 patients with rectum cancer were studied. The treatment included 3-hour artificial hyperglycemia first, then local SHF hyperthermia and telegamma irradiation using large-fractioned doses (ROD is 5 Gy, COD is 20 Gy). No serious side-effects were observed during the preoperative treatment period. The immediate and early results of combined treatment promise to improve the effectiveness of treatment of patients with rectum cancer. 3 refs

  2. Prostate and seminal vesicle volume based consideration of prostate cancer patients for treatment with 3D-conformal or intensity-modulated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Nandanuri M. S.; Nori, Dattatreyudu; Chang, Hyesook; Lange, Christopher S.; Ravi, Akkamma [Department of Radiation Oncology, New York Hospital Queens, Flushing, New York 11355 (United States); Department of Radiation Oncology, State University of New York Downstate Medical Center, Brooklyn, New York 11203 (United States); Department of Radiation Oncology, New York Hospital Queens, Flushing, New York 11355 (United States)

    2010-07-15

    Purpose: The purpose of this article was to determine the suitability of the prostate and seminal vesicle volumes as factors to consider patients for treatment with image-guided 3D-conformal radiation therapy (3D-CRT) or intensity-modulated radiation therapy (IMRT), using common dosimetry parameters as comparison tools. Methods: Dosimetry of 3D and IMRT plans for 48 patients was compared. Volumes of prostate, SV, rectum, and bladder, and prescriptions were the same for both plans. For both 3D and IMRT plans, expansion margins to prostate+SV (CTV) and prostate were 0.5 cm posterior and superior and 1 cm in other dimensions to create PTV and CDPTV, respectively. Six-field 3D plans were prepared retrospectively. For 3D plans, an additional 0.5 cm margin was added to PTV and CDPTV. Prescription for both 3D and IMRT plans was the same: 45 Gy to CTV followed by a 36 Gy boost to prostate. Dosimetry parameters common to 3D and IMRT plans were used for comparison: Mean doses to prostate, CDPTV, SV, rectum, bladder, and femurs; percent volume of rectum and bladder receiving 30 (V30), 50 (V50), and 70 Gy (V70), dose to 30% of rectum and bladder, minimum and maximum point dose to CDPTV, and prescription dose covering 95% of CDPTV (D95). Results: When the data for all patients were combined, mean dose to prostate and CDPTV was higher with 3D than IMRT plans (P<0.01). Mean D95 to CDPTV was the same for 3D and IMRT plans (P>0.2). On average, among all cases, the minimum point dose was less for 3D-CRT plans and the maximum point dose was greater for 3D-CRT than for IMRT (P<0.01). Mean dose to 30% rectum with 3D and IMRT plans was comparable (P>0.1). V30 was less (P<0.01), V50 was the same (P>0.2), and V70 was more (P<0.01) for rectum with 3D than IMRT plans. Mean dose to bladder was less with 3D than IMRT plans (P<0.01). V30 for bladder with 3D plans was less than that of IMRT plans (P<0.01). V50 and V70 for 3D plans were the same for 3D and IMRT plans (P>0.2). Mean dose to femurs

  3. Paraneoplastic digital necrosis associated with rectum carcinoma

    Directory of Open Access Journals (Sweden)

    Ali Alkan

    2015-12-01

    Full Text Available Paraneoplastic vascular pathologies are rare in daily practice. There is limited data about this phenomenon. Patient with a diagnosis of metastatic rectum carcinoma presented with digital necrosis. The work up for vascular and rheumatological pathology was inconclusive. Lesions progressively improved with steroid therapy. Paraneoplastic vascular lesions are rare in oncology practice. Our case points out important parts of a rare clinical entity. J Clin Exp Invest 2015; 6 (4: 391-392

  4. Virtual reality training and assessment in laparoscopic rectum surgery.

    Science.gov (United States)

    Pan, Jun J; Chang, Jian; Yang, Xiaosong; Liang, Hui; Zhang, Jian J; Qureshi, Tahseen; Howell, Robert; Hickish, Tamas

    2015-06-01

    Virtual-reality (VR) based simulation techniques offer an efficient and low cost alternative to conventional surgery training. This article describes a VR training and assessment system in laparoscopic rectum surgery. To give a realistic visual performance of interaction between membrane tissue and surgery tools, a generalized cylinder based collision detection and a multi-layer mass-spring model are presented. A dynamic assessment model is also designed for hierarchy training evaluation. With this simulator, trainees can operate on the virtual rectum with both visual and haptic sensation feedback simultaneously. The system also offers surgeons instructions in real time when improper manipulation happens. The simulator has been tested and evaluated by ten subjects. This prototype system has been verified by colorectal surgeons through a pilot study. They believe the visual performance and the tactile feedback are realistic. It exhibits the potential to effectively improve the surgical skills of trainee surgeons and significantly shorten their learning curve. Copyright © 2014 John Wiley & Sons, Ltd.

  5. Clinical and anatomical guidelines in pelvic cancer contouring for radiotherapy treatment planning; Definition de regles simples anatomocliniques dans la determination du volume cible des tumeurs pelviennes pour le planning radiotherapeutique

    Energy Technology Data Exchange (ETDEWEB)

    Portaluri, M.; Bambace, S.; Giuliano, G.; Pili, G.; Didonna, V. [General Hospital Di Summa-Perrino, Dept. of Radiation Oncology, Medical Physics, Brindisi (Italy); Perez, C.; Angone, G.; Alloro, E. [General Hospital Di Summa-Perrino, Dept. of Radiology, Medical Physics, Brindisi (Italy); Scialpi, M. [General Hospital SS. Annunziata, Dept. of Radiology, Taranto (Italy)

    2004-08-01

    Background and purpose. Many observations on potential inadequate coverage of tumour volume at risk in advanced cervical cancer (CC) when conventional radiation fields are used, have further substantiated by investigators using MRI, CT or lymph-angiographic imaging. This work tries to obtain three dimensional margins by observing enlarged nodes in CT scans in order to improve pelvic nodal chains clinical target volumes (CTVs) drawing, and by looking for corroborative evidence in the literature for a better delineation of tumour CTV. Method. Eleven consecutive patients (seven males, four females, mean age 62 years, range 43 8) with CT diagnosis of nodal involvement caused by pathologically proved carcinoma of the cervix (n = 2), carcinoma of the rectum (n = 2), carcinoma of the prostate (n = 2), non-Hodgkin lymphoma (n 2), Hodgkin lymphoma (n = 1), carcinoma of the penis (n = 1) and carcinoma of the corpus uteri (n = 1) were retrospectively reviewed. Sixty CT scans with 67 enlarged pelvic nodes were reviewed in order to record the more proximal structures (muscle, bone, vessels, cutis or sub-cutis and other organs) to each enlarged node or group of nodes according to the four surfaces (anterior, lateral, posterior and medial) in a clockwise direction. Results. summary of the observations of each nodal chain and the number of occurrences of every marginal structure on axial CT slices is presented. Finally, simple guidelines are proposed. Conclusions. Tumour CTV should be based on individual tumour anatomy mainly for lateral beams as it results from sagittal T2 weighted MRI images. Boundaries of pelvic nodes CTVs can be derived from observations of enlarged lymph nodes in CT scans. (author)

  6. Interposition of Ileal J-Pouch for Rectum Reconstruction in Dog

    Science.gov (United States)

    Ghahramani, Leila; Yazdani, Saeed; Derakhshani, Saeed; Rezaianzadeh, Abbas; Jalli, Reza; Geramizadeh, Bita; Safarpour, Ali Reza; Rahimikazerooni, Salar; Hosseini, Seyed Vahid

    2014-01-01

    Background: The gold standard of the management of rectal cancer in the middle and lower parts is low anterior resection with coloanal anastomosis. About 50% of the patients undergoing this procedure might experience some complications because of the low capacity of the neorectum. The aim of this study was to evaluate ileal J-pouch interposition as a neorectum between the anal canal and the remaining colon in comparison to coloanal anastomosis and transverse coloplasty. Methods: Twelve dogs, weighing 23-27 kg, were divided into three groups. After laparotomy, the volume of the primary rectum was measured so that it could be compared with that of the neorectum at the end of the study. After rectal resection in Group A, the colon was directly anastomosed to the anus. In Group B, a 5-cm longitudinal incision was made 2 cm proximal to the anastomosis and was sutured transversely (coloplasty). In Group C, a 5-cm ileal J-pouch was interposed between the colon and anus. After 8 weeks, the neorectum was evaluated for volume, radiology, and pathology. Results: All the samples were alive until the end of the study. The healing of the anastomotic lines was acceptable (pathologically) in all. The mean volume expansion was 20.9% in Group A, 21.7% in Group B, and 118.2% in Group C, with the latter being significantly higher than that of the other groups (P=0.03). Colon J-pouch and coloplasty after proctectomy in some situations have not been performable. This study evaluated the performance of ileal J-pouch interposition. Conclusion: This study showed that ileal J-pouch interposition might produce an acceptable reservoir function and that it seems feasible and safe in selected cases. PMID:24644380

  7. Interposition of ileal j-pouch for rectum reconstruction in dog.

    Science.gov (United States)

    Ghahramani, Leila; Yazdani, Saeed; Derakhshani, Saeed; Rezaianzadeh, Abbas; Jalli, Reza; Geramizadeh, Bita; Safarpour, Ali Reza; Rahimikazerooni, Salar; Hosseini, Seyed Vahid

    2014-03-01

    The gold standard of the management of rectal cancer in the middle and lower parts is low anterior resection with coloanal anastomosis. About 50% of the patients undergoing this procedure might experience some complications because of the low capacity of the neorectum. The aim of this study was to evaluate ileal J-pouch interposition as a neorectum between the anal canal and the remaining colon in comparison to coloanal anastomosis and transverse coloplasty. Twelve dogs, weighing 23-27 kg, were divided into three groups. After laparotomy, the volume of the primary rectum was measured so that it could be compared with that of the neorectum at the end of the study. After rectal resection in Group A, the colon was directly anastomosed to the anus. In Group B, a 5-cm longitudinal incision was made 2 cm proximal to the anastomosis and was sutured transversely (coloplasty). In Group C, a 5-cm ileal J-pouch was interposed between the colon and anus. After 8 weeks, the neorectum was evaluated for volume, radiology, and pathology. All the samples were alive until the end of the study. The healing of the anastomotic lines was acceptable (pathologically) in all. The mean volume expansion was 20.9% in Group A, 21.7% in Group B, and 118.2% in Group C, with the latter being significantly higher than that of the other groups (P=0.03). Colon J-pouch and coloplasty after proctectomy in some situations have not been performable. This study evaluated the performance of ileal J-pouch interposition. This study showed that ileal J-pouch interposition might produce an acceptable reservoir function and that it seems feasible and safe in selected cases.

  8. Iatrogen perforation of the rectum following barium enema

    International Nuclear Information System (INIS)

    Eggum, R.; Kressner, U.; Haffner, J.

    1998-01-01

    Perforation of the rectum following barium enema is relatively rare, occurring in 1 of 3,000 procedures. Colorectal perforation is a serious condition and early diagnosis is of paramount importance in order to avoid any delay in treating the patient. Direct suture of the perforation, lavage, presacral drainage and stomia are the preferred methods of primary surgical treatment. 10 refs., 1 fig

  9. Cervix-to-rectum measuring device in a radiation applicator for use in the treatment of cervical cancer

    International Nuclear Information System (INIS)

    Fischell, D.R.; Mazique, J.C.

    1981-10-01

    A cervix-to-rectum measuring device to be used in the treatment of cervical cancer is described. It includes a handle and a probe pivotably connected to the handle for insertion in the rectum. The measuring device further includes means for coupling the handle to an intrauterine radiation applicator when the latter is positioned in the uterine cervix and the probe is inserted in the rectum to pivot the handle about the probe. A gear is provided which is adapted to pivot with the probe. A pinion pivotably connected to the handle meshes with the gear. A pointer fixed to the pinion is displaced in response to the pivoting of the handle about the probe, and this displacement can be read from a scale on the handle, providing an indication of the cervix-to-rectum distance. Official Gazette of the U.S. Patent and Trademark Office

  10. [Study on effect of pH on rectum permeability of active ingredients in Reduning suppositories in vitro].

    Science.gov (United States)

    Yan, Ming; Wei, Ying-chun; Meng, Jin; Xu, Dian-hong; Wu, Yun; Xiao, Wei

    2015-04-01

    To investigate the effect of different pH on rectum permeability of chlorogenic acid and geniposide. Four kinds of Reduning suppositories of different pH were separated and put into the rectum to study the suppositories in vitro and the content of chlorogenic acid and geniposide samples was determined by HPLC to calculate the permeation in 24 hours. With increase of pH within 2.5-7.4, the steady state flux of chlorogenic acid was increased, but the steady state flux of geniposidesamples was steady. Adjusted the pH can increase the rectum permeability of active ingredients in Reduning auppositories.

  11. Laparoscopic radical prostatectomy and resection of rectum performed together: first experience.

    Science.gov (United States)

    Brodak, Milos; Orhalmi, Julius; Kosina, Josef; Balik, Michal; Pacovsky, Jaroslav

    2015-09-01

    Laparoscopy is an increasingly used approach in the surgical treatment of rectal cancer and prostate cancer. The anatomical proximity of the two organs is the main reason to consider performing both procedures simultaneously. To present our first experience of laparoscopic rectal resection and radical prostatectomy, performed simultaneously, in 3 patients. The first patient was diagnosed with locally advanced rectal cancer and tumor infiltration of the prostate and seminal vesicles. The other 2 patients were diagnosed with tumor duplicity. The surgery of the first patient started with laparoscopic prostatectomy except division of the prostate from the rectal wall. The next step was resection of the rectum, extralevator amputation of the rectum and vesicourethral anastomosis. In the other patients, resection of the rectum, followed by radical prostatectomy, was performed. The median follow-up was 12 months. The median operation time was 4 h 40 min, with blood loss of 300 ml. The operations and postoperative course were without incident in the case of 2 patients. However, 1 patient had stercoral peritonitis and a vesicorectal fistula in the early postoperative stage. Sigmoidostomy and postponed ureteroileal conduit were carried out. All patients were in oncologic remission. Combined laparoscopic rectal resection and radical prostatectomy is a viable option for selected patients with locally advanced rectal cancer or tumor duplication. The procedures were completed without complications in 2 out of 3 patients.

  12. Barium granuloma of the rectum: case report

    International Nuclear Information System (INIS)

    Kim, Dae Jin; Kim, Se Hyung; Jeoung, Ah Young; Lee, Kyoung Ho; Choi, Byung Ihn; Han, Joon Koo

    2003-01-01

    Barium granulomas usually occur after barium enema within 8 cm of the anal verge probably due to minute laceration of rectal wall by enema tip and extravasation of barium during barium enema. We report a case of barium granuloma of rectum in a 47-year-old man, who did not have history of barium enema. In rare instance, barium granuloma can occur without a history of barium enema and careful interpretation of radiologic image is essential to make a correct diagnosis

  13. New methods of X-ray study of the rectum and colon in patients with constipation

    International Nuclear Information System (INIS)

    Zarodnyuk, I.V.; Tikhonov, A.A.; Sinyaeva, L.M.

    1998-01-01

    Rectal and colonic X-ray findings of 100 patients with constipation are presented. Modified irrigoscopic procedure using barium enema was used. This made it possible not only to determine the shape, dimensions, and position of the rectum and colon, but to reveal a number of anatomic and functional changes in the rectum and pelvic floor, which was helpful in choosing a treatment policy for patients with colonic evacuator dysfunction

  14. Etude de la structure interne du nucleon en diffusion profondement inelastique de muons sur cibles fixes.

    CERN Document Server

    Granier, Thierry

    Dans ce mémoire est présentée l'analyse, dans le but de l'extraction des fonctions de structure, d'une partie des données de diffusion profondément inélastique de muons sur cibles fixes d'hydrogène et de detérium obtenues dans l'expérience NMC (New Muon Collaboration) du CERN. Les fonctions de structure, à partir desquelles s'exprime la probabilité de diffusion à un certain angle et une certaine énergie, contiennent de l'information sur la structure interne du nucléon, plus précisément sur la distribution en énergie des quarks à l'intérieur de celui-ci. L'étude de la variation des fonctions de structure avec le degré d'inélasticité de la diffusion permet de tester la validité de la chromodynamique quantique, la théorie de jauge des interactions fortes

  15. Single-access laparoscopic low anterior resection with vertical suspension of the rectum.

    Science.gov (United States)

    Uematsu, Dai; Akiyama, Gaku; Narita, Maiko; Magishi, Akiko

    2011-05-01

    Single-access laparoscopic surgery was first introduced for colectomy and later adapted for anterior resection. During single-access laparoscopic pelvic procedures, such as total mesorectal excision, it is often difficult to obtain an adequate operative field. By suspending the rectum vertically, we were able to execute a total mesorectal excision with single-access laparoscopy. We describe here the use of this new procedure to treat rectal cancer. The selected 7 patients (1 male and 6 female) with stage II or III rectal cancer underwent the procedure. Single-port access to the abdomen was provided by a 3.0-cm incision at the right iliac fossa. The descending mesocolon was dissected by use of a medial approach, and a columnar magnet was placed on the surface of the abdominal wall to restore triangulation. The inferior mesenteric artery was skeletonized and the superior rectal artery divided during lymph node dissection. The total mesorectal excision extended to the pelvic floor and the rectum was vertically retracted with a suspending bar in collaboration with an extracorporeal magnet tool. The rectum was then transected below the reflection of the peritoneum. Intracorporeal anastomosis was performed with the double-stapling technique. Two pelvic drains were inserted through the single incision and the anus, respectively, for all patients. A defunctioning ileostomy was not created in any patient. Median total surgical time was 205 minutes (range, 175-245 min). Intraoperative blood loss was minimal in all patients (range, 1-20 mL). None of the cases required conversion to open surgery or addition of a second port. The only preoperative or postoperative complication occurred in one patient with clinical anastomotic leakage. Low anterior single-access laparoscopic resection seems safe and feasible when the rectum is suspended like a swing to ensure an adequate operative field.

  16. Study of the secondary electron emission during bombardment of metal targets by positive D{sup +} and D{sub 2}{sup +} ions (1960); Etude de l'emission secondaire d'electrons au cours du bombardement de cibles metalliques par des ions positifs D{sup +} et D{sub 2}{sup +} (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Leroy, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Prelec, K [Institut Rudjer Boskovic, Zagreb (Croatia)

    1960-07-01

    The secondary electron yield {gamma}-bar due to primary positive ions D{sup +} and D{sup +}{sub 2} has been measured in the 70 keV to 300 keV ion energy range. Several metallic targets have been used. The variation of this yield with the angle of incidence is proportional to sec {theta} where {theta} is the angle between the beam of primary ions and the normal to the target surface. The values {gamma}-bar decrease for increasing energy ions. At a given energy all the targets tried gave approximately the same electron yield. (author) [French] Le facteur d'emission secondaire a ete mesure pour des ions positifs D{sup +} et D{sup +}{sub 2} ayant une energie comprise entre 70 keV et 300 keV, sur differentes cibles metalliques. La variation de ce facteur avec l'angle d'incidence suit une loi de la forme {gamma}{sub 0} sec {theta}, {theta} etant l'angle entre le faisceau et la normale a la cible. Les valeurs de {gamma}-bar trouvees decroissent lorsque l'energie des ions incidents augmente, mais sont assez voisines les unes des autres, a une energie donnee, pour les differentes cibles essayees. (auteur)

  17. Forward-viewing radial-array echoendoscope for staging of colon cancer beyond the rectum.

    Science.gov (United States)

    Kongkam, Pradermchai; Linlawan, Sittikorn; Aniwan, Satimai; Lakananurak, Narisorn; Khemnark, Suparat; Sahakitrungruang, Chucheep; Pattanaarun, Jirawat; Khomvilai, Supakij; Wisedopas, Naruemon; Ridtitid, Wiriyaporn; Bhutani, Manoop S; Kullavanijaya, Pinit; Rerknimitr, Rungsun

    2014-03-14

    To evaluate feasibility of the novel forward-viewing radial-array echoendoscope for staging of colon cancer beyond rectum as the first series. A retrospective study with prospectively entered database. From March 2012 to February 2013, a total of 21 patients (11 men) (mean age 64.2 years) with colon cancer beyond the rectum were recruited. The novel forward-viewing radial-array echoendoscope was used for ultrasonographic staging of colon cancer beyond rectum. Ultrasonographic T and N staging were recorded when surgical pathology was used as a gold standard. The mean time to reach the lesion and the mean time to complete the procedure were 3.5 and 7.1 min, respectively. The echoendoscope passed through the lesions in 13 patients (61.9%) and reached the cecum in 10 of 13 patients (76.9%). No adverse events were found. The lesions were located in the cecum (n = 2), ascending colon (n = 1), transverse colon (n = 2), descending colon (n = 2), and sigmoid colon (n = 14). The accuracy rate for T1 (n = 3), T2 (n = 4), T3 (n = 13) and T4 (n = 1) were 100%, 60.0%, 84.6% and 100%, respectively. The overall accuracy rates for the T and N staging of colon cancer were 81.0% and 52.4%, respectively. The accuracy rates among traversable lesions (n = 13) and obstructive lesions (n = 8) were 61.5% and 100%, respectively. Endoscopic ultrasound and computed tomography had overall accuracy rates of 81.0% and 68.4%, respectively. The echoendoscope is a feasible staging tool for colon cancer beyond rectum. However, accuracy of the echoendoscope needs to be verified by larger systematic studies.

  18. Target volume definition in conformal radiotherapy for prostate cancer: quality assurance in the MRC RT-01 trial

    International Nuclear Information System (INIS)

    Seddon, B.S.; Wilson, J.; Khoo, V.; Dearnaley, D.; Bidmead, M.

    2000-01-01

    Prior to randomization of patients into the UK Medical Research Council multicentre randomized trial (RT-01) of conformal radiotherapy (CFRT) in prostate cancer, clinicians at participating centres were required to complete a quality assurance (QA) clinical planning exercise to enable an investigation of inter-observer variability in gross target volume (GTV) and normal structure outlining. Thirteen participating centres and two investigators completed the clinical planning exercise of three practice planning cases. Clinicians were asked to draw outlines of the GTV, rectum and bladder on hard-copy computerized tomography (CT) films of the pelvis, which were transferred onto the Cadplan computer planning system by a single investigator. Centre, inferior and superior CT levels of GTV, rectum and bladder were noted, and volume calculations performed. Planning target volumes (PTV) were generated using automatic volume expansion of GTVs by a 1 cm margin. Anterior, right and left lateral beam eye views (BEV) of the PTVs were generated. Using a common central point, the BEV PTVs were superimposed for each beam direction of each case. Radial PTV variation was investigated by measurement of a novel parameter, termed the radial line measurement variation (RLMV). GTV central slice and length were defined with reasonable consistency. The RLMV analysis showed that the main part of the prostate gland, bladder and inferior rectum were outlined with good consistency among clinicians. However, the outlining of the prostatic apex, superior aspect of the prostate projecting into the bladder, seminal vesicles, the base of seminal vesicles and superior rectum were more variable. This exercise has demonstrated adequate consistency of GTV definition. The RLMV method of analysis indicates particular regions of clinician uncertainty. Appropriate feedback has been given to all participating clinicians, and the final RT-01 trial protocol has been modified to accommodate these findings

  19. Perceptions of phantom rectum syndrome and health-related quality of life in patients following abdominoperineal resection for rectal cancer.

    Science.gov (United States)

    Fingren, Jeanette; Lindholm, Elisabet; Carlsson, Eva

    2013-01-01

    The aim of the study was to investigate how patients described their perceptions of phantom rectum syndrome after abdominoperineal resection and ostomy creation, and its influence on daily living and health-related quality of life. A further aim was to find out strategies patients use to alleviate phantom rectum syndrome sensations. Twenty-five patients who underwent abdominoperineal resection and a colostomy (18 men and 7 women; median age 5 63 years; range, 40-78 years) at Sahlgrenska University Hospital, Göteborg, Sweden, participated in the study. At follow-up 8 months postsurgery, a WOC nurse interviewed patients with a structured questionnaire about the experience of nonpainful and painful sensations in the perineal area. Health-related quality of life was evaluated using a general cancer-specific instrument (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire version 3.0). Twenty-four patients (96%) experienced painful or nonpainful phantom rectum syndrome at some point during the first 8 postoperative months. The nonpainful sensations (20 patients) occurred in connection with emptying of feces via the stoma, when performing colostomy irrigation, at rest, or in various positions. Fifteen patients experienced painful sensations, characterized as pins and needles, pain in the perineal area, stinging, and burning occurring mostly in sitting positions. Patients with painful sensations had statistically significant higher scores regarding pain and lower scores for social function than those without painful sensations (P < .031). Phantom rectum symptoms caused worries and concerns and influenced daily life in 29% (n = 5). Phantom rectum syndrome is prevalent in patients undergoing abdominoperineal resection and ostomy creation. Information about phantom rectum syndrome should be shared preoperatively and during follow-up in order to promote optimal quality of life and alleviate bothersome symptoms and concerns associated with

  20. Aganglionosis of rectum present in the adult

    International Nuclear Information System (INIS)

    Lorenzo Rodriguez, Tulio; Marti Corunna, Maria; Ferreira Moreno, Victor

    2009-01-01

    We report the case a female patient referred with the diagnostic criterion of colon tumor. Patients had a marked abdominal distension from more than a month, without defecation, although with gases ejection, and neither reports of pain nor vomits. At admission and to study in depth the anamnesis, she expressed that during its childhood had a delay to defecate. She was operated on with a rectum biopsy, and its study defined la presence of aganglionosis. The non habitual documentation of this disease present in adults emphasizes the singularity of this case. (author)

  1. Duplication of the urethra with communication to the rectum

    International Nuclear Information System (INIS)

    Bruce, R.; Alton, D.

    1986-01-01

    The posterior channel of duplicated urethrae usually follows a straight course to end in the perineum just inside the anal verge. This unique urethra dipped into the perineum and then turned cephalad to enter the rectum above the anus. Delineation of the course of the urethra simplified management by assisting the urologist to convert the rectal passage to a hypospadiac urethra. (orig.)

  2. Gastric heterotopia in the rectum. A rare cause of ectopic gastric tissue.

    Science.gov (United States)

    Salem, George A; Fazili, Javid; Ali, Tauseef

    2017-03-01

    Gastric heterotopia refers to the discovery of normal gastric tissue at foreign, unexpected sites. It has been described anywhere in the alimentary tract, even in the mediastinum, scrotum, and spinal cord. It is not uncommonly seen in the oesophagus or small intestine. However, large bowel lesions are rare, with the most common location of colonic lesions is the rectum. Although it is a rare entity, it may be the source for significant problems such as rectal bleeding, abdominal pain, deep rectal pain, and malignancy. Here, we report an additional case of gastric heterotopia in the rectum of a 56year old gentleman, and review the literature. Copyright © 2017 Pan-Arab Association of Gastroenterology. Published by Elsevier B.V. All rights reserved.

  3. SU-F-T-447: The Impact of Treatment Planning Methods On RapidPlan Modeling for Rectum Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lu, S; Peng, J; Li, K; Wang, J; Hu, W [Fudan University Shanghai Cancer Center, Shanghai, Shanghai (China)

    2016-06-15

    Purpose: To investigate the dose volume histogram (DVH) prediction varieties based on intensity modulate radiotherapy (IMRT) plan or volume arc modulate radiotherapy (VMAT) plan models on the RapidPlan. Methods: Two DVH prediction models were generated in this study, including an IMRT model trained from 83 IMRT rectum plans and a VMAT model trained from 60 VMAT rectum plans. In the internal validation, 20 plans from each training database were selected to verify the clinical feasibility of the model. Then, 10 IMRT plans (PIMRT-by-IMRT-model) generated from IMRT model and 10 IMRT plans generated from VMAT model (PIMRT-by-VMAT-model) were compared on the dose to organs at risk (OAR), which included bladder, left and right femoral heads. The similar comparison was also performed on the VMAT plans generated from IMRT model (PVMAT-by-IMRT-model) and VMAT plans generated from VMAT (PVMAT-by-VMAT-model) model. Results: For the internal validation, all plans from IMRT or VMAT model shows significantly improvement on OAR sparing compared with the corresponded clinical ones. Compared to the PIMRT-by-VMAT-model, the PIMRT-by-IMRT-model has a reduction of 6.90±3.87%(p<0.001) on V40 6.63±3.62%(p<0.001) on V45 and 4.74±2.26%(p<0.001) on V50 in bladder; and a mean dose reduction of 2.12±1.75Gy(p=0.004) and 2.84±1.53Gy(p<0.001) in right and left femoral head, respectively. There was no significant difference on OAR sparing between PVMAT-by-IMRT-model and PVMAT-by-VMAT-model. Conclusion: The IMRT model for the rectal cancer in the RapidPlan can be applied to for VMAT planning. However, the VMAT model is not suggested to use in the IMRT planning. Cautions should be taken that the planning model based on some technique may not feasible to other planning techniques.

  4. A model to simulate day-to-day variations in rectum shape

    NARCIS (Netherlands)

    Hoogeman, Mischa S.; van Herk, Marcel; Yan, Di; Boersma, Liesbeth J.; Koper, Peter C. M.; Lebesque, Joos V.

    2002-01-01

    PURPOSE: To develop a model that predicts possible rectum configurations that can occur during radiotherapy of prostate cancer on the basis of a planning CT scan and patient group data. MATERIALS AND METHODS: We used a stochastic shape description model with a limited number of parameters (area,

  5. The spreading of radiolabelled fatty suppository bases in the human rectum

    International Nuclear Information System (INIS)

    Sugito, Keiko; Ogata, Hiroyasu; Noguchi, Masahiro; Kogure, Takahashi; Takano, Masaaki; Maruyama, Yuzo; Sasaki, Yasuhito

    1988-01-01

    The purpose of this study was to develop a radiolabelling method for assessing the spreading of fatty suppository bases (Witepsol H-5, W-35 and S-55), and to apply this technique to the evaluation of suppository disposition in the human rectum. 99m/Tc was bound chemically to the bases Witepsol H-5 and W-35, and mixed physically with Witepsol S-55. The spreading of each suppository base was monitored by gamma-scintigraphy following rectal administration. The mean radioactivity remaining at the inserted region 4 h after administration was 44.2% of total activity. The mean perpendicular maximum spreading distance from this region was 7.7 cm on the scintigram near to the sigmoid colon. Defecation was suggested to be a factor influencing the spread of suppository bases. However, there was no clear relationship between the type of suppository base used and the extent of its spread within the rectum. 6 refs.; 4 figs.; 1 table

  6. The forecasting of radiation injuries of the urinary bladder and rectum in patients with uterine cervix carcinoma

    International Nuclear Information System (INIS)

    Zharinov, G.M.; Gabelov, A.A.

    1984-01-01

    The frequency and degree of severity of radiation in unjuries of the urinary bladder and rectum after combined treatment of 725 patients with uterine cercix carcigoma are analysed. A quantitative index was worked out permi-- tting one to give an ob ective evaluation of the degree of early radiation reactions of the ad acent organs. The determination of the ''radiation injuries prognosis index'' (RIPI) makes it possible to forecast the occurence and degree of severity of late radiation injuries of the urinary bladder and rectum. The evaluation of RIPI mean values in the patients' groups provides an opportunity to oompare the damaging effect of different methods and regiment directly in the process of radiation therapy. The above method improves the potentialities of the forecasting of radiation injuries of the urinary bladder and rectum in patients with uterine cervix carcinoma

  7. In vitro study of acetylcholine and histamine induced contractions in colon and rectum of adult and neonate rats.

    Science.gov (United States)

    Singh, Shuchita; Mandal, Maloy B

    2013-01-01

    Contractile mechanisms of different parts of the gut in adult and neonate may not be identical due to developmental processes. The present study was undertaken to investigate acetylcholine (ACh) and histamine induced contractile responses of colon and rectum in adult and neonatal albino rats. Contractile responses were recorded from isolated in vitro preparations. The dose-response curve for ACh (0.001-100 microM) revealed dose dependent increase in contractile responses. A significantly (P pheniramine (100 microM) in adult rectum. This potentiating response of pheniramine was absent in neonate rectum. Such effect was also not seen in colon of both adult and neonate. The present investigation indicates that the contractile responses induced by ACh are similar in both adult and neonate, excepting that the blocking effect of atropine in colon was more pronounced in adult as compared to neonate. Further, the results also indicated different mechanism of histamine action in adults and neonates as evidenced by the significant enhancement of contractions by pheniramine only in adult rectum. Therefore, the present results indicate the existence of a different cholinergic and histaminergic activity in adult and neonate as well as in rectal and colonic tissue.

  8. Comparison of rectal volume definition techniques and their influence on rectal toxicity in patients with prostate cancer treated with 3D conformal radiotherapy: a dose-volume analysis

    International Nuclear Information System (INIS)

    Onal, Cem; Topkan, Erkan; Efe, Esma; Yavuz, Melek; Sonmez, Serhat; Yavuz, Aydin

    2009-01-01

    To evaluate the impact of four different rectum contouring techniques and rectal toxicities in patients with treated with 3D conformal radiotherapy (3DCRT). Clinical and dosimetric data were evaluated for 94 patients who received a total dose 3DCRT of 70 Gy, and rectal doses were compared in four different rectal contouring techniques: the prostate-containing CT sections (method 1); 1 cm above and below the planning target volume (PTV) (method 2); 110 mm starting from the anal verge (method 3); and from the anal verge to the sigmoid flexure (method 4). The percentage of rectal volume receiving RT doses (30–70 Gy) and minimum, mean rectal doses were assessed. Median age was 69 years. Percentage of rectal volume receiving high doses (≥ 70 Gy) were higher with the techniques that contoured smaller rectal volumes. In methods 2 and 3, the percentage of rectal volume receiving ≥ 70 Gy was significantly higher in patients with than without rectal bleeding (method 2: 30.8% vs. 22.5%, respectively (p = 0.03); method 3: 26.9% vs. 18.1%, respectively (p = 0.006)). Mean rectal dose was significant predictor of rectal bleeding only in method 3 (48.8 Gy in patients with bleeding vs. 44.4 Gy in patients without bleeding; p = 0.02). Different techniques of rectal contouring significantly influence the calculation of radiation doses to the rectum and the prediction of rectal toxicity. Rectal volume receiving higher doses (≥ 70 Gy) and mean rectal doses may significantly predict rectal bleeding for techniques contouring larger rectal volumes, as was in method 3

  9. Abdominoendorectal resection with peranal anastomosis in the treatment of radiation injuries of the rectum

    Energy Technology Data Exchange (ETDEWEB)

    Athanasiadis, S.; Girona, J.

    1982-01-01

    During the period 1974-1980 39 patients underwent operations at the Prosper Hospital in Recklinghausen for radiation injuries to the rectum or rectosigmoid. They comprised 22 patients with rectovaginal fistulas, 6 with ulcers, 3 suffering from severe hemorrhagic proctitis, 5 with rectal strictures, 1 with necrosis, and 2 with radiation ulcers and carcinoma. A sphincter-saving operative method of treating postirradiation damage of the rectum is presented. The technique involves the peranal anastomosis of healthy colon to the midanal canal using a sleeve anastomosis. Technical and functional results of resectional surgery for the rectal complications of radiation therapy are reported. Subjectively, total continence was present in 78%, only 1 patient was incontinent because of flatus and watery stools.

  10. Dose-Volume Constraints to Reduce Rectal Side Effects From Prostate Radiotherapy: Evidence From MRC RT01 Trial ISRCTN 47772397

    International Nuclear Information System (INIS)

    Gulliford, Sarah L.; Foo, Kerwyn; Morgan, Rachel C.; Aird, Edwin G.; Bidmead, A. Margaret; Critchley, Helen; Evans, Philip M. D.Phil.; Gianolini, Stefano; Mayles, W. Philip; Moore, A. Rollo; Sanchez-Nieto, Beatriz; Partridge, Mike; Sydes, Matthew R. C.Stat; Webb, Steve; Dearnaley, David P.

    2010-01-01

    Purpose: Radical radiotherapy for prostate cancer is effective but dose limited because of the proximity of normal tissues. Comprehensive dose-volume analysis of the incidence of clinically relevant late rectal toxicities could indicate how the dose to the rectum should be constrained. Previous emphasis has been on constraining the mid-to-high dose range (≥50 Gy). Evidence is emerging that lower doses could also be important. Methods and Materials: Data from a large multicenter randomized trial were used to investigate the correlation between seven clinically relevant rectal toxicity endpoints (including patient- and clinician-reported outcomes) and an absolute 5% increase in the volume of rectum receiving the specified doses. The results were quantified using odds ratios. Rectal dose-volume constraints were applied retrospectively to investigate the association of constraints with the incidence of late rectal toxicity. Results: A statistically significant dose-volume response was observed for six of the seven endpoints for at least one of the dose levels tested in the range of 30-70 Gy. Statistically significant reductions in the incidence of these late rectal toxicities were observed for the group of patients whose treatment plans met specific proposed dose-volume constraints. The incidence of moderate/severe toxicity (any endpoint) decreased incrementally for patients whose treatment plans met increasing numbers of dose-volume constraints from the set of V30≤80%, V40≤65%, V50≤55%, V60≤40%, V65≤30%, V70≤15%, and V75≤3%. Conclusion: Considering the entire dose distribution to the rectum by applying dose-volume constraints such as those tested here in the present will reduce the incidence of late rectal toxicity.

  11. Stem cell carcinoma of the colon and rectum. Report of two cases and review of the literature

    DEFF Research Database (Denmark)

    Palvio, D H; Sørensen, Flemming Brandt; Kløve-Mogensen, M

    1985-01-01

    Two cases of highly malignant tumors, one originating in the sigmoid colon and the other in the rectum, are presented. Both tumors showed light microscopic, electron microscopic, and immunohistochemical evidence of multidirectional differentiation. The tumors were composed mainly of undifferentia......Two cases of highly malignant tumors, one originating in the sigmoid colon and the other in the rectum, are presented. Both tumors showed light microscopic, electron microscopic, and immunohistochemical evidence of multidirectional differentiation. The tumors were composed mainly...

  12. Nerve supply to the internal anal sphincter differs from that to the distal rectum: an immunohistochemical study of cadavers.

    Science.gov (United States)

    Kinugasa, Yusuke; Arakawa, Takashi; Murakami, Gen; Fujimiya, Mineko; Sugihara, Kenichi

    2014-04-01

    Fecal incontinence is a common problem after anal sphincter-preserving operations. The intersphincteric autonomic nerves supplying the internal anal sphincter (IAS) are formed by the union of: (1) nerve fibers from Auerbach's nerve plexus of the most distal part of the rectum and (2) the inferior rectal branches of the pelvic plexus (IRB-PX) running along the conjoint longitudinal muscle coat. The aim of the present study is to identify the detailed morphology of nerves to the IAS. The study comprised histological and immunohistochemical evaluations of paraffin-embedded sections from a large block of anal canal from the preserved 10 cadavers. The IRB-PX came from the superior aspect of the levator ani and ran into the anal canal on the anterolateral side. These nerves contained both sympathetic and parasympathetic fibers, but the sympathetic content was much higher than in nerves from the distal rectum. All intramural ganglion cells in the distal rectum were neuronal nitric oxide synthase-positive and tyrosine hydroxylase-negative and were restricted to above the squamous-columnar epithelial junction. Parasympathetic nerves formed a lattice-like plexus in the circular smooth muscles of the distal rectum, whereas the IAS contained short, longitudinally running sympathetic and parasympathetic nerves, although sympathetic nerves were dominant. The major autonomic nerve input to the IAS seemed not to originate from the distal rectum but from the IRB-PX. Injury to the IRB-PX during surgery seemed to result in loss of innervation to the major part of the IAS.

  13. Treatment planning for adenocarcinoma of the rectum and sigmoid: a patterns of care study

    International Nuclear Information System (INIS)

    Kline, Robert W.; Smith, Alfred R.; Coia, Lawrence R.; Owen, Jean B.; Hanlon, Alexandra; Wallace, Marsha; Hanks, Gerald

    1997-01-01

    Purpose: To conduct a study of the process of treatment planning and treatment of adenocarcinoma of the rectum and sigmoid in the United States, and to compare survey results to consensus guidelines. Methods and Materials: A consensus committee developed guidelines for the radiotherapeutic management of adenocarcinoma of the rectum and sigmoid, and also developed a survey form that was used to gather data to evaluate the practice patterns for patients treated in 1989 and 1990 against the consensus guidelines. Seventy-three facilities were randomly selected for site visits from the 1321 radiation therapy facilities in the US: 21 academic, 26 hospital based, and 26 free standing. During the site visits, the radiotherapy records were examined by the surveyor physicist and radiation oncologist to extract and record the required data. Data collected included items related to treatment specific parameters, including treatment planning considerations. Analyses included stratification as to the types of institutions, academic, hospital based, or free standing. Results: For many treatment parameters there are discrepancies between the patterns of practice determined by the surveys and the consensus guidelines for radiotherapy treatment of adenocarcinoma of the rectum and sigmoid. Significant differences in practice among the stratified institution types were found in only a few parameters

  14. Linfadectomy in cancer treatment colon rectum; Linfadectomia en el Tratamiento del Cancer colorrectal

    Energy Technology Data Exchange (ETDEWEB)

    Canesa, C

    2003-01-15

    The purpose of this revision is to describe the anatomical basic aspects and histopatologicos of interest in the lymphatic dissection and to discuss the list of the radical linfadectomy in the treatment of the cancer colon rectum.

  15. Rectum perforation during transanal irrigation: a case story

    DEFF Research Database (Denmark)

    Biering-Sørensen, F; Bing, J; Berggreen, P

    2008-01-01

    STUDY DESIGN: Case report. OBJECTIVES: Report a case of rectum perforation during transanal irrigation (TAI). SETTING: Clinic for Spinal Cord Injuries, and Departments of Gastroenterological Surgery and Radiology. CASE REPORT: A 54-year-old woman with spinal cord lesion for 35 years emptied...... for years her bowel using oral laxative. This became more difficult and took more than 2 h three times a week with reflex stimulation after a chlysma. She wanted to try TAI, and went through the procedure with a nurse one time. The next time she performed the TAI by herself without difficulty. Two hours...

  16. [Covering stoma in anterior rectum resection with TME for rectal cancer in elderly patients].

    Science.gov (United States)

    Cirocchi, Roberto; Grassi, Veronica; Barillaro, Ivan; Cacurri, Alban; Koltraka, Bledar; Coccette, Marco; Sciannameo, Francesco

    2010-01-01

    The aim of our study is to evaluate the advisability of covering stoma in Anterior Rectum Resection with TME in elderly patients. A research of both the Ministry of Health and Terni Hospital databases has been conducted so as to collect information about patients with rectal tumor. Such research allowed to identify the amount of patients diagnosed with rectal cancer, the type of intervention, and the average hospitalization time. Between January 1997 and June 2008, 209 patients have undergone chirurgical surgery at Terni hospital's General and Emergency Surgical Clinic. An Anterior Rectum Resection with TME has been performed in 135 patients out of the sample (64.59%). The average hospitalization time of geriatric patients does not show significant differences compared to that of younger patients. An age-cohort analysis has been performed among patients who have been subject to stomia and those who have not. The former have been further split up between those who underwent ileostomy and those subject to colostomy. While ileostomy patients face a similar hospitalization time across all age cohorts, geriatric colostomy patients face longer hospitalizations than younger patients. Patients subject to Anterior Rectum Resection show no meaningful differences, in terms of hospitalization time, across all age cohorts. In geriatric patients the construction of covering stoma has resulted in longer hospitalizations only when a loop colostomy was executed, as opposed to loop ileostomy.

  17. Effect of age on radiation-induced early changes of rat rectum. A histological time sequence

    International Nuclear Information System (INIS)

    Olofsen-van Acht, Manouk J.J.; Hooije, Christel M.C. van; Aardweg, Gerard J.M.J. van den; Levendag, Peter C.; Velthuysen, Marie Louise F. van

    2001-01-01

    Background and purpose: Radiation treatment of the elderly (>75 years) is often modified due to an assumed decrease in normal tissue tolerance in this age group. Since more radiobiological data concerning normal tissue toxicity as a function of age are needed, a histological study of age-related radiation changes of the rectum was performed. Materials and methods: The rectum of young and old female Wistar rats (12 and 78 weeks, respectively) was irradiated with single doses of 22 and 39 Gy. The field size was 1.5x2.0 cm. The animals were sacrificed at 1, 2, 4 and 10 weeks after treatment. To evaluate radiation damage, 12 histological parameters were scored in four areas of the rectum. A total radiation injury score was calculated. The number of proliferative epithelial cells was evaluated by 5-bromo-2'-deoxyuridine labeling. Results: Some age-related histological differences were observed; especially, the incidence of ulceration and vascular occlusion was higher in the older group. In the low dose group of the older animals, 60% showed ulceration, which was 0% for the young low dose animals. Severe vascular changes occurred early and were more extensive in older animals (4 weeks) than in the younger group (10 weeks). In the area adjacent to the treatment field, cell proliferation increased significantly in older rats at 1 week after 22 Gy, which did not occur in the young group. Conclusions: Discrete radiation-induced histological differences were observed between the rectum of young and old Wistar rats, especially in the development of ulceration and vascular changes. Although the survival of these Wistar rats in earlier studies was not affected by age, the impact of the observed histological differences for their importance in the long-term is currently being investigated

  18. Endocavitary radiotherapy of rectal tumours; Endokavitaer straalebehandling ved distale rectum tumorers

    Energy Technology Data Exchange (ETDEWEB)

    Tanum, G.; Wiig, J. [Norske Radiumhospital, Oslo (Norway); Andersen, O.K. [Sentralsykehuset i Akershus, Loerenskog (Norway)

    1997-02-01

    The authors describe their experience of endocavitary radiotherapy of adenomas and carcinomas of the lower rectum. The method is an alternative for patients who cannot undergo standard surgical procedure or do no want a permanent colostomy. This method is cheap, fast and causes little discomfort to the patients, gives reasonable long-term results and has low morbidity. 11 refs., 4 figs., 2 tabs.

  19. Dose Distribution of Rectum and Bladder in Intracavitary Irradiation

    International Nuclear Information System (INIS)

    Chu, S. S.; Oh, W. Y.; Suh, C. O.; Kim, G. E.

    1984-01-01

    The intrauterine irradiation is essential to achieve adequate tumor dose to central tumor mass of uterine malignancy in radiotherapy. The complications of pelvic organ are known to be directly related to radiation dose and physical parameters. The simulation radiogram and medical records of 206 patients, who were treated with intrauterine irradiation from Feb. 1983 to Oct. 1983, were critically analyzed. The physical parameters to include distances between lateral walls of vaginal fornices, longitudinal and lateral cervix to the central axis of ovoid were measured for low dose rate irradiation system and high dose rate remote control after loading system. The radiation doses and dose distributions within cervical area including interesting points and bladder, rectum, according to sources arrangement and location of applicator, were estimated with personal computer. Followings were summary of study results; 1. In distances between lateral walls of vaginal fornices, the low dose rate system showed as 4-7cm width and high dose rate system showed as 5-6cm. 2. In Horizontal angulation of tandem to body axis, the low dose rate system revealed mid position 64.6%, left deviation 19.2% and right deviation 16.2%. 3. In longitudinal angulation of tandem to body axis, the mid position was 11.8% and anterior angulation 88.2% in low dose rate system but in high dose rate system, anterior angulation was 98.5%. 4. Down ward displacement of ovoid below external os was only 3% in low dose rate system and 66.6% in high dose rate system. 5. In radiation source arrangement, the most activities of tandem and ovoid were 35 by 30 in low dose rate system but 50 by 40 in high dose rate system. 6. In low and high dose rate system, the total doses and TDF were 80, 70 Gy and 131, 123 including 40 Gy external irradiation. 7. The doses and TDF in interesting points Co, B, were 98, 47 Gy and 230, 73 in high dose rate system but in low dose rate system 125, 52 Gy and 262, 75 respectively. 8. Doses

  20. Ectopic prostatic tissue in the rectum: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Myung Jin; Noh, Kyung Hee; Jeon, Doo Sung; Lee, Kwang Min [Presbyterian Medical Center, Jeonju (Korea, Republic of)

    2017-02-15

    Ectopic prostatic tissue (EPT) outside the male genitourinary tract is an unusual finding, and it is very rarely found in the rectum or around the peri-rectal region. In addition, the radiologic features of EPT are seldom reported. Also, it is difficult to differentiate EPT found in the rectal subepithelium from the other types of subepithelial tumors. We present here a unique case of EPT found in the retrorectal region, along with the radiologic findings of transrectal ultrasonography, computed tomography, and magnetic resonance imaging with their pathologic correlations.

  1. Pelvic Myxoid Leiomyoma Mass between Vagina and Rectum

    Directory of Open Access Journals (Sweden)

    Omar AlShalabi

    2016-01-01

    Full Text Available Leiomyomas are the most common pelvic tumors in women. About 20–30% of women older than 35 are affected. Rare conditions of leiomyomas have extrauterine locations. Myxoid degeneration is a rare type of leiomyoma degeneration. We report a case of solid-cystic myxoid leiomyoma in a 53-year-old woman complained of constipation, urinary hesitation, and malodorous vaginal discharge with palpable 17×12 cm mass between vagina and rectum. Regarding the inferior location of the mass, a perineal approach was used to enucleate it. This rare location has not been mentioned before. The woman was finally diagnosed by pathologists which was myxoid leiomyoma.

  2. Pelvic Myxoid Leiomyoma Mass between Vagina and Rectum.

    Science.gov (United States)

    AlShalabi, Omar; Alahmar, Fadi Obaied; Aljasem, Hazem; Alsaid, Bayan; AlShalabi, Abdulghani

    2016-01-01

    Leiomyomas are the most common pelvic tumors in women. About 20-30% of women older than 35 are affected. Rare conditions of leiomyomas have extrauterine locations. Myxoid degeneration is a rare type of leiomyoma degeneration. We report a case of solid-cystic myxoid leiomyoma in a 53-year-old woman complained of constipation, urinary hesitation, and malodorous vaginal discharge with palpable 17 × 12 cm mass between vagina and rectum. Regarding the inferior location of the mass, a perineal approach was used to enucleate it. This rare location has not been mentioned before. The woman was finally diagnosed by pathologists which was myxoid leiomyoma.

  3. The abdominoendorectal resection with peranal anastomosis in the treatment of radiation injuries of the rectum

    International Nuclear Information System (INIS)

    Athanasiadis, S.; Girona, J.

    1982-01-01

    During the period 1974-1980 39 patients underwent operations at the Prosper Hospital in Recklinghausen for radiation injuries to the rectum or rectosigmoid. They comprised 22 patients with rectovaginal fistulas, 6 with ulcers, 3 suffering from severe hemorrhagic proctitis, 5 with rectal strictures, 1 with necrosis, and 2 with radiation ulcers and carcinoma. A sphincter-saving operative method of treating postirradiation damage of the rectum is presented. The technique involves the peranal anastomosis of healthy colon to the midanal canal using a sleeve anastomosis. Technical and functional results of resectional surgery for the rectal complications of radiation therapy are reported. Subjectively, total continence was present in 78%, only 1 patient was incontinent because of flatus and watery stools. (orig.) [de

  4. Impact of knee support and shape of tabletop on rectum and prostate position

    NARCIS (Netherlands)

    Steenbakkers, Roel J. H. M.; Duppen, Joop C.; Betgen, Anja; Lotz, Heidi Th; Remeijer, Peter; Fitton, Isabelle; Nowak, Peter J. C. M.; van Herk, Marcel; Rasch, Coen R. N.

    2004-01-01

    PURPOSE: To evaluate the impact of different tabletops with or without a knee support on the position of the rectum, prostate, and bulb of the penis; and to evaluate the effect of these patient-positioning devices on treatment planning. METHODS AND MATERIALS: For 10 male volunteers, five MRI scans

  5. A model to incorporate organ deformation in the evaluation of dose/volume relationship

    International Nuclear Information System (INIS)

    Yan, D.; Jaffray, D.; Wong, J.; Brabbins, D.; Martinez, A. A.

    1997-01-01

    treatment have been collected prospectively during their course of treatment. The data was used retrospectively to examine the model, and to evaluate the cumulative dose/volume relationships of the prostate, rectum and bladder in comparison with those in the initial treatment plan. Results: Characteristics of daily organ deformation were specific to the individual patient and could not be easily represented by a global description. Daily deformation of the prostate secondary to local filling of rectum and bladder could not be simply modeled using the linear transformation of rigid body motion. The cumulative dose distribution in the prostate was either overestimated or underestimated using the linear model. Deformation of the rectum due to rectal filling occurred at different positions on different days. Consequently, daily hot spots occurred on different locations of the rectal wall. Therefore, the direct combination of the daily dose volume histograms would overestimate the actual dose/volume relation. Furthermore, the shapes and positions of the prostate, rectum, and bladder defined in the initial planning CT scan were not representative of the mean shape and position as assumed in the linear model for rigid organ motion. As such, the linear convolution method based upon rigid motion of the initial CT volumes led to misleading results in the planning evaluation and optimization for the individual patient. Conclusion: Our proposed model provides a more realistic description of the viscoelastic nature of daily organ deformation than the current rigid body models. It provides a systematic framework to incorporate the daily organ motion in the calculation of cumulative dose/volume relationships throughout the course of treatment. This information may play an important role in the treatment evaluation and reoptimization for the individual patient

  6. Prostate and seminal vesicle volume based consideration of prostate cancer patients for treatment with 3D-conformal or intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Reddy, Nandanuri M. S.; Nori, Dattatreyudu; Chang, Hyesook; Lange, Christopher S.; Ravi, Akkamma

    2010-01-01

    Purpose: The purpose of this article was to determine the suitability of the prostate and seminal vesicle volumes as factors to consider patients for treatment with image-guided 3D-conformal radiation therapy (3D-CRT) or intensity-modulated radiation therapy (IMRT), using common dosimetry parameters as comparison tools. Methods: Dosimetry of 3D and IMRT plans for 48 patients was compared. Volumes of prostate, SV, rectum, and bladder, and prescriptions were the same for both plans. For both 3D and IMRT plans, expansion margins to prostate+SV (CTV) and prostate were 0.5 cm posterior and superior and 1 cm in other dimensions to create PTV and CDPTV, respectively. Six-field 3D plans were prepared retrospectively. For 3D plans, an additional 0.5 cm margin was added to PTV and CDPTV. Prescription for both 3D and IMRT plans was the same: 45 Gy to CTV followed by a 36 Gy boost to prostate. Dosimetry parameters common to 3D and IMRT plans were used for comparison: Mean doses to prostate, CDPTV, SV, rectum, bladder, and femurs; percent volume of rectum and bladder receiving 30 (V30), 50 (V50), and 70 Gy (V70), dose to 30% of rectum and bladder, minimum and maximum point dose to CDPTV, and prescription dose covering 95% of CDPTV (D95). Results: When the data for all patients were combined, mean dose to prostate and CDPTV was higher with 3D than IMRT plans (P 0.2). On average, among all cases, the minimum point dose was less for 3D-CRT plans and the maximum point dose was greater for 3D-CRT than for IMRT (P 0.1). V30 was less (P 0.2), and V70 was more (P 0.2). Mean dose to femurs was more with 3D than IMRT plans (P 3 (39/48), respectively (P 3 , respectively, would be suitable for 3D-CRT. Patients with prostate and prostate+SV volumes >65 and 85 cm 3 , respectively, might get benefit from IMRT.

  7. Transanal endoscopic microsurgery for giant polyps of the rectum

    DEFF Research Database (Denmark)

    Levic, K; Bulut, O; Hesselfeldt, P

    2014-01-01

    in the rectum. We present our results with TEM in the removal of giant polyps equal or greater than 4 cm in diameter. METHODS: In the period between 1998 and 2012, TEM was performed in 39 patients with rectal polyps measuring at least 4 cm in diameter. Transrectal ultrasound and/or magnetic resonance imaging......, these recurrences were treated with endoscopic removal or re-TEM. The remaining 5 underwent total mesorectal excision and/or chemotherapy. CONCLUSIONS: Full-thickness TEM provides a safe and efficient treatment for excision of giant polyps. In case of unexpected cancer, TEM can be curative. Local recurrence can...

  8. ROLE OF CT IN DIFFERENTIATION OF MUCINOUS AND NON-MUCINOUS CARCINOMAS OF THE RECTUM

    Directory of Open Access Journals (Sweden)

    Piyush Joshi

    2017-01-01

    Full Text Available BACKGROUND Colorectal carcinomas can broadly be classified as either non-mucinous or mucinous. Usually, mucinous adenocarcinomas present at a more advanced stage, have more aggressive local spread and have an increased incidence of lymph node involvement. Those cancers occurring in the rectum are considered more aggressive and require careful planning for treatment. Screening Computed Tomography (CT is widely used for the initial evaluation of these tumours. The aim of the study is to retrospectively analyse the CT images of rectal adenocarcinomas and suggest parameters to aid differentiation of mucinous and non-mucinous tumours. MATERIALS AND METHODS The CT images of 24 cases of mucinous and 26 cases of non-mucinous adenocarcinoma were retrospectively reviewed and evaluated for parameters like morphology, wall thickness, size, pattern and degree of enhancement and the presence or absence of calcification. Also, evaluated was involvement of adjacent structures, lymph nodes and distant metastases. RESULTS All the parameters were analysed for significance using the chi-square test. Mucinous adenocarcinomas of the rectum showed a greater propensity for eccentric bowel thickening, heterogenous enhancement and calcification with a p value less than 0.05. Heterogenous enhancement showed the greatest sensitivity (75% and calcification the greatest specificity (83.3%. The other parameters did not show any difference between the two groups. CONCLUSION CT features most likely to suggest rectal mucinous carcinoma are heterogenous contrast enhancement, eccentric wall thickening and intratumoural calcification. As mucinous carcinomas follow an aggressive course, if a diagnosis of mucinous carcinoma of the rectum can be suggested on the staging CT, it may influence patient management.

  9. High-dose (70-78 GY) conformal radiotherapy for prostate cancer; the relation between observed late bladder and rectum complications and parameters derived from the dose volume histograms

    International Nuclear Information System (INIS)

    Lebesque, J.V.; Bruce, A.; Boersma, L.J.; Velde, A. te

    1996-01-01

    Purpose: To determine the incidence of late gastrointestinal (GI) and genitourinary (GU) complications after conformal radiotherapy for prostate cancer, and to investigate the relation between these observed incidences and parameters derived from the Dose Volume Histograms (DVHs) of rectum and bladder wall. Patients and Methods: Hundred and thirty patients with T 2-4 G 1-3 N 0 M 0 prostate cancer were treated with conformal radiotherapy with the simultaneous boost technique in a dose-escalating protocol; 78 patients received a total dose of 70 Gy, 11 patients 74 - 76 Gy and 41 patients 78 Gy, each with a dose of 2 Gy per fraction. DVHs of the rectal wall were used to calculate NTCPs according to the model of Kutcher et al. with the estimated parameter values (n = 0.12, m = 0.15, TD 50 = 80 Gy) according to Burman et al. The median follow-up was 17 months (range 6 - 72 months). The crude and actuarial incidence of late (> 6 months) GI and GU complications were determined using the RTOG/EORTC morbidity scoring system (Grade I to IV). Results: Neither for late GI nor for GU complaints, a grade IV complication was observed. GU complaints occurred in 90 patients (69%): 54 patients (42%) only experienced grade I toxicity, 26 patients (20%) had grade II toxicity, and 10 patients (8%) had grade III complications, of which 8 patients (6%) developed a urethral (7 pts) or ureteric stenosis (1 pt). The actuarial incidence of grade III GU complications was 10% at 2 years. Since bladder wall DVHs are unreliable and most grade III complications were not related to the bladder, the grade II and/or III complications were analyzed in terms of the total prescribed dose only, but no correlation could be demonstrated. GI complications occurred in 71 patients (55%): 59 patients (45%) developed a grade I complication, 11 a grade II complication and only 1 patient required laser treatment twice and blood transfusion because of rectal bleeding (grade III). The actuarial incidence of GI

  10. Effect of the γ-IFN on radiation damage and radiation fibrosis of the rabbit rectum after cavitas pelvisrute fractionated irradiation

    International Nuclear Information System (INIS)

    Yang Yunyi; Zhang Li; Wang Juan; Zhao Hengfang; Dai Li; Liu Zi

    2009-01-01

    Objective: To investigate the effect of γ-IFN on the radiation-induced injury and fibrosis of the rabbit rectum after the fractionated irradiation to pelvic cavity. Methods: The animal model of radiation rectum injury was established. 52 New Zealand rabbits were divided into 3 groups as the normal control group, the conventional radiation group, and γ-IFN group. Except the normal control group, the pelvic cavity of the two other groups were irradiated with 6 MV X-rays. At 5 d post-irradiatio the γ-IFN group was administered with 250 000 U/kg of γ-IFN once a week, while the conventional radiation group with 5 ml of saline solution. The rabbits were executed after 4, 8, 12 and 16 weeks, and the recta in the irradiated field were taken out. HE dyeing, in-situ hybridization and immuno-histochemical methods were used to analyze the radiation-induced rectrum injury and fibrosis. Results: At 4, 8, and 12 weeks post-irradiation, the radiation rectum injury and fibrosis were significantly different between the conventional radiation group and γ-IFN group(P 0.05) . At 4, 8, 12 and 16 weeks post-irradiation, the expression of TGF-β1 mRNA in-situ hybridization in the γ-IFN group were significantly different compared to the conventional radiation group and the normal control group (P <0.05) . The immuno-histochemical results of Col III showed the significant difference among the γ-IFN group and both the normal control group and conventional radiation group ( P < 0.05). Conclusions: γ-IFN could reduce the radiation rectum injury, suppress the expression of TGF-β1 mRNA in the rectum mucosa, inhibit the expression of Col III, and delay the formation of radiation-induced fibrosis. (authors)

  11. Automatic definition of targeted biological volumes for the radiotherapy applications; Definition automatique des volumes biologiques cibles pour les applications de radiotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Hatt, M.; Visvikis, D. [LaTIM, U650 Inserm, 29 - Brest (France); Cheze-Le-Rest, C. [Service de medecine nucleaire, 29 - Brest (France); Pradier, O. [Service de radiotherapie, 29 - Brest (France)

    2009-10-15

    The proposed method: Fuzzy locally adaptive Bayesian (F.L.A.B.) showed its reliability and its precision on very complete collection of realistic simulated and real data. Its use in the context of radiotherapy allows to consider easily the studies implementation and scenari of dose painting or dose escalation, including in complex cases of heterogenous fixations. It is conceivable to apply F.L.A.B. on PET images with F.M.I.S.O. ({sup 18}F fluoro misonidazole) or F.L.T. (fluoro-L-thymidine) to complete the definition of the biological target volume. (N.C.)

  12. Filiform serrated adenomatous polyposis arising in a diverted rectum of an inflammatory bowel disease patient

    DEFF Research Database (Denmark)

    Klarskov, Louise; Mogensen, Anne Mellon; Jespersen, Niels

    2011-01-01

    Klarskov L, Mogensen AM, Jespersen N, Ingeholm P, Holck S. Filiform serrated adenomatous polyposis arising in a diverted rectum of an inflammatory bowel disease patient. APMIS 2011; 119: 393-8. A 54-year-old man, previously colectomized for inflammatory bowel disease, developed carcinoma in the i......Klarskov L, Mogensen AM, Jespersen N, Ingeholm P, Holck S. Filiform serrated adenomatous polyposis arising in a diverted rectum of an inflammatory bowel disease patient. APMIS 2011; 119: 393-8. A 54-year-old man, previously colectomized for inflammatory bowel disease, developed carcinoma...... during the adenoma carcinoma sequence included the acquisition of CK7 expression in the malignant portion. Gastric mucin may play a role in the initial step of the neoplastic evolution and CK7 may denote neoplastic progression. This case confirms the notion of a widely variegated morphology of precursor...

  13. Recto-sigmoid polypectomy by a handmade snare: Experience of 24 children with bleeding per rectum

    Directory of Open Access Journals (Sweden)

    Manoj Saha

    2014-01-01

    Full Text Available A handmade snare is designed from easily available materials to treat bleeding per rectum in children due to rectosigmoid polyps. A total of 29 polypectomies were done in 24 patients. It is simple, effective, safe and economic.

  14. Changes in Treatment Volume of Hormonally Treated and Untreated Cancerous Prostate and its Impact on Rectal Dose

    International Nuclear Information System (INIS)

    Lilleby, Wolfgang; Dale, Einar; Olsen, Dag R.; Gude, Unn; Fossaa, Sophie D.

    2003-01-01

    Late chronic side effects of the rectum constitute one of the principal limiting factors for curative radiation therapy in patients with prostate cancer. The purpose of the study was to determine the impact of immediate androgen deprivation (IAD) prior to conformal radiotherapy on rectal volume exposed to high doses, as compared with a deferred treatment strategy (DAD). Twenty-five patients (13 in the IAD group and 12 in the DAD group) with bulky tumours of the prostate, T3pN1-2M0 from the prospective EORTC trial 30846 were analysed. Three-dimensional conformal radiation treatment plans (3D CRT) using a 4-field box technique were generated based on the digitized computed tomographic or magnetic resonance findings acquired during the first 9 months after inclusion in the EORTC trial. Dose-volume histograms (DVHs) were calculated for the prostate and rectum. In the DAD group, there was no obvious alteration in the mean size of the prostate or other evaluated structures. In the IAD patients, a statistically significant reduction of approximately 40% of the gross tumour volume (GTV) was reached after a 6 months' course of hormonal treatment (p<0.001). High-dose rectal volume was correlated with the volume changes of the GTV (p<0.001). Mean rectal volume receiving 95% or more of the target dose was significantly reduced by 20%. Our study confirms the effect of downsizing of locally advanced prostate tumours following AD treatment and demonstrates the interdependence of the high-dose rectal volume with the volume changes of the GTV. However, the mean beneficial sparing of rectal volume was outweighed in some patients by considerable inter-patient variations

  15. Duplication of the urethra with communication to the rectum. Report of a case

    Energy Technology Data Exchange (ETDEWEB)

    Bruce, R.; Alton, D.

    1986-01-01

    The posterior channel of duplicated urethrae usually follows a straight course to end in the perineum just inside the anal verge. This unique urethra dipped into the perineum and then turned cephalad to enter the rectum above the anus. Delineation of the course of the urethra simplified management by assisting the urologist to convert the rectal passage to a hypospadiac urethra. (orig.).

  16. Large Cell Neuroendocrine Carcinoma of the Rectum Presenting with Extensive Metastatic Disease

    Directory of Open Access Journals (Sweden)

    Vinay Minocha

    2014-01-01

    Full Text Available Introduction. Rectal large cell neuroendocrine carcinoma (LCNEC is a poorly differentiated neoplasm that is very rare and belongs within the poorest prognostic subgroup among primary colorectal neoplasms. Here, we describe a case of LCNEC of the rectum, which highlights the aggressive clinical course and poor prognosis associated with this disease. Case Presentation. We report a case of a 63-year-old male who presented to our hospital with a one-month history of lower abdominal pain, constipation, and weight loss. A computed tomography (CT scan of the chest, abdomen, and pelvis revealed a rectal mass as well as metastatic disease of the liver and lung. Flexible sigmoidoscopy revealed a fungating, ulcerated and partially obstructing rectal mass located 6 cm from the anal verge. This mass was biopsied and pathological examination of the resected specimen revealed features consistent with a large cell neuroendocrine carcinoma. Conclusion. Rectal large cell neuroendocrine carcinomas are rare and have a significantly worse prognosis than adenocarcinomas. At diagnosis, a higher stage and metastatic disease are likely to be found. It is important to differentiate large cell, poorly differentiated neuroendocrine carcinomas from adenocarcinomas of the colon and rectum pathologically because patients may benefit from alternative cytotoxic chemotherapeutic regimens.

  17. Dose Distribution in Bladder and Surrounding Normal Tissues in Relation to Bladder Volume in Conformal Radiotherapy for Bladder Cancer

    International Nuclear Information System (INIS)

    Majewski, Wojciech; Wesolowska, Iwona; Urbanczyk, Hubert; Hawrylewicz, Leszek; Schwierczok, Barbara; Miszczyk, Leszek

    2009-01-01

    Purpose: To estimate bladder movements and changes in dose distribution in the bladder and surrounding tissues associated with changes in bladder filling and to estimate the internal treatment margins. Methods and Materials: A total of 16 patients with bladder cancer underwent planning computed tomography scans with 80- and 150-mL bladder volumes. The bladder displacements associated with the change in volume were measured. Each patient had treatment plans constructed for a 'partially empty' (80 mL) and a 'partially full' (150 mL) bladder. An additional plan was constructed for tumor irradiation alone. A subsequent 9 patients underwent sequential weekly computed tomography scanning during radiotherapy to verify the bladder movements and estimate the internal margins. Results: Bladder movements were mainly observed cranially, and the estimated internal margins were nonuniform and largest (>2 cm) anteriorly and cranially. The dose distribution in the bladder worsened if the bladder increased in volume: 70% of patients (11 of 16) would have had bladder underdosed to 70%, 80%, and 90% of the prescribed dose was 23%, 20%, and 15% for the rectum and 162, 144, 123 cm 3 for the intestines, respectively) than with a 'partially full' bladder (volume that received >70%, 80%, and 90% of the prescribed dose was 28%, 24%, and 18% for the rectum and 180, 158, 136 cm 3 for the intestines, respectively). The change in bladder filling during RT was significant for the dose distribution in the intestines. Tumor irradiation alone was significantly better than whole bladder irradiation in terms of organ sparing. Conclusion: The displacements of the bladder due to volume changes were mainly related to the upper wall. The internal margins should be nonuniform, with the largest margins cranially and anteriorly. The changes in bladder filling during RT could influence the dose distribution in the bladder and intestines. The dose distribution in the rectum and bowel was slightly better with

  18. 6007 Volume 12 No. 2 April 2012 EFFECT OF MORINGA OLEIFERA ...

    African Journals Online (AJOL)

    GASSOU

    2 avr. 2012 ... médicaments ARV chez les sujets vivant avec le VIH/SIDA. La consommation ... de l'effet recherché et des particularités du groupe cible. MATERIEL ET ... Ces derniers avaient diagnostiqué l'état d'anémie suite ..... technique.

  19. Oncological outcome after laparoscopic abdominoperineal excision of the rectum.

    Science.gov (United States)

    Jefferies, M T; Evans, M D; Hilton, J; Chandrasekaran, T V; Beynon, J; Khot, U

    2012-08-01

    Abdominoperineal excision of the rectum (APER) for cancer has been associated with higher circumferential resection margin (CRM) involvement and failure of local disease control. The aim of this study was to investigate whether the introduction of laparoscopic APER altered the incidence of CRM involvement. Consecutive patients undergoing open or laparoscopic APER for adenocarcinomas of the rectum were studied. Patient demographics, preoperative staging, neoadjuvant treatment, operative findings, length of stay and pathological details were collected from operative and radiology databases and compared. There were 16 laparoscopic and 25 open APER performed over a 3-year period. Neoadjuvant therapy was given to 43.8% (7/16) of the laparoscopic group and 56.0% (14/25) of the open group. Complete laparoscopic resection was possible in 14 (87.5%) of 16 patients. The median harvested number of nodes was 14 (4-33) in both groups. The median length of stay was 7 (3-13) and 15 (9-40) days in the laparoscopic and open groups (P CRM was clear in all cases. There was no local recurrence in either group at a median follow-up of 23 months. There were no in-hospital deaths and no significant differences in overall survival. There were no significant differences in preoperative or postoperative histopathological T stage between the two groups (P = 0.057 and P = 0.121). Laparoscopic APER for selected rectal cancers can achieve comparable oncological outcome to open surgery but is associated with a much shorter length of stay. Patient and tumour characteristics must be taken into consideration when deciding on a laparoscopic approach for low rectal cancer. © 2011 The Authors. Colorectal Disease © 2011 The Association of Coloproctology of Great Britain and Ireland.

  20. [Colon and rectum histoplasmosis in a patient from Peru].

    Science.gov (United States)

    Alcántara Figueroa, Christian; Sánchez Cerna, Víctor

    2016-01-01

    We report a case of a male patient of 52 years old with a 3 months history of pushing, tenesmus, hematochezia, pain while defecating, lost of 18 kg of weight, fever, fecaloid and purulent discharge through an perianal hole. During the colonoscopy procedure, we found many ulcers in the ascending, transverse and descending colon.We also found an elevated lesion of about 5 cm in the rectum. We used hematoxylin - eosin and Gomori-Grocott stain in the biopsies and identified many microorganisms inside macrophages which were compatible with histoplasmosis. ELISA tests for HIV, HTLV I- II were negative. Colon and rectal histoplasmosis in an immunocompetent patient is extremely rare. There are few cases of colonic histoplasmosis reported.

  1. Use of benchmark dose-volume histograms for selection of the optimal technique between three-dimensional conformal radiation therapy and intensity-modulated radiation therapy in prostate cancer

    International Nuclear Information System (INIS)

    Luo Chunhui; Yang, Claus Chunli; Narayan, Samir; Stern, Robin L.; Perks, Julian; Goldberg, Zelanna; Ryu, Janice; Purdy, James A.; Vijayakumar, Srinivasan

    2006-01-01

    Purpose: The aim of this study was to develop and validate our own benchmark dose-volume histograms (DVHs) of bladder and rectum for both conventional three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT), and to evaluate quantitatively the benefits of using IMRT vs. 3D-CRT in treating localized prostate cancer. Methods and Materials: During the implementation of IMRT for prostate cancer, our policy was to plan each patient with both 3D-CRT and IMRT. This study included 31 patients with T1b to T2c localized prostate cancer, for whom we completed double-planning using both 3D-CRT and IMRT techniques. The target volumes included prostate, either with or without proximal seminal vesicles. Bladder and rectum DVH data were summarized to obtain an average DVH for each technique and then compared using two-tailed paired t test analysis. Results: For 3D-CRT our bladder doses were as follows: mean 28.8 Gy, v60 16.4%, v70 10.9%; rectal doses were: mean 39.3 Gy, v60 21.8%, v70 13.6%. IMRT plans resulted in similar mean dose values: bladder 26.4 Gy, rectum 34.9 Gy, but lower values of v70 for the bladder (7.8%) and rectum (9.3%). These benchmark DVHs have resulted in a critical evaluation of our 3D-CRT techniques over time. Conclusion: Our institution has developed benchmark DVHs for bladder and rectum based on our clinical experience with 3D-CRT and IMRT. We use these standards as well as differences in individual cases to make decisions on whether patients may benefit from IMRT treatment rather than 3D-CRT

  2. Radiation Therapy for Loco-Regional Recurrence of Adenocarcinoma of the Rectum

    International Nuclear Information System (INIS)

    Cho, K. H.; Seong, J. S.; Suh, C. O.; Kim, G. E.

    1984-01-01

    Thirty patients with loco-regional recurrence following curative surgery for adenocarcinoma of the rectum were retrospectively. Evaluated to determine factors influencing survival and the efficacy of radiation therapy. In this review of 30 patients undergoing radiation therapy, more than 50 percent (17/30) had definite symptomatic and objective response. Ninety percent of patients (27/30) received significant palliation. Over all 2-year survival rate was 7.4% and their median was 13.0 months. Grade of response and Sex were statistically related to survival

  3. The effect of anterior proton beams in the setting of a prostate-rectum spacer

    Energy Technology Data Exchange (ETDEWEB)

    Christodouleas, John P., E-mail: christojo@uphs.upenn.edu [Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, PA (United States); Tang, Shikui [Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, PA (United States); Susil, Robert C.; McNutt, Todd R.; Song, Danny Y. [Department of Radiation Oncology and Radiation Molecular Sciences, Johns Hopkins Hospital, Baltimore, MD (United States); Bekelman, Justin; Deville, Curtiland; Vapiwala, Neha [Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, PA (United States); DeWeese, Theodore L. [Department of Radiation Oncology and Radiation Molecular Sciences, Johns Hopkins Hospital, Baltimore, MD (United States); Lu, Hsiao-Ming [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Both, Stefan [Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, PA (United States)

    2013-10-01

    Studies suggest that anterior beams with in vivo range verification would improve rectal dosimetry in proton therapy for prostate cancer. We investigated whether prostate-rectum spacers would enhance or diminish the benefits of anterior proton beams in these treatments. Twenty milliliters of hydrogel was injected between the prostate and rectum of a cadaver using a transperineal approach. Computed tomography (CT) and magnetic resonance (MR) images were used to generate 7 uniform scanning (US) and 7 single-field uniform dose pencil-beam scanning (PBS) plans with different beam arrangements. Pearson correlations were calculated between rectal, bladder, and femoral head dosimetric outcomes and beam arrangement anterior scores, which characterize the degree to which dose is delivered anteriorly. The overall quality of each plan was compared using a virtual dose-escalation study. For US plans, rectal mean dose was inversely correlated with anterior score, but for PBS plans there was no association between rectal mean dose and anterior score. For both US and PBS plans, full bladder and empty bladder mean doses were correlated with anterior scores. For both US and PBS plans, femoral head mean doses were inversely correlated with anterior score. For US plans and a full bladder, 4 beam arrangements that included an anterior beam tied for the highest maximum prescription dose (MPD). For US plans and an empty bladder, the arrangement with 1 anterior and 2 anterior oblique beams achieved the highest MPD in the virtual dose-escalation study. The dose-escalation study did not differentiate beam arrangements for PBS. All arrangements in the dose-escalation study were limited by bladder constraints except for the arrangement with 2 posterior oblique beams. The benefits of anterior proton beams in the setting of prostate-rectum spacers appear to be proton modality dependent and may not extend to PBS.

  4. The effect of anterior proton beams in the setting of a prostate-rectum spacer

    Science.gov (United States)

    Christodouleas, John P.; Tang, Shikui; Susil, Robert C.; McNutt, Todd R.; Song, Danny Y.; Bekelman, Justin; Deville, Curtiland; Vapiwala, Neha; DeWeese, Theodore L.; Lu, Hsiao-Ming; Both, Stefan

    2014-01-01

    Studies suggest that anterior beams with in vivo range verification would improve rectal dosimetry in proton therapy for prostate cancer. We investigated whether prostate-rectum spacers would enhance or diminish the benefits of anterior proton beams in these treatments. Twenty milliliters of hydrogel was injected between the prostate and rectum of a cadaver using a transperineal approach. Computed tomography (CT) and magnetic resonance (MR) images were used to generate 7 uniform scanning (US) and 7 single-field uniform dose pencil-beam scanning (PBS) plans with different beam arrangements. Pearson correlations were calculated between rectal, bladder, and femoral head dosimetric outcomes and beam arrangement anterior scores, which characterize the degree to which dose is delivered anteriorly. The overall quality of each plan was compared using a virtual dose-escalation study. For US plans, rectal mean dose was inversely correlated with anterior score, but for PBS plans there was no association between rectal mean dose and anterior score. For both US and PBS plans, full bladder and empty bladder mean doses were correlated with anterior scores. For both US and PBS plans, femoral head mean doses were inversely correlated with anterior score. For US plans and a full bladder, 4 beam arrangements that included an anterior beam tied for the highest maximum prescription dose (MPD). For US plans and an empty bladder, the arrangement with 1 anterior and 2 anterior oblique beams achieved the highest MPD in the virtual dose-escalation study. The dose-escalation study did not differentiate beam arrangements for PBS. All arrangements in the dose-escalation study were limited by bladder constraints except for the arrangement with 2 posterior oblique beams. The benefits of anterior proton beams in the setting of prostate-rectum spacers appear to be proton modality dependent and may not extend to PBS. PMID:23578497

  5. {sup 18}F-FDG-Avid Adenocarcinoma of the Rectum Presenting as a Subtle Filling Defect on Maximum Intensity Projection Image: Report of a Case

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Yong Whee; Lee, Kwang Chan [SungAe General Hospital, Seoul (Korea, Republic of)

    2009-04-15

    {sup 18}F-FDG avid polypoid or tumefacient carcinomas of the gastrointestinal (GI) tract including the rectum are characteristically featured on PET-CT as an intraluminal tumor surrounded by completely or partially cleared background. However, the carcinomas of intramural or sessile variant may not so easily be detected especially when tumors are obliterated by feces or mucus retained in the host bowel loop. Recently, we observed a case of cauliflower-like adenocarcinoma of the rectum that was diagnosed by noting a subtle, flat filling defect created against the background of 'black' feces-mucus filled rectum. To our knowledge such a 'filling defect' produced by sessile tumor has not previously been reported as a useful diagnostic sign of GI tract carcinoma on PET-CT.

  6. When treating prostate cancer with three-dimensional conformal radiation therapy the impact of bladder filling status on the volume and integral dose distribution of the target and critical organs should be kept in mind

    International Nuclear Information System (INIS)

    Liu Yueping; Liu Xinfan; Li Yexiong; Guang Ying

    2007-01-01

    Objective: In prostate cancer treated with three-dimensional conformal radiation therapy (3DCRT), we tried to prospectively assess the impact of the filling status of bladder on the volume and the integral dose distribution to the target and surrounding critical organs. Methods: Ten patients with stage T1-T2N0M0 prostate cancer were studied. All patients received 3DCRT to the prostate and inferior seminal vesicle. One hour before CT simulation, the bladder was first voided, and then 400 ml of oral contrast solution was given at every half hour before the CT scan. Urethral catheterization was used for voiding or distending the bladder. When distending the bladder, 250-300 ml of contrast was injected into the bladder with the patient fixed at the supine position. Two sets of transverse images were taken for the whole pelvis in empty and full bladder. After the target and critical organs (bladder, rectum, pelvic small bowel, and femoral heads) were contoured, a treatment plan of three-dimensional conformal radiotherapy was made using the CMS Focus-Xio treatment planning system. The volume and mean doses of CTV, PTV, rectum, bladder, femoral heads, and small bowel with the bladder empty and full were evaluated. The percentage of volume which received 50 Gy in the rectum and bladder, 30 Gy in the femoral heads, and the maximal dose to the pelvic small bowel were also assessed . The variability of volume and dose distribution in these targets or organs was compared between the empty and full bladder status. Results: Comparing to the bladder empty status, full bladder led to a mean increase of 499% in the bladder volume, (67±9) ml and (336±48) ml (P=0.000), respectively. No volume change was found in the CTV, PTV, rectum, femoral heads and pel- vic small bowel(P=0.153,0.501,0.929,0.771,0.081). The mean dose to the bladder in full status was only 35% of that in empty status, (1501±201 ) cGy and (4267±216) cGy(P =0.000), respectively. The mean dose to the pelvic small

  7. [Progress in the early diagnosis of cancer of the colon and rectum].

    Science.gov (United States)

    Canessa, N; Roset, J; Boffi, A; Ferrara, J B; Galano, A; Albertengo, J C

    1978-09-01

    Our experience with the air contrast examination in the cancer of colon and rectum diagnoses is showed. The colaboration among radiologist, endoscopist, pathologist and surgeon is important. In the large bowel tumors diagnosis, the radiologic and endoscopic prodedures should be evaluated together. The double colonic contrast has showed in our experience, better results than with the barium enema. Over 31 patients with both studies, we obtained 13 false negatives (with barium enema, doing then the double colonic contrast became positive 12 (92.4%).

  8. 2005 Tri-Service Infrastructure Systems Conference and Exhibition. Volume 1, Track 1

    Science.gov (United States)

    2005-08-04

    Alan Tool Sediment Impact Assessment Model (SIAM), by David S. Biedenharn and Meg Jonas Mississippi River Sedimentation Study, by Basil Arthur Sediment...Questionnaire Client Report Reports Criteria/Lesson Learned Project Details PRO JEC TS DAT ABA SE 9 eProjects 1. Business Line CIBL Program ANY MILCON 2

  9. Evaluation of spiral CT in staging of colon and rectum carcinoma

    International Nuclear Information System (INIS)

    Hundt, W.; Braunschweig, R.; Reiser, M.

    1999-01-01

    The purpose of our study was to evaluate the capability of a subsecond spiral-CT scanner using two contrast medium phases in staging of colorectal cancer. In our study we included 37 patients with proven rectum or colon carcinoma. Spiral CT was performed following tap-water enema of the colon in the arterial and venous phases of contrast medium enhancement. Our results were compared with the findings of pathological examination after surgery. The tumor's size and extension were evaluated in the arterial and venous phases, the lymph nodes in the venous phase of the CT scan. The tumor was in the rectum (n = 14), sigma (n = 11), descending colon (n = 6), and cecum (n = 6). Two-phase spiral CT had a sensitivity of 97.2 % in the arterial phase and 89.1 % in the venous phase in detecting the carcinoma. The staging results were in the arterial phase in 30 of 37 cases (81.0 %) and in the venous phase in 24 of 37 cases (64.8 %) according to pathology. In 27 of 32 patients (84.3 %) lymph nodes were detected. The correct classification of the N-stage was possible in 23 of 34 cases (67.6 %). The combined use of arterial and venous phases in staging of colorectal cancer can improve the T- and N-stage classification in comparison with using only one contrast medium phase. The arterial phase is superior compared with the venous phase for local tumor staging and the venous phase is used for lymph node assessment. (orig.) (orig.)

  10. Implantation of a biodegradable rectum balloon implant: Tips, Tricks and Pitfalls

    Directory of Open Access Journals (Sweden)

    Ben G. L. Vanneste

    Full Text Available ABSTRACT Introduction: A rectum balloon implant (RBI is a new device to spare rectal structures during prostate cancer radiotherapy. The theoretical advantages of a RBI are to reduce the high radiation dose to the anterior rectum wall, the possibility of a post-implant correction, and their predetermined shape with consequent predictable position. Objective: To describe, step-by-step, our mini-invasive technique for hands-free transperineal implantation of a RBI before start of radiotherapy treatment. Materials and Methods: We provide step-by-step instructions for optimization of the transperineal implantation procedure performed by urologists and/or radiation oncologists experienced with prostate brachytherapy and the use of the real-time bi-plane transrectal ultrasonography (TRUS probe. A RBI was performed in 15 patients with localised prostate cancer. Perioperative side-effects were reported. Results: We provide ‘tips and tricks’ for optimizing the procedure and proper positioning of the RBI. Please watch the animation, see video in https://vimeo.com/205852376/789df4fae4. The side-effects included mild discomfort to slight pain at the perineal region in 8 out of 15 patients. Seven patients (47% had no complaints at all. Two patients developed redness of the skin, where prompt antibiotic regimen was started with no further sequelae. One patient revealed a temporary urine retention, which resolved in a few hours following conservative treatment. Further no perioperative complications occurred. Conclusion: This paper describes in detail the implantation procedure for an RBI. It is a feasible, safe and very well-tolerated procedure.

  11. Extramoucous transversal coloplasty – new method of reconstruction after rectum resection

    Directory of Open Access Journals (Sweden)

    Miran Rems

    2007-11-01

    Full Text Available Background: In patients, diagnosed with rectal cancer in lower thirds of rectum, a total mesorectal excision is warranted. The aim is to preserve of all vegetative functions as well. Because of better functional results anastomosis with J-pouch is preferred procedure. Formation of colonic J-pouch can not always be performed due to anatomic reasons. Transverse coloplasty have the same functional results and can be constructed almost always. In some studies there were more dehiscence reported in the group with transverse coloplasty, probably because of impaired vascularization. With sparing of submucous layer better vascularization can be achieved and all advantages of transverse coloplasty preserved.Methods: After preparing the patient following the principles of enhanced recovery surgery, resection of rectum by the oncologic principles is done. Colon is prepared for reconstruction and alongside of tenia the incision of muscular layer is done a few centimeters above the predicted anastomosis. The incision is 6 to 8 centimeters long. After the separation of muscular layer incision is sutured transversely. Submucous layer must not be opened or divided in order to obtained better vascularization of the terminal anastomosis and lower fecal inoculation. Postoperative treatment and follow-up is regular.Conclusions: Extramucous transverse coloplasty can obtain functions of reservoir for neorectum and improve quality of life in a same way transverse coloplasty can. With preservation of submucous layer the vascularization of anastomosis is better and therefore the rate of dehiscence lower. For final consent more randomized studies have to be performed.

  12. Metastasis of breast cancer rectum

    International Nuclear Information System (INIS)

    Suárez, L.; Santander, G.

    2004-01-01

    Introduction: Metastases to the breast are rare, corresponding approximately to 3% of breast cancers. Primary tumors that spread more commonly are own breast, often following them in melanomas, neuroendocrine, ovarian and lymphoma. Medical history: A 59-year consultation rectoragias repeated and thinning. It is studied and finally intervenes (low anterior resection) diagnosed with rectal cancer whose Histopathology revealed a poorly differentiated adenocarcinoma stage III. Concomitantly the patient has a left breast lump that was studied with mammography, which revealed a dense mass of larger diameter 4 cm in topografiada 3 hour left breast with well defined contours and ultrasonographic structure solid. MI lumpectomy is performed whose pathology reports a poorly differentiated adenocarcinoma with cytoarchitectural features matching the lesion of rectum. Hormone receptors were negative. The patient is treated as a rectal cancer with RT spread over QT (5FU i /c). Died 7 months after diagnosis. Discusion: In literature are reported only 3 cases of breast metastases secondary to rectal cancer; how unusual this presentation justify this report.In this event they occurred in patients with a previous diagnosis of rectal cancer and in the context of systemic lesion progression. In our case clinician early diagnosis of rectal and breast metastases was synchronous. The mammographic image consistent with those described for these cases in the literature.The development of metastases in breast tissue is associated with a poor prognosis as which correlates with the survival of the patient

  13. Volume arc therapy of gynaecological tumours: target volume coverage improvement without dose increase for critical organs; Arctherapie volumique des tumeurs gynecologiques: amelioration de la couverture du volume cible sans augmentation de la dose aux organes critiques

    Energy Technology Data Exchange (ETDEWEB)

    Ducteil, A.; Kerr, C.; Idri, K.; Fenoglietto, P.; Vieillot, S.; Ailleres, N.; Dubois, J.B.; Azria, D. [CRLC Val-d' Aurelle, Montpellier (France)

    2011-10-15

    The authors report the assessment of the application of conventional intensity-modulated conformational radiotherapy (IMRT) and volume arc-therapy (RapidArc) for the treatment of cervical cancers, with respect to conventional radiotherapy. Dosimetric plans associated with each of these techniques have been compared. Dose-volume histograms of these three plans have also been compared for the previsional target volume (PTV), organs at risk, and sane tissue. IMCT techniques are equivalent in terms of sparing of organs at risk, and improve target volume coverage with respect to conventional radiotherapy. Arc-therapy reduces significantly treatment duration. Short communication

  14. A new type of defecation disorder due to insufficient fixation of the rectum to the sacrum is improved by rectopexy: A report of three cases

    Directory of Open Access Journals (Sweden)

    Wataru Sumida

    2016-07-01

    Full Text Available Chronic constipation is the most common clinical disorder in children. However, some cases of constipation do not meet the criteria defined by Rome III. We encountered such defecation disorders in three patients who presented with constipation as a chief complaint along with excessive strain and bleeding hemorrhoids during defecation despite normal stools. Contrast enema revealed that the rectum was separated from the sacrum in each patient, which may have been caused by insufficient fixation of the rectum. Conservative treatment with laxatives and suppositories failed to achieve improvement. Therefore, all underwent a laparoscopic rectopexy. After surgery, each patient was able to evacuate without strain and the hemorrhoids disappeared. Insufficient fixation of the rectum should be considered as a potential cause of defecation disorders. Rectopexy is effective for this type of defecation disorder.

  15. Target volume delineation for head and neck cancer intensity-modulated radiotherapy; Delineation des volumes cibles des cancers des voies aerodigestives superieures en radiotherapie conformationnelle avec modulation d'intensite

    Energy Technology Data Exchange (ETDEWEB)

    Lapeyre, M.; Toledano, I.; Bourry, N. [Departement de radiotherapie, centre Jean-Perrin, 58, rue Montalembert, BP 5026, 63011 Clermont-Ferrand cedex 1 (France); Bailly, C. [Unite de radiodiagnostic, centre Jean-Perrin, 58, rue Montalembert, BP 5026, 63011 Clermont-Ferrand cedex 1 (France); Cachin, F. [Unite de medecine nucleaire, centre Jean-Perrin, 58, rue Montalembert, BP 5026, 63011 Clermont-Ferrand cedex 1 (France)

    2011-10-15

    This article describes the determination and the delineation of the target volumes for head-and-neck cancers treated with intensity-modulated radiotherapy (IMRT). The delineation of the clinical target volumes (CTV) on the computerized tomography scanner (CT scan) requires a rigorous methodology due to the complexity of head-and-neck anatomy. The clinical examination with a sketch of pretreatment tumour extension, the surgical and pathological reports and the adequate images (CT scan, magnetic resonance imaging and fluorodeoxyglucose positron emission tomography) are necessary for the delineation. The target volumes depend on the overall strategy: sequential IMRT or simultaneous integrated boost-IMRT (SIB-IMRT). The concept of selectivity of the potential subclinical disease near the primary tumor and the selection of neck nodal targets are described according to the recommendations and the literature. The planing target volume (PTV), mainly reflecting setup errors (random and systematic), results from a uniform 4-5 mm expansion around the CTV. We propose the successive delineation of: (1) the gross volume tumour (GTV); (2) the 'high risk' CTV1 around the GTV or including the postoperative tumour bed in case of positive margins or nodal extra-capsular spread (65-70 Gy in 30-35 fractions); (3) the CTV2 'intermediate risk' around the CTV1 for SIB-IMRT (59-63 Gy in 30-35 fractions); (4) the 'low-risk' CTV3 (54-56 Gy in 30-35 fractions); (5) the PTVs. (authors)

  16. Rectal cancer: The radiation basis of radiotherapy, target volume

    International Nuclear Information System (INIS)

    Bosset, J.F.; Servagi-Vernat, S.; Crehange, G.; Azria, D.; Gerard, J.P.; Hennequin, C.

    2011-01-01

    Since the implementation of preoperative chemo-radiotherapy and meso-rectal excision, the 5-year rates of locoregional failures in T3-T4 N0-N1M0 rectal cancer fell from 25-30% thirty years ago to 5-8% nowadays. A critical analysis of the locoregional failures sites and mechanisms, as well as the identification of nodal extension, helps the radiation oncologist to optimize the radiotherapy target definition. The upper limit of the clinical target volume is usually set at the top of the third sacral vertebra. The lateral pelvic nodes should be included when the tumor is located in the distal part of the rectum. The anal sphincter and the levator muscles should be spared when a conservative surgery is planned. In case of abdomino-perineal excision, the ischio-rectal fossa and the sphincters should be included in the clinical target volume. A confrontation with radiologist and surgeon is mandatory to improve the definition of the target volumes to be treated. (authors)

  17. Differential roles of stretch-sensitive pelvic nerve afferents innervating mouse distal colon and rectum

    OpenAIRE

    Feng, Bin; Brumovsky, Pablo R.; Gebhart, Gerald F.

    2010-01-01

    Information about colorectal distension (i.e., colorectal dilation by increased intraluminal pressure) is primarily encoded by stretch-sensitive colorectal afferents in the pelvic nerve (PN). Despite anatomic differences between rectum and distal colon, little is known about the functional roles of colonic vs. rectal afferents in the PN pathway or the quantitative nature of mechanosensory encoding. We utilized an in vitro mouse colorectum-PN preparation to investigate pressure-encoding charac...

  18. Abscess of the iliopsoas muscle associated external fistula of the rectum caused by radiation proctitis. A case report

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Shigeru; Imazu, Hiroki; Matubara, Toshiki; Sakurai, Yoichi; Ochiai, Masahiro; Funabiki, Takahiko [Fujita Health Univ., Toyoake, Aichi (Japan). School of Medicine

    1999-12-01

    This paper deals with a case of abscess of the iliopsoas muscle, an intractable external fistula of the rectum caused by radiation proctitis in a 68-year-old man. There were previous histories of undergoing an A-C bypass operation for coronary stricture 10 years before; and undergoing aportial resection of the bladder with radiation therapy for urinary bladder cancer, followed by colostomy for hemorrhage and stricture of the rectum for radiation proctitis 2 years before admission. In April, 1997 when he had been treated at outpatient clinic, exhumation of pusfrom the sacurred that was diagnosed external fistula of the rectum on a fistulography and he was continuously treated on an ambulant basis. On November 17, 1997, the patient had a temperature 38.7deg C, the white blood cell count increased to 35 x 10{sup 4} /ml, inflammation reaction increased, and unconsciousness appeared. An emergency CT revealed retention of fluid in the retroperitoneum covering from the fistulation through the iliopsoas muscle to pelvis. An abscess of the iliopsoas muscle was diagnosed. It was determined that any operations under general anesthesia were impossible due to poor general condition, and an emergency incision drainage was performed under local anesthesia. Thereafter, the patient developed MRSA septicemia which demanded redrainage and strict general management, but he was successfully freed from the management. Although the intractable fistula in persistently present, he was discharged after a resection of sequestrum and is followed on an ambulant basis. (author)

  19. The Outlet Patch: Gastric Heterotopia of the Colo-rectum and Anus.

    Science.gov (United States)

    Mannan, Abul Ala Syed Rifat; Vieth, Michael; Khararjian, Armen; Khandakar, Binny; Lam-Himlin, Dora; Heydt, David; Bhaijee, Feriyl; Venbrux, Henry J; Byrnes, Kathleen; Voltaggio, Lysandra; Barker, Norman; Yuan, Songyang; Montgomery, Elizabeth

    2018-04-18

    Gastric heterotopia (GH) has been described throughout the gastrointestinal tract. However, the colorectal region is an extremely rare location for it. We describe the clinicopathologic features of GH of the colon, rectum, and anus. We identified 33 cases in 20 males and 13 females (median age 54 years; range, 4 months to 73 years). Sites included the rectum (N=26), anus (N=4), ileocecal junction (N=1), ascending colon (N=1) and descending colon (N=1). Presenting symptoms(N=27) included hematochezia (41%) and altered bowel habits (4%); 15 patients (55%) were asymptomatic. On colonoscopy (N=31), all appeared as solitary lesions, (median size 6.5 mm, range 2 mm - 55 mm), either as polyps (61%), raised erythematous patches (23%), an ulcer(10%), within a rectal diverticulum (3%), or a hemorrhoid (3%). Patients were managed by polypectomy. One with an associated carcinoma in the area of GH underwent resection. No morbidity related to GH itself was reported following excision. Histologically, heterotopic gastric mucosa was oxyntic type (85%), mixed oxyntic and non-oxyntic type (12%), and not specified (3%). In 5 patients a pyloric gland adenoma (PGA) arose from heterotopic gastric mucosa, two of which contained a focus of invasive adenocarcinoma. One case had associated surface foveolar type low-grade dysplasia. Another had associated adenocarcinoma arising from the heterotopic mucosa. One example harbored Helicobacter pylori organisms. We highlight the features of GH in the distal GIT - the 'outlet patch'. Association with PGA, surface dysplasia and adenocarcinoma suggests that lower tract GH can undergo neoplastic transformation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. Target and Clutter Scattering and their Effects on Military Radar Performance: Electromagnetic Wave Propagation Panel Specialists Meeting Held in Ottawa, Canada on 6-9 May 1991 (Diffraction par les Cibles et le Fouillis et ses Effets sur les Performances des Radars Militaires)

    Science.gov (United States)

    1991-09-01

    34ULPLR sian de l’operateur IEHR, montre que celul -ci La premiere idee lora do Ia construction fait intorvenir Ia Transformie do Fourier d’une Image...modifier neurones conaiste A. determiner le nombre do los coefficients synaptiquos de fagon A. obtenir neurones d’entries, celul des couches cachies, une...caractiriser.sans liaito. Celul -ci eat fix6 A 6, correapon-Lamtied trifuonstal dant au nombre de cIbles canoniques definissant La mastruie, dor treondiffusdion l

  1. Definitive radiation therapy for selected cancers of the rectum

    Energy Technology Data Exchange (ETDEWEB)

    Sischy, B.; Hinson, E.J.; Wilkinson, D.R.

    1988-09-01

    During the last 15 years, over 400 patients with adenocarcinoma of the rectum have undergone a course of endocavitary irradiation for cure or palliation of Dukes' A and B disease. This treatment method makes use of an unconventional fractionation scheme, by which the tumour receives 10000-12000 cGy in approximately four fractions over a period of about 60 days. The treatments are separated by an interval of 2 or 3 weeks. This method of definitive irradiation allows suitable patients to avoid abdominoperineal resection and its drawbacks. Hospitalization is avoided and the patients maintain a normal daily life. Approximately 15-20% of all rectal cancer patients may be expected to fulfil the criteria for selection, which are sufficiently strict that the local control (95%) and 5-year survival rates (94%) can exceed those of surgery for comparable disease.

  2. Answer to preoperative chemie radiation in locally advanced rectum cancer; Respuesta a quimioradiacion preoperatoria en cancer de recto localmente avanzado

    Energy Technology Data Exchange (ETDEWEB)

    Villegas Mendez, Silvia [Costa Rica

    2006-07-01

    Study the pre-operative combined therapy effect in the treatment of the rectum cancer cases of the Servicio de Cirugia General 2 of the Hospital Mexico. The study covers since January of 2003 until December of 2005. It has like specific objectives to analyze the effect in the tumour stages, the sphincters preservation and the recurrence. In the conclusions, it notes that the pre-operative chemie-radiation in the rectum cancer is indicated in II and III stages, in which it has showed most advantages for the patient. It describes that the time between the end of pre-operative combined treatment and the surgery must has at least six weeks to guarantee the effect in the tumour and to reduce the treatment toxicity. It concludes besides, that the complication rate after the pre-operative combined therapy and the total meso rectum excision is approximately of 33%; however, the pelvic septic complications can reduce with an ostomy of protection. It focus that the technique of sphincters preservation has showed to be effective and secure if it does a previous selection to the patients in appropriate form. To get an suitable stages must count with trans rectum endoscopic ultrasound and a tomography of suitable quality. It concludes, also, in intervened tumours after of neo-adjuvancy they don't need free distal margins of illness higher to 2 cm. The total meso rectum excision is the updated surgical recommendation in the rectum cancer. [Spanish] Estudia el efecto de la terapia combinada preoperatoria en el tratamiento de los casos de cancer rectal del Servicio de Cirugia General 2 del Hospital Mexico; desde enero del 2003 hasta diciembre del 2005. Tiene como objetivos especificos analizar el efecto en el estadiaje del tumor, la preservacion de esfinteres y la recurrencia. Entre las conclusiones anota que la quimioradiacion preoperatoria en el cancer rectal esta indicada en estadios II y III, en los cuales ha demostrado mayores ventajas para el paciente. Describe que el tiempo

  3. Tl-201 per rectum scintigraphy in chronic liver disease: assessment of Tl-201 uptake indices

    International Nuclear Information System (INIS)

    Moon, Won Jin; Choi, Yun Young; Cho, Suk Shin; Lee, Min Ho

    1999-01-01

    Heart to liver ratio on Tl-201 per rectal scintigraphy (shunt index) is known to be useful in the assessment of portal systemic shunt. We assessed Tl-201 uptake pattern and early liver/heart uptake rate of Tl-201 and correlated with shunt index in patients with chronic active hepatitis (CAH) and liver cirrhosis (LC). Fifty eight patients with biopsy-proven chronic liver disease (35 with CAH, 23 with LC) underwent Tl-201 per rectum scintigraphy after instillation of 18.5 MBq of Tl-201 into the upper rectum. We evaluated hepatic uptake (type 1: homogeneous, 2: inhomogeneous segmental, 3: inhomogeneous nonsegmental) and extrahepatic uptake of spleen, heart and kidney (grade 0: no uptake, 1: less than liver, 2: equal to liver, 3: greater than liver). We measured the early liver/heart uptake rate (the slope of the liver to heart uptake ratio for 10 mim) and shunt index (heart to liver uptake ratio). Tl-201 uptake pattern and early liver/heart uptake rate of Tl-201 was correlated with the pathologic diagnosis and shunt index. Hepatic uptake patterns of type 1 and 2 were dominant in CAH (CAH: 27/35, LC: 8/23), and type 3 in LC (CAH: 8/35, LC: 15/23)(p<0.005). The grades of extrahepatic uptake were higher in LC than in CAH (spleen: p<0.001, other soft tissue: p<0.005). The early liver/heart uptake rate of CAH (0.110±0.111) was significantly higher than that of LC (0.014±0.090)(p<0.001). The sensitivity and specificity of the early liver/heart uptake rate were 77.7% and 67.7% in differentiating LC from CAH. There was negative correlation between early liver/heart uptake rate and shunt index (r=-0.3347, p<0.01). Hepatic and extrahepatic uptake pattern and early liver/heart uptake rate on Tl-201 per rectum scintigraphy are useful in the assessment of portal systemic shunt in patients with chronic liver disease

  4. Treatment of postradiation structure of the rectum by the modified Duhamel procedure

    Energy Technology Data Exchange (ETDEWEB)

    Starr, D.S.; Lawrie, G.M.; Morris, G.C. Jr.

    1979-06-01

    Benign rectosigmoid stenosis secondary to pelvic radiation presents a difficult problem in management and is usually treated by permanent colostomy with its attendant discomfort and inconvenience. Other approaches include low anterior resection or even transsacral resection of the affected area of rectosigmoid, but they involve risk to rectal, bladder, and sexual function. The Martin modification of the Duhamel procedure is specifically designed to avoid these problems and was used successfully in the present case for treatment of rectosigmoid stenosis. The patient has been followed up 8 years and reports normal sensation and function of bladder and rectum and no disturbance of sexual function.

  5. Interstitial curietherapy with iridium 192 applied to small cancers of the rectum

    International Nuclear Information System (INIS)

    Papillon, J.; Montbarbon, J.F.; Gerard, J.P.

    1975-01-01

    Intracavity irradiation aimed at curing cancers of the rectum mainly calls on contact radiotherapy but also on interstitial curietherapy. Iridium curietherapy has replaced radium-therapy owing to the better homogeneousness of its action and precise method of assay. It uses a 2 pronged fork containing 2 iridium wires which can be very simply placed in position. It is applied on the one hand to the base of the ulcerated tumour, after abrasion by contactotherapy and on the other hand as a method of prophylactic irradiation after exeresis of a malignant or degenerated polyp where the scar is badly adapted to contactotherapy [fr

  6. Volume and hormonal effects for acute side effects of rectum and bladder during conformal radiotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Peeters, Stephanie T.H.; Hoogeman, Mischa S.; Heemsbergen, Wilma D.; Slot, Annerie; Tabak, Hans; Koper, Peter C.M.; Lebesque, Joos V.

    2005-01-01

    Purpose: To identify dosimetric variables predictive of acute gastrointestinal (GI) and genitourinary (GU) toxicity and to determine whether hormonal therapy (HT) is independently associated with acute GI and GU toxicity in prostate cancer patients treated with conformal radiotherapy (RT). Methods and Materials: This analysis was performed on 336 patients participating in a multicenter (four hospitals) randomized trial comparing 68 Gy and 78 Gy. The clinical target volume consisted of the prostate with or without the seminal vesicles, depending on the risk of seminal vesicle involvement. The margin from the clinical target volume to the planning target volume was 1 cm. For these patients, the treatment plan for a total dose of 68 Gy was used, because nearly all toxicity appeared before the onset of the 10-Gy boost. Acute toxicity ( 3 months before RT). Results: Acute GI toxicity Grade 2 or worse was seen in 46% of the patients. Patients with long-term neoadjuvant HT experienced less Grade 2 or worse toxicity (27%) compared with those receiving short-term neoadjuvant HT (50%) and no HT (50%). The volumes of the prostate and seminal vesicles were significantly smaller in both groups receiving neoadjuvant HT compared with those receiving no HT. In multivariate logistic regression analysis, including the two statistically significant clinical variables neoadjuvant HT and hospital, a volume effect was found for the relative, as well as absolute, rectal wall volumes exposed to intermediate and high doses. Of all the length parameters, the relative rectal length irradiated to doses of ≥5 Gy and ≥30 Gy and absolute lengths receiving ≥5-15 and 30 Gy were significant. Acute GU toxicity Grade 2 or worse was reported in 56% of cases. For patients with pretreatment GU symptoms, the rate was 93%. The use of short-term and long-term neoadjuvant HT resulted in more GU toxicity (73% and 71%) compared with no HT (50%). In multivariate analysis, containing the variables

  7. Sphincter-saving procedure for radiation-injuried rectum. A report of four cases with special reference to pull-through procedure

    Energy Technology Data Exchange (ETDEWEB)

    Moriya, Y.; Koyama, Y.; Hojo, K. (National Cancer Center, Tokyo (Japan))

    1982-09-01

    Up to this time the sigmoid colostomy has been widely accepted and conventional treatment for radiation-injured rectum, but patients without residual malignancy strongly desire to live without colostomy. We have tried to remove the involved rectal segments by sphincter-saving procedures. Four patients underwent these procedures, pull-through procedure in three and low anterior resection in one. Among sphincter-saving procedures, pull-through procedure was most adequate. Provided the following five conditions are fulfilled, pull-through procedure should be considered for severe radiation-injured rectum. (1) No recurrence of initial malignancy in the pelvis. (2) More than 2 cm intact rectal segment above dentate line may be preserved. (3) No radiation-injured segment in upper sigmoid. (4) No severe radiation damage in small intestine. (5) Patients under 70 year-old, with normal tonus of anal sphincter.

  8. Increased risk of biochemical and local failure in patients with distended rectum on the planning CT for prostate cancer radiotherapy

    International Nuclear Information System (INIS)

    Crevoisier, Renaud de; Tucker, Susan L.; Dong Lei; Mohan, Radhe; Cheung, Rex; Cox, James D.; Kuban, Deborah A.

    2005-01-01

    Purpose: To retrospectively test the hypothesis that rectal distension on the planning computed tomography (CT) scan is associated with an increased risk of biochemical and local failure among patients irradiated for prostate carcinoma when a daily repositioning technique based on direct prostate-organ localization is not used. Methods and Materials: This study included 127 patients who received definitive three-dimensional conformal radiotherapy for prostate cancer to a total dose of 78 Gy at University of Texas M.D. Anderson Cancer Center. Rectal distension was assessed by calculation of the average cross-sectional rectal area (CSA; defined as the rectal volume divided by length) and measuring three rectal diameters on the planning CT. The impact of rectal distension on biochemical control, 2-year prostate biopsy results, and incidence of Grade 2 or greater late rectal bleeding was assessed. Results: The incidence of biochemical failure was significantly higher among patients with distended rectums (CSA >11.2 cm 2 ) on the planning CT scan (p 0.0009, log-rank test). Multivariate analysis indicates that rectal distension and high-risk disease are independent risk factors for biochemical failure, with hazard ratios of 3.89 (95% C.I. 1.58 to 9.56, p = 0.003) and 2.45 (95% C.I. 1.18 to 5.08, p = 0.016), respectively. The probability of residual tumor without evidence of radiation treatment (as scored by the pathologist) increased significantly with rectal distension (p = 0.010, logistic analysis), and a lower incidence of Grade 2 or greater late rectal bleeding within 2 years was simultaneously observed with higher CSA values (p = 0.031, logistic analysis). Conclusions: We found strong evidence that rectal distension on the treatment-planning CT scan decreased the probability of biochemical control, local control, and rectal toxicity in patients who were treated without daily image-guided prostate localization, presumably because of geographic misses. Therefore, an

  9. Biological-effective versus conventional dose volume histograms correlated with late genitourinary and gastrointestinal toxicity after external beam radiotherapy for prostate cancer: a matched pair analysis

    Directory of Open Access Journals (Sweden)

    Roeske John C

    2003-05-01

    Full Text Available Abstract Background To determine whether the dose-volume histograms (DVH's for the rectum and bladder constructed using biological-effective dose (BED-DVH's better correlate with late gastrointestinal (GI and genitourinary (GU toxicity after treatment with external beam radiotherapy for prostate cancer than conventional DVH's (C-DVH's. Methods The charts of 190 patients treated with external beam radiotherapy with a minimum follow-up of 2 years were reviewed. Six patients (3.2% were found to have RTOG grade 3 GI toxicity, and similarly 6 patients (3.2% were found to have RTOG grade 3 GU toxicity. Average late C-DVH's and BED-DVH's of the bladder and rectum were computed for these patients as well as for matched-pair control patients. For each matched pair the following measures of normalized difference in the DVH's were computed: (a δAUC = (Area Under Curve [AUC] in grade 3 patient – AUC in grade 0 patient/(AUC in grade 0 patient and (b δV60 = (Percent volume receiving = 60 Gy [V60] in grade 3 patient – V60 in grade 0 patient/(V60 in grade 0 patient. Results As expected, the grade 3 curve is to the right of and above the grade 0 curve for all four sets of average DVH's – suggesting that both the C-DVH and the BED-DVH can be used for predicting late toxicity. δAUC was higher for the BED-DVH's than for the C-DVH's – 0.27 vs 0.23 (p = 0.036 for the rectum and 0.24 vs 0.20 (p = 0.065 for the bladder. δV60 was also higher for the BED-DVH's than for the C-DVH's – 2.73 vs 1.49 for the rectum (p = 0.021 and 1.64 vs 0.71 (p = 0.021 for the bladder. Conclusions When considering well-established dosimetric endpoints used in evaluating treatment plans, BED-DVH's for the rectum and bladder correlate better with late toxicity than C-DVH's and should be considered when attempting to minimize late GI and GU toxicity after external beam radiotherapy for prostate cancer.

  10. Isobio software: biological dose distribution and biological dose volume histogram from physical dose conversion using linear-quadratic-linear model.

    Science.gov (United States)

    Jaikuna, Tanwiwat; Khadsiri, Phatchareewan; Chawapun, Nisa; Saekho, Suwit; Tharavichitkul, Ekkasit

    2017-02-01

    To develop an in-house software program that is able to calculate and generate the biological dose distribution and biological dose volume histogram by physical dose conversion using the linear-quadratic-linear (LQL) model. The Isobio software was developed using MATLAB version 2014b to calculate and generate the biological dose distribution and biological dose volume histograms. The physical dose from each voxel in treatment planning was extracted through Computational Environment for Radiotherapy Research (CERR), and the accuracy was verified by the differentiation between the dose volume histogram from CERR and the treatment planning system. An equivalent dose in 2 Gy fraction (EQD 2 ) was calculated using biological effective dose (BED) based on the LQL model. The software calculation and the manual calculation were compared for EQD 2 verification with pair t -test statistical analysis using IBM SPSS Statistics version 22 (64-bit). Two and three-dimensional biological dose distribution and biological dose volume histogram were displayed correctly by the Isobio software. Different physical doses were found between CERR and treatment planning system (TPS) in Oncentra, with 3.33% in high-risk clinical target volume (HR-CTV) determined by D 90% , 0.56% in the bladder, 1.74% in the rectum when determined by D 2cc , and less than 1% in Pinnacle. The difference in the EQD 2 between the software calculation and the manual calculation was not significantly different with 0.00% at p -values 0.820, 0.095, and 0.593 for external beam radiation therapy (EBRT) and 0.240, 0.320, and 0.849 for brachytherapy (BT) in HR-CTV, bladder, and rectum, respectively. The Isobio software is a feasible tool to generate the biological dose distribution and biological dose volume histogram for treatment plan evaluation in both EBRT and BT.

  11. Surgical management of colorectal cancer for the aging population—A survey by the Japanese Society for Cancer of Colon and Rectum

    Directory of Open Access Journals (Sweden)

    Hiroshi Matsuoka

    2018-03-01

    Conclusion: Japanese Society for Cancer of the Colon and Rectum member institutions often used the same surgical treatment strategies for both elderly and younger patients with the exception of performing intersphincteric resection.

  12. Technical Note: System for evaluating local hypothermia as a radioprotector of the rectum in a small animal model.

    Science.gov (United States)

    Hrycushko, Brian A; Bing, Chenchen; Futch, Cecil; Wodzak, Michelle; Stojadinovic, Strahinja; Medin, Paul M; Chopra, Rajiv

    2017-08-01

    The protective effects of induced or even accidental hypothermia on the human body are widespread with several medical uses currently under active research. In vitro experiments using human cell lines have shown hypothermia provides a radioprotective effect that becomes more pronounced at large, single-fraction doses common to stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS) treatments. This work describes the development of a system to evaluate local hypothermia for a radioprotective effect of the rat rectum during a large dose of radiation relevant to prostate SBRT. This includes the evaluation of a 3D-printed small animal rectal cooling device and the integration with a small animal irradiator. A 3-cm long, dual-lumen rectal temperature control apparatus (RTCA) was designed in SOLIDWORKS CAD for 3D printing. The RTCA was capable of recirculating flow in a device small enough for insertion into the rat rectum, with a metal support rod for strength as well as visibility during radiation treatment planning. The outer walls of the RTCA comprised of thin heat shrink plastic, achieving efficient heat transfer into adjacent tissues. Following leak-proof testing, fiber optic temperature probes were used to evaluate the temperature over time when placed adjacent to the cooling device within the rat rectum. MRI thermometry characterized the relative temperature distribution in concentric ROIs surrounding the probe. Integration with an image-guided small animal irradiator and associated treatment planning system included evaluation for imaging artifacts and effect of brass tubing on dose calculation. The rectal temperature adjacent to the cooling device decreased from body temperature to 15°C within 10-20 min from device insertion and was maintained at 15 ± 3°C during active cooling for the evaluated time of one hour. MR thermometry revealed a steep temperature gradient with increasing distance from the cooling device with the desired

  13. Sphincter-saving reconstruction for radiation-injured rectum. A report of four cases with special reference to the pull-through procedure

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, Yasuo; Moriya, Yoshihiro; Hojo, Keiichi (National Cancer Center, Tokyo (Japan). Hospital)

    1982-12-01

    Up to now sigmoid colostomy has been a widely accepted and conventional treatment for the radiation-injured rectum, but patients without residual malignancy strongly desire to live without a colostomy. We have tried to remove the involved rectal segments by sphincter-saving procedures. Four patients underwent these procedures, pull-through procedure in three and low anterior resection in one. Among sphincter-saving procedures, the pull-through procedure was the most adequate. Provided the following five conditions are fulfilled, the pull-through procedure should be considered for the severely radiation-injured rectum. (1) No recurrence of the initial malignancy in the pelvis. (2) Preferably, a more than 2 cm intact rectal segment above the dentate line preserved. (3) No radiation-injured segment in the upper sigmoid. (4) No severe radiation damage in the small intestine. (5) Normal anal function.

  14. Diagnosis by computer-aided tomography in patients with carcinomas in the rectum-sigma area

    International Nuclear Information System (INIS)

    Gnann, H.; Huebener, K.H.; Ahlemann, L.M.; Harms, S.

    1984-01-01

    In a retrospective study on the patients at Tuebingen between 1977 and 1980, the diagnostic value of computer-aided tomography was investigated in 232 cases of carcinomas in the rectum-sigma area. 192 examinations were post-operative. Whether computer-aided tomography will catch on as a staging measure in the pre-operative phase must for now remain unanswered until prospective studies on a large number of patients have been carried through. However, it is useful as a decision-taking aid as regards the choice of the operation method and to clarify whether the carcinoma is operable. Far more important in view of the known high rate of recurvency and metastatic spread seems to be the role of computer-aided tomography in the aftercare especially of those patients who had their rectum removed: the diagnosis of the recidivation permits direct therapeutic action (a second operation, radiation therapy) at an early date. The search for clinically not previously known recidivations revealed that computer-aided tomography had in 124 patients with operated rectal carcinoma a high sensitivity of 98 per cent, a specificity of 87 per cent and an accuracy of 91.9 percent. How long after the operation CAT checks should be carried through is quite as uncertain at present as the role of CAT in the staging of those tumors. The authors recommend intervals of 2-3 months within the first two post-operative years. (orig.) [de

  15. Determination of dose received by bladder and rectum in external cervical irradiation

    International Nuclear Information System (INIS)

    Omer, Mohamed Ahmed Ali

    2001-12-01

    The cervical carcinoma is the common type of malignant tumor among sudanese females during the last years. The conventional external irradiation therapy is the common model of treatment for cervical carcinoma in (RICK). The irradiation of such cases implemented via four fields (box technique), two anterior and posterior and two lateral opposed fields, as central dose calculation, giving a dose of 5000 c Gy fractionated into 25 to 30 fractions. The parameter of the fields lie at the promontory of the sacral cephalic and at the obturators foramen caudally and laterally at the bony pelvic by one centimeter. The aim of the research is to determine the dose received by the rectum and bladder (critical organs), out of central dose calculation versus off axis dose calculation to (Day's method). The data obtained by using simulator and radiation oncological computerized system (Rocs). The results are analyzed by using statistical processing for social science program (SPSS) that shows the mean dose received by the bladder is 3821 cGy, due to central dose calculation that accompanied by an un-optimum encompassment of treatment line and 4210.6 c Gy. due to Off Axis Dose calculation dose 3324.4 c Gy and 3712.1 c Gy due to central dose calculation. The increment of dose received by the rectum and the bladder is due to utilizing of wider width of the filed size for lateral irradiation. To score the aim of International Atomic Energy Agency (IAEA) and (ALARA) principle A s Low As As Reasonable Available , we have to use the simulator to obtain the anatomical structures on the contour, or will be better to use CT. Scan for calculation of dose at the side of interest. (Author)

  16. Persistently better treatment planning results of intensity-modulated (IMRT) over conformal radiotherapy (3D-CRT) in prostate cancer patients with significant variation of clinical target volume and/or organs-at-risk

    International Nuclear Information System (INIS)

    Fenoglietto, Pascal; Laliberte, Benoit; Allaw, Ali; Ailleres, Norbert; Idri, Katia; Hay, Meng Huor; Moscardo, Carmen Llacer; Gourgou, Sophie; Dubois, Jean-Bernard; Azria, David

    2008-01-01

    Purpose: To compare the dose coverage of planning and clinical target volume (PTV, CTV), and organs-at-risk (OAR) between intensity-modulated (3D-IMRT) and conventional conformal radiotherapy (3D-CRT) before and after internal organ variation in prostate cancer. Methods and materials: We selected 10 patients with clinically significant interfraction volume changes. Patients were treated with 3D-IMRT to 80 Gy (minimum PTV dose of 76 Gy, excluding rectum). Fictitious, equivalent 3D-CRT plans (80 Gy at isocenter, with 95% isodose (76 Gy) coverage of PTV, with rectal blocking above 76 Gy) were generated using the same planning CT data set ('CT planning'). The plans were then also applied to a verification CT scan ('CT verify') obtained at a different moment. PTV, CTV, and OAR dose coverage were compared using non-parametric tests statistics for V95, V90 (% of the volume receiving ≥95 or 90% of the dose) and D50 (dose to 50% of the volume). Results: Mean V95 of the PTV for 'CT planning' was 94.3% (range, 88-99) vs 89.1% (range, 84-94.5) for 3D-IMRT and 3D-CRT (p = 0.005), respectively. Mean V95 of the CTV for 'CT verify' was 97% for both 3D-IMRT and 3D-CRT. Mean D50 of the rectum for 'CT planning' was 26.8 Gy (range, 22-35) vs 43.5 Gy (range, 33.5-50.5) for 3D-IMRT and 3D-CRT (p = 0.0002), respectively. For 'CT verify', this D50 was 31.1 Gy (range, 16.5-44) vs 44.2 Gy (range, 34-55) for 3D-IMRT and 3D-CRT (p = 0.006), respectively. V95 of the rectum was 0% for both plans for 'CT planning', and 2.3% (3D-IMRT) vs 2.1% (3D-CRT) for 'CT verify' (p = non-sig.). Conclusion: Dose coverage of the PTV and OAR was better with 3D-IMRT for each patient and remained so after internal volume changes

  17. Dose-volume analysis of predictors for chronic rectal toxicity after treatment of prostate cancer with adaptive image-guided radiotherapy

    International Nuclear Information System (INIS)

    Vargas, Carlos; Martinez, Alvaro; Kestin, Larry L.; Yan Di; Grills, Inga; Brabbins, Donald S.; Lockman, David M.; Liang Jian; Gustafson, Gary S.; Chen, Peter Y.; Vicini, Frank A.; Wong, John W.

    2005-01-01

    Purpose We analyzed our experience treating localized prostate cancer with image-guided off-line correction with adaptive high-dose radiotherapy (ART) in our Phase II dose escalation study to identify factors predictive of chronic rectal toxicity. Materials and Methods From 1999-2002, 331 patients with clinical stage T1-T3N0M0 prostate cancer were prospectively treated in our Phase II 3D conformal dose escalation ART study to a median dose of 75.6 Gy (range, 63.0-79.2 Gy), minimum dose to confidence limited-planning target volume (cl-PTV) in 1.8 Gy fractions (median isocenter dose = 79.7 Gy). Seventy-four patients (22%) also received neoadjuvant/adjuvant androgen deprivation therapy. A patient-specific cl-PTV was constructed using 5 computed tomography scans and 4 sets of electronic portal images by applying an adaptive process to assure target accuracy and minimize PTV margin. For each case, the rectum (rectal solid) was contoured from the sacroiliac joints or rectosigmoid junction (whichever was higher) to the anal verge or ischial tuberosities (whichever was lower), with a median volume of 81.2 cc. The rectal wall was defined using the rectal solid with an individualized 3-mm wall thickness (median volume = 29.8 cc). Rectal wall dose-volume histogram was used to determine the prescribed dose. Toxicity was quantified using the National Cancer Institute Common Toxicity Criteria 2.0. Multiple dose-volume endpoints were evaluated for their association with chronic rectal toxicity. Results Median follow-up was 1.6 years. Thirty-four patients (crude rate 10.3%) experienced Grade 2 chronic rectal toxicity at a median interval of 1.1 years. Nine patients (crude rate = 2.7%) experienced Grade ≥3 chronic rectal toxicity (1 was Grade 4) at a median interval of 1.2 years. The 3-year rates of Grade ≥2 and Grade ≥3 chronic rectal toxicity were 20% and 4%, respectively. Acute toxicity predicted for chronic: Acute Grade 2-3 rectal toxicity (p 40% respectively. The volume

  18. Transanal endoscopic microsurgery for advanced polyps and early cancers in the rectum-Long-term outcome

    DEFF Research Database (Denmark)

    Al-Najami, Issam; Rancinger, Carl Philip; Larsen, Morten Kobaek

    2016-01-01

    procedures for adenomas and cancers with focus on local recurrence and complications.All 280 patients who had a TEM procedure between January 2008 and September 2015 were enrolled in a prospective cohort study. Outcome was described for benign and malignant tumors. Mortality, recurrence, and complications.......8% in the benign and malignant group, respectively.TEM seems to be a safe and viable procedure for removing both benign and malignant lesions from the rectum. TEM offers low mortality and complication rates also recurrence after resection of malignant tumors....

  19. Histological changes in rectum following radiotherapy in cases of carcinoma cervix uteri

    Energy Technology Data Exchange (ETDEWEB)

    Gill, J K; Rohatgi, V K; Lahiri, B; Aggarwal, B M [S.N. Medical Coll., Agra (India)

    1978-05-01

    Rectal biopsy was done in 39 follow-up cases of squamous cell carcinoma of cervix treated with radiotherapy who clinically presented as cases of radiation proctitis. On histological examination, definite evidence of radiation injury was found in 23 cases. In rectal mucosa, radiation ulcers, broken epithelial lining, glandular atrophy, inflammatory cell infiltration, and edema of stroma were seen. Muscularis mucosa was either intact or partially broken. In submucosa, blood vessels showed endarteritis, plasma cell infiltration, fibrinoid necrosis, and hyalinization of vessel wall. In a few cases, hyalinization, edema, and vacuolation of muscle fibres were seen in muscle layer. In one case, squamous cell carcinoma of rectum was diagnosed. During follow-up examinations no complication due to rectal biopsy was observed.

  20. Preoperative combination therapy of 5-fluorouracil suppository and radiation for carcinoma of the rectum

    International Nuclear Information System (INIS)

    Mizusawa, Hirokazu; Takahashi, Toshio

    1983-01-01

    Twelve cases of carcinoma of the rectum were treated preoperatively by combination therapy with 5-fluorouracil (5-FU) suppository (100 mg twice a day consecutively, a total dose of more than 4,000 mg) and irradiation (300 rad x 3/week, a total dose of 3,000 rad). This group was compared with 34 cases given single preoperative 5-FU therapy and 24 control cases given no preoperative adjuvant modality. The group treated by preoperative combination therapy showed marked antitumor effects macroscopically and histologically. In addition, decrease in local recurrence was expected for this group, compared with the other two groups. (Chiba, N.)

  1. Probiotics for Rectal Volume Variation During Radiation Therapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Ki, Yongkan; Kim, Wontaek; Nam, Jiho; Kim, Donghyun; Lee, Juhye; Park, Dahl; Jeon, Hosang; Ha, Honggu; Kim, Taenam; Kim, Dongwon

    2013-01-01

    Purpose: To investigate the effect of the probiotic Lactobacillus acidophilus on the percentage volume change of the rectum (PVC R ), a crucial factor of prostate movement. Methods and Materials: Prostate cancer patients managed with tomotherapy as a radical treatment were enrolled in the study to take a probiotic capsule containing 1.0 × 10 8 colony-forming units of L acidophilus or a placebo capsule twice daily. Radiation therapy was performed at a dose of 78 Gy in 39 fractions. The PVC R , defined as the difference in rectal volume between the planning computed tomographic (CT) and daily megavoltage CT images, was analyzed. Results: Forty patients were randomized into 2 groups. The L acidophilus group showed significantly lower median rectal volume and median PVC R values than the placebo group. L acidophilus showed a significant reduction effect on the PVC R (P R . Conclusions: L acidophilus was useful in reducing the PVC R , which is the most important determining factor of prostate position, during radiation therapy for prostate cancer

  2. Culture-Independent Evaluation of the Appendix and Rectum Microbiomes in Children with and without Appendicitis

    Science.gov (United States)

    Davenport, Katherine P.; Fraser, Claire M.; Sandler, Anthony D.; Zeichner, Steven L.

    2014-01-01

    Purpose The function of the appendix is largely unknown, but its microbiota likely contributes to function. Alterations in microbiota may contribute to appendicitis, but conventional culture studies have not yielded conclusive information. We conducted a pilot, culture-independent 16S rRNA-based microbiota study of paired appendix and rectal samples. Methods We collected appendix and rectal swabs from 21 children undergoing appendectomy, six with normal appendices and fifteen with appendicitis (nine perforated). After DNA extraction, we amplified and sequenced 16S rRNA genes and analyzed sequences using CLoVR. We identified organisms differing in relative abundance using ANOVA (pappendicitis vs. normal), and disease severity (perforated vs. non-perforated). Results We identified 290 taxa in the study's samples. Three taxa were significantly increased in normal appendices vs. normal rectal samples: Fusibacter (p = 0.009), Selenomonas (p = 0.026), and Peptostreptococcus (p = 0.049). Five taxa were increased in abundance in normal vs. diseased appendices: Paenibacillaceae (p = 0.005), Acidobacteriaceae GP4 (p = 0.019), Pseudonocardinae (p = 0.019), Bergeyella (p = 0.019) and Rhizobium (p = 0.045). Twelve taxa were increased in the appendices of appendicitis patients vs. normal appendix: Peptostreptococcus (p = 0.0003), Bilophila (p = 0.0004), Bulleidia (p = 0.012), Fusobacterium (p = 0.018), Parvimonas (p = 0.003), Mogibacterium (p = 0.012), Aminobacterium (p = 0.019), Proteus (p = 0.028), Actinomycineae (p = 0.028), Anaerovorax (p = 0.041), Anaerofilum (p = 0.045), Porphyromonas (p = 0.010). Five taxa were increased in appendices in patients with perforated vs. nonperforated appendicitis: Bulleidia (p = 0.004), Fusibacter (p = 0.005), Prevotella (p = 0.021), Porphyromonas (p = 0.030), Dialister (p = 0.035). Three taxa were increased in rectum samples of patients with

  3. Effect of Chang Run Tong on the Biomechanical and Morphometric Remodeling of Colon and Rectum in STZ Induced Diabetic Rats

    DEFF Research Database (Denmark)

    Sha, Hong; Zhao, Dong; Zhao, Jingbo

    2013-01-01

    The present study investigates the effect of Chang Run Tong (CRT) on the biomechanical and morphometrical remodeling of colon and rectum in streptozotocin-induced diabetic rats. The colonic and rectal segments were obtained from diabetic (DM), CRT-treated diabetic (T1, high dosage: 50 g/kg/day; T2...

  4. The incidence of inclusion of the sigmoid colon and small bowel in the planning target volume in radiotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Meerleer, G.O. de; Vakaet, L.; Neve, W.J. de; Villeirs, G.M.; Delrue, L.J.

    2004-01-01

    Background and purpose: in radiotherapy for prostate cancer, the rectum is considered the dose-limiting organ. The incidence of overlap between the sigmoid colon and/or small bowel and the planning target volume (PTV) as well as the dose to sigmoid colon and small bowel were investigated. Patients and methods: the CT data of 75 prostate cancer patients were analyzed. The clinical target volume (CTV) consisted of prostate and seminal vesicles. The PTV was defined as a three-dimensional expansion of the CTV with a 10-mm margin in craniocaudal and a 7-mm margin in the other directions. All patients were planned to a mean CTV dose of at least 76 Gy. Minimum CTV dose was set at 70 Gy. Dose inhomogeneity within the CTV was kept between 12% and 17%. Sigmoid colon was defined upward from the level where the rectum turned in a transverse plane. Contrast-filled small bowel was contoured on all slices where it was visible. The presence of sigmoid colon and/or small bowel in close vicinity to or overlapping with the PTV was recorded. For each case, the dose to the sigmoid colon and small bowel was calculated. Results: the PTV was found to overlap with the sigmoid colon in 60% and with the small bowel in 19% of the cases. In these patients, mean maximum dose to the sigmoid colon was 76.2 Gy (5th-95th percentile: 70.0-80.7 Gy). Mean maximum dose to the small bowel was 74.9 Gy (5th-95th percentile: 68.0-80.0 Gy). Conclusion: when systematically investigating the anatomic position of sigmoid colon and small bowel in patients accepted for prostate irradiation, parts of both organs were often observed in close vicinity to the PTV. Apart from the rectum, these organs may be dose-limiting in prostate radiotherapy. (orig.)

  5. The incidence of inclusion of the sigmoid colon and small bowel in the planning target volume in radiotherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Meerleer, G.O. de; Vakaet, L.; Neve, W.J. de [Dept. of Radiation Oncology, Gent Univ. Hospital, Gent (Belgium); Villeirs, G.M.; Delrue, L.J. [Dept. of Radiology, Gent Univ. Hospital, Gent (Belgium)

    2004-09-01

    Background and purpose: in radiotherapy for prostate cancer, the rectum is considered the dose-limiting organ. The incidence of overlap between the sigmoid colon and/or small bowel and the planning target volume (PTV) as well as the dose to sigmoid colon and small bowel were investigated. Patients and methods: the CT data of 75 prostate cancer patients were analyzed. The clinical target volume (CTV) consisted of prostate and seminal vesicles. The PTV was defined as a three-dimensional expansion of the CTV with a 10-mm margin in craniocaudal and a 7-mm margin in the other directions. All patients were planned to a mean CTV dose of at least 76 Gy. Minimum CTV dose was set at 70 Gy. Dose inhomogeneity within the CTV was kept between 12% and 17%. Sigmoid colon was defined upward from the level where the rectum turned in a transverse plane. Contrast-filled small bowel was contoured on all slices where it was visible. The presence of sigmoid colon and/or small bowel in close vicinity to or overlapping with the PTV was recorded. For each case, the dose to the sigmoid colon and small bowel was calculated. Results: the PTV was found to overlap with the sigmoid colon in 60% and with the small bowel in 19% of the cases. In these patients, mean maximum dose to the sigmoid colon was 76.2 Gy (5th-95th percentile: 70.0-80.7 Gy). Mean maximum dose to the small bowel was 74.9 Gy (5th-95th percentile: 68.0-80.0 Gy). Conclusion: when systematically investigating the anatomic position of sigmoid colon and small bowel in patients accepted for prostate irradiation, parts of both organs were often observed in close vicinity to the PTV. Apart from the rectum, these organs may be dose-limiting in prostate radiotherapy. (orig.)

  6. Rectal bladder-type: ileum-sigma-rectum pouch

    International Nuclear Information System (INIS)

    Krajka, K.; Mikszewicz, A.; Stachurski, L.; Perkowski, D.

    1994-01-01

    The paper presents a method of creating rectal bladder by using the proximal part of rectum, the distal part of sigma and a 40 cm long segment of detubularized ileum. Ureters were attached to the proximal end of ileal segment by Wallace-I technique. Initially the retrograde pyelonephritis was to be prevented by intussuscepting a 4 cm long part of the uretero-ilea anastomosis and by positioning isoperistaltically a 15-16 cm long part of the ileal segment. Because of the insufficiency of such a mechanism, in 4 latest cases the intussuscepted segment was increased to 8 cm. 8 patients suffering from stage T3a and T3b invasive carcinoma of the bladder were treated by this procedure. The ureteral stens were led out via the rectal tube. They were removed days after the operation. The whole post-operative period was uneventful. The patients were under close follow-up from 5 to 22 months. Three of them died due to a progression of the disease. All the patients had 3-4 watery stools a day and one at night. Check-ups performed three and six months after the operation revealed a proper out flow of contrast medium from kidneys and a reduction in the dilatation of ureters. In one case the kidney that failed to function before the procedure, restored its secretion afterwards. The contrast medium reached colon descendens only when more than 350 ml of it were infused into the rectal bladder. (author)

  7. Finding dose-volume constraints to reduce late rectal toxicity following 3D-conformal radiotherapy (3D-CRT) of prostate cancer

    International Nuclear Information System (INIS)

    Greco, Carlo; Mazzetta, Chiara; Cattani, Federica; Tosi, Giampiero; Castiglioni, Simona; Fodor, Andrei; Orecchia, Roberto

    2003-01-01

    Background and purpose: The rectum is known to display a dose-volume effect following high-dose 3D-conformal radiotherapy (3D-CRT). The aim of the study is to search for significant dose-volume combinations with the specific treatment technique and patient set-up currently used in our institution. Patients and methods: We retrospectively analyzed the dose-volume histograms (DVH) of 135 patients with stage T1b-T3b prostate cancer treated consecutively with 3D-CRT between 1996 and 2000 to a total dose of 76 Gy. The median follow-up was 28 months (range 12-62). All late rectal complications were scored using RTOG criteria. Time to late toxicity was assessed using the Kaplan-Meyer method. The association between variables at baseline and ≥2 rectal toxicity was tested using χ 2 test or Fisher's exact test. A multivariate analysis using logistic regression was performed. Results: Late rectal toxicity grade ≥2 was observed in 24 of the 135 patients (17.8%). A 'grey area' of increased risk has been identified. Average DVHs of the bleeding and non-bleeding patients were generated. The area under the percent volume DVH for the rectum of the bleeding patients was significantly higher than that of patients without late rectal toxicity. On multivariate analysis the correlation between the high risk DVHs and late rectal bleeding was confirmed. Conclusions: The present analysis confirms the role of the rectal DVH as a tool to discriminate patients undergoing high-dose 3D-CRT into a low and a high risk of developing late rectal bleeding. Based on our own results and taking into account the data published in the literature, we have been able to establish new dose-volume constraints for treatment planning: if possible, the percentage of rectal volume exposed to 40, 50, 60, 72 and 76 Gy should be limited to 60, 50, 25, 15 and 5%, respectively

  8. Endoscopic Mucosectomy in a Child Presenting with Gastric Heterotopia of the Rectum

    Directory of Open Access Journals (Sweden)

    Joana Soares

    2017-09-01

    Full Text Available Gastric mucosal heterotopia has been described in all levels of the gastrointestinal tract. Its occurrence in the rectum is uncommon. We report the case of a 4-year-old boy referred to Pediatric Gastroenterology for intermittent rectal bleeding for the past 2 years. Total ileocolonoscopy revealed a flat, well-circumscribed lesion of 4 cm, with elevated margins, localized at 10 cm from the anal verge. Histologic examination showed typical gastric mucosa of the oxyntic type. Treatment with proton pump inhibitors was started without resolution of the symptoms and, therefore, an endoscopic mucosal resection was performed. Heterotopic gastric mucosa represents a rare cause of rectal bleeding in children and endoscopic evaluation is fundamental for diagnosis. Although not usually performed in pediatric ages, endoscopic mucosectomy allows complete resolution of the problem avoiding surgery.

  9. Endoscopic Mucosectomy in a Child Presenting with Gastric Heterotopia of the Rectum.

    Science.gov (United States)

    Soares, Joana; Ferreira, Carla; Marques, Margarida; Corujeira, Susana; Tavares, Marta; Lopes, Joanne; Carneiro, Fátima; Amil Dias, Jorge; Trindade, Eunice

    2017-11-01

    Gastric mucosal heterotopia has been described in all levels of the gastrointestinal tract. Its occurrence in the rectum is uncommon. We report the case of a 4-year-old boy referred to Pediatric Gastroenterology for intermittent rectal bleeding for the past 2 years. Total ileocolonoscopy revealed a flat, well-circumscribed lesion of 4 cm, with elevated margins, localized at 10 cm from the anal verge. Histologic examination showed typical gastric mucosa of the oxyntic type. Treatment with proton pump inhibitors was started without resolution of the symptoms and, therefore, an endoscopic mucosal resection was performed. Heterotopic gastric mucosa represents a rare cause of rectal bleeding in children and endoscopic evaluation is fundamental for diagnosis. Although not usually performed in pediatric ages, endoscopic mucosectomy allows complete resolution of the problem avoiding surgery.

  10. Dieulafoy's Lesions of the Rectum: A Rare Cause of Lower Gastrointestinal Bleeding

    Directory of Open Access Journals (Sweden)

    Robert Enns

    2001-01-01

    Full Text Available Dieulafoy's lesions located outside of the stomach are rare occurrences. Lesions found within the colon typically present with painless, massive hematochezia (ie, greater than 5 U. If they can be accurately located, endoscopic therapy in the form of adrenaline injection, sclerotherapy or cauterization appears to have long term success. The present report details the case of a 72-year-old man who presented with massive hematochezia and who was discovered to have a Dieulafoy's lesion within the rectum. The lesion was located just distal to a previous surgical anastomosis, and was successfully treated with adrenaline and electrocautery. Colonic Dieulafoy's lesions are rare but should always be considered in the differential diagnosis of massive hematochezia, because endoscopic therapy appears to result in complete cessation of bleeding.

  11. Dosimetric Evaluation of High-Dose-Rate Interstitial Brachytherapy Boost Treatments for Localized Prostate Cancer

    International Nuclear Information System (INIS)

    Froehlich, Georgina; Agoston, Peter; Loevey, Jozsef; Somogyi, Andras; Fodor, Janos; Polgar, Csaba; Major, Tibor

    2010-01-01

    Purpose: to quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Material and methods: treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D min ) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D r ) and urethra (D u ), dose to volume of 2 cm 3 of the rectum (D 2ccm ), and 0.1 cm 3 and 1% of the urethra (D 0.1ccm and D1) were determined. Nonparametric correlation analysis was performed between these parameters. Results: the median number of needles was 16, the mean prostate volume (V p ) was 27.1 cm 3 . The mean V90, V100, V150, and V200 were 90%, 97%, 39% and 13%, respectively. The mean D90 was 109%, and the D min was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D 2ccm = 49% for the rectum, D 0.1ccm = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D r , D 2ccm ) = 0.69, R(D u , D 0.1ccm ) = 0.64, R(D u , D1) = 0.23. Conclusion: US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose-volume parameters. For urethra dose characterization, the use of D1 volumetric

  12. Dosimetric evaluation of high-dose-rate interstitial brachytherapy boost treatments for localized prostate cancer.

    Science.gov (United States)

    Fröhlich, Georgina; Agoston, Péter; Lövey, József; Somogyi, András; Fodor, János; Polgár, Csaba; Major, Tibor

    2010-07-01

    To quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D(min)) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D(r)) and urethra (D(u)), dose to volume of 2 cm(3) of the rectum (D(2ccm)), and 0.1 cm(3) and 1% of the urethra (D(0.1ccm) and D1) were determined. Nonparametric correlation analysis was performed between these parameters. The median number of needles was 16, the mean prostate volume (V(p)) was 27.1 cm(3). The mean V90, V100, V150, and V200 were 99%, 97%, 39%, and 13%, respectively. The mean D90 was 109%, and the D(min) was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D(2ccm) = 49% for the rectum, D(0.1ccm) = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D(r),D(2ccm)) = 0.69, R(D(u),D0.(1ccm)) = 0.64, R(D(u),D1) = 0.23. US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose-volume parameters. For urethra dose characterization, the use of D1 volumetric parameter is recommended.

  13. Perfusion CT assessment of the colon and rectum: Feasibility of quantification of bowel wall perfusion and vascularization

    International Nuclear Information System (INIS)

    Khan, Sairah; Goh, Vicky; Tam, Emily; Wellsted, David; Halligan, Steve

    2012-01-01

    The aim was to determine the feasibility of vascular quantification of the bowel wall for different anatomical segments of the colorectum. Following institutional ethical approval and informed consent, 39 patients with colorectal cancer underwent perfusion CT. Blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface area product (PS) were assessed for different segments of the colorectum: ascending, transverse, descending colon, sigmoid, or rectum, that were distant from the tumor, and which were proven normal on contemporary colonoscopy, and subsequent imaging and clinical follow up. Mean (SD) for BF, BV, MTT and PS for the different anatomical colorectal segments were obtained and compared using a pooled t-test. Significance was at 5%. Assessment was not possible in 9 of 39 (23%) patients as the bowel wall was ≤5 mm precluding quantitative analysis. Forty-four segments were evaluated in the remaining 30 patients. Mean BF was higher in the proximal than distal colon: 24.0 versus 17.8 mL/min/100 g tissue; p = 0.009; BV, MTT and PS were not significantly different; BV: 3.46 versus 3.15 mL/100 g tissue, p = 0.45; MTT: 15.1 versus 18.3 s; p = 0.10; PS: 6.84 versus 8.97 mL/min/100 tissue, p = 0.13, respectively. In conclusion, assessment of bowel wall perfusion may fail in 23% of patients. The colorectum demonstrates segmental differences in perfusion.

  14. Late radiation effects to the rectum and bladder in gynecologic cancer patients: the comparison of LENT/SOMA and RTOG/EORTC late-effects scoring systems

    International Nuclear Information System (INIS)

    Anacak, Yavuz; Yalman, Deniz; Oezsaran, Zeynep; Haydaroglu, Ayfer

    2001-01-01

    Purpose: To test the correlation of LENT/SOMA and RTOG/EORTC late-effect scales for rectum and bladder, 116 cases with gynecologic malignancies that were treated with radiotherapy were assessed with both scales. Methods and Materials: All cases had been treated at least 6 months before the date of assessment with external beam radiotherapy (50-54 Gy to midline) and 1-2 fractions of HDR brachytherapy (2x8.5 Gy to point-A for 32 inoperable cases; 1x9.25 Gy to 5-9 mm from the ovoid surface for 84 postoperative cases). The patients were questioned with both scales, and the correlation between the two scales was analyzed by Spearman's rho (rank correlation) test. Results: There were 64 cases with uterine cervix carcinoma and 52 cases with endometrium carcinoma, The overall (external + brachy) doses to ICRU points were 57.8±3.8 Gy for rectum and 59.3±4.9 Gy for bladder. The statistical analysis of LENT/SOMA and RTOG/EORTC scales revealed a very good correlation for rectum (r=0.81; p<0.01) and a good correlation for bladder (r=0.72; p<0.01). Conclusion: The LENT/SOMA system is a further step on the reporting of late radiation effects. Some modifications will improve its precision, and multicentric randomized studies are needed to test its validity

  15. A dose-volume comparison of prostate cancer (PC) radiotherapy (RT) techniques for penile-structures (PNS) - a neglected critical organ in PC RT

    International Nuclear Information System (INIS)

    Dabrowski, Jolanta; Myrianthopoulos, Leon; Nguyen, Ai; Chen, George; Vijayakumar, Srinivasan

    1996-01-01

    Purpose/Objective: Three-dimensional conformal RT(3DCRT) is revolutionizing the use of RT in PC. Rectum and bladder, and in some studies femoral heads are included as critical structures (CS) in comparing rival plans in 3DCRT. Although RT-induced impotence is a major complication of conventional RT, with 30-50% incidence, to date no study has included PNS as a CS. This study is an attempt to remedy this deficiency in the 3DCRT planning in PC. Materials and Methods: After immobilization with Aquaplast, computed-tomography (CT) scans were obtained in supine treatment position from top of lumbar-3 vertebra to lesser-trochanter of the femora with 5-8mm slice-thicknesses; IV contrast was used in all patients. Prostate, seminal vesicles (GTV), and CSs were outlined, including PNS. Corpora cavernosa and bulbous spongiosum together were identified as PNS. Appropriate margins for CTV and PTV were used; total margin to the block from GTV was 2cm. Tumor-minimum doses were prescribed to the 100% isodose line. Dose-volume histograms (DVHs) were obtained to compare three different techniques: 1. Conventional 4 field box technique (4FC) with equal weighting; 2. Six field (2 laterals and 4 obliques [45 degrees from midline] (6FO), with 50% dose delivery from the laterals; and 3. Four equally weighted, non-axial fields [2 laterals and 2 inferior anterior obliques at 45 degree couch and gantry rotations] (4FN). Results: A total of 12 patients are included in the study. The mean and range of percentage volume of PNS receiving more than 30, 60, and 90% of the prescribed dose are shown in the table below: Box plots, such as the example shown above, were used to compare techniques overall. The 6-field coplanar technique treated the least PNS volume beyond a given dose, followed by 4FC and 4FN techniques. The order of least to maximum percent of PNS treated in most individual patients also followed the same trend. In the majority, 6FO and 4FN delivered relatively comparable doses to

  16. A prospective three-dimensional analysis about the impact of differences in the clinical target volume in prostate cancer irradiation on normal-tissue exposure. A potential for increasing the benefit/risk ratio

    International Nuclear Information System (INIS)

    Hille, A.; Toews, N.; Schmidberger, H.; Hess, C.F.

    2005-01-01

    Background and purpose: rectal toxicity following external-beam irradiation of prostate cancer correlates with the exposed percentage of rectal volume. Recently, it has been recommended to reduce the volume of the seminal vesicles that should be included in the clinical target volume (CTV). The purpose of this study was to quantitatively assess the impact of this CTV reduction on the expected rectal and bladder dose sparing. Patients and methods: 14 patients with localized prostate cancer undergoing external-beam radiotherapy were investigated. The prostate, the prostate + entire seminal vesicles, or the prostate + proximal seminal vesicles were delineated as CTV. Treatment plans were generated and compared concerning rectum and bladder dose-volume histograms (DVHs). Results: the exposure of rectum and bladder volume was significantly lower in case of irradiation of the prostate only compared to inclusion of the proximal or entire seminal vesicles into the CTV. The reduction of the CTV from prostate + entire seminal vesicles to prostate + proximal seminal vesicles led to a significant reduction of the rectal and bladder dose exposure. Conclusion: reduction of the CTV to the prostate only, or to the prostate + proximal seminal vesicles led to significant rectal and bladder dose sparing compared to irradiation of the prostate + entire seminal vesicles. In patients with a higher risk for seminal vesicles involvement, irradiation of the prostate + proximal seminal vesicles should be preferred. In case of a need for irradiation of the entire seminal vesicles, patients should be informed about a higher risk for chronic rectal toxicity and, possibly, for bladder complications. (orig.)

  17. dose in cervical cancer intracavitary brachytherapy

    Directory of Open Access Journals (Sweden)

    Zahra Siavashpour

    2016-04-01

    Full Text Available Purpose: To analyze the optimum organ filling point for organs at risk (OARs dose in cervical cancer high-dose-rate (HDR brachytherapy. Material and methods : In a retrospective study, 32 locally advanced cervical cancer patients (97 insertions who were treated with 3D conformal external beam radiation therapy (EBRT and concurrent chemotherapy during 2010-2013 were included. Rotterdam HDR tandem-ovoid applicators were used and computed tomography (CT scanning was performed after each insertion. The OARs delineation and GEC-ESTRO-based clinical target volumes (CTVs contouring was followed by 3D forward planning. Then, dose volume histogram (DVH parameters of organs were recorded and patients were classified based on their OARs volumes, as well as their inserted tandem length. Results : The absorbed dose to point A ranged between 6.5-7.5 Gy. D 0.1cm ³ and D 2cm ³ of the bladder significantly increased with the bladder volume enlargement (p value < 0.05. By increasing the bladder volume up to about 140 cm3, the rectum dose was also increased. For the cases with bladder volumes higher than 140 cm3, the rectum dose decreased. For bladder volumes lower than 75 cm3, the sigmoid dose decreased; however, for bladder volumes higher than 75 cm3, the sigmoid dose increased. The D 2cm ³ of the bladder and rectum were higher for longer tandems than for shorter ones, respectively. The divergence of the obtained results for different tandem lengths became wider by the extension of the bladder volume. The rectum and sigmoid volume had a direct impact on increasing their D 0.1cm ³ and D 2cm ³, as well as decreasing their D 10 , D 30 , and D 50 . Conclusions : There is a relationship between the volumes of OARs and their received doses. Selecting a bladder with a volume of about 70 cm3 or less proved to be better with regards to the dose to the bladder, rectum, and sigmoid.

  18. Limitations of the planning organ at risk volume (PRV) concept.

    Science.gov (United States)

    Stroom, Joep C; Heijmen, Ben J M

    2006-09-01

    Previously, we determined a planning target volume (PTV) margin recipe for geometrical errors in radiotherapy equal to M(T) = 2 Sigma + 0.7 sigma, with Sigma and sigma standard deviations describing systematic and random errors, respectively. In this paper, we investigated margins for organs at risk (OAR), yielding the so-called planning organ at risk volume (PRV). For critical organs with a maximum dose (D(max)) constraint, we calculated margins such that D(max) in the PRV is equal to the motion averaged D(max) in the (moving) clinical target volume (CTV). We studied margins for the spinal cord in 10 head-and-neck cases and 10 lung cases, each with two different clinical plans. For critical organs with a dose-volume constraint, we also investigated whether a margin recipe was feasible. For the 20 spinal cords considered, the average margin recipe found was: M(R) = 1.6 Sigma + 0.2 sigma with variations for systematic and random errors of 1.2 Sigma to 1.8 Sigma and -0.2 sigma to 0.6 sigma, respectively. The variations were due to differences in shape and position of the dose distributions with respect to the cords. The recipe also depended significantly on the volume definition of D(max). For critical organs with a dose-volume constraint, the PRV concept appears even less useful because a margin around, e.g., the rectum changes the volume in such a manner that dose-volume constraints stop making sense. The concept of PRV for planning of radiotherapy is of limited use. Therefore, alternative ways should be developed to include geometric uncertainties of OARs in radiotherapy planning.

  19. Probiotics for Rectal Volume Variation During Radiation Therapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ki, Yongkan [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of); Kim, Wontaek, E-mail: rokwt@hanmail.net [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of); Nam, Jiho; Kim, Donghyun; Lee, Juhye; Park, Dahl; Jeon, Hosang [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of); Ha, Honggu; Kim, Taenam [Department of Urology, Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan (Korea, Republic of); Kim, Dongwon [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of)

    2013-11-15

    Purpose: To investigate the effect of the probiotic Lactobacillus acidophilus on the percentage volume change of the rectum (PVC{sub R}), a crucial factor of prostate movement. Methods and Materials: Prostate cancer patients managed with tomotherapy as a radical treatment were enrolled in the study to take a probiotic capsule containing 1.0 × 10{sup 8} colony-forming units of L acidophilus or a placebo capsule twice daily. Radiation therapy was performed at a dose of 78 Gy in 39 fractions. The PVC{sub R}, defined as the difference in rectal volume between the planning computed tomographic (CT) and daily megavoltage CT images, was analyzed. Results: Forty patients were randomized into 2 groups. The L acidophilus group showed significantly lower median rectal volume and median PVC{sub R} values than the placebo group. L acidophilus showed a significant reduction effect on the PVC{sub R} (P<.001). However, the radiation therapy fraction number did not significantly influence the PVC{sub R}. Conclusions: L acidophilus was useful in reducing the PVC{sub R}, which is the most important determining factor of prostate position, during radiation therapy for prostate cancer.

  20. Anorectal function following colo-anal sleeve anastomosis for chronic radiation injury to the rectum

    Energy Technology Data Exchange (ETDEWEB)

    Varma, J S; Smith, A N

    1986-04-01

    This paper reports the results of anorectal manometry and electrophysiological studies of the pelvic floor in eight patients who had undergone anterior resection of the rectum with mucosal proctectomy and colo-anal sleeve anastomosis for radiation rectal injury. The group comprised six women and two men (age range 61-84 years, mean 71 years). Six bladder carcinoma patients had received small field (10 x 10 cm) external beam radiotherapy (5500 cGy in 20 treatments over 4 weeks); two cervical cancer patients had been given whole pelvis, external beam radiotherapy supplemented by a single caesium implant (cumulative dosage of 9500 cGy to the vaginal vault, equivalent to 7500 cG to point A).

  1. Anorectal function following colo-anal sleeve anastomosis for chronic radiation injury to the rectum

    International Nuclear Information System (INIS)

    Varma, J.S.; Smith, A.N.

    1986-01-01

    This paper reports the results of anorectal manometry and electrophysiological studies of the pelvic floor in eight patients who had undergone anterior resection of the rectum with mucosal proctectomy and colo-anal sleeve anastomosis for radiation rectal injury. The group comprised six women and two men (age range 61-84 years, mean 71 years). Six bladder carcinoma patients had received small field (10 x 10 cm) external beam radiotherapy (5500 cGy in 20 treatments over 4 weeks); two cervical cancer patients had been given whole pelvis, external beam radiotherapy supplemented by a single caesium implant (cumulative dosage of 9500 cGy to the vaginal vault, equivalent to 7500 cG to point A). (UK)

  2. Dosimetric Evaluation of High-Dose-Rate Interstitial Brachytherapy Boost Treatments for Localized Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Georgina [Semmelweis Univ., Budapest (Hungary); Dept. of Radiotherapy, National Inst. of Oncology, Budapest (Hungary); Agoston, Peter; Loevey, Jozsef; Somogyi, Andras; Fodor, Janos; Polgar, Csaba; Major, Tibor [Dept. of Radiotherapy, National Inst. of Oncology, Budapest (Hungary)

    2010-07-15

    Purpose: to quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Material and methods: treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D{sub min}) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D{sub r}) and urethra (D{sub u}), dose to volume of 2 cm{sup 3} of the rectum (D{sub 2ccm}), and 0.1 cm{sup 3} and 1% of the urethra (D{sub 0.1ccm} and D1) were determined. Nonparametric correlation analysis was performed between these parameters. Results: the median number of needles was 16, the mean prostate volume (V{sub p}) was 27.1 cm{sup 3}. The mean V90, V100, V150, and V200 were 90%, 97%, 39% and 13%, respectively. The mean D90 was 109%, and the D{sub min} was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D{sub 2ccm} = 49% for the rectum, D{sub 0.1ccm} = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D{sub r}, D{sub 2ccm}) = 0.69, R(D{sub u}, D{sub 0.1ccm}) = 0.64, R(D{sub u}, D1) = 0.23. Conclusion: US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose-volume

  3. Internal hemorrhoids - their typical radiological appearance and differential diagnosis to carcinoma of rectum and anus

    Energy Technology Data Exchange (ETDEWEB)

    Fiedler, V.; Koester, R.

    1984-11-01

    The main indication for colon barium enema examination is occult bleeding or bleeding noticed by the patient himself. The radiologist has to take into account all clinical details that could lead to bleeding and to document them. The most frequent causes of rectal bleeding are hemorrhoids and diverticulosis/itis which in marked cases may have a tumor-like appearance. A good double-contrast examination of the colon must not only exclude tumors, polyps or inflammatary diseases but also demonstrate other causes of bleeding. The presented paper describes typical roentgen signs and gives criteria to differentiate hemorrhoids from deeply situated cancer of the rectum or anus.

  4. Internal hemorrhoids - their typical radiological appearance and differential diagnosis to carcinoma of rectum and anus

    International Nuclear Information System (INIS)

    Fiedler, V.; Koester, R.

    1984-01-01

    The main indication for colon barium enema examination is occult bleeding or bleeding noticed by the patient himself. The radiologist has to take into account all clinical details that could lead to bleeding and to document them. The most frequent causes of rectal bleeding are hemorrhoids and diverticulosis/itis which in marked cases may have a tumor-like appearence. A good double-contrast examination of the colon must not only exclude tumors, polyps or inflammotary diseases but also demonstrate other causes of bleeding. The presented paper describes typical roentgen signs and gives criteria to differentiate hemorrhoids from deeply situated cancer of the rectum or anus. (orig.) [de

  5. Major Anaerobic Bacteria Responsible for the Production of Carcinogenic Acetaldehyde from Ethanol in the Colon and Rectum.

    Science.gov (United States)

    Tsuruya, Atsuki; Kuwahara, Akika; Saito, Yuta; Yamaguchi, Haruhiko; Tenma, Natsuki; Inai, Makoto; Takahashi, Seiji; Tsutsumi, Eri; Suwa, Yoshihide; Totsuka, Yukari; Suda, Wataru; Oshima, Kenshiro; Hattori, Masahira; Mizukami, Takeshi; Yokoyama, Akira; Shimoyama, Takefumi; Nakayama, Toru

    2016-07-01

    The importance of ethanol oxidation by intestinal aerobes and facultative anaerobes under aerobic conditions in the pathogenesis of ethanol-related colorectal cancer has been proposed. However, the role of obligate anaerobes therein remains to be established, and it is still unclear which bacterial species, if any, are most important in the production and/or elimination of carcinogenic acetaldehyde under such conditions. This study was undertaken to address these issues. More than 500 bacterial strains were isolated from the faeces of Japanese alcoholics and phylogenetically characterized, and their aerobic ethanol metabolism was studied in vitro to examine their ability to accumulate acetaldehyde beyond the minimum mutagenic concentration (MMC, 50 µM). Bacterial strains that were considered to potentially accumulate acetaldehyde beyond the MMC under aerobic conditions in the colon and rectum were identified and referred to as 'potential acetaldehyde accumulators' (PAAs). Ruminococcus, an obligate anaerobe, was identified as a genus that includes a large number of PAAs. Other obligate anaerobes were also found to include PAAs. The accumulation of acetaldehyde by PAAs colonizing the colorectal mucosal surface could be described, at least in part, as the response of PAAs to oxidative stress. Ethanol oxidation by intestinal obligate anaerobes under aerobic conditions in the colon and rectum could also play an important role in the pathogenesis of ethanol-related colorectal cancer. © The Author 2016. Medical Council on Alcohol and Oxford University Press. All rights reserved.

  6. Neoadjuvant chemoradiotherapy in the advanced rectum cancers. Results of a retrospective study. Rate of sphincter preservation; Chimioradiotherapie neoadjuvante dans les cancers avances du rectum. Resultats d'une etude retrospective. Taux de preservation sphincterienne

    Energy Technology Data Exchange (ETDEWEB)

    Ayad, M.; Rabahi, K.; Mesli, S.; Boualga, K. [Centre anticancer, Blida (Algeria)

    2009-10-15

    Objectives: the concomitant chemoradiotherapy given before surgery improves the therapeutic results in the evolved cancers of the rectum v( classified T3-T4 clinically and/or N+). We report our experience for 114 patients that received a preoperative radiotherapy associated to the 5-fluoro-uracil-folinic acid (fufol) or 5-fluoro-uracil-oxaliplatin (Folfox) type chemotherapy. The other objective of this study was to determine the sphincter preservation rate for the patients suffering of a low rectal tumor. This retrospective study showed a good tolerance and an acceptable toxicity for the patient. The adjuvant chemoradiotherapy allowed a down staging and a conservation of the sphincter function for the patient suffering of a very low tumor. (N.C.)

  7. Clinical results after ten years of the Lyon R96-02 trial: improving rectum conservation by increasing irradiation dose; Resultats cliniques a dix ans de l'essai Lyon R96-02: ameliorer la conservation du rectum en augmentant la dose d'irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gerard, J.P. [Centre Antoine-Lacassagne, Nice (France); Ortholan, C. [Hopital Princesse-Grace, Monaco (Monaco); Chapet, O. [Centre hospitalier de Lyon-Sud, Pierre-Benite (France); Romestaing, P. [Hopital prive J.-Mermoz, Lyon (France)

    2011-10-15

    The author report and comments the results after ten years of a trial which aimed at testing the influence of a boost by pre-operative 50 kV contact radiotherapy on the sphincter or rectum conservation rate. Patient had been treated by external radiotherapy with or without this contact radiotherapy. Results are analysed in terms of complete or partial clinical response, global survival, local recurrence, and absence of colostomy. Short communication

  8. Reduced dose to urethra and rectum with the use of variable needle spacing in prostate brachytherapy: a potential role for robotic technology.

    Science.gov (United States)

    Vyas, Shilpa; Le, Yi; Zhang, Zhe; Armour, Woody; Song, Daniel Y

    2015-08-01

    Several robotic delivery systems for prostate brachytherapy are under development or in pre-clinical testing. One of the features of robotic brachytherapy is the ability to vary spacing of needles at non-fixed intervals. This feature may play an important role in prostate brachytherapy, which is traditionally template-based with fixed needle spacing of 0.5 cm. We sought to quantify potential reductions in the dose to urethra and rectum by utilizing variable needle spacing, as compared to fixed needle spacing. Transrectal ultrasound images from 10 patients were used by 3 experienced planners to create 120 treatment plans. Each planner created 4 plan variations per patient with respect to needle positions: (125)I fixed spacing, (125)I variable spacing, (103)Pd fixed spacing, and (103)Pd variable spacing. The primary planning objective was to achieve a prostate V100 of 100% while minimizing dose to urethra and rectum. All plans met the objective of achieving prostate V100 of 100%. Combined results for all plans show statistically significant improvements in all assessed dosimetric variables for urethra (Umax, Umean, D30, D5) and rectum (Rmax, Rmean, RV100) when using variable spacing. The dose reductions for mean and maximum urethra dose using variable spacing had p values of 0.011 and 0.024 with (103)Pd, and 0.007 and 0.029 with (125)I plans. Similarly dose reductions for mean and maximum rectal dose using variable spacing had p values of 0.007 and 0.052 with (103)Pd, and 0.012 and 0.037 with (125)I plans. The variable needle spacing achievable by the use of robotics in prostate brachytherapy allows for reductions in both urethral and rectal planned doses while maintaining prostate dose coverage. Such dosimetric advantages have the potential in translating to significant clinical benefits with the use of robotic brachytherapy.

  9. Squamous cell dysplasia in the proximal rectum of three patients treated for ulcerative colitis on immunomodulators.

    Science.gov (United States)

    Connolly, James G; Goldstone, Stephen E

    2017-05-01

    Anal canal high-grade squamous intraepithelial lesion (HSIL) is the precursor to anal cancer. Immunocompromised patients are at increased risk and disease is usually within 3 cm from the anal verge. High-resolution anoscopy (HRA) with an 8-cm anoscope is used to identify and guide cautery treatment of HSIL. We report three patients with a long-term history of ulcerative colitis (UC) treated with systemic immunomodulators who developed proximally located rectal HSIL. Two patients were HIV-negative women, 63 and 48 years old, and the third was a 51-year-old HIV-positive man with underlying UC for 10, 16, and 3 years, respectively. They each presented with a HPV-positive HSIL visibly extending above the limits of the anoscope used for HRA. None developed cancer. All had episodes of active UC. It is unclear what causative role systemic immunomodulators play in predisposing UC patients to proximal HSIL. HSIL probably developed on a tongue of HPV-infected squamous epithelium growing proximally over the inflamed rectum. Islands developed when areas of squamous epithelium degenerated, creating skip areas. This study highlights the potential for HSIL to extend into the rectum either as a contiguous patch or isolated islands and the need for heightened surveillance in patients with extensive anal canal HSIL treated with immunodulator therapy. HSIL identified at the limit of the anoscope should be investigated further with colonoscopy, and argon plasma coagulation (APC) ablation can serve as an effective treatment option. Patients are at risk for stricture, but it is unclear what role the UC or the ablation played in stricture formation.

  10. Characterisation of radiotherapy planning volumes using textural analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nailon, William H.; Redpath, Anthony T.; McLaren, Duncan B. (Dept. of Oncology Physics, Edinburgh Cancer Centre, Western General Hospital, Edinburgh (United Kingdom))

    2008-08-15

    Computer-based artificial intelligence methods for classification and delineation of the gross tumour volume (GTV) on computerised tomography (CT) and magnetic resonance (MR) images do not, at present, provide the accuracy required for radiotherapy applications. This paper describes an image analysis method for classification of distinct regions within the GTV, and other clinically relevant regions, on CT images acquired on eight bladder cancer patients at the radiotherapy planning stage and thereafter at regular intervals during treatment. Statistical and fractal textural features (N=27) were calculated on the bladder, rectum and a control region identified on axial, coronal and sagittal CT images. Unsupervised classification results demonstrate that with a reduced feature set (N=3) the approach offers significant classification accuracy on axial, coronal and sagittal CT image planes and has the potential to be developed further for radiotherapy applications, particularly towards an automatic outlining approach

  11. Characterisation of radiotherapy planning volumes using textural analysis

    International Nuclear Information System (INIS)

    Nailon, William H.; Redpath, Anthony T.; McLaren, Duncan B.

    2008-01-01

    Computer-based artificial intelligence methods for classification and delineation of the gross tumour volume (GTV) on computerised tomography (CT) and magnetic resonance (MR) images do not, at present, provide the accuracy required for radiotherapy applications. This paper describes an image analysis method for classification of distinct regions within the GTV, and other clinically relevant regions, on CT images acquired on eight bladder cancer patients at the radiotherapy planning stage and thereafter at regular intervals during treatment. Statistical and fractal textural features (N=27) were calculated on the bladder, rectum and a control region identified on axial, coronal and sagittal CT images. Unsupervised classification results demonstrate that with a reduced feature set (N=3) the approach offers significant classification accuracy on axial, coronal and sagittal CT image planes and has the potential to be developed further for radiotherapy applications, particularly towards an automatic outlining approach

  12. Defining probabilities of bowel resection in deep endometriosis of the rectum: Prediction with preoperative magnetic resonance imaging.

    Science.gov (United States)

    Perandini, Alessio; Perandini, Simone; Montemezzi, Stefania; Bonin, Cecilia; Bellini, Gaia; Bergamini, Valentino

    2018-02-01

    Deep endometriosis of the rectum is a highly challenging disease, and a surgical approach is often needed to restore anatomy and function. Two kinds of surgeries may be performed: radical with segmental bowel resection or conservative without resection. Most patients undergo magnetic resonance imaging (MRI) before surgery, but there is currently no method to predict if conservative surgery is feasible or whether bowel resection is required. The aim of this study was to create an algorithm that could predict bowel resection using MRI images, that was easy to apply and could be useful in a clinical setting, in order to adequately discuss informed consent with the patient and plan the an appropriate and efficient surgical session. We collected medical records from 2010 to 2016 and reviewed the MRI results of 52 patients to detect any parameters that could predict bowel resection. Parameters that were reproducible and with a significant correlation to radical surgery were investigated by statistical regression and combined in an algorithm to give the best prediction of resection. The calculation of two parameters in MRI, impact angle and lesion size, and their use in a mathematical algorithm permit us to predict bowel resection with a positive predictive value of 87% and a negative predictive value of 83%. MRI could be of value in predicting the need for bowel resection in deep endometriosis of the rectum. Further research is required to assess the possibility of a wider application of this algorithm outside our single-center study. © 2017 Japan Society of Obstetrics and Gynecology.

  13. Total mesorectum resection and coloanal anastomosis with J colonic reservoir for treatment of medium and low rectum cancer

    International Nuclear Information System (INIS)

    Guerra Mesa, Jose Luis; Vazquez Gonzalez, Jose Manuel; Diaz Salas, Carlos; Perez Penna, Lourdes; Naranjo Hernandez, Daisy

    2010-01-01

    INTRODUCTION: Proctosigmoidectomy with total mesorectum resection, reservoir in J and colorectal is useful in patients with low and middle rectum cancer, to avoid the definite terminal colostomy. The aim of present paper was to analyze the feasibility of such surgical technique, the multidisciplinary integral treatment and the results obtained. METHODS: Fifteen patients were studied suffering of low and middle adenocarcinoma treated between January, 1996 and December, 2002 in Splanchnic Surgery Service of National Institute of Oncology and Radiobiology of La Habana City. Treatment included a combination of radiotherapy plus neocoadjuvant concurrent chemotherapy, followed by adjuvant chemotherapy and surgery. RESULTS: Mean age of patients was of 56 years. The adenocarcinoma was the histological type diagnosed in all patients. Tumor staging the following: T1 and T2, in four patients (27%, respectively); T3 in seven patients (46%). Four patients (20%) had complications due to radiation treatment and five (33,3%), by surgical treatment. Surgical mortality occurred in one patient (6,6%) and eleven patients (73,3%) survived over 5 years. Neither patient had pelvic tumor relapse or by colorectal anastomosis. There was good sphincter continence. CONCLUSIONS: Total mesorectum resection and colorectal anastomosis with a colonic reservoir in J prevent the definite terminal colostomy, to cure a high percentage of patients with low and middle rectum cancer without respecting the oncology surgery principles, is well accepted by patients and it is feasible in our practice. (author)

  14. Association of anorectal dose-volume histograms and impaired fecal continence after 3D conformal radiotherapy for carcinoma of the prostate

    International Nuclear Information System (INIS)

    Vordermark, Dirk; Schwab, Michael; Ness-Dourdoumas, Rhea; Sailer, Marco; Flentje, Michael; Koelbl, Oliver

    2003-01-01

    Purpose: The late toxicity of fecal incontinence after pelvic radiotherapy is now frequently recognized but the etiology poorly understood. We therefore investigated associations between dose-volume histogram (DVH) parameters of the rectum and the anal canal with fecal continence as measured by an established 10-item questionnaire. Methods and materials: Forty-four patients treated for carcinoma of the prostate with 58-72 Gy of 3D conformal radiotherapy between 1995 and 1999 who completed the questionnaire formed the study population. Total continence scores of treated patients obtained 1.5 years (median) after radiotherapy were compared to a control group of 30 patients before radiotherapy. Median, mean, minimum and maximum doses as well as the volume (% and ml) treated to 40, 50, 60 and 70 Gy were determined separately for anal canal and rectum. DVH parameters were correlated with total continence score (Spearman rank test) and patients grouped according to observed continence were compared regarding DVH values (Mann-Whitney U-test). Results: Median fecal continence scores were significantly worse in the irradiated than in the control group (31 vs. 35 of a maximum 36 points). In treated patients, 59%/27%/14% were classified as fully continent, slightly incontinent and severely incontinent. Continence was similar in the 58-to-62-Gy, 66-Gy and 68-to-72-Gy dose groups. No DVH parameter was significantly correlated with total continence score, but severely incontinent patients had a significantly higher minimum dose to the anal canal than fully continent/slightly incontinent, accompanied by portals extending significantly further inferiorly with respect to the ischial tuberosities. Conclusions: Excluding the inferior part of the anal canal from the treated volume in 3D conformal therapy for carcinoma of the prostate appears to be a promising strategy to prevent radiation-induced fecal incontinence

  15. Dosimetric Effect of Online Image-Guided Anatomical Interventions for Postprostatectomy Cancer Patients

    International Nuclear Information System (INIS)

    Diot, Quentin; Olsen, Christine; Kavanagh, Brian; Raben, David; Miften, Moyed

    2011-01-01

    Purpose: To assess daily variations in delivered doses in postprostatectomy patients, using kilovoltage cone-beam CT (CBCT) datasets acquired before and after interventions to correct for observed distortions in volume/shape of rectum and bladder. Methods and Materials: Seventeen consecutive patients treated with intensity-modulated radiotherapy to the prostate bed were studied. For patients with large anatomical variations, quantified by either a rectal wall displacement of >5 mm or bladder volume change of >50% on the CBCT compared with the planning CT, an intervention was performed to adjust the rectum and/or bladder filling. Cumulative doses over the pre- and post-intervention fractions were calculated by tracking the position of the planning CT voxels on different CBCTs using a deformable surface-mapping algorithm. Dose and displacements vectors were projected on two-dimensional maps, the minimal dose received by the highest 95% of the planing target volume (PTV D95) and the highest 10% of the rectum volume (D10) as well as the bladder volume receiving >2 Gy (V2) were evaluated. Results: Of 544 fractions, 96 required intervention. Median (range) number of interventions per patient was 5 (2-12). Compared with the planning values, the mean (SD) pre- vs. postintervention value for PTV D95 was -2% (2%) vs. -1% (2%) (p < 0.12), for rectum D10 was -1% (4%) vs. +1% (4%) (p < 0.24), and for bladder V2 was +6% vs. +20% (p < 0.84). Conclusions: Interventions to reduce treatment volume deformations due to bladder and rectum fillings are not necessary when patients receive daily accurate CBCT localization, and the frequency of those potential interventions is low. However, for hypofractionated treatments, the relative frequency can significantly increase, and interventions can become more dosimetrically beneficial.

  16. Using the computed tomography in comparison to the orthogonal radiography based treatment planning in high dose rate (HDR) brachytherapy in cervical uteri cancer patients; a single institution feasibility study.

    Science.gov (United States)

    Bahadur, Yasir A; El-Sayed, Mohamed E; El-Taher, Zeinab H; Zaza, Khaled O; Moftah, Belal A; Hassouna, Ashraf H; Ghassal, Noor M

    2008-03-01

    Brachytherapy is an integral part in the treatment of cervical uteri cancer patients. Orthogonal treatment planning is the standard mode of calculation based on reference points. Introduction of the innovative 3-D computer based treatment planning allows accurate calculation based on volumetric information as regards the target volume and organs at risk (OAR). Also provide dose volume histogram (DVH) for proper estimation of the dose in relation to the volume. To correlate and compare the information obtained from the two approaches for high dose rate brachytherapy of cervical uteri cancer; the orthogonal conventional method and the computerized tomography (CT) three dimensions (3D) based calculation method in relation to the target and organ at risk (OAR). From 6 patients of cervical uteri cancer, 21 applications with orthogonal planning using the Brachy Vision treatment planning system version 7.3.10 were performed. In 10 applications; comparison between orthogonal and CT based planning was done. In orthogonal planning; the dose to point A, rectum and bladder were defined according to the American Brachytherapy Society (ABS) recommendation. From the CT based planning the target volume and dose volume histogram lpar;DVH) were calculated for the clinical target volume (CTV), rectum and bladder. From these two sets, information was obtained and compared and mean values were derived. For dose prescription at point A, an average of 63.5% of CTV received the prescribed dose. The mean ICRU dose to the bladder point is 2.9 Gy+/-1.2 SD (Standard Deviation) and 17% of the bladder volume derived from CT was encompassed by 2.9 Gy isodose line. The mean ICRU dose at the rectum point is 3.4 Gy+/-1.2 SD and 21% of the rectum volume from CT was encompassed by 3.4 Gy isodose line. The maximum dose to the rectum and the bladder derived from the CT and compared to the maximal dose at ICRU is 1.7 and 2.8 times higher than the orthogonal reference points; with the corresponding p

  17. Using the Computed Tomography in Comparison to the Orthogonal Radiography Based Treatment Planning in High dose Rate (HDR) Brachytherapy in Cervical Uteri Cancer Patients; A Single Institution Feasibility Study

    International Nuclear Information System (INIS)

    BAHADUR, Y.A.; EL-SAYED, M.E.; HASSOUNA, A.H.; EL-TAHER, Z.H.; GHASSAL, N.M.; ZAZA, Kh.O.M.D.; OFTAH, B.A.

    2008-01-01

    Brachytherapy is an integral part in the treatment of cervical uteri cancer patients. Orthogonal treatment planning is the standard mode of calculation based on reference points. Introduction of the innovative 3-D computer based treatment planning allows accurate calculation based on volumetric information as regards the target volume and organs at risk (OAR). Also provide dose volume histogram (DVH) for proper estimation of the dose in relation to the volume. Aim: To correlate and compare the information obtained from the two approaches for high dose rate brachytherapy of cervical uteri cancer; the orthogonal conventional method and the computerized tomography (CT) three dimensions (3D) based calculation method in relation to the target and organ at risk (OAR). Methods: From 6 patients of cervical uteri cancer, 21 applications with orthogonal planning using the Brachy Vision treatment planning system version 7.3.10 were performed. In 10 applications; comparison between orthogonal and CT based planning was done. In orthogonal planning; the dose to point A, rectum and bladder were defined according to the American Brachytherapy Society (ABS) recommendation. From the CT based planning the target volume and dose volume histogram (DVH) were calculated for the clinical target volume (CTV), rectum and bladder. From these two sets, information was obtained and compared and mean values were derived. Results: For dose prescription at point A, an average of 63.5% of CTV received the prescribed dose. The mean ICRU dose to the bladder point is 2.9 Gy±l .2 SD (Standard Deviation) and 17% of the bladder volume derived from CT was encompassed by 2.9 Gy isodose line. The mean ICRU dose at the rectum point is 3.4 Gy±1.2 SD and 21% of the rectum volume from CT was encompassed by 3.4 Gy isodose line. The maximum dose to the rectum and the bladder derived from the CT and compared to the maximal dose at ICRU is 1.7 and 2.8 times higher than the orthogonal reference points; with the

  18. Effect of Tangweian Jianji on the Biomechanical and Morphometric Remodeling of Colon and Rectum in STZ Induced Diabetic Rats

    DEFF Research Database (Denmark)

    Sha, Hong; Tong, Xiao-Lin; Liu, Gui-Fang

    2012-01-01

    .01). Furthermore, the circumferential and longitudinal stiffness of the colonic wall increased in DM group compared those with CON group. TH but not TL treatment could significantly decrease the colonic wall stiffness in both directions (P...AIM: The aim of the study was to investigate the effect of TWAJJ on the biomechanical and morphometrical remodeling of colon and rectum in streptozotocin (STZ) induced diabetic rats. METHODS: The colonic and rectal segments obtained from diabetic (DM), TWAJJ treated diabetic (TH, high dosage: 10 g...

  19. Comparison of Rectal and Esophageal Sensitivity in Women With Functional Heartburn.

    Science.gov (United States)

    Freede, Margaret; Leasure, A Renee; Proskin, Howard M; Hatch, Daniel; Edwards, Karethy; Pascucci, MaryAnn; Smith, Patsy R

    2016-01-01

    This study tested the primary hypothesis that there is a correlation of maximum pain threshold (MPT) in the esophagus and rectum in persons with functional heartburn. Secondary aims evaluated correlations with initial perception threshold (IPT) and pain threshold (PT). This study explored objective sensory endpoints of IPT, PT, and MPT in the esophagus and rectum of 14 females with functional heartburn to determine whether visceral hypersensitivity is generalized or organ-specific. Data on volume and pressure measurements at IPT, PT, and MPT with esophageal and rectal barostat distention were collected. The relationship of sensation and pain to volume, pressure, and compliance was analyzed. Esophageal and rectal IPT balloon volume scores were highly and significantly correlated (r = .61, p = .02). Esophageal and rectal PT balloon volume scores were highly and significantly correlated (r = .6, p = .02). Esophageal and rectal MPT balloon volume scores were not correlated (r = .35, p = .26). The correlation of visceral sensitivity in the esophagus and rectum in persons with functional heartburn supports the hypothesis that visceral sensory changes in functional gastrointestinal disorders are not organ specific.

  20. MANUAL COLON-ANAL OR MECHANICAL COLORECTAL ANASTOMOSIS? COMPARATIVE ANALYSIS OF LAPAROSCOPIC LOW RESECTIONS OF THE RECTUM

    Directory of Open Access Journals (Sweden)

    I. L. Chernikovsky

    2015-01-01

    Full Text Available The purpose of the study was to compare immediate surgical outcomes of low anterior resections (LAR and intersphincteric resections (ISR of the rectum. Materials and methods. Treatment outcomes of 42 patients operated on between March, 2014 and January, 2015 were presented. Group I consisted of 24 patients who underwent laparoscopic ultra-low anterior resection (uLAR for rectal cancer. Group II comprised 18 patients who underwent laparoscopic ISR. Results. No significant differences in the median length of surgery and blood loss between two groups were observed. Circular and distal resection margins were negative in all cases. In 18 (75 % patients of Group I and in 14 (77.7 % patients of Group II, total mesorectumectomy(TME was assessed as grade 3 (p=0.83. The frequency of postoperative complications in uLAR-treated group was 20.8 %, not requiring a secondary revision procedure, and 27.8 % in ISR-treated group, requiring repeated surgery. The mean value of the fecal incontinence according to the Wechsler scale in a month after surgery was significantly higher in group II than in Group I patients (9.3 versus 6.2, р=0.01. The average treatment cost for uLAR was higher by 45,000 rubles than that for ISR. Conclusion. Both surgical procedures were matched by the duration of operation, amount of blood loss and the quality of mesorectumectomy. The complication rate was not significantly different between two groups, however, 16.8 % of Group II patients required relaparotomy, likely due to the mastering of the ISR technique. Ultra-low anterior resections of the rectum are functionally preferred. When performing ISR, the technique of reservoir colo-anal anastomosis with preservation of the portion of the internal sphincter provides functional results comparable with those obtained using LAR.

  1. La trajectoire des symptômes dépressifs de l'enfance à l'adolescence et les cibles d'intervention préventive

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    Diane Marcotte

    2014-03-01

    Full Text Available Cette étude longitudinale s'intéresse à la trajectoire développementale des symptômes de dépression sur une période de cinq ans entre l'enfance et l'adolescence ainsi qu'à ses facteurs associés. À partir de l'analyse de courbes de croissance latente (Latent Growth Model-LGM, les résultats indiquent que les symptômes de dépression augmentent entre l'âge de 11-12 ans et 15-16 ans chez les filles, mais non chez les garçons. Cependant, pour chacun des sexes, la variance de la pente de la trajectoire reflète l'hétérogénéité des sous-groupes, révélant que les trajectoires varient chez les individus. Parmi les facteurs mesurés au temps 1 de l'étude, ceux qui sont le plus étroitement associés à la variation longitudinale des symptômes dépressifs sont le soutien des amis pour les deux genres et l'âge pour les filles. Plusieurs facteurs sont également associés à la présence de dépression au temps initial. Les cibles d'intervention pour une prévention universelle de la dépression chez les jeunes sont ensuite discutées et un programme visant le développement de facteurs de protection chez les adolescents est présenté

  2. A rectum shield for the circular applicator system of a selectron unit (HDR and LDR afterloading)

    International Nuclear Information System (INIS)

    Hetzel, H.; McCoy, M.; Kamleitner, H.; Frommhold, H.

    1987-01-01

    In order to decrease the morbidity rate after combined radiotherapy of the cervix carcinoma, a tungsten shield 3 and 5 mm thick for the rectum has been developed by the authors which is applied with the ring and pin applicator of the selectron unit (LDR and HDR afterloading). The isodose curves were measured in a plexiglas phantom, and the radiation dose at the reference points was determined by means of a ionization dosemeter. The phantom measurements were performed with the same arrangement of sources as applied in radiotherapy. The measurements showed a dose reduction at point Rmax of 33% (HDR) and 44% (LDR) with the tungsten shield 5 mm thick. (orig.) [de

  3. Comparison of two radiotherapy schemes, conventional and fractionated, in elderly patients suffering from a locally advanced rectum cancer; Comparaison de deux schemas de radiotherapie, classique et hypofractionne, chez les patients ages atteints d'un cancer du rectum localement evolue

    Energy Technology Data Exchange (ETDEWEB)

    Guillerme, F.; Clavier, J.B.; Guihard, S.; Schumacher, C.; Nehme-Schuster, H.; Ben Abdelghani, M.; Noel, G. [Centre Paul-Strauss, Strasbourg (France); Kurtz, J.E.; Brigand, C. [Hopitaux universitaires, Strasbourg (France)

    2011-10-15

    Based on results obtained on 177 patients older than 65 and suffering from T3-4 rectum cancer, and treated either according to a conventional scheme (45 to 50,4 Gy by 1,8 to 2 Gy fractions) or according to a fractionated scheme (39 Gy by 3 Gy fractions), the authors report the comparison of these both methods in terms of toxicity, delay between end of radiotherapy and surgery), histological response, global survival. The hypo-fractionated treatment allows the treatment duration to be reduced, is therefore less constraining and seems more suitable for elderly people. Short communication

  4. Reduced dose to urethra and rectum with the use of variable needle spacing in prostate brachytherapy: a potential role for robotic technology

    Science.gov (United States)

    Vyas, Shilpa; Le, Yi; Zhang, Zhe; Armour, Woody

    2015-01-01

    Purpose Several robotic delivery systems for prostate brachytherapy are under development or in pre-clinical testing. One of the features of robotic brachytherapy is the ability to vary spacing of needles at non-fixed intervals. This feature may play an important role in prostate brachytherapy, which is traditionally template-based with fixed needle spacing of 0.5 cm. We sought to quantify potential reductions in the dose to urethra and rectum by utilizing variable needle spacing, as compared to fixed needle spacing. Material and methods Transrectal ultrasound images from 10 patients were used by 3 experienced planners to create 120 treatment plans. Each planner created 4 plan variations per patient with respect to needle positions: 125I fixed spacing, 125I variable spacing, 103Pd fixed spacing, and 103Pd variable spacing. The primary planning objective was to achieve a prostate V100 of 100% while minimizing dose to urethra and rectum. Results All plans met the objective of achieving prostate V100 of 100%. Combined results for all plans show statistically significant improvements in all assessed dosimetric variables for urethra (Umax, Umean, D30, D5) and rectum (Rmax, Rmean, RV100) when using variable spacing. The dose reductions for mean and maximum urethra dose using variable spacing had p values of 0.011 and 0.024 with 103Pd, and 0.007 and 0.029 with 125I plans. Similarly dose reductions for mean and maximum rectal dose using variable spacing had p values of 0.007 and 0.052 with 103Pd, and 0.012 and 0.037 with 125I plans. Conclusions The variable needle spacing achievable by the use of robotics in prostate brachytherapy allows for reductions in both urethral and rectal planned doses while maintaining prostate dose coverage. Such dosimetric advantages have the potential in translating to significant clinical benefits with the use of robotic brachytherapy. PMID:26622227

  5. Aggressive treatment of metastatic squamous cell carcinoma of the rectum to the liver: a case report and a brief review of the literature

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    Carvounis Eleni E

    2006-08-01

    Full Text Available Abstract Background Rectal squamous cell carcinoma (SCC is a rare tumor. The incidence of this malignancy has been reported to be 0.25 to 1 per 1000 colorectal carcinomas. From a review of the English literature 55 cases of SCC of the rectum have been published. In this study we report a rectal metastatic SCC to the liver, discussing the efficacy of aggressive adjuvant and neo-adjuvant therapies on survival and prognosis. Case presentation A 39-year-old female patient with a pure SCC of the rectum diagnosed endoscopically is presented. The patient underwent initially neoadjuvant chemo-radiotherapy and then abdominoperineal resection with concomitant bilateral oophorectomy and hysterectomy, followed by adjuvant chemo-radiotherapy. Five months after the initial operation liver metastasis was demonstrated and a liver resection was carried out, followed by adjuvant chemotherapy. Eighteen months after the initial operation the patient is alive. Conclusion Although prognosis of rectal SCC is worse than that of adenocarcinoma, an aggressive therapeutic approach with surgery as the primary treatment, followed by combined neo- and adjuvant chemo-radiotherapy, may be necessary in order to improve survival and prognosis.

  6. Magnetic Resonance Imaging (MRI) with retrograde intralumen contrast enhancement of the rectum in diagnostics of rectovaginal fistulas after combination therapy of rectal cancer. Experience of application

    Science.gov (United States)

    Usova, A.; Frolova, I.; Afanasev, S.; Tarasova, A.; Molchanov, S.

    2016-02-01

    Experiment of use of MRI in diagnostics of rectovaginal fistulas after combination therapy of rectal cancer is shown on clinical examples. We used retrograde contrasting of a rectum with 150ml ultrasonic gel to make MRI more informative in case of low diagnostic efficiency of ultrasound, colonoscopy and gynecological examination.

  7. Optimized Planning Target Volume for Intact Cervical Cancer

    International Nuclear Information System (INIS)

    Khan, Alvin; Jensen, Lindsay G.; Sun Shuai; Song, William Y.; Yashar, Catheryn M.; Mundt, Arno J.; Zhang Fuquan; Jiang, Steve B.; Mell, Loren K.

    2012-01-01

    Purpose: To model interfraction clinical target volume (CTV) variation in patients with intact cervical cancer and design a planning target volume (PTV) that minimizes normal tissue dose while maximizing CTV coverage. Methods and Materials: We analyzed 50 patients undergoing external-beam radiotherapy for intact cervical cancer using daily online cone-beam computed tomography (CBCT). The CBCTs (n = 972) for each patient were rigidly registered to the planning CT. The CTV was delineated on the planning CT (CTV 0 ) and the set of CBCTs ({CTV 1 –CTV 25 }). Manual (n = 98) and automated (n = 668) landmarks were placed over the surface of CTV 0 with reference to defined anatomic structures. Normal vectors were extended from each landmark, and the minimum length required for a given probability of encompassing CTV 1 –CTV 25 was computed. The resulting expansions were used to generate an optimized PTV. Results: The mean (SD; range) normal vector length to ensure 95% coverage was 4.3 mm (2.7 mm; 1–16 mm). The uniform expansion required to ensure 95% probability of CTV coverage was 13 mm. An anisotropic margin of 20 mm anteriorly and posteriorly and 10 mm superiorly, inferiorly, and laterally also would have ensured a 95% probability of CTV coverage. The volume of the 95% optimized PTV (1470 cm 3 ) was significantly lower than both the anisotropic PTV (2220 cm 3 ) and the uniformly expanded PTV (2110 cm 3 ) (p 0 , 5–10 mm along the interfaces of CTV 0 with the bladder and rectum, and 10–14 mm along the anterior surface of CTV 0 at the level of the uterus. Conclusion: Optimizing PTV definition according to surface landmarking resulted in a high probability of CTV coverage with reduced PTV volumes. Our results provide data justifying planning margins to use in practice and clinical trials.

  8. The evaluation of the feasibility about prostate SBRT by analyzing interfraction errors of internal organs

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Soon Gi; Son, Sang Joon; Moon, Joon Gi; KIm, Bo Kyum; Lee, Je Hee [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2016-12-15

    To figure out if the treatment plan for rectum, bladder and prostate that have a lot of interfraction errors satisfies dosimetric limits without adaptive plan by analyzing MR image. This study was based on 5 prostate cancer patients who had IMRT(total dose: 70 Gy) Using ViewRay MRIdian System(ViewRay, ViewRay Inc., Cleveland, OH, USA) The treatment plans were made on the same CT images to compare with the plan quality according to adaptive plan, and the Eclipse(Ver 10.0.42, Varian, USA) was used. After registrate the 5 treatment MR images to the CT images for treatment plan to analyze the interfraction changes of organ, we measured the dose volume histogram and the changes of the absolute volume for each organ by applying the first treatment plan to each image. Over 5 fractions, the total dose for PTV was V{sub 36.25} Gy ≧ 95%. To confirm that the prescription dose satisfies the SBRT dose limit for prostate, we measured V{sub 100%} , V{sub 95%}, V{sub 90%} for CTV and V{sub 100%}, V{sub 90%}, V{sub 80%}, V{sub 50%} of rectum and bladder. All dose average value of CTV, rectum and bladder satisfied dose limit, but there was a case that exceeded dose limit more than one after analyzing the each image of treatment. After measuring the changes of absolute volume comparing the MR image of the first treatment plan with the one of the interfraction treatment, the difference values were maximum 1.72 times at rectum and maximum 2.0 times at bladder. In case of rectum, the expected values were planned under the dose limit, on average, V{sub 100%}=0.32%, V{sub 90%}=3.33%, V{sub 80%}=7.71%, V{sub 50%}=23.55% in the first treatment plan. In case of rectum, the average of absolute volume in first plan was 117.9 cc. However, the average of really treated volume was 79.2 cc. In case of CTV, the 100% prescription dose area didn't satisfy even though the margin for PTV was 5 mm because of the variation of rectal and bladder volume. There was no case that the value from average

  9. The evaluation of the feasibility about prostate SBRT by analyzing interfraction errors of internal organs

    International Nuclear Information System (INIS)

    Hong, Soon Gi; Son, Sang Joon; Moon, Joon Gi; KIm, Bo Kyum; Lee, Je Hee

    2016-01-01

    To figure out if the treatment plan for rectum, bladder and prostate that have a lot of interfraction errors satisfies dosimetric limits without adaptive plan by analyzing MR image. This study was based on 5 prostate cancer patients who had IMRT(total dose: 70 Gy) Using ViewRay MRIdian System(ViewRay, ViewRay Inc., Cleveland, OH, USA) The treatment plans were made on the same CT images to compare with the plan quality according to adaptive plan, and the Eclipse(Ver 10.0.42, Varian, USA) was used. After registrate the 5 treatment MR images to the CT images for treatment plan to analyze the interfraction changes of organ, we measured the dose volume histogram and the changes of the absolute volume for each organ by applying the first treatment plan to each image. Over 5 fractions, the total dose for PTV was V_3_6_._2_5 Gy ≧ 95%. To confirm that the prescription dose satisfies the SBRT dose limit for prostate, we measured V_1_0_0_% , V_9_5_%, V_9_0_% for CTV and V_1_0_0_%, V_9_0_%, V_8_0_%, V_5_0_% of rectum and bladder. All dose average value of CTV, rectum and bladder satisfied dose limit, but there was a case that exceeded dose limit more than one after analyzing the each image of treatment. After measuring the changes of absolute volume comparing the MR image of the first treatment plan with the one of the interfraction treatment, the difference values were maximum 1.72 times at rectum and maximum 2.0 times at bladder. In case of rectum, the expected values were planned under the dose limit, on average, V_1_0_0_%=0.32%, V_9_0_%=3.33%, V_8_0_%=7.71%, V_5_0_%=23.55% in the first treatment plan. In case of rectum, the average of absolute volume in first plan was 117.9 cc. However, the average of really treated volume was 79.2 cc. In case of CTV, the 100% prescription dose area didn't satisfy even though the margin for PTV was 5 mm because of the variation of rectal and bladder volume. There was no case that the value from average of five fractions is over the

  10. Strategies to evaluate the impact of rectal volume on prostate motion during three-dimensional conformal radiotherapy for prostate cancer

    Directory of Open Access Journals (Sweden)

    Ana Paula Diniz Fortuna Poli

    2016-02-01

    Full Text Available Abstract Objective: To evaluate the rectal volume influence on prostate motion during three-dimensional conformal radiotherapy (3D-CRT for prostate cancer. Materials and Methods: Fifty-one patients with prostate cancer underwent a series of three computed tomography scans including an initial planning scan and two subsequent scans during 3D-CRT. The organs of interest were outlined. The prostate contour was compared with the initial CT images considering the anterior, posterior, superior, inferior and lateral edges of the organ. Variations in the anterior limits and volume of the rectum were assessed and correlated with prostate motion in the anteroposterior direction. Results: The maximum range of prostate motion was observed in the superoinferior direction, followed by the anteroposterior direction. A significant correlation was observed between prostate motion and rectal volume variation ( p = 0.037. A baseline rectal volume superior to 70 cm3 had a significant influence on the prostate motion in the anteroposterior direction ( p = 0.045. Conclusion: The present study showed a significant interfraction motion of the prostate during 3D-CRT with greatest variations in the superoinferior and anteroposterior directions, and that a large rectal volume influences the prostate motion with a cutoff value of 70 cm3. Therefore, the treatment of patients with a rectal volume > 70 cm3 should be re-planned with appropriate rectal preparation.

  11. Critical-Inquiry-Based-Learning: Model of Learning to Promote Critical Thinking Ability of Pre-service Teachers

    Science.gov (United States)

    Prayogi, S.; Yuanita, L.; Wasis

    2018-01-01

    This study aimed to develop Critical-Inquiry-Based-Learning (CIBL) learning model to promote critical thinking (CT) ability of preservice teachers. The CIBL learning model was developed by meeting the criteria of validity, practicality, and effectiveness. Validation of the model involves 4 expert validators through the mechanism of the focus group discussion (FGD). CIBL learning model declared valid to promote CT ability, with the validity level (Va) of 4.20 and reliability (r) of 90,1% (very reliable). The practicality of the model was evaluated when it was implemented that involving 17 of preservice teachers. The CIBL learning model had been declared practice, its measuring from learning feasibility (LF) with very good criteria (LF-score = 4.75). The effectiveness of the model was evaluated from the improvement CT ability after the implementation of the model. CT ability were evaluated using the scoring technique adapted from Ennis-Weir Critical Thinking Essay Test. The average score of CT ability on pretest is - 1.53 (uncritical criteria), whereas on posttest is 8.76 (critical criteria), with N-gain score of 0.76 (high criteria). Based on the results of this study, it can be concluded that developed CIBL learning model is feasible to promote CT ability of preservice teachers.

  12. Strategies to evaluate the impact of rectal volume on prostate motion during three-dimensional conformal radiotherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Poli, Ana Paula Diniz Fortuna, E-mail: anapaulafortuna@yahoo.com.br [Universidade Estadual de Campinas (CAISM/UNICAMP), Campinas, SP (Brazil). Centro de Atencao Integrada a Saude da Mulher. Divisao de Radioterapia; Dias, Rodrigo Souza; Giordani, Adelmo Jose; Segreto, Helena Regina Comodo; Segreto, Roberto Araujo [Universidade Federal de Sao Paulo (EPM/UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Divisao de Radioterapia

    2016-01-15

    Objective: To evaluate the rectal volume influence on prostate motion during three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer. Materials and Methods: Fifty-one patients with prostate cancer underwent a series of three computed tomography scans including an initial planning scan and two subsequent scans during 3D-CRT. The organs of interest were outlined. The prostate contour was compared with the initial CT images considering the anterior, posterior, superior, inferior and lateral edges of the organ. Variations in the anterior limits and volume of the rectum were assessed and correlated with prostate motion in the anteroposterior direction. Results: The maximum range of prostate motion was observed in the superoinferior direction, followed by the anteroposterior direction. A significant correlation was observed between prostate motion and rectal volume variation (p = 0.037). A baseline rectal volume superior to 70 cm{sup 3} had a significant influence on the prostate motion in the anteroposterior direction (p = 0.045). Conclusion: The present study showed a significant interfraction motion of the prostate during 3D-CRT with greatest variations in the superoinferior and anteroposterior directions, and that a large rectal volume influences the prostate motion with a cutoff value of 70 cm{sup 3}. Therefore, the treatment of patients with a rectal volume > 70 cm{sup 3} should be re-planned with appropriate rectal preparation. Keywords: Rectal volume; Prostate cancer; Three-dimensional conformal radiotherapy. (author)

  13. The relationship between the bladder volume and optimal treatment planning in definitive radiotherapy for localized prostate cancer

    International Nuclear Information System (INIS)

    Nakamura, Naoki; Sekiguchi, Kenji; Akahane, Keiko; Shikama, Naoto; Takahashi, Osamu; Hama, Yukihiro; Nakagawa, Keiichi

    2012-01-01

    Background and purpose: There is no current consensus regarding the optimal bladder volumes in definitive radiotherapy for localized prostate cancer. The aim of this study was to clarify the relationship between the bladder volume and optimal treatment planning in radiotherapy for localized prostate cancer. Material and methods: Two hundred and forty-three patients underwent definitive radiotherapy with helical tomotherapy for intermediate- and high-risk localized prostate cancer. The prescribed dose defined as 95 % of the planning target volume (PTV) receiving 100 % of the prescription dose was 76 Gy in 38 fractions. The clinical target volume (CTV) was defined as the prostate with a 5-mm margin and 2 cm of the proximal seminal vesicle. The PTV was defined as the CTV with a 5-mm margin. Treatment plans were optimized to satisfy the dose constraints defined by in-house protocols for PTV and organs at risk (rectum wall, bladder wall, sigmoid colon and small intestine). If all dose constraints were satisfied, the plan was defined as an optimal plan (OP). Results: An OP was achieved with 203 patients (84%). Mean bladder volume (± 1 SD) was 266 ml (± 130 ml) among those with an OP and 214 ml (±130 ml) among those without an OP (p = 0.02). Logistic regression analysis also showed that bladder volumes below 150 ml decreased the possibility of achieving an OP. However, the percentage of patients with an OP showed a plateau effect at bladder volumes above 150 ml. Conclusions. Bladder volume is a significant factor affecting OP rates. However, our results suggest that bladder volumes exceeding 150 ml may not help meet planning dose constraints

  14. Estimation of tumor volume and its prognostic significance to study the biological behavior of carcinoma of cervix

    Directory of Open Access Journals (Sweden)

    Leelavathi Dawson

    2016-01-01

    Results: The median age of the patients in this group was 47.5 years, with a range of 30–80 years. The major histological type of carcinoma among 40 cases is squamous cell carcinoma (SCC (in 90% of cases, and 10% had adenocarcinoma. Pathological staging of the carcinoma cervix showed stage Ib, IIa, IIb, and IVa (35%, 20%, 40%, and 5%. Tumor volume estimated on pathological specimens of 40 cases ranged from 230 cumm to 49,760 cumm with a mean of 14,844 cumm. 12 (30% cases had tumor volume more than 15,000 cumm, 12 (30% cases had tumor volume <5000 cumm and 16 (40% cases had tumor volume between 5000 and 15,000 cumm. 17% of the tumors with tumor volume <5000 cumm showed lymph node metastases, whereas 67% (out of 12cases of cases with tumor volume more than 15,000 cumm showed lymph node metastases. 67% of the tumors with tumor volume <5000 cumm showed 0/4 organs involvement, whereas all cases with tumor volume more than 15,000 cumm showed more than one organ involvement among vagina, uterus, parametrium or bladder/rectum. Fibronectin positivity was seen in 22 out of 44 cases (55%. Macrophages were seen surrounding the group of tumor cells by LN5 immunostaining. Conclusion: Tumor volume can be considered as an independent prognostic factor to assess the spread of the tumor. Cases with tumor volume <5000 cumm show low risk in terms of parametrial involvement and lymph node metastasis and those with tumor volume more than 15,000 cumm showed more organ spread. Fibronectin positivity carries some importance in low-risk cases. For macrophages, further detailed study needs to be carried out.

  15. Is early detection of anastomotic leakage possible by intraperitoneal microdialysis and intraperitoneal cytokines after anterior resection of the rectum for cancer?

    Science.gov (United States)

    Matthiessen, Peter; Strand, Ida; Jansson, Kjell; Törnquist, Cathrine; Andersson, Magnus; Rutegård, Jörgen; Norgren, Lars

    2007-11-01

    This prospective study assessed methods of detecting intraperitoneal ischemia and inflammatory response in patients with and without postoperative complications after anterior resection of the rectum. In 23 patients operated on with anterior resection of the rectum for rectal carcinoma, intraperitoneal lactate, pyruvate, and glucose levels were monitored postoperatively for six days by using microdialysis with catheters applied in two locations: intraperitoneally near the anastomosis, and in the central abdominal cavity. A reference catheter was placed subcutaneously in the pectoral region. Cytokines, interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-alpha, were measured in intraperitoneal fluid by means of a pelvic drain for two postoperative days. The intraperitoneal lactate/pyruvate ratio near the anastomosis was higher on postoperative Day 5 (P = 0.029) and Day 6 (P = 0.009) in patients with clinical anastomotic leakage (n = 7) compared with patients without leakage (n = 16). The intraperitoneal levels of IL-6 (P = 0.002; P = 0.012, respectively) and IL-10 (P = 0.002; P = 0.041, respectively) were higher on postoperative Days 1 and 2 in the leakage group, and TNF-alpha was higher in the leakage group on Day 1 (P = 0.011). In-hospital clinical anastomotic leakage was diagnosed on median Day 6, and leakage after hospital discharge on median Day 20. The intraperitoneal lactate/pyruvate ratio and cytokines, IL-6, IL-10, and TNF-alpha, were increased in patients who developed symptomatic anastomotic leakage before clinical symptoms were evident.

  16. Dosimetric comparison of different dose prescription systems with CT based intracavitary brachytherapy and manual back projection technique to reconstruct the applicator

    International Nuclear Information System (INIS)

    Oinam, A.S.; Dubey, S.; Kehwar, T.S.; Rout, Sanjaya K.; Patel, F.D.; Sharma, S.C.; Goyal, D.R.; Narayan, P.

    2002-01-01

    Intracavitary brachytherapy is one of the well-established techniques for the treatment of carcinoma of cervix. The prediction of late effect of normal tissue like rectum and bladder needs the defining of the volume of the bladder and rectum in situ. In the normal planning of intracavitary and interstitial implants, simulated radiograph films are used to reconstruct the applicator geometry and dose points to represent the dose to critical organs. CT based brachytherapy can define such volume instead of defining dose points, which represent the dose to these critical organs

  17. Analysis of dose volume histogram parameters to estimate late bladder and rectum complications after high-dose (70-78 Gy) conformal radiotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Boersma, L.J.; Brink, M. van den; Bruce, A.; Gras, L.; Velde, A. te; Lebesque, J.V.

    1997-01-01

    Purpose: To investigate whether Dose Volume Histogram (DVH) parameters can be used to identify risk groups for developing late gastrointestinal (GI) and genitourinary (GU) complications after conformal radiotherapy for prostate cancer, and to examine the effect of using different morbidity scoring systems on the results of these analyses. Materials and Methods: DVH parameters were analyzed for 130 patients with localized prostate cancer, treated with conformal radiotherapy in a dose-escalating protocol (70-78 Gy, 2 Gy per fraction). The incidence of late (> 6 months) GI and GU complications was scored based on questionnaires and classified using the RTOG/EORTC and the SOMA/LENT scoring system. Moreover, patients were classified as being a rectal bleeder or no rectal bleeder and a distinction was made between non-severe and severe (requiring one or more laser treatments) rectal bleeding. The median follow-up time was 22 months. It was investigated whether the relative and absolute rectal wall volumes, irradiated to various dose levels (≥ 60 Gy, ≥ 65 Gy, ≥ 70 Gy and ≥ 75 Gy) were correlated with the observed actuarial incidences of GI complications. First, the analysis was performed using volume as a continuous variable. Subsequently, for each dose level in the DVH the rectal wall volumes were dichotomized using different volumes as cut-off levels. Twenty cut-off levels were tested on their ability to discriminate between high and low risk for developing GI complications (Fig.). The relationship between bladder wall volumes irradiated to various dose levels and observed actuarial GU complications was investigated using the absolute bladder wall volumes, measured as a continuous variable. For both GI and GU complications, the role of the prescribed radiation dose and the maximum radiation dose in the rectal and bladder wall was analyzed as well. Results: None of the DVH parameters of the rectal wall was significantly correlated with the actuarial incidences of

  18. Pneumaturia signaling a fistula between the rectum anastomosis and seminal vesicle as a complication after transanal endorectal pull-through operation for Hirschsprung's disease. A method of repair

    Directory of Open Access Journals (Sweden)

    Christina Granéli

    2014-09-01

    Full Text Available A 2-year-old boy underwent an uneventful transanal endorectal pull-through for Hirschsprung's disease. Postoperatively he suffered from pneumaturia which prompted surgical evaluation. He was found to have a rectum to seminal vesicle fistula. He was re-operated closing the fistula through an anterior transperineal approach with a successful operative outcome.

  19. Late radiation injury of the colon and rectum. Surgical management and outcome

    International Nuclear Information System (INIS)

    Kimose, H.H.; Fischer, L.; Spjeldnaes, N.; Wara, P.

    1989-01-01

    After a median latency of 2 years, the initial late colorectal radiation injuries in 182 patients were: stricture (37 percent), minor lesions (36 percent), rectovaginal fistula (22 percent), and gangrene or other fistulas (5 percent). Due to progression, new colorectal injuries, primarily stricture (55 percent) and fistula (42 percent), occurred in 68 patients (37 percent). Resection provided the best results. However, the resectability rate was low (46 percent) and resection was primarily performed in patients with a circumscript well-defined stricture of the proximal rectum or sigmoid colon with an anastomotic leakage rate of 5 percent. The prevailing management of 78 patients with fistula or stricture with synchronous fistula was defunctioning colostomy, primarily end-sigmoidostomy, providing fair results in half of the patients. Stomal complications occurred in 15 percent. The radiation-induced colorectal mortality was 8 percent. Colorectal fistula and associated radiation injuries of the urinary tract, and especially of the small bowel, were the major determinants of fatal outcome, yielding an overall radiation-induced mortality of 25 percent. After a median observation time of 13 years, half of the patients were alive at follow-up; 56 percent of these had a fair outcome whereas the remaining patients continued to have mild symptoms responding to conservative measures (34 percent) or disabling symptoms (10 percent)

  20. Estimation of the incidence of late bladder and rectum complications after high-dose (70-78 Gy) conformal radiotherapy for prostate cancer, using dose-volume histograms

    International Nuclear Information System (INIS)

    Boersma, Liesbeth J.; Brink, Mandy van den; Bruce, Allison M.; Shouman, Tarek; Gras, Luuk; Velde, Annet te; Lebesque, Joos V.

    1998-01-01

    Purpose: To investigate whether Dose-Volume Histogram (DVH) parameters can be used to identify risk groups for developing late gastrointestinal (GI) and genitourinary (GU) complications after conformal radiotherapy for prostate cancer. Methods and Materials: DVH parameters were analyzed for 130 patients with localized prostate cancer, treated with conformal radiotherapy in a dose-escalating protocol (70-78 Gy, 2 Gy per fraction). The incidence of late (>6 months) GI and GU complications was classified using the RTOG/EORTC and the SOMA/LENT scoring system. In addition, GI complications were divided in nonsevere and severe (requiring one or more laser treatments or blood transfusions) rectal bleeding. The median follow-up time was 24 months. We investigated whether rectal and bladder wall volumes, irradiated to various dose levels, correlated with the observed actuarial incidences of GI and GU complications, using volume as a continuous variable. Subsequently, for each dose level in the DVH, the rectal wall volumes were dichotomized using different volumes as cutoff levels. The impact of the total radiation dose, and the maximum radiation dose in the rectal and bladder wall was analyzed as well. Results: The actuarial incidence at 2 years for GI complications ≥Grade II was 14% (RTOG/EORTC) or 20% (SOMA/LENT); for GU complications ≥Grade III 8% (RTOG/EORTC) or 21% (SOMA/LENT). Neither for GI complications ≥Grade II (RTOG/EORTC or SOMA/LENT), nor for GU complications ≥Grade III (RTOG/EORTC or SOMA/LENT), was a significant correlation found between any of the DVH parameters and the actuarial incidence of complications. For severe rectal bleeding (actuarial incidence at 2 years 3%), four consecutive volume cutoff levels were found, which significantly discriminated between high and low risk. A trend was observed that a total radiation dose ≥ 74 Gy (or a maximum radiation dose in the rectal wall >75 Gy) resulted in a higher incidence of severe rectal bleeding (p

  1. The role of tumor markers (CEA, TPA, CA 19-9) in colon and rectum carcinomas

    International Nuclear Information System (INIS)

    Cangemi, V.; Volpino, P.; Fiori, E.; Giammarco, A.; Piat, G.

    1987-01-01

    We have evaluated the diagnostic efficacy (sensitivity, specificity, accuracy, predictive malignancy index) of CEA, TPA, CA 19-9 in colon and rectum tumors (56 cases), the difference in behaviour of these markers in relation to the stage and grading of the cancer, their reliability regarding postsurgical relapses and/or metastases. The sensitivity of CEA (>10 ng/ml), TPA (>130 U/L), CA 19-9 (>37 u/ml) for diagnostic purpose was rather limited (28.6% - 30% - 18.5%) with a malignancy prediction value of 100% - 81.8% - 62.5%. With regard to relapses and/or metastases, the diagnostic efficacy of the marker proved to be evident only for CEA, TPA, CA 19-9 value greater than 25 ng/ml, 250 U/L and 100 u/ml. The use of thethree markers together was certainly an advantage both for primitive tumors (sensitivity: 52.8%) and relapses and/or metastases after surgery (sensitivity: 66.7%)

  2. A Dose-Volume Analysis of Magnetic Resonance Imaging-Aided High-Dose-Rate Image-Based Interstitial Brachytherapy for Uterine Cervical Cancer

    International Nuclear Information System (INIS)

    Yoshida, Ken; Yamazaki, Hideya; Takenaka, Tadashi; Kotsuma, Tadayuki; Yoshida, Mineo; Furuya, Seiichi; Tanaka, Eiichi; Uegaki, Tadaaki; Kuriyama, Keiko; Matsumoto, Hisanobu; Yamada, Shigetoshi; Ban, Chiaki

    2010-01-01

    Purpose: To investigate the feasibility of our novel image-based high-dose-rate interstitial brachytherapy (HDR-ISBT) for uterine cervical cancer, we evaluated the dose-volume histogram (DVH) according to the recommendations of the Gynecological GEC-ESTRO Working Group for image-based intracavitary brachytherapy (ICBT). Methods and Materials: Between June 2005 and June 2007, 18 previously untreated cervical cancer patients were enrolled. We implanted magnetic resonance imaging (MRI)-available plastic applicators by our unique ambulatory technique. Total treatment doses were 30-36 Gy (6 Gy per fraction) combined with external beam radiotherapy (EBRT). Treatment plans were created based on planning computed tomography with MRI as a reference. DVHs of the high-risk clinical target volume (HR CTV), intermediate-risk CTV (IR CTV), and the bladder and rectum were calculated. Dose values were biologically normalized to equivalent doses in 2-Gy fractions (EQD 2 ). Results: The median D90 (HR CTV) and D90 (IR CTV) per fraction were 6.8 Gy (range, 5.5-7.5) and 5.4 Gy (range, 4.2-6.3), respectively. The median V100 (HR CTV) and V100 (IR CTV) were 98.4% (range, 83-100) and 81.8% (range, 64-93.8), respectively. When the dose of EBRT was added, the median D90 and D100 of HR CTV were 80.6 Gy (range, 65.5-96.6) and 62.4 Gy (range, 49-83.2). The D 2cc of the bladder was 62 Gy (range, 51.4-89) and of the rectum was 65.9 Gy (range, 48.9-76). Conclusions: Although the targets were advanced and difficult to treat effectively by ICBT, MRI-aided image-based ISBT showed favorable results for CTV and organs at risk compared with previously reported image-based ICBT results.

  3. A dose-volume analysis of magnetic resonance imaging-aided high-dose-rate image-based interstitial brachytherapy for uterine cervical cancer.

    Science.gov (United States)

    Yoshida, Ken; Yamazaki, Hideya; Takenaka, Tadashi; Kotsuma, Tadayuki; Yoshida, Mineo; Furuya, Seiichi; Tanaka, Eiichi; Uegaki, Tadaaki; Kuriyama, Keiko; Matsumoto, Hisanobu; Yamada, Shigetoshi; Ban, Chiaki

    2010-07-01

    To investigate the feasibility of our novel image-based high-dose-rate interstitial brachytherapy (HDR-ISBT) for uterine cervical cancer, we evaluated the dose-volume histogram (DVH) according to the recommendations of the Gynecological GEC-ESTRO Working Group for image-based intracavitary brachytherapy (ICBT). Between June 2005 and June 2007, 18 previously untreated cervical cancer patients were enrolled. We implanted magnetic resonance imaging (MRI)-available plastic applicators by our unique ambulatory technique. Total treatment doses were 30-36 Gy (6 Gy per fraction) combined with external beam radiotherapy (EBRT). Treatment plans were created based on planning computed tomography with MRI as a reference. DVHs of the high-risk clinical target volume (HR CTV), intermediate-risk CTV (IR CTV), and the bladder and rectum were calculated. Dose values were biologically normalized to equivalent doses in 2-Gy fractions (EQD(2)). The median D90 (HR CTV) and D90 (IR CTV) per fraction were 6.8 Gy (range, 5.5-7.5) and 5.4 Gy (range, 4.2-6.3), respectively. The median V100 (HR CTV) and V100 (IR CTV) were 98.4% (range, 83-100) and 81.8% (range, 64-93.8), respectively. When the dose of EBRT was added, the median D90 and D100 of HR CTV were 80.6 Gy (range, 65.5-96.6) and 62.4 Gy (range, 49-83.2). The D(2cc) of the bladder was 62 Gy (range, 51.4-89) and of the rectum was 65.9 Gy (range, 48.9-76). Although the targets were advanced and difficult to treat effectively by ICBT, MRI-aided image-based ISBT showed favorable results for CTV and organs at risk compared with previously reported image-based ICBT results. (c) 2010 Elsevier Inc. All rights reserved.

  4. Late rectal toxicity: dose-volume effects of conformal radiotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Huang, Eugene H.; Pollack, Alan; Levy, Larry; Starkschall, George; Lei Dong; Rosen, Isaac; Kuban, Deborah A.

    2002-01-01

    Purpose: To identify dosimetric, anatomic, and clinical factors that correlate with late rectal toxicity after three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer. Methods and Materials: We retrospectively analyzed the dose-volume histograms and clinical records of 163 Stage T1b-T3c prostate cancer patients treated between 1992 and 1999 with 3D-CRT, to a total isocenter dose of 74-78 Gy at The University of Texas M. D. Anderson Cancer Center. The median follow-up was 62 months (range 24-102). All late rectal complications were scored using modified Radiation Therapy Oncology Group and Late Effects Normal Tissue Task Force criteria. The 6-year toxicity rate was assessed using Kaplan-Meier analysis and the log-rank test. A univariate proportional hazards regression model was used to test the correlation between Grade 2 or higher toxicity and the dosimetric, anatomic, and clinical factors. In a multivariate regression model, clinical factors were added to the dosimetric and anatomic variables to determine whether they significantly altered the risk of developing late toxicity. Results: At 6 years, the rate of developing Grade 2 or higher late rectal toxicity was 25%. A significant volume effect was observed at rectal doses of 60, 70, 75.6, and 78 Gy, and the risk of developing rectal complications increased exponentially as greater volumes were irradiated. Although the percentage of rectal volume treated correlated significantly with the incidence of rectal complications at all dose levels (p 3 of the rectum. Of the clinical variables tested, only a history of hemorrhoids correlated with rectal toxicity (p=0.003). Multivariate analysis showed that the addition of hemorrhoids increased the risk of toxicity for each dosimetric variable found to be significant on univariate analysis (p<0.05 for all comparisons). Conclusion: Dose-volume histogram analyses clearly indicated a volume effect on the probability of developing late rectal complications

  5. Inter-fractional Target Displacement in the Prostate Image-Guided Radiotherapy using Cone Beam Computed Tomography

    International Nuclear Information System (INIS)

    Dong, Kap Sang; Back, Chang Wook; Jeong, Yun Jeong; Bae, Jae Beom; Choi, Young Eun; Sung, Ki Hoon

    2016-01-01

    To quantify the inter-fractional variation in prostate displacement and their dosimetric effects for prostate cancer treatment. A total of 176 daily cone-beam CT (CBCT) sets acquired for 6 prostate cancer patients treated with volumetric-modulated arc therapy (VMAT) were retrospectively reviewed. For each patient, the planning CT (pCT) was registered to each daily CBCT by aligning the bony anatomy. The prostate, rectum, and bladder were delineated on daily CBCT, and the contours of these organs in the pCT were copied to the daily CBCT. The concordance of prostate displacement, deformation, and size variation between pCT and daily CBCT was evaluated using the Dice similarity coefficient (DSC). The mean volume of prostate was 37.2 cm3 in the initial pCT, and the variation was around ±5% during the entire course of treatment for all patients. The mean DSC was 89.9%, ranging from 70% to 100% for prostate displacement. Although the volume change of bladder and rectum per treatment fraction did not show any correlation with the value of DSC (r=-0.084, p=0.268 and r=-0.162, p=0.032, respectively), a decrease in the DSC value was observed with increasing volume change of the bladder and rectum (r=-0.230,p=0.049 and r=-0.240,p=0.020, respectively). Consistency of the volume of the bladder and rectum cannot guarantee the accuracy of the treatment. Our results suggest that patient setup with the registration between the pCT and daily CBCT should be considered aligning soft tissue

  6. Inter-fractional Target Displacement in the Prostate Image-Guided Radiotherapy using Cone Beam Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Kap Sang; Back, Chang Wook; Jeong, Yun Jeong; Bae, Jae Beom; Choi, Young Eun; Sung, Ki Hoon [Dept. of Radiation Oncology, Gachon University Gil Medical Center, Incheon (Korea, Republic of)

    2016-12-15

    To quantify the inter-fractional variation in prostate displacement and their dosimetric effects for prostate cancer treatment. A total of 176 daily cone-beam CT (CBCT) sets acquired for 6 prostate cancer patients treated with volumetric-modulated arc therapy (VMAT) were retrospectively reviewed. For each patient, the planning CT (pCT) was registered to each daily CBCT by aligning the bony anatomy. The prostate, rectum, and bladder were delineated on daily CBCT, and the contours of these organs in the pCT were copied to the daily CBCT. The concordance of prostate displacement, deformation, and size variation between pCT and daily CBCT was evaluated using the Dice similarity coefficient (DSC). The mean volume of prostate was 37.2 cm3 in the initial pCT, and the variation was around ±5% during the entire course of treatment for all patients. The mean DSC was 89.9%, ranging from 70% to 100% for prostate displacement. Although the volume change of bladder and rectum per treatment fraction did not show any correlation with the value of DSC (r=-0.084, p=0.268 and r=-0.162, p=0.032, respectively), a decrease in the DSC value was observed with increasing volume change of the bladder and rectum (r=-0.230,p=0.049 and r=-0.240,p=0.020, respectively). Consistency of the volume of the bladder and rectum cannot guarantee the accuracy of the treatment. Our results suggest that patient setup with the registration between the pCT and daily CBCT should be considered aligning soft tissue.

  7. The effect of tandem-ovoid titanium applicator on points A, B, bladder, and rectum doses in gynecological brachytherapy using 192Ir.

    Science.gov (United States)

    Sadeghi, Mohammad Hosein; Sina, Sedigheh; Mehdizadeh, Amir; Faghihi, Reza; Moharramzadeh, Vahed; Meigooni, Ali Soleimani

    2018-02-01

    The dosimetry procedure by simple superposition accounts only for the self-shielding of the source and does not take into account the attenuation of photons by the applicators. The purpose of this investigation is an estimation of the effects of the tandem and ovoid applicator on dose distribution inside the phantom by MCNP5 Monte Carlo simulations. In this study, the superposition method is used for obtaining the dose distribution in the phantom without using the applicator for a typical gynecological brachytherapy (superposition-1). Then, the sources are simulated inside the tandem and ovoid applicator to identify the effect of applicator attenuation (superposition-2), and the dose at points A, B, bladder, and rectum were compared with the results of superposition. The exact dwell positions, times of the source, and positions of the dosimetry points were determined in images of a patient and treatment data of an adult woman patient from a cancer center. The MCNP5 Monte Carlo (MC) code was used for simulation of the phantoms, applicators, and the sources. The results of this study showed no significant differences between the results of superposition method and the MC simulations for different dosimetry points. The difference in all important dosimetry points was found to be less than 5%. According to the results, applicator attenuation has no significant effect on the calculated points dose, the superposition method, adding the dose of each source obtained by the MC simulation, can estimate the dose to points A, B, bladder, and rectum with good accuracy.

  8. Public Reporting of Hospital-Level Cancer Surgical Volumes in California: An Opportunity to Inform Decision Making and Improve Quality.

    Science.gov (United States)

    Clarke, Christina A; Asch, Steven M; Baker, Laurence; Bilimoria, Karl; Dudley, R Adams; Fong, Niya; Holliday-Hanson, Merry L; Hopkins, David S P; Imholz, Elizabeth M; Malin, Jennifer; Moy, Lisa; O'Sullivan, Maryann; Parker, Joseph P; Saigal, Christopher S; Spurlock, Bruce; Teleki, Stephanie; Zingmond, David; Lang, Lance

    2016-10-01

    Most patients, providers, and payers make decisions about cancer hospitals without any objective data regarding quality or outcomes. We developed two online resources allowing users to search and compare timely data regarding hospital cancer surgery volumes. Hospital cancer surgery volumes for all California hospitals were calculated using ICD-9 coded hospital discharge summary data. Cancer surgeries included (bladder, brain, breast, colon, esophagus, liver, lung, pancreas, prostate, rectum, and stomach) were selected on the basis of a rigorous literature review to confirm sufficient evidence of a positive association between volume and mortality. The literature could not identify threshold numbers of surgeries associated with better or worse outcomes. A multidisciplinary working group oversaw the project and ensured sound methodology. In California in 2014, about 60% of surgeries were performed at top-quintile-volume hospitals, but the per-hospital median numbers of surgeries for esophageal, pancreatic, stomach, liver, or bladder cancer surgeries were four or fewer. At least 670 patients received cancer surgery at hospitals that performed only one or two surgeries for a particular cancer type; 72% of those patients lived within 50 miles of a top-quintile-volume hospital. There is clear potential for more readily available information about hospital volumes to help patient, providers, and payers choose cancer surgery hospitals. Our successful public reporting of hospital volumes in California represents an important first step toward making publicly available even more provider-specific data regarding cancer care quality, costs, and outcomes, so those data can inform decision-making and encourage quality improvement.

  9. An Adaptive Off-Line Procedure for Radiotherapy of Prostate Cancer

    International Nuclear Information System (INIS)

    Nuver, Tonnis T.; Hoogeman, Mischa S.; Remeijer, Peter; Herk, Marcel van; Lebesque, Joos V.

    2007-01-01

    Purpose: To determine the planning target volume (PTV) margin for an adaptive radiotherapy procedure that uses five computed tomography (CT) scans to calculate an average prostate position and rectum shape. To evaluate alternative methods to determine an average rectum based on a single delineation. Methods and Materials: Repeat CT scans (8-13) of 19 patients were used. The contoured prostates of the first four scans were matched on the planning CT (pCT) prostate contours. With the resulting translations and rotations the average prostate position was determined. An average rectum was obtained by either averaging the coordinates of corresponding points on the rectal walls or by selecting the 'best' rectum or transforming the pCT rectum. Dose distributions were calculated for various expanded average prostates. The remaining CT scans were used to determine the dose received by prostate and rectum during treatment. Results: For the prostate of the pCT scan and a 10-mm margin, all patients received more than 95% of the prescribed dose to 95% of the prostate. For the average prostate, a margin of 7 mm was needed to obtain a similar result (average PTV reduction 30%). The average rectum overestimated the mean dose to the rectum by 0.4 ± 1.6 Gy, which was better than the pCT rectum (2.1 ± 3.0 Gy) and the alternative average rectums (1.0 ± 2.6 Gy and 1.4 ± 3.2 Gy). Conclusions: Our adaptive procedure allows for reduction of the PTV margin to 7 mm without decreasing prostate coverage during treatment. For accurate estimation of the rectum dose, rectums need to be delineated and averaged over multiple scans

  10. SU-F-T-35: Optimization of Bladder and Rectal Doses Using a Multi-Lumen Intracavitary Applicator for Gynecological Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Laoui, S; Dietrich, S; Sehgal, V; Al-Ghazi, M [University of California, Irvine, Orange, CA (United States)

    2016-06-15

    Purpose: Radiation dose delivery for endometrial cancer using HDR techniques is limited by dose to bladder and rectum. A dosimetric study was performed using Varian Capri vaginal brachytherapy applicator to determine the optimal channel configuration which minimizes dose to bladder and rectum, while providing good target coverage. Methods: A total of 17 patients, 63 plans clinically delivered, and 252 simulated plans using Varian BrachyVision planning system were generated to investigate optimal channel configuration which results in minimum dose to bladder and rectum while providing adequate target coverage. The Capri applicator consists of 13 lumens arranged in two concentric rings, one central lumen and six lumens per ring. Manual dose shaping is invariably required to lower the dose to critical organs. Three-dimensional plans were simulated for 4 channel arrangements, all 13 channels, channel 12 o’clock (close to bladder) and 6 o’clock (close to rectum) deactivated, central channel deactivated, and central channel in addition to 12 o’clock and 6 o’clock deactivated. A relationship between V100, the volume that receives the prescribed dose, and the amount of curie-seconds required to deliver it, was established. Results: Using all 13 channels results in maximum dose to bladder and rectum. Deactivating central channel in addition to 12 o’clock and 6 o’clock resulted in minimizing bladder and rectum doses but compromised target coverage. The relationship between V100, the volume that receives the prescribed dose, and the curie seconds was found to be linear. Conclusion: Deactivating channels 12 o’clock and 6 o’clock was shown to be the optimal configuration leading to minimum dose to bladder and rectum without compromising target coverage. The linear relationship between V100 and the curie- seconds can be used as a verification parameter.

  11. Is Dose Deformation–Invariance Hypothesis Verified in Prostate IGRT?

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Antoine, E-mail: antoine.simon@univ-rennes1.fr [INSERM, U1099, 35000 Rennes (France); Laboratoire Traitement du Signal et de l' Image, Université de Rennes 1, 35000 Rennes (France); Le Maitre, Amandine; Nassef, Mohamed; Rigaud, Bastien [INSERM, U1099, 35000 Rennes (France); Laboratoire Traitement du Signal et de l' Image, Université de Rennes 1, 35000 Rennes (France); Castelli, Joël [INSERM, U1099, 35000 Rennes (France); Laboratoire Traitement du Signal et de l' Image, Université de Rennes 1, 35000 Rennes (France); Department of Radiotherapy, Centre Eugène Marquis, 35000 Rennes (France); Acosta, Oscar; Haigron, Pascal [INSERM, U1099, 35000 Rennes (France); Laboratoire Traitement du Signal et de l' Image, Université de Rennes 1, 35000 Rennes (France); Lafond, Caroline; Crevoisier, Renaud de [INSERM, U1099, 35000 Rennes (France); Laboratoire Traitement du Signal et de l' Image, Université de Rennes 1, 35000 Rennes (France); Department of Radiotherapy, Centre Eugène Marquis, 35000 Rennes (France)

    2017-03-15

    Purpose: To assess dose uncertainties resulting from the dose deformation–invariance hypothesis in prostate cone beam computed tomography (CT)–based image guided radiation therapy (IGRT), namely to evaluate whether rigidly propagated planned dose distribution enables good estimation of fraction dose distributions. Methods and Materials: Twenty patients underwent a CT scan for planning intensity modulated radiation therapy–IGRT delivering 80 Gy to the prostate, followed by weekly CT scans. Two methods were used to obtain the dose distributions on the weekly CT scans: (1) recalculating the dose using the original treatment plan; and (2) rigidly propagating the planned dose distribution. The cumulative doses were then estimated in the organs at risk for each dose distribution by deformable image registration. The differences between recalculated and propagated doses were finally calculated for the fraction and the cumulative dose distributions, by use of per-voxel and dose-volume histogram (DVH) metrics. Results: For the fraction dose, the mean per-voxel absolute dose difference was <1 Gy for 98% and 95% of the fractions for the rectum and bladder, respectively. The maximum dose difference within 1 voxel reached, however, 7.4 Gy in the bladder and 8.0 Gy in the rectum. The mean dose differences were correlated with gas volume for the rectum and patient external contour variations for the bladder. The mean absolute differences for the considered volume receiving greater than or equal to dose x (V{sub x}) of the DVH were between 0.37% and 0.70% for the rectum and between 0.53% and 1.22% for the bladder. For the cumulative dose, the mean differences in the DVH were between 0.23% and 1.11% for the rectum and between 0.55% and 1.66% for the bladder. The largest dose difference was 6.86%, for bladder V{sub 80Gy}. The mean dose differences were <1.1 Gy for the rectum and <1 Gy for the bladder. Conclusions: The deformation–invariance hypothesis was

  12. A comparative study of set up variations and bowel volumes in supine versus prone positions of patients treated with external beam radiation for carcinoma rectum.

    Science.gov (United States)

    Rajeev, K R; Menon, Smrithy S; Beena, K; Holla, Raghavendra; Kumar, R Rajaneesh; Dinesh, M

    2014-01-01

    A prospective study was undertaken to evaluate the influence of patient positioning on the set up variations to determine the planning target volume (PTV) margins and to evaluate the clinical relevance volume assessment of the small bowel (SB) within the irradiated volume. During the period of months from December 2011 to April 2012, a computed tomography (CT) scan was done either in supine position or in prone position using a belly board (BB) for 20 consecutive patients. All the patients had histologically proven rectal cancer and received either post- or pre-operative pelvic irradiation. Using a three-dimensional planning system, the dose-volume histogram for SB was defined in each axial CT slice. Total dose was 46-50 Gy (2 Gy/fraction), delivered using the 4-field box technique. The set up variation of the study group was assessed from the data received from the electronic portal imaging device in the linear accelerator. The shift along X, Y, and Z directions were noted. Both systematic and random errors were calculated and using both these values the PTV margin was calculated. The systematic errors of patients treated in the supine position were 0.87 (X-mm), 0.66 (Y-mm), 1.6 (Z-mm) and in the prone position were 1.3 (X-mm), 0.59 (Y-mm), 1.17 (Z-mm). The random errors of patients treated in the supine positions were 1.81 (X-mm), 1.73 (Y-mm), 1.83 (Z-mm) and in prone position were 2.02 (X-mm), 1.21 (Y-mm), 3.05 (Z-mm). The calculated PTV margins in the supine position were 3.45 (X-mm), 2.87 (Y-mm), 5.31 (Z-mm) and in the prone position were 4.91 (X-mm), 2.32 (Y-mm), 5.08 (Z-mm). The mean volume of the peritoneal cavity was 648.65 cm 3 in the prone position and 1197.37 cm 3 in the supine position. The prone position using BB device was more effective in reducing irradiated SB volume in rectal cancer patients. There were no significant variations in the daily set up for patients treated in both supine and prone positions.

  13. Validation of multi-detector computed tomography as a non-invasive method for measuring ovarian volume in macaques (Macaca fascicularis).

    Science.gov (United States)

    Jones, Jeryl C; Appt, Susan E; Werre, Stephen R; Tan, Joshua C; Kaplan, Jay R

    2010-06-01

    The purpose of this study was to validate low radiation dose, contrast-enhanced, multi-detector computed tomography (MDCT) as a non-invasive method for measuring ovarian volume in macaques. Computed tomography scans of four known-volume phantoms and nine mature female cynomolgus macaques were acquired using a previously described, low radiation dose scanning protocol, intravenous contrast enhancement, and a 32-slice MDCT scanner. Immediately following MDCT, ovaries were surgically removed and the ovarian weights were measured. The ovarian volumes were determined using water displacement. A veterinary radiologist who was unaware of actual volumes measured ovarian CT volumes three times, using a laptop computer, pen display tablet, hand-traced regions of interest, and free image analysis software. A statistician selected and performed all tests comparing the actual and CT data. Ovaries were successfully located in all MDCT scans. The iliac arteries and veins, uterus, fallopian tubes, cervix, ureters, urinary bladder, rectum, and colon were also consistently visualized. Large antral follicles were detected in six ovaries. Phantom mean CT volume was 0.702+/-SD 0.504 cc and the mean actual volume was 0.743+/-SD 0.526 cc. Ovary mean CT volume was 0.258+/-SD 0.159 cc and mean water displacement volume was 0.257+/-SD 0.145 cc. For phantoms, the mean coefficient of variation for CT volumes was 2.5%. For ovaries, the least squares mean coefficient of variation for CT volumes was 5.4%. The ovarian CT volume was significantly associated with actual ovarian volume (ICC coefficient 0.79, regression coefficient 0.5, P=0.0006) and the actual ovarian weight (ICC coefficient 0.62, regression coefficient 0.6, P=0.015). There was no association between the CT volume accuracy and mean ovarian CT density (degree of intravenous contrast enhancement), and there was no proportional or fixed bias in the CT volume measurements. Findings from this study indicate that MDCT is a valid non

  14. Volume and health outcomes: evidence from systematic reviews and from evaluation of Italian hospital data.

    Science.gov (United States)

    Amato, Laura; Fusco, Danilo; Acampora, Anna; Bontempi, Katia; Rosa, Alessandro Cesare; Colais, Paola; Cruciani, Fabio; D'Ovidio, Mariangela; Mataloni, Francesca; Minozzi, Silvia; Mitrova, Zuzana; Pinnarelli, Luigi; Saulle, Rosella; Soldati, Salvatore; Sorge, Chiara; Vecchi, Simona; Ventura, Martina; Davoli, Marina

    2017-01-01

    on the association between volume and outcome. Analysis of the distribution of Italian hospitals by volume of activity and the association between volume of activity and outcomes: the Italian National Outcome evaluation Programme 2016 The analyses were performed using the Hospital Information System and the National Tax Register (year 2015). For each condition, the number of hospitals by volume of activity was calculated. Hospitals with a volume lower than 3-5 cases/year were excluded. For conditions with more than 1,500 cases/year and frequency of outcome ≥1%, the association between volume of care and outcome was analyzed estimating risk-adjusted outcomes. RESULTS Bibliographic searches identified 80 reviews, evaluating 48 different clinical areas. The main outcome considered was intrahospital/30-day mortality. The other outcomes vary depending on the type of condition or intervention in study. The relationship between hospital volume and outcomes was considered in 47 out of 48 conditions: 34 conditions showed evidence of a positive association; • 14 conditions consider cancer surgery for bladder, breast, colon, rectum, colon rectum, oesophagus, kidney, liver, lung, ovaries, pancreas, prostate, stomach, head and neck; • 11 conditions consider cardiocerebrovascular area: nonruptured and ruptured abdominal aortic aneurysm, acute myocardial infarction, brain aneurysm, carotid endarterectomy, coronary angioplasty, coronary artery bypass, paediatric heart surgery, revascularization of lower limbs, stroke, subarachnoid haemorrhage; • 2 conditions consider orthopaedic area: knee arthroplasty, hip fracture; • 7 conditions consider other areas: AIDS, bariatric surgery, cholecystectomy, intensive care unit, neonatal intensive care unit, sepsis, and traumas; for 3 conditions, no association was demonstrated: hip arthroplasty, dialysis, and thyroidectomy. for the remaining 10 conditions, the available evidence does not allow to draw firm conclusions about the

  15. The effect of 6 and 15 MV on intensity-modulated radiation therapy prostate cancer treatment: plan evaluation, tumour control probability and normal tissue complication probability analysis, and the theoretical risk of secondary induced malignancies

    Science.gov (United States)

    Hussein, M; Aldridge, S; Guerrero Urbano, T; Nisbet, A

    2012-01-01

    Objective The aim of this study was to investigate the effect of 6 and 15-MV photon energies on intensity-modulated radiation therapy (IMRT) prostate cancer treatment plan outcome and to compare the theoretical risks of secondary induced malignancies. Methods Separate prostate cancer IMRT plans were prepared for 6 and 15-MV beams. Organ-equivalent doses were obtained through thermoluminescent dosemeter measurements in an anthropomorphic Aldersen radiation therapy human phantom. The neutron dose contribution at 15 MV was measured using polyallyl-diglycol-carbonate neutron track etch detectors. Risk coefficients from the International Commission on Radiological Protection Report 103 were used to compare the risk of fatal secondary induced malignancies in out-of-field organs and tissues for 6 and 15 MV. For the bladder and the rectum, a comparative evaluation of the risk using three separate models was carried out. Dose–volume parameters for the rectum, bladder and prostate planning target volume were evaluated, as well as normal tissue complication probability (NTCP) and tumour control probability calculations. Results There is a small increased theoretical risk of developing a fatal cancer from 6 MV compared with 15 MV, taking into account all the organs. Dose–volume parameters for the rectum and bladder show that 15 MV results in better volume sparing in the regions below 70 Gy, but the volume exposed increases slightly beyond this in comparison with 6 MV, resulting in a higher NTCP for the rectum of 3.6% vs 3.0% (p=0.166). Conclusion The choice to treat using IMRT at 15 MV should not be excluded, but should be based on risk vs benefit while considering the age and life expectancy of the patient together with the relative risk of radiation-induced cancer and NTCPs. PMID:22010028

  16. Dosimetric uncertainties related to the elasticity of bladder and rectal walls: Adenocarcinoma of the prostate; Incertitudes dosimetriques relatives a l'elasticite de la paroi rectale et vesicale: adenocarcinome de la prostate

    Energy Technology Data Exchange (ETDEWEB)

    Voyant, C. [University of Corsica, Campus Grimaldi, 20250 Corte (France); CNRS UMR SPE 6134, University of Corsica, Campus Grimaldi, 20250 Corte (France); Radiotherapy Unit, Hospital of Castelluccio, BP 85, 20177 Ajaccio (France); Biffi, K.; Leschi, D.; Briancon, J.; Lantieri, C. [Radiotherapy Unit, Hospital of Castelluccio, BP 85, 20177 Ajaccio (France)

    2011-07-15

    Purpose. - Radiotherapy is an important treatment for prostate cancer. During treatment sessions, bladder and rectal repletion is difficult to quantify and cannot be measured with a single and initial CT scan acquisition. Some methods, such as image-guided radiation therapy and dose-guided radiation therapy, aim to compensate this missing information through periodic CT acquisitions. The aim is to adapt patient's position, beam configuration or prescribed dose for a dosimetric compliance. Methods. - We evaluated organ motion (and repletion) for 54 patients after having computed the original ballistic on a new CT scan acquisition. A new delineation was done on the prostate, bladder and rectum to determine the new displacements and define organ doses mistakes (equivalent uniform dose, average dose and dose-volume histograms). Results. - The new CT acquisitions confirmed that bladder and rectal volumes were not constant during sessions. Some cases showed that previously validated treatment plan became unsuitable. A proposed solution is to correct dosimetries when bladder volume modifications are significant. The result is an improvement for the stability of bladder doses, D50 error is reduced by 25.3%, mean dose error by 5.1% and equivalent uniform dose error by 2.6%. For the rectum this method decreases errors by only 1%. This process can reduce the risk of mismatch between the initial scan and following treatment sessions. Conclusion. - For the proposed method, the cone-beam CT is necessary to properly position the isocenter and to quantify bladder and rectal volume variation and deposited doses. The dosimetries are performed in the event that bladder (or rectum) volume modification limits are exceeded. To identify these limits, we have calculated that a tolerance of 10% for the equivalent uniform dose (compared to the initial value of the first dosimetry), this represents 11% of obsolete dosimetries for the bladder, and 4% for the rectum. (authors)

  17. Normal tissue tolerance to external beam radiation therapy: Rectum; Dose de tolerance a l'irradiation des tissus sains: le rectum

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, P. [Departement de radiotherapie, institut Gustave-Roussy, 94 - Villejuif (France); Chapet, O. [Service d' oncologie-radiotherapie, centre hospitalier Lyon-Sud, 69 - Pierre-Benite (France)

    2010-07-15

    Radiation proctitis is among the most frequent radiation-induced toxicities. This is related to the high frequency of pelvic tumours and the key role of radiotherapy in the treatment of these tumours. Late rectal toxicity usually occurs within the first two years after the completion of a radiotherapy course. Rectal bleeding and a rectal syndrome are the main symptoms, and can be associated to fistulas or rectal ulcers. Clinical factors, such as diabetes mellitus, a severe acute radiation toxicity, small rectal volume or radiation hypersensitivity, are associated with late rectal toxicity. Dosimetric factors derived from the analysis of dose-volume histograms can also predict the occurrence of radiation proctitis, and help to adapt the prescribed dose and the ballistic of irradiation. (authors)

  18. Preoperative irradiation for carcinoma of the rectum and rectosigmoid colon: report of a national veterans adminstration randomized study

    International Nuclear Information System (INIS)

    Roswit, B.; Higgins, G.A.; Keehn, R.J.

    1975-01-01

    In 1964 the Veterans Administration Surgical Adjuvant Group (VASAG) initiated a large-scale, controlled, randomized protocol to study the role of low-dose preoperative irradiation (2000 to 2500 rads/10 fractions/12 days) in patients with operable adenocarcinoma of the sigmoid colon and rectum. This report analyzes the data in 700 patients, all at 5-year risk. There appears to be a definite benefit to irradiated patients who undergo abdominoperineal resections, when compared with the controls. This advantage is reflected in improvement of 5-year survival, and reductions in lymph node invasion, local recurrence, and distant metastases. A second protocol has been initiated in 30 VA hospitals employing a higher dose (3150 rads) to extended portals (to L2) to male patients who require abdominoperineal resections. (U.S.)

  19. SU-F-T-31: Shape and Isodose Distributions in Co60 HDR Brachytherapy for Different Utero-Vaginal Time Ratios

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Sprinberg, G [Faculty of Sciences, Montevideo, Montevideo (Venezuela, Bolivarian Republic of); Piriz, G [Hospital Pereyra Rossell, Montevideo, Montevideo (Venezuela, Bolivarian Republic of)

    2016-06-15

    Purpose: To optimize the dose in bladder and rectum and show the different shapes of the isodose volumes in Co60-HDR brachytherapy, considering different utero and vaginal sources dwell ratio times (TU:TV). Methods: Besides Ir192-HDR, new Co60-HDR sources are being incorporated. We considered different TU:TV times and computed the dosis in bladder, rectum and at the reference points of the Manchester system. Also, we calculated the isodose volume and shape in each case. We used a EZAG-BEBIG Co0.A86 model with TPS HDRplus3.0.4. and LCT42-7, LCT42-2(R,L) applicators. A reference dose RA= 1.00 Gy was given to the A-right point. We considered the TU:TV dwell time ratios 1:0.25, 1:0.33, 1:0.5, 1:1, 1:2, 1:3, and 1:4. Given TU:TV, the stop time at each dwell position is fixed for each applicator. Results: Increasing TU:TV systematically results in a decreasing of the dose in bladder and rectum, e.g. 9% and 27% reduction were found in 1:0.25 with respect to 1:1, while 12% and 34% increase were found in 1:4 with respect to 1:1. Also, the isodose volume parameters height (h), width (w), thickness (t) and volume (hwt) increased from the 1:0.25 case to the 1:4 value: hwt is 25% lower and 31% higher than the 1:1 reference volume in these cases. Also w decreased for higher TU:TV and may compromise the tumoral volume coverage, decreasing 17% in the 1:0.25 case compared to the 1:1 case. The shape of the isodose volume was obtained for the different TU:TV considered. Conclusion: We obtained the shape of isodose volumes for different TU:TV values in gynecological Co60-HDR. We studied the dose reduction in bladder and rectum for different TU:TV ratios. The volume parameters and hwt are strongly dependent on this ratio. This information is useful for a quantitative check of the TPS and as a starting point towards optimization.

  20. A Modified Spontaneously Closed Defunctioning Tube Ileostomy After Anterior Resection of the Rectum for Rectal Cancer with a Low Colorectal Anastomosis.

    Science.gov (United States)

    Sheng, Qin-Song; Hua, Han-Ju; Cheng, Xiao-Bin; Wang, Wei-Bing; Chen, Wen-Bin; Xu, Jia-He; Lin, Jian-Jiang

    2016-04-01

    The aim of this study is to introduce a new technique of modified spontaneously closed defunctioning tube ileostomy after anterior resection of the rectum for rectal cancer with a low colorectal anastomosis. Patients with rectal cancer who underwent anterior resection of rectum with a low colorectal anastomosis and chose a modified defunctioning tube ileostomy between March 2012 and August 2013 were retrospectively reviewed. Data on the success of the operation procedures, post-operative hospital stay, and post-operative tube ileostomy-related complications were analyzed. One hundred fifty-two patients (87 males and 65 females; 57.1 ± 17.4 years) undergoing the modified defunctioning tube ileostomy after anterior resection for rectal cancer were included. The post-operative hospital stay was 11.9 ± 3.2 days. The tube was removed on days 22.6 ± 4.1 after operation and the ileostomy wound closed spontaneously within 13.1 ± 1.9 days. Twenty-five patients felt tube-associated pain or discomfort, which was relieved after a period of adaptation and appropriate tube adjustment. Nine patients suffered from tube blockage and were treated successfully with saline irrigation. Two patients had intestinal obstruction, which was resolved with conservative treatment. Three patients developed leakage of the distal anastomosis: two were successfully treated with conservative measures and the other completely recovered after reoperation. The modified spontaneously closed defunctioning tube ileostomy appears efficacious and safe. This technique may be used to protect the distal anastomosis and simultaneously decrease the ileostomy complications, and minimize the morbidity and mortality associated with stoma takedown.

  1. Adenocarcinoma of the rectum treated by radical external radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Catton, Charles N; Brierley, James D; Cummings, Bernard J; Wong, C Shun; Keane, Thomas J; O' Sullivan, Brian; Goodman, Phyllis

    1995-01-15

    Purpose: To assess the long-term survival and response rates of patients with primary rectal cancer to radical radiation therapy. Methods and Materials: Between 1978 and 1987, 229 patients were treated at the Princess Margaret Hospital with radical external radiation therapy for adenocarcinoma of the rectum. Patients were treated with radiation either because they were considered to have unresectable tumors, were medically unfit, or refused surgery, or for a combination of these factors. Doses ranged from 40 Gy in 10 fractions by a split course over 6 weeks to 60 Gy in 30 fractions in 6 weeks. The most commonly prescribed treatment was 52 Gy target absorbed dose in 20 daily fractions over 4 weeks. Results: The overall 5-year actuarial survival rate was 27%; for patients with mobile tumors, it was 48%, partially fixed 27%, and fixed tumor 4%. Forty-eight of the 97 patients (50%) with mobile tumors, 11 of the 37 patients (30%) with partially fixed tumors, and 7 of the 77 patients (9%) with fixed tumors had clinically complete tumor regression following radiation. Of these, 18 of the mobile, 6 of the partially fixed, and 5 of the fixed tumors later relapsed locally. Fifty patients had salvage surgery after failing to achieve complete remission or for local relapse, with a 5-year actuarial survival rate of 42% from the time of surgery. Conclusion: Although radiation therapy can cure some patients with mobile or partially fixed rectal adenocarcinomas who refuse or are unsuitable for surgery, local control remains a problem; salvage surgery should be considered in patients who relapse or fail to go into complete remission and who are fit to undergo surgery. For patients with fixed rectal cancers, high-dose external-beam radiation should be part of a planned preoperative regimen or be palliative in intent.

  2. Modeling Gas Bubble Behaviour and Loading on a Rigid Target due to Close-Proximity Underwater Explosions: Comparison to Tests Conducted at DRDC Suffield

    Science.gov (United States)

    2010-11-01

    rayon de bulle de type champ libre, d’une cible rigide. À cette distance de sécurité, l’onde de choc et la bulle de gaz contribuent de façon...produisent des prédictions d’impulsion améliorées pour les cibles rigides. DRDC Atlantic TM 2010-238 iii Executive summary Modeling...i Executive summary

  3. Rectal Balloon for the Immobilization of the Prostate Internal Motion

    International Nuclear Information System (INIS)

    Lee, Sang Kyu; Beak, Jong Geal; Kim, Joo Ho; Jeon, Byong Chul; Cho, Jeong Hee; Kim, Dong Wook; Song, Tae Soo; Cho, Jae Ho; Na, Soo Kyong

    2005-01-01

    The using of endo-rectal balloon has proposed as optimal method that minimized the motion of prostate and the dose of rectum wall volume for treated prostate cancer patients, so we make the customized rectal balloon device. In this study, we analyzed the efficiency of the Self-customized rectal balloon in the aspects of its reproducibility. In 5 patients, for treatment planning, each patient was acquired CT slice images in state of with and without rectal balloon. Also they had CT scanning same repeated third times in during radiation treatment (IMRT). In each case, we analyzed the deviation of rectal balloon position and verified the isodose distribution of rectum wall at closed prostate. Using the rectal balloon, we minimized the planning target volume (PTV) by decreased the internal motion of prostate and overcome the dose limit of radiation therapy in prostate cancer by increased the gap between the rectum wall and high dose region. The using of rectal balloon, although, was reluctant to treat by patients. View a point of immobilization of prostate internal motion and dose escalation of GTV (gross tumor volume), its using consider large efficient for treated prostate cancer patients.

  4. A PROSPECTIVE STUDY ON PREOPERATIVE CONCURRENT CHEMORADIATION WITH CAPECITABINE IN STAGE II/III CARCINOMA OF RECTUM

    Directory of Open Access Journals (Sweden)

    Anish Kuttappan Soman

    2017-09-01

    Full Text Available BACKGROUND Fluorouracil (5-FU based chemoradiotherapy represents the standard treatment option for the preoperative treatment of advanced rectal cancer. Capecitabine is an oral precursor of 5-FU with the advantage of delivering the chemotherapy in an outpatient setup. NSABP R-04 & a German phase 3 trial by Hofheinz et al showed that Capecitabine was equivalent to 5-FU. The primary objective of this study was to evaluate pathological response (PR, clinical & surgical outcomes of stage II & III patients treated with chemoradiation with Capecitabine. The secondary objective was to evaluate toxicity and compliance to treatment. MATERIALS AND METHODS This single arm prospective study included 35 patients with stages II & III adenocarcinoma of rectum who after evaluation were treated with pelvic radiotherapy and concurrent Capecitabine. Toxicities were graded using RTOG scoring criteria. Clinical response was assessed after EBRT completion, and patients were referred for surgery after 4-6 weeks. Pathologic response and completeness of resection were assessed from the histopathology report. RESULTS Growth located within 5 cm from anal verge was seen in 24 (68.5% patients and 6 were inoperable upfront. All patients completed the intended preoperative treatment and 88.6% did not have any toxicity related break in RT. Clinical response was seen in 80% of patients after Chemoradiation. Out of 35 treated 80% of them underwent surgery. APR was performed in 64.2% and 35.7% had LAR. Out of 6 upfront inoperable patients, 3 were converted to operable. Out of 23 APR cases, 7 were converted to anterior resection (30.4%, p=0.046. 96% of operated patients had an R0 resection, including all the 3 upfront inoperable patients. Minimal pathologic response was seen in 89.2% of patients and 7.14% had complete pathologic response. There were no Grade 4 or 5 toxicities. Only 2.9% had a Grade 3 event. 45.7% had maximum of Grade 1 events and 48.6% had maximum of Grade 2

  5. Evidence of Limited Motion of the Prostate by Carefully Emptying the Rectum as Assessed by Daily MVCT Image Guidance with Helical Tomotherapy

    International Nuclear Information System (INIS)

    Fiorino, Claudio Ph.D.; Di Muzio, Nadia; Broggi, Sara; Cozzarini, Cesare; Maggiulli, Eleonora M.Sc.; Alongi, Filippo; Valdagni, Riccardo; Fazio, Ferruccio; Calandrino, Riccardo

    2008-01-01

    Purpose: To assess setup and organ motion error by means of analysis of daily megavoltage computed tomography (MVCT) of patients treated with hypofractionated helical tomotherapy (71.4-74.2 Gy in 28 fractions). Methods and Materials: Data from 21 patients were analyzed. Patients were instructed to empty the rectum carefully before planning CT and every morning before therapy by means of a self-applied rectal enema. The position of the prostate was assessed by means of automatic bone matching (BM) with the planning kilovoltage CT (BM, setup error) followed by a direct visualization (DV) match on the prostate. Deviations between planning and therapy positions referred to BM and BM + DV were registered for the three main axes. In case of a full rectum at MVCT with evident shift of the prostate, treatment was postponed until after additional rectal emptying procedures; in this case, additional MVCT was performed before delivering the treatment. Data for 522 fractions were available; the impact of post-MVCT procedure was investigated for 17 of 21 patients (410 fractions). Results: Prostate motion relative to bony anatomy was limited. Concerning posterior-anterior shifts, only 4.9% and 2.7% of fractions showed deviation of 3 mm or greater of the prostate relative to BM without and with consideration of post-MVCT procedures, respectively. Interobserver variability for BM + DV match was within 0.8 mm (1 SD). Conclusions: Daily MVCT-based correction is feasible. The BM + DV matching was found to be consistent between operators. Rectal emptying using a daily enema is an efficient tool to minimize prostate motion, even for centers that have not yet implemented image-guided radiotherapy

  6. Segmentation of organs at risk in CT volumes of head, thorax, abdomen, and pelvis

    Science.gov (United States)

    Han, Miaofei; Ma, Jinfeng; Li, Yan; Li, Meiling; Song, Yanli; Li, Qiang

    2015-03-01

    Accurate segmentation of organs at risk (OARs) is a key step in treatment planning system (TPS) of image guided radiation therapy. We are developing three classes of methods to segment 17 organs at risk throughout the whole body, including brain, brain stem, eyes, mandible, temporomandibular joints, parotid glands, spinal cord, lungs, trachea, heart, livers, kidneys, spleen, prostate, rectum, femoral heads, and skin. The three classes of segmentation methods include (1) threshold-based methods for organs of large contrast with adjacent structures such as lungs, trachea, and skin; (2) context-driven Generalized Hough Transform-based methods combined with graph cut algorithm for robust localization and segmentation of liver, kidneys and spleen; and (3) atlas and registration-based methods for segmentation of heart and all organs in CT volumes of head and pelvis. The segmentation accuracy for the seventeen organs was subjectively evaluated by two medical experts in three levels of score: 0, poor (unusable in clinical practice); 1, acceptable (minor revision needed); and 2, good (nearly no revision needed). A database was collected from Ruijin Hospital, Huashan Hospital, and Xuhui Central Hospital in Shanghai, China, including 127 head scans, 203 thoracic scans, 154 abdominal scans, and 73 pelvic scans. The percentages of "good" segmentation results were 97.6%, 92.9%, 81.1%, 87.4%, 85.0%, 78.7%, 94.1%, 91.1%, 81.3%, 86.7%, 82.5%, 86.4%, 79.9%, 72.6%, 68.5%, 93.2%, 96.9% for brain, brain stem, eyes, mandible, temporomandibular joints, parotid glands, spinal cord, lungs, trachea, heart, livers, kidneys, spleen, prostate, rectum, femoral heads, and skin, respectively. Various organs at risk can be reliably segmented from CT scans by use of the three classes of segmentation methods.

  7. Dosimetric benefit of DMLC tracking for conventional and sub-volume boosted prostate intensity-modulated arc radiotherapy

    Science.gov (United States)

    Pommer, Tobias; Falk, Marianne; Poulsen, Per R.; Keall, Paul J.; O'Brien, Ricky T.; Meidahl Petersen, Peter; Rosenschöld, Per Munck af

    2013-04-01

    This study investigated the dosimetric impact of uncompensated motion and motion compensation with dynamic multileaf collimator (DMLC) tracking for prostate intensity modulated arc therapy. Two treatment approaches were investigated; a conventional approach with a uniform radiation dose to the target volume and an intraprostatic lesion (IPL) boosted approach with an increased dose to a subvolume of the prostate. The impact on plan quality of optimizations with a leaf position constraint, which limited the distance between neighbouring adjacent MLC leaves, was also investigated. Deliveries were done with and without DMLC tracking on a linear acceleration with a high-resolution MLC. A cylindrical phantom containing two orthogonal diode arrays was used for dosimetry. A motion platform reproduced six patient-derived prostate motion traces, with the average displacement ranging from 1.0 to 8.9 mm during the first 75 s. A research DMLC tracking system was used for real-time motion compensation with optical monitoring for position input. The gamma index was used for evaluation, with measurements with a static phantom or the planned dose as reference, using 2% and 2 mm gamma criteria. The average pass rate with DMLC tracking was 99.9% (range 98.7-100%, measurement as reference), whereas the pass rate for untracked deliveries decreased distinctly as the average displacement increased, with an average pass rate of 61.3% (range 32.7-99.3%). Dose-volume histograms showed that DMLC tracking maintained the planned dose distributions in the presence of motion whereas traces with >3 mm average displacement caused clear plan degradation for untracked deliveries. The dose to the rectum and bladder had an evident dependence on the motion direction and amplitude for untracked deliveries, and the dose to the rectum was slightly increased for IPL boosted plans compared to conventional plans for anterior motion with large amplitude. In conclusion, optimization using a leaf position

  8. Models for predicting objective function weights in prostate cancer IMRT

    International Nuclear Information System (INIS)

    Boutilier, Justin J.; Lee, Taewoo; Craig, Tim; Sharpe, Michael B.; Chan, Timothy C. Y.

    2015-01-01

    Purpose: To develop and evaluate the clinical applicability of advanced machine learning models that simultaneously predict multiple optimization objective function weights from patient geometry for intensity-modulated radiation therapy of prostate cancer. Methods: A previously developed inverse optimization method was applied retrospectively to determine optimal objective function weights for 315 treated patients. The authors used an overlap volume ratio (OV) of bladder and rectum for different PTV expansions and overlap volume histogram slopes (OVSR and OVSB for the rectum and bladder, respectively) as explanatory variables that quantify patient geometry. Using the optimal weights as ground truth, the authors trained and applied three prediction models: logistic regression (LR), multinomial logistic regression (MLR), and weighted K-nearest neighbor (KNN). The population average of the optimal objective function weights was also calculated. Results: The OV at 0.4 cm and OVSR at 0.1 cm features were found to be the most predictive of the weights. The authors observed comparable performance (i.e., no statistically significant difference) between LR, MLR, and KNN methodologies, with LR appearing to perform the best. All three machine learning models outperformed the population average by a statistically significant amount over a range of clinical metrics including bladder/rectum V53Gy, bladder/rectum V70Gy, and dose to the bladder, rectum, CTV, and PTV. When comparing the weights directly, the LR model predicted bladder and rectum weights that had, on average, a 73% and 74% relative improvement over the population average weights, respectively. The treatment plans resulting from the LR weights had, on average, a rectum V70Gy that was 35% closer to the clinical plan and a bladder V70Gy that was 29% closer, compared to the population average weights. Similar results were observed for all other clinical metrics. Conclusions: The authors demonstrated that the KNN and MLR

  9. Models for predicting objective function weights in prostate cancer IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Boutilier, Justin J., E-mail: j.boutilier@mail.utoronto.ca; Lee, Taewoo [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, Ontario M5S 3G8 (Canada); Craig, Tim [Radiation Medicine Program, UHN Princess Margaret Cancer Centre, 610 University of Avenue, Toronto, Ontario M5T 2M9, Canada and Department of Radiation Oncology, University of Toronto, 148 - 150 College Street, Toronto, Ontario M5S 3S2 (Canada); Sharpe, Michael B. [Radiation Medicine Program, UHN Princess Margaret Cancer Centre, 610 University of Avenue, Toronto, Ontario M5T 2M9 (Canada); Department of Radiation Oncology, University of Toronto, 148 - 150 College Street, Toronto, Ontario M5S 3S2 (Canada); Techna Institute for the Advancement of Technology for Health, 124 - 100 College Street, Toronto, Ontario M5G 1P5 (Canada); Chan, Timothy C. Y. [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, Ontario M5S 3G8, Canada and Techna Institute for the Advancement of Technology for Health, 124 - 100 College Street, Toronto, Ontario M5G 1P5 (Canada)

    2015-04-15

    Purpose: To develop and evaluate the clinical applicability of advanced machine learning models that simultaneously predict multiple optimization objective function weights from patient geometry for intensity-modulated radiation therapy of prostate cancer. Methods: A previously developed inverse optimization method was applied retrospectively to determine optimal objective function weights for 315 treated patients. The authors used an overlap volume ratio (OV) of bladder and rectum for different PTV expansions and overlap volume histogram slopes (OVSR and OVSB for the rectum and bladder, respectively) as explanatory variables that quantify patient geometry. Using the optimal weights as ground truth, the authors trained and applied three prediction models: logistic regression (LR), multinomial logistic regression (MLR), and weighted K-nearest neighbor (KNN). The population average of the optimal objective function weights was also calculated. Results: The OV at 0.4 cm and OVSR at 0.1 cm features were found to be the most predictive of the weights. The authors observed comparable performance (i.e., no statistically significant difference) between LR, MLR, and KNN methodologies, with LR appearing to perform the best. All three machine learning models outperformed the population average by a statistically significant amount over a range of clinical metrics including bladder/rectum V53Gy, bladder/rectum V70Gy, and dose to the bladder, rectum, CTV, and PTV. When comparing the weights directly, the LR model predicted bladder and rectum weights that had, on average, a 73% and 74% relative improvement over the population average weights, respectively. The treatment plans resulting from the LR weights had, on average, a rectum V70Gy that was 35% closer to the clinical plan and a bladder V70Gy that was 29% closer, compared to the population average weights. Similar results were observed for all other clinical metrics. Conclusions: The authors demonstrated that the KNN and MLR

  10. Dosimetric analysis of daily use of IGRT in prostate treatment with intensity modulated; Analise dosimetrica da utilizacao diaria de IGRT no tratamento de prostata com intensidade modulada

    Energy Technology Data Exchange (ETDEWEB)

    Sandrini, E.S.; Silveira, T.B.; Vieira, D.S.; Batista, D.V.S., E-mail: emmilyfisica@gmail.com [Instituto Nacional de Cancer Jose de Alencar Gomes da Silva, Rio de Janeiro, RJ (Brazil)

    2014-12-15

    The main application of image-guided radiotherapy (IGRT) in the cancer prostate treatment is to ensure the delivery of the prescribed dose to the tumor. With the modality cone beam computed tomography (CBCT) prostate, seminal vesicles, bladder and rectum can be previewed before each treatment and the actual dose delivered to these organs can be controlled, through the alignment of patient isocenter. The aim of this study was to analyze the tumor coverage and dose to organs at risk effectively obtained during the patient's treatment. Three patients with prostate cancer were treated with intensity modulated radiotherapy (IMRT) or volumetric modulated arc radiotherapy (VMAT) techniques with 74 Gy and 2 Gy per fraction. It was performed daily isocenter location of the prostate with CBCT. A radioncologist drew the clinical target volume (CTV), rectum and bladder in CBCT's and treatment fields were applied retrospectively in each CBCT for dose calculation. For the CTV it was considered the D95 (dose that covers 95% of the volume), for the rectum V50 (volume receiving 50 Gy), V60, V65 and V70 and for bladder V65 and V70. The average D95 of the prostate after the offset was 202 cGy, the V50, V60 and V65 of the rectum for one patient was reduced by 9.6%, 16.6% and 31%, respectively, and V65 of the bladder to another patient was also reduced by 3.5% in IGRT. The results showed that the use of IGRT provided a reduction in the irradiated volume of healthy organs. Thus it is concluded that the use of daily CBCT allows reproducibility of treatment, reducing delayed toxicities and increasing the probability of tumor control. (author)

  11. Dosimetric impacts of endorectal balloon in CyberKnife stereotactic body radiation therapy (SBRT) for early-stage prostate cancer.

    Science.gov (United States)

    Xiang, Hong F; Lu, Hsiao-Ming; Efstathiou, Jason A; Zietman, Anthony L; De Armas, Ricardo; Harris, Kathryn; Bloch, B Nicolas; Qureshi, Muhammad Mustafa; Keohan, Sean; Hirsch, Ariel E

    2017-05-01

    In SBRT for prostate cancer, higher fractional dose to the rectum is a major toxicity concern due to using smaller PTV margin and hypofractionation. We investigate the dosimetric impact on rectum using endorectal balloon (ERB) in prostate SBRT. Twenty prostate cancer patients were included in a retrospective study, ten with ERB and 10 without ERB. Optimized SBRT plans were generated on CyberKnife MultiPlan for 5 × 7.25 Gy to PTV under RTOG-0938 protocol for early-stage prostate cancer. For the rectum and the anterior half rectum, mean dose and percentage of volumes receiving 50%, 80%, 90%, and 100% prescription dose were compared. Using ERB, mean dose to the rectum was 62 cGy (P = 0.001) lower per fraction, and 50 cGy (P = 0.024) lower per fraction for the anterior half rectum. The average V 50% , V 80% , V 90% , and V 100% were lower by 9.9% (P = 0.001), 5.3% (P = 0.0002), 3.4% (P = 0.0002), and 1.2% (P = 0.005) for the rectum, and lower by 10.4% (P = 0.009), 8.3% (P = 0.0004), 5.4% (P = 0.0003), and 2.1% (P = 0.003) for the anterior half rectum. Significant reductions of dose to the rectum using ERB were observed. This may lead to improvement of the rectal toxicity profiles in prostate SBRT. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  12. Dosimetric and Radiobiologic Comparison of 3D Conformal Versus Intensity Modulated Planning Techniques for Prostate Bed Radiotherapy

    International Nuclear Information System (INIS)

    Koontz, Bridget F.; Das, Shiva; Temple, Kathy; Bynum, Sigrun; Catalano, Suzanne; Koontz, Jason I.; Montana, Gustavo S.; Oleson, James R.

    2009-01-01

    Adjuvant radiotherapy for locally advanced prostate cancer improves biochemical and clinical disease-free survival. While comparisons in intact prostate cancer show a benefit for intensity modulated radiation therapy (IMRT) over 3D conformal planning, this has not been studied for post-prostatectomy radiotherapy (RT). This study compares normal tissue and target dosimetry and radiobiological modeling of IMRT vs. 3D conformal planning in the postoperative setting. 3D conformal plans were designed for 15 patients who had been treated with IMRT planning for salvage post-prostatectomy RT. The same computed tomography (CT) and target/normal structure contours, as well as prescription dose, was used for both IMRT and 3D plans. Normal tissue complication probabilities (NTCPs) were calculated based on the dose given to the bladder and rectum by both plans. Dose-volume histogram and NTCP data were compared by paired t-test. Bladder and rectal sparing were improved with IMRT planning compared to 3D conformal planning. The volume of the bladder receiving at least 75% (V75) and 50% (V50) of the dose was significantly reduced by 28% and 17%, respectively (p = 0.002 and 0.037). Rectal dose was similarly reduced, V75 by 33% and V50 by 17% (p = 0.001 and 0.004). While there was no difference in the volume of rectum receiving at least 65 Gy (V65), IMRT planning significant reduced the volume receiving 40 Gy or more (V40, p = 0.009). Bladder V40 and V65 were not significantly different between planning modalities. Despite these dosimetric differences, there was no significant difference in the NTCP for either bladder or rectal injury. IMRT planning reduces the volume of bladder and rectum receiving high doses during post-prostatectomy RT. Because of relatively low doses given to the bladder and rectum, there was no statistically significant improvement in NTCP between the 3D conformal and IMRT plans.

  13. Dosimetric and radiobiologic comparison of 3D conformal versus intensity modulated planning techniques for prostate bed radiotherapy.

    Science.gov (United States)

    Koontz, Bridget F; Das, Shiva; Temple, Kathy; Bynum, Sigrun; Catalano, Suzanne; Koontz, Jason I; Montana, Gustavo S; Oleson, James R

    2009-01-01

    Adjuvant radiotherapy for locally advanced prostate cancer improves biochemical and clinical disease-free survival. While comparisons in intact prostate cancer show a benefit for intensity modulated radiation therapy (IMRT) over 3D conformal planning, this has not been studied for post-prostatectomy radiotherapy (RT). This study compares normal tissue and target dosimetry and radiobiological modeling of IMRT vs. 3D conformal planning in the postoperative setting. 3D conformal plans were designed for 15 patients who had been treated with IMRT planning for salvage post-prostatectomy RT. The same computed tomography (CT) and target/normal structure contours, as well as prescription dose, was used for both IMRT and 3D plans. Normal tissue complication probabilities (NTCPs) were calculated based on the dose given to the bladder and rectum by both plans. Dose-volume histogram and NTCP data were compared by paired t-test. Bladder and rectal sparing were improved with IMRT planning compared to 3D conformal planning. The volume of the bladder receiving at least 75% (V75) and 50% (V50) of the dose was significantly reduced by 28% and 17%, respectively (p = 0.002 and 0.037). Rectal dose was similarly reduced, V75 by 33% and V50 by 17% (p = 0.001 and 0.004). While there was no difference in the volume of rectum receiving at least 65 Gy (V65), IMRT planning significant reduced the volume receiving 40 Gy or more (V40, p = 0.009). Bladder V40 and V65 were not significantly different between planning modalities. Despite these dosimetric differences, there was no significant difference in the NTCP for either bladder or rectal injury. IMRT planning reduces the volume of bladder and rectum receiving high doses during post-prostatectomy RT. Because of relatively low doses given to the bladder and rectum, there was no statistically significant improvement in NTCP between the 3D conformal and IMRT plans.

  14. Flight Test Techniques

    Science.gov (United States)

    1989-01-01

    the airframe for col1A 300 jauges pour un essal d𔄀preuve a ground "proof test" with a 0.8 charge, au sol A charge 0,8 recalant ce modile ; to update...the model. 200 among these 200 de ces jauges ont 6t6 cibl~es bonnes gauges had been wired to be "airworthy", de vol mats le domaine de vol a 4t6 but

  15. Associations between volume changes and spatial dose metrics for the urinary bladder during local versus pelvic irradiation for prostate cancer.

    Science.gov (United States)

    Casares-Magaz, Oscar; Moiseenko, Vitali; Hopper, Austin; Pettersson, Niclas Johan; Thor, Maria; Knopp, Rick; Deasy, Joseph O; Muren, Ludvig Paul; Einck, John

    2017-06-01

    Inter-fractional variation in urinary bladder volumes during the course of radiotherapy (RT) for prostate cancer causes deviations between planned and delivered doses. This study compared planned versus daily cone-beam CT (CBCT)-based spatial bladder dose distributions, for prostate cancer patients receiving local prostate treatment (local treatment) versus prostate including pelvic lymph node irradiation (pelvic treatment). Twenty-seven patients (N = 15 local treatment; N = 12 pelvic treatment) were treated using daily image-guided RT (1.8 Gy@43-45 fx), adhering to a full bladder/empty rectum protocol. For each patient, 9-10 CBCTs were registered to the planning CT, using the clinically applied translations. The urinary bladder was manually segmented on each CBCT, 3 mm inner shells were generated, and semi and quadrant sectors were created using axial/coronal cuts. Planned and delivered DVH metrics were compared across patients and between the two groups of treatment (t-test, p bladder volume variations and the dose-volume histograms (DVH) of the bladder and its sectors were evaluated (Spearman's rank correlation coefficient, r s ). Bladder volumes varied considerably during RT (coefficient of variation: 16-58%). The population-averaged planned and delivered DVH metrics were not significantly different at any dose level. Larger treatment bladder volumes resulted in increased absolute volume of the posterior/inferior bladder sector receiving intermediate-high doses, in both groups. The superior bladder sector received less dose with larger bladder volumes for local treatments (r s  ± SD: -0.47 ± 0.32), but larger doses for pelvic treatments (r s  ± SD: 0.74 ± 0.24). Substantial bladder volume changes during the treatment course occurred even though patients were treated under a full bladder/daily image-guided protocol. Larger bladder volumes resulted in less bladder wall spared at the posterior-inferior sector, regardless the

  16. [Hospital variation in anastomotic leakage after rectal cancer surgery in the Spanish Association of Surgeons project: The contribution of hospital volume].

    Science.gov (United States)

    Ortiz, Héctor; Biondo, Sebastiano; Codina, Antonio; Ciga, Miguel Á; Enríquez-Navascués, José; Espín, Eloy; García-Granero, Eduardo; Roig, José Vicente

    2016-04-01

    This multicentre observational study aimed to determine the anastomotic leak rate in the hospitals included in the Rectal Cancer Project of the Spanish Society of Surgeons and examine whether hospital volume may contribute to any variation between hospitals. Hospital variation was quantified using a multilevel approach on prospective data derived from the multicentre database of all adenocarcinomas of the rectum operated by an anterior resection at 84 surgical departments from 2006 to 2013. The following variables were included in the analysis; demographics, American Society of Anaesthesiologists classification, use of defunctioning stoma, tumour location and stage, administration of neoadjuvant treatment, and annual volume of elective surgical procedures. A total of 7231 consecutive patients were included. The rate of anastomotic leak was 10.0%. Stratified by annual surgical volume hospitals varied from 9.9 to 11.3%. In multilevel regression analysis, the risk of anastomotic leak increased in male patients, in patients with tumours located below 12 cm from the anal verge, and advanced tumour stages. However, a defunctioning stoma seemed to prevent this complication. Hospital surgical volume was not associated with anastomotic leak (OR: 0.852, [0.487-1.518]; P=.577). Furthermore, there was a statistically significant variation in anastomotic leak between all departments (MOR: 1.475; [1.321-1.681]; P<0.001). Anastomotic leak varies significantly among hospitals included in the project and this difference cannot be attributed to the annual surgical volume. Copyright © 2015 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. A noninvasive method for evaluating portal circulation by administration of Tl-201 per rectum

    International Nuclear Information System (INIS)

    Tonami, N.; Nakajima, K.; Hisada, K.; Tanaka, N.; Kobayashi, K.

    1982-01-01

    A new method for evaluating portal systemic circulation by administration of Tl-201 per rectum was performed in 13 control subjects and in 65 patients with various liver diseases. In normal controls, the liver was visualized on the 0-5-min image whereas the images of other organs such as the heart, spleen, and lungs were very poor. In patients with liver cirrhosis associated with portal-systemic shunt, and in many other patients with hepatocellular damage, the liver was not so clearly visualized, whereas radioactivity in other organs, especially the heart, became evident. The heart-to-liver uptake ratio at 20 min after administration (H/L ratio) was significantly higher in liver cirrhosis than in normals and patients with chronic hepatitis (p<0.001). The patients with esophageal varices showed a significantly higher H/L ratio compared with that in cirrhotic patients without esophageal varices (p<0.001). The H/L ratio also showed a significant difference (p<0.01) between Stage 1 and Stage 3 esophageal varices. Since there were many other patients with hepatocellular damage who had high H/L ratios similar to those in liver cirrhosis, the effect that hepatocellular damage has on the liver uptake of T1-201 is also considered. Our present data suggest that this noninvasive method seems to be useful in evaluating portal-to-systemic shunting

  18. Clinical value of Tl per rectum scintigraphy in the work-up of patients with alcoholic liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Urbain, D.; Reding, P.; Georges, B.; Thys, O.; Ham, H.R.

    1986-09-01

    The clinical value of thallium 201 per rectum scintigraphy in the work-up of patients with alcoholic liver disease was evaluated using data obtained in 104 patients. The 25th min ratio of heart to liver activities was used as an index of portal systemic shunting. This ratio was found to be normal in alcoholic patients with normal liver biopsy and also in those presenting only steatosis. It was slightly higher in patients with liver fibrosis and significantly higher values were observed in patients with liver cirrhosis. High values of the ratio were associated with a higher risk of portal systemic encephalopathy and/or gastrointestinal bleeding. The prognostic value of the test was supported by the fact that good correlations were observed between the ratio and widely accepted prognostic scores such as the Child score or the Orrego index. Moreover, high ratios were associated with an increased mortality risk at one year. We conclude that this simple test is interesting in the screening of cirrhotics at risk of encephalopathy, gastrointestinal hemorrhage, or early death.

  19. Correlations between contouring similarity metrics and simulated treatment outcome for prostate radiotherapy

    Science.gov (United States)

    Roach, D.; Jameson, M. G.; Dowling, J. A.; Ebert, M. A.; Greer, P. B.; Kennedy, A. M.; Watt, S.; Holloway, L. C.

    2018-02-01

    Many similarity metrics exist for inter-observer contouring variation studies, however no correlation between metric choice and prostate cancer radiotherapy dosimetry has been explored. These correlations were investigated in this study. Two separate trials were undertaken, the first a thirty-five patient cohort with three observers, the second a five patient dataset with ten observers. Clinical and planning target volumes (CTV and PTV), rectum, and bladder were independently contoured by all observers in each trial. Structures were contoured on T2-weighted MRI and transferred onto CT following rigid registration for treatment planning in the first trial. Structures were contoured directly on CT in the second trial. STAPLE and majority voting volumes were generated as reference gold standard volumes for each structure for the two trials respectively. VMAT treatment plans (78 Gy to PTV) were simulated for observer and gold standard volumes, and dosimetry assessed using multiple radiobiological metrics. Correlations between contouring similarity metrics and dosimetry were calculated using Spearman’s rank correlation coefficient. No correlations were observed between contouring similarity metrics and dosimetry for CTV within either trial. Volume similarity correlated most strongly with radiobiological metrics for PTV in both trials, including TCPPoisson (ρ  =  0.57, 0.65), TCPLogit (ρ  =  0.39, 0.62), and EUD (ρ  =  0.43, 0.61) for each respective trial. Rectum and bladder metric correlations displayed no consistency for the two trials. PTV volume similarity was found to significantly correlate with rectum normal tissue complication probability (ρ  =  0.33, 0.48). Minimal to no correlations with dosimetry were observed for overlap or boundary contouring metrics. Future inter-observer contouring variation studies for prostate cancer should incorporate volume similarity to provide additional insights into dosimetry during analysis.

  20. Impact of database quality in knowledge-based treatment planning for prostate cancer.

    Science.gov (United States)

    Wall, Phillip D H; Carver, Robert L; Fontenot, Jonas D

    2018-03-13

    This article investigates dose-volume prediction improvements in a common knowledge-based planning (KBP) method using a Pareto plan database compared with using a conventional, clinical plan database. Two plan databases were created using retrospective, anonymized data of 124 volumetric modulated arc therapy (VMAT) prostate cancer patients. The clinical plan database (CPD) contained planning data from each patient's clinically treated VMAT plan, which were manually optimized by various planners. The multicriteria optimization database (MCOD) contained Pareto-optimal plan data from VMAT plans created using a standardized multicriteria optimization protocol. Overlap volume histograms, incorporating fractional organ at risk volumes only within the treatment fields, were computed for each patient and used to match new patient anatomy to similar database patients. For each database patient, CPD and MCOD KBP predictions were generated for D 10 , D 30 , D 50 , D 65 , and D 80 of the bladder and rectum in a leave-one-out manner. Prediction achievability was evaluated through a replanning study on a subset of 31 randomly selected database patients using the best KBP predictions, regardless of plan database origin, as planning goals. MCOD predictions were significantly lower than CPD predictions for all 5 bladder dose-volumes and rectum D 50 (P = .004) and D 65 (P databases affects the performance and achievability of dose-volume predictions from a common knowledge-based planning approach for prostate cancer. Bladder and rectum dose-volume predictions derived from a database of standardized Pareto-optimal plans were compared with those derived from clinical plans manually designed by various planners. Dose-volume predictions from the Pareto plan database were significantly lower overall than those from the clinical plan database, without compromising achievability. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Association of a XRCC3 polymorphism and rectum mean dose with the risk of acute radio-induced gastrointestinal toxicity in prostate cancer patients

    International Nuclear Information System (INIS)

    Fachal, Laura; Gómez-Caamaño, Antonio; Peleteiro, Paula; Carballo, Ana; Calvo-Crespo, Patricia; Sánchez-García, Manuel; Lobato-Busto, Ramón; Carracedo, Ángel; Vega, Ana

    2012-01-01

    Background and purpose: We have performed a case–control study among prostate cancer patients treated with three-dimensional conformational radiotherapy (3D-CRT) in order to investigate the association between single nucleotide polymorphisms (SNPs), treatment and patient features with gastrointestinal and genitourinary acute toxicity. Material and methods: A total of 698 patients were screened for 14 SNPs located in the ATM, ERCC2, LIG4, MLH1 and XRCC3 genes. Gastrointestinal and genitourinary toxicities were recorded prospectively using the Common Terminology Criteria for Adverse Events v3.0. Results: The XRCC3 SNP rs1799794 (G/G OR = 5.65; 95% CI: 1.95–16.38; G/A OR = 2.75; 95% CI: 1.25–6.05; uncorrected p-value = 2.8 × 10 −03 ; corrected p-value = 0.03; FDR q-value = 0.06) as well as the mean dose received by the rectum (OR = 1.06; 95% CI: 1.02–1.1; uncorrected p-value = 2.49 × 10 −03 ; corrected p-value = 0.03; FDR q-value = 0.06) were significantly associated with gastrointestinal toxicity after correction for multiple testing. Those patients who undergone previous prostatectomy were less prone to develop genitourinary toxicity (OR = 0.38; 95% CI: 0.18–0.71; uncorrected p-value = 4.95 × 10 −03 ; corrected p-value = 0.03; FDR q-value = 0.08). Our study excludes the possibility of a >2-fold risk increase in genitourinary acute toxicity being due to rs1801516 ATM SNP, the rs1805386 and rs1805388 LIG4 markers, as well as all the SNPs evaluated in the ERCC2, MLH1 and XRCC3 genes. Conclusions: The XRCC3 rs1799794 SNP and the mean dose received by the rectum are associated with the development of gastrointestinal toxicity after 3D-CRT.

  2. Conformal irradiation of the prostate: estimating long-term rectal bleeding risk using dose-volume histograms

    International Nuclear Information System (INIS)

    Hartford, Alan C.; Niemierko, Andrzej; Adams, Judith A.; Urie, Marcia M.; Shipley, William U.

    1996-01-01

    Purpose: Dose-volume histograms (DVHs) may be very useful tools for estimating probability of normal tissue complications (NTCP), but there is not yet an agreed upon method for their analysis. This study introduces a statistical method of aggregating and analyzing primary data from DVHs and associated outcomes. It explores the dose-volume relationship for NTCP of the rectum, using long-term data on rectal wall bleeding following prostatic irradiation. Methods and Materials: Previously published data were reviewed and updated on 41 patients with Stages T3 and T4 prostatic carcinoma treated with photons followed by perineal proton boost, including dose-volume histograms (DVHs) of each patient's anterior rectal wall and data on the occurrence of postirradiation rectal bleeding (minimum FU > 4 years). Logistic regression was used to test whether some individual combination of dose and volume irradiated might best separate the DVHs into categories of high or low risk for rectal bleeding. Further analysis explored whether a group of such dose-volume combinations might be superior in predicting complication risk. These results were compared with results of the 'critical volume model', a mathematical model based on assumptions of underlying radiobiological interactions. Results: Ten of the 128 tested dose-volume combinations proved to be 'statistically significant combinations' (SSCs) distinguishing between bleeders (14 out of 41) and nonbleeders (27 out of 41), ranging contiguously between 60 CGE (Cobalt Gray Equivalent) to 70% of the anterior rectal wall and 75 CGE to 30%. Calculated odds ratios for each SSC were not significantly different across the individual SSCs; however, analysis combining SSCs allowed segregation of DVHs into three risk groups: low, moderate, and high. Estimates of probabilities of normal tissue complications (NTCPs) based on these risk groups correlated strongly with observed data (p = 0.003) and with biomathematical model-generated NTCPs

  3. Evaluation of different set-up error corrections on dose-volume metrics in prostate IMRT using CBCT images

    International Nuclear Information System (INIS)

    Hirose, Yoshinori; Tomita, Tsuneyuki; Kitsuda, Kenji; Notogawa, Takuya; Miki, Katsuhito; Nakamura, Mitsuhiro; Nakamura, Kiyonao; Ishigaki, Takashi

    2014-01-01

    We investigated the effect of different set-up error corrections on dose-volume metrics in intensity-modulated radiotherapy (IMRT) for prostate cancer under different planning target volume (PTV) margin settings using cone-beam computed tomography (CBCT) images. A total of 30 consecutive patients who underwent IMRT for prostate cancer were retrospectively analysed, and 7-14 CBCT datasets were acquired per patient. Interfractional variations in dose-volume metrics were evaluated under six different set-up error corrections, including tattoo, bony anatomy, and four different target matching groups. Set-up errors were incorporated into planning the isocenter position, and dose distributions were recalculated on CBCT images. These processes were repeated under two different PTV margin settings. In the on-line bony anatomy matching groups, systematic error (Σ) was 0.3 mm, 1.4 mm, and 0.3 mm in the left-right, anterior-posterior (AP), and superior-inferior directions, respectively. Σ in three successive off-line target matchings was finally comparable with that in the on-line bony anatomy matching in the AP direction. Although doses to the rectum and bladder wall were reduced for a small PTV margin, averaged reductions in the volume receiving 100% of the prescription dose from planning were within 2.5% under all PTV margin settings for all correction groups, with the exception of the tattoo set-up error correction only (≥ 5.0%). Analysis of variance showed no significant difference between on-line bony anatomy matching and target matching. While variations between the planned and delivered doses were smallest when target matching was applied, the use of bony anatomy matching still ensured the planned doses. (author)

  4. SU-F-J-11: Radiobiologically Optimized Patient Localization During Prostate External Beam Localization

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y; Gardner, S; Liu, C; Zhao, B; Wen, N; Brown, S; Chetty, I [Henry Ford Health System, Detroit, MI (United States)

    2016-06-15

    Purpose: To present a novel positioning strategy which optimizes radiation delivery with radiobiological response knowledge, and to evaluate its application during prostate external beam radiotherapy. Methods: Ten patients with low or intermediate risk prostate cancer were evaluated retrospectively in this IRB-approved study. For each patient, a VMAT plan was generated on the planning CT (PCT) to deliver 78 Gy in 39 fractions with PTV = prostate + 7 mm margin, except for 5mm in the posterior direction. Five representative pretreatment CBCT images were selected for each patient, and prostate, rectum, and bladder were delineated on all CBCT images. Each CBCT was auto-registered to the corresponding PCT. Starting from this auto-matched position (AM-position), a search for optimal treatment position was performed utilizing a score function based on radiobiological and dosimetric indices (D98-DTV, NTCP-rectum, and NTCP-bladder) for the daily target volume (DTV), rectum, and bladder. DTV was defined as prostate + 4 mm margin to account for intra-fraction motion as well as contouring variability on CBCT. We termed the optimal treatment position the radiobiologically optimized couch shift position (ROCS-position). Results: The indices, averaged over the 10 patients’ treatment plans, were (mean±SD): 77.7±0.2 Gy (D98-PTV), 12.3±2.7% (NTCP-rectum), and 53.2±11.2% (NTCP-bladder). The corresponding values calculated on all 50 CBCT images at the AM-positions were 72.9±11.3 Gy (D98-DTV), 15.8±6.4% (NTCP-rectum), and 53.0±21.1% (NTCP-bladder), respectively. In comparison, calculated on CBCT at the ROCS-positions, the indices were 77.0±2.1 Gy (D98-DTV), 12.1±5.7% (NTCP-rectum), and 60.7±16.4% (NTCP-bladder). Compared to autoregistration, ROCS-optimization recovered dose coverage to target volume and lowered the risk to rectum. Moreover, NTCPrectum for one patient remained high after ROCS-optimization and therefore could potentially benefit from adaptive planning

  5. Wandering Fish Bone: a Case of Pelvic Abscess due to Rectum Perforation Resulting from an Accidental Fish Bone Ingestion

    Directory of Open Access Journals (Sweden)

    Sirous Abbasi

    2010-09-01

    Full Text Available Fish bone is the most common foreign body that is ingested accidentally and can be caused gastrointestinal complications such as perforation, abstraction, and abscess. We describe a 75-year-old man who suffered from constipation, diarrhea, and fever and chills for 3 months. He had mild tenderness in hypogasteric region and also mild tenderness and swelling on anterior rectal wall and prostate upon clinical examination. The abdominal and pelvic sonography and CT scan findings suggested existence of abscess in the space of between bladder and rectum. The patient underwent laparotomy to drainage the pelvic abscess. The surgeon found a 6-cm fish bone which was embedded in the abscess. The presented case indicated the importance of accidental fish bone ingestion and its possible complications. In addition, the patients with abdominal pain, GI bleeding, and fever of unknown origin living in the seaside regions, the wandering fish bone as a differential diagnosis should be kept in mind.

  6. SU-F-BRD-01: A Logistic Regression Model to Predict Objective Function Weights in Prostate Cancer IMRT

    International Nuclear Information System (INIS)

    Boutilier, J; Chan, T; Lee, T; Craig, T; Sharpe, M

    2014-01-01

    Purpose: To develop a statistical model that predicts optimization objective function weights from patient geometry for intensity-modulation radiotherapy (IMRT) of prostate cancer. Methods: A previously developed inverse optimization method (IOM) is applied retrospectively to determine optimal weights for 51 treated patients. We use an overlap volume ratio (OVR) of bladder and rectum for different PTV expansions in order to quantify patient geometry in explanatory variables. Using the optimal weights as ground truth, we develop and train a logistic regression (LR) model to predict the rectum weight and thus the bladder weight. Post hoc, we fix the weights of the left femoral head, right femoral head, and an artificial structure that encourages conformity to the population average while normalizing the bladder and rectum weights accordingly. The population average of objective function weights is used for comparison. Results: The OVR at 0.7cm was found to be the most predictive of the rectum weights. The LR model performance is statistically significant when compared to the population average over a range of clinical metrics including bladder/rectum V53Gy, bladder/rectum V70Gy, and mean voxel dose to the bladder, rectum, CTV, and PTV. On average, the LR model predicted bladder and rectum weights that are both 63% closer to the optimal weights compared to the population average. The treatment plans resulting from the LR weights have, on average, a rectum V70Gy that is 35% closer to the clinical plan and a bladder V70Gy that is 43% closer. Similar results are seen for bladder V54Gy and rectum V54Gy. Conclusion: Statistical modelling from patient anatomy can be used to determine objective function weights in IMRT for prostate cancer. Our method allows the treatment planners to begin the personalization process from an informed starting point, which may lead to more consistent clinical plans and reduce overall planning time

  7. SU-F-BRD-01: A Logistic Regression Model to Predict Objective Function Weights in Prostate Cancer IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Boutilier, J; Chan, T; Lee, T [University of Toronto, Toronto, Ontario (Canada); Craig, T; Sharpe, M [University of Toronto, Toronto, Ontario (Canada); The Princess Margaret Cancer Centre - UHN, Toronto, ON (Canada)

    2014-06-15

    Purpose: To develop a statistical model that predicts optimization objective function weights from patient geometry for intensity-modulation radiotherapy (IMRT) of prostate cancer. Methods: A previously developed inverse optimization method (IOM) is applied retrospectively to determine optimal weights for 51 treated patients. We use an overlap volume ratio (OVR) of bladder and rectum for different PTV expansions in order to quantify patient geometry in explanatory variables. Using the optimal weights as ground truth, we develop and train a logistic regression (LR) model to predict the rectum weight and thus the bladder weight. Post hoc, we fix the weights of the left femoral head, right femoral head, and an artificial structure that encourages conformity to the population average while normalizing the bladder and rectum weights accordingly. The population average of objective function weights is used for comparison. Results: The OVR at 0.7cm was found to be the most predictive of the rectum weights. The LR model performance is statistically significant when compared to the population average over a range of clinical metrics including bladder/rectum V53Gy, bladder/rectum V70Gy, and mean voxel dose to the bladder, rectum, CTV, and PTV. On average, the LR model predicted bladder and rectum weights that are both 63% closer to the optimal weights compared to the population average. The treatment plans resulting from the LR weights have, on average, a rectum V70Gy that is 35% closer to the clinical plan and a bladder V70Gy that is 43% closer. Similar results are seen for bladder V54Gy and rectum V54Gy. Conclusion: Statistical modelling from patient anatomy can be used to determine objective function weights in IMRT for prostate cancer. Our method allows the treatment planners to begin the personalization process from an informed starting point, which may lead to more consistent clinical plans and reduce overall planning time.

  8. Individualized Nonadaptive and Online-Adaptive Intensity-Modulated Radiotherapy Treatment Strategies for Cervical Cancer Patients Based on Pretreatment Acquired Variable Bladder Filling Computed Tomography Scans

    International Nuclear Information System (INIS)

    Bondar, M.L.; Hoogeman, M.S.; Mens, J.W.; Quint, S.; Ahmad, R.; Dhawtal, G.; Heijmen, B.J.

    2012-01-01

    Purpose: To design and evaluate individualized nonadaptive and online-adaptive strategies based on a pretreatment established motion model for the highly deformable target volume in cervical cancer patients. Methods and Materials: For 14 patients, nine to ten variable bladder filling computed tomography (CT) scans were acquired at pretreatment and after 40 Gy. Individualized model-based internal target volumes (mbITVs) accounting for the cervix and uterus motion due to bladder volume changes were generated by using a motion-model constructed from two pretreatment CT scans (full and empty bladder). Two individualized strategies were designed: a nonadaptive strategy, using an mbITV accounting for the full-range of bladder volume changes throughout the treatment; and an online-adaptive strategy, using mbITVs of bladder volume subranges to construct a library of plans. The latter adapts the treatment online by selecting the plan-of-the-day from the library based on the measured bladder volume. The individualized strategies were evaluated by the seven to eight CT scans not used for mbITVs construction, and compared with a population-based approach. Geometric uniform margins around planning cervix–uterus and mbITVs were determined to ensure adequate coverage. For each strategy, the percentage of the cervix–uterus, bladder, and rectum volumes inside the planning target volume (PTV), and the clinical target volume (CTV)-to-PTV volume (volume difference between PTV and CTV) were calculated. Results: The margin for the population-based approach was 38 mm and for the individualized strategies was 7 to 10 mm. Compared with the population-based approach, the individualized nonadaptive strategy decreased the CTV-to-PTV volume by 48% ± 6% and the percentage of bladder and rectum inside the PTV by 5% to 45% and 26% to 74% (p < 0.001), respectively. Replacing the individualized nonadaptive strategy by an online-adaptive, two-plan library further decreased the percentage of

  9. A comparison of different three-dimensional treatment planning techniques for localized radiotherapy of prostate cancer

    International Nuclear Information System (INIS)

    Koswig, S.; Dinges, S.; Buchali, A.; Boehmer, D.; Salk, J.; Rosenthal, P.; Harder, C.; Schlenger, L.; Budach, V.

    1999-01-01

    Purpose: Four different three-dimensional planning techniques for localized radiotherapy of prostate cancer were compared with regard to dose homogeneity within the target volume and dose to organs at risk, dependent upon tumor stage. Patients and Methods: Six patients with stage T1, 7 patients with stage T2 and 4 patients with stage T3 were included in this study. Four different 3D treatment plans (rotation, 4-field, 5-field and 6-field technique) were calculated for each patient. Dose was calculated with the reference point at the isocenter (100%). The planning target volume was encompassed within the 95% isodose surface. All the techniques used different shaped portal for each beam. Dose volume histograms were created and compared for the planning target volume and the organs at risk (33%, 50%, 66% volume level) in all techniques. Results: The 4 different three-dimensional planning techniques revealed no differences concerning dose homogeneity within the planning target volume. The dose volume distribution at organs at risk show differences between the calculated techniques. In our study the best protection for bladder and rectum in stage T1 and T2 was achieved by the 6-field technique. A significant difference was achieved between 6-field and 4-field technique only in the 50% volume of the bladder (p=0.034), between the 6-field and rotation technique (all volume levels) and between 5-field and rotation technique (all volume levels). In stage T1, T2 6-field and 4-field technique in 50% (p-0.033) and 66% (p=0.011) of the rectum volume. In stage T3 a significant difference was not observed between the 4 techniques. The best protection of head of the femur was achieved by the rotation technique. Conclusion: In the localized radiotherapy of prostate cancer in stage T1 or T2 the best protection for bladder and rectum was achieved by a 3D-planned conformal 6-field technique. If the seminal vesicles have been included in the target volume and in the case of large

  10. SU-F-J-122: Rectal Sparing Reproducibility in Prostate Cancer Patients Treated with Hydrogel Spacer and Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hedrick, S; Robison, B; Blakey, M; Artz, M; Renegar, J; Schreuder, A; Fagundes, M [Provision Center for Proton Therapy, Knoxville, TN (United States); Case, S [Vanderbilt University, Nashville, TN (United States)

    2016-06-15

    Purpose: Rectal hydrogel spacer has been shown to improve rectal sparing in prostate radiotherapy. The purpose of this study was to determine the reproducibility of rectal sparing throughout treatment in patients undergoing proton therapy. Methods: At our facility, prostate cancer patients are treated with pencil beam scanning proton therapy, utilizing an endorectal balloon (ERB) or rectal spacer hydrogel (Gel) “SpaceOAR” implant. All patients were treated with a full bladder and empty rectum (low residue diet and stool softeners). A quality assurance CT (QACT) was performed periodically throughout treatment to ensure rectal filling consistency and sparing in 41 patients treated with Gel. The treatment planning (TP) dose was calculated on each QACT and the rectum V90%, V75%, V65%, V50%, and V40% were recorded. QACT scans were acquired on day 0, week 1, week 3, and week 5. Results: 144 QACT scans were analyzed, each patient receiving 3–4 QACTs. Rectum V90% was within +/−1% of the TP dose in 70% of the QACTs and within +/−5% in 95% of scans. From previous data analyses, our ERB rectum V90% average is 6%. This value was used as an upper threshold for the Gel QACT analysis. 5 of the 41 patients (12%), corresponding to 7 QACTs, had a rectum V90% that exceeded 6% on one or more QACTs. However, the average rectal V90% measured over multiple QACTs never exceeded 6%. 55% of the QACTs had a rectum volume within 5cc of the TPCT volume, 68% were within 10cc. Conclusion: In this study, we have shown that a majority of our prostate patients can maintain consistent rectal sparing when treated with a hydrogel spacer. QACT rectal V90% exceeding our threshold was most often related to increased rectal filling and gas, which was addressed with improved dietary compliance and the intensification of stool softeners or laxatives.

  11. SU-F-J-122: Rectal Sparing Reproducibility in Prostate Cancer Patients Treated with Hydrogel Spacer and Proton Therapy

    International Nuclear Information System (INIS)

    Hedrick, S; Robison, B; Blakey, M; Artz, M; Renegar, J; Schreuder, A; Fagundes, M; Case, S

    2016-01-01

    Purpose: Rectal hydrogel spacer has been shown to improve rectal sparing in prostate radiotherapy. The purpose of this study was to determine the reproducibility of rectal sparing throughout treatment in patients undergoing proton therapy. Methods: At our facility, prostate cancer patients are treated with pencil beam scanning proton therapy, utilizing an endorectal balloon (ERB) or rectal spacer hydrogel (Gel) “SpaceOAR” implant. All patients were treated with a full bladder and empty rectum (low residue diet and stool softeners). A quality assurance CT (QACT) was performed periodically throughout treatment to ensure rectal filling consistency and sparing in 41 patients treated with Gel. The treatment planning (TP) dose was calculated on each QACT and the rectum V90%, V75%, V65%, V50%, and V40% were recorded. QACT scans were acquired on day 0, week 1, week 3, and week 5. Results: 144 QACT scans were analyzed, each patient receiving 3–4 QACTs. Rectum V90% was within +/−1% of the TP dose in 70% of the QACTs and within +/−5% in 95% of scans. From previous data analyses, our ERB rectum V90% average is 6%. This value was used as an upper threshold for the Gel QACT analysis. 5 of the 41 patients (12%), corresponding to 7 QACTs, had a rectum V90% that exceeded 6% on one or more QACTs. However, the average rectal V90% measured over multiple QACTs never exceeded 6%. 55% of the QACTs had a rectum volume within 5cc of the TPCT volume, 68% were within 10cc. Conclusion: In this study, we have shown that a majority of our prostate patients can maintain consistent rectal sparing when treated with a hydrogel spacer. QACT rectal V90% exceeding our threshold was most often related to increased rectal filling and gas, which was addressed with improved dietary compliance and the intensification of stool softeners or laxatives.

  12. Intense pulsed sources of ions and electrons produced by lasers; Sources pulsees intenses d'ions et d'electrons produites par laser

    Energy Technology Data Exchange (ETDEWEB)

    Bourrabier, G [Centre de Recherche de la C.S.F., Corbeville (France); Consoli, T; Slama, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-11-01

    We describe a device for the acceleration of the plasma burst produced by focusing a laser beam into a metal target. We extract the electrons and the ions from the plasma. The maximum current is around 2000 amperes during few microseconds. The study of the effect of the kind of the target on the characteristics of the current shows the great importance of the initial conditions that is the ionisation potential of the target and the energy laser. (authors) [French] On decrit un dispositif destine a accelerer la bouffee de plasma produite par focalisation d'un faisceau laser sur une cible solide. On extrait du plasma les electrons et les ions. Le courant maximum atteint pres de 2000 amperes pendant quelques microsecondes. L'etude de l'effet de la nature de la cible sur les caracteristiques du courant collecte, met en evidence l'importance des conditions initiales (potentiel d'ionisation de la cible, energie du laser). (auteurs)

  13. Finite element simulation of interactions between pelvic organs: predictive model of the prostate motion in the context of radiotherapy.

    Science.gov (United States)

    Boubaker, Mohamed Bader; Haboussi, Mohamed; Ganghoffer, Jean-François; Aletti, Pierre

    2009-08-25

    The setting up of predictive models of the pelvic organ motion and deformation may prove an efficient tool in the framework of prostate cancer radiotherapy, in order to deliver doses more accurately and efficiently to the clinical target volume (CTV). A finite element (FE) model of the prostate, rectum and bladder motion has been developed, investigating more specifically the influence of the rectum and bladder repletions on the gland motion. The required organ geometries are obtained after processing the computed tomography (CT) images, using specific softwares. Due to their structural characteristics, a 3D shell discretization is adopted for the rectum and the bladder, whereas a volume discretization is adopted for the prostate. As for the mechanical behavior modelling, first order Ogden hyperelastic constitutive laws for both the rectum and bladder are identified. The prostate is comparatively considered as more rigid and is accordingly modelled as an elastic tissue undergoing small strains. A FE model is then created, accounting for boundary and contact conditions, internal and applied loadings being selected as close as possible to available anatomic data. The order of magnitude of the prostate motion predicted by the FE simulations is similar to the measurements done on a deceased person, accounting for the delineation errors, with a relative error around 8%. Differences are essentially due to uncertainties in the constitutive parameters, pointing towards the need for the setting up of direct measurement of the organs mechanical behavior.

  14. Dosimetric and radiobiological comparison of volumetric modulated arc therapy, high-dose rate brachytherapy, and low-dose rate permanent seeds implant for localized prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ruijie, E-mail: ruijyang@yahoo.com; Zhao, Nan; Liao, Anyan; Wang, Hao; Qu, Ang

    2016-10-01

    To investigate the dosimetric and radiobiological differences among volumetric modulated arc therapy (VMAT), high-dose rate (HDR) brachytherapy, and low-dose rate (LDR) permanent seeds implant for localized prostate cancer. A total of 10 patients with localized prostate cancer were selected for this study. VMAT, HDR brachytherapy, and LDR permanent seeds implant plans were created for each patient. For VMAT, planning target volume (PTV) was defined as the clinical target volume plus a margin of 5 mm. Rectum, bladder, urethra, and femoral heads were considered as organs at risk. A 78 Gy in 39 fractions were prescribed for PTV. For HDR and LDR plans, the dose prescription was D{sub 90} of 34 Gy in 8.5 Gy per fraction, and 145 Gy to clinical target volume, respectively. The dose and dose volume parameters were evaluated for target, organs at risk, and normal tissue. Physical dose was converted to dose based on 2-Gy fractions (equivalent dose in 2 Gy per fraction, EQD{sub 2}) for comparison of 3 techniques. HDR and LDR significantly reduced the dose to rectum and bladder compared with VMAT. The D{sub mean} (EQD{sub 2}) of rectum decreased 22.36 Gy in HDR and 17.01 Gy in LDR from 30.24 Gy in VMAT, respectively. The D{sub mean} (EQD{sub 2}) of bladder decreased 6.91 Gy in HDR and 2.53 Gy in LDR from 13.46 Gy in VMAT. For the femoral heads and normal tissue, the mean doses were also significantly reduced in both HDR and LDR compared with VMAT. For the urethra, the mean dose (EQD{sub 2}) was 80.26, 70.23, and 104.91 Gy in VMAT, HDR, and LDR brachytherapy, respectively. For localized prostate cancer, both HDR and LDR brachytherapy were clearly superior in the sparing of rectum, bladder, femoral heads, and normal tissue compared with VMAT. HDR provided the advantage in sparing of urethra compared with VMAT and LDR.

  15. Dosimetric and radiobiological comparison of volumetric modulated arc therapy, high-dose rate brachytherapy, and low-dose rate permanent seeds implant for localized prostate cancer

    International Nuclear Information System (INIS)

    Yang, Ruijie; Zhao, Nan; Liao, Anyan; Wang, Hao; Qu, Ang

    2016-01-01

    To investigate the dosimetric and radiobiological differences among volumetric modulated arc therapy (VMAT), high-dose rate (HDR) brachytherapy, and low-dose rate (LDR) permanent seeds implant for localized prostate cancer. A total of 10 patients with localized prostate cancer were selected for this study. VMAT, HDR brachytherapy, and LDR permanent seeds implant plans were created for each patient. For VMAT, planning target volume (PTV) was defined as the clinical target volume plus a margin of 5 mm. Rectum, bladder, urethra, and femoral heads were considered as organs at risk. A 78 Gy in 39 fractions were prescribed for PTV. For HDR and LDR plans, the dose prescription was D 90 of 34 Gy in 8.5 Gy per fraction, and 145 Gy to clinical target volume, respectively. The dose and dose volume parameters were evaluated for target, organs at risk, and normal tissue. Physical dose was converted to dose based on 2-Gy fractions (equivalent dose in 2 Gy per fraction, EQD 2 ) for comparison of 3 techniques. HDR and LDR significantly reduced the dose to rectum and bladder compared with VMAT. The D mean (EQD 2 ) of rectum decreased 22.36 Gy in HDR and 17.01 Gy in LDR from 30.24 Gy in VMAT, respectively. The D mean (EQD 2 ) of bladder decreased 6.91 Gy in HDR and 2.53 Gy in LDR from 13.46 Gy in VMAT. For the femoral heads and normal tissue, the mean doses were also significantly reduced in both HDR and LDR compared with VMAT. For the urethra, the mean dose (EQD 2 ) was 80.26, 70.23, and 104.91 Gy in VMAT, HDR, and LDR brachytherapy, respectively. For localized prostate cancer, both HDR and LDR brachytherapy were clearly superior in the sparing of rectum, bladder, femoral heads, and normal tissue compared with VMAT. HDR provided the advantage in sparing of urethra compared with VMAT and LDR.

  16. Concordance of gonorrhoea of the rectum, pharynx and urethra in same-sex male partnerships attending a sexual health service in Melbourne, Australia.

    Science.gov (United States)

    Cornelisse, Vincent J; Zhang, Lei; Law, Matthew; Chen, Marcus Y; Bradshaw, Catriona S; Bellhouse, Clare; Fairley, Christopher K; Chow, Eric P F

    2018-02-27

    We aimed to describe anatomic site-specific concordance of gonococcal infections in partnerships of men who have sex with men (MSM). We conducted a cross-sectional analysis of data from MSM partnerships attending Melbourne Sexual Health Centre between March 2011 and February 2015. Logistic regression models (random effect) were used to examine the association between gonococcal infections of the urethra, rectum and pharynx. Gonococci were detected by culture at all anatomic sites. The analysis included 495 partnerships. Of the men with urethral gonorrhoea, 33% (95% CI 18-52) had partners with pharyngeal gonorrhoea and 67% (95% CI 48-82) had partners with rectal gonorrhoea. The adjusted odds of having urethral gonorrhoea was 4.6 (95% CI 1.2-17.1) for a man whose partner had pharyngeal gonorrhoea, and 48.1 (95% CI 18.3-126.7) for a man whose partner had rectal gonorrhoea. Of the men with rectal gonorrhoea, 46% (95% CI 31-61) had a partner with urethral gonorrhoea and 23% (95% CI 12-37) had a partner with pharyngeal gonorrhoea. The adjusted odds of having rectal gonorrhoea was 63.9 (95% CI 24.7-165.6) for a man whose partner had urethral gonorrhoea. Of the men with pharyngeal gonorrhoea, 42% (95% CI 23-63) had a partner with rectal gonorrhoea and 23% (95% CI 9-44) had a partner with had a partner with pharyngeal gonorrhoea. The adjusted odds of having pharyngeal gonorrhoea was 8.9 (95% CI 3.2-24.6) for a man whose partner had rectal gonorrhoea. The crude odds of having pharyngeal gonorrhoea was 14.2 (95% CI 5.1-39.0) for a man whose partner had pharyngeal gonorrhoea. These data provide the first estimates of concordance of anatomic site-specific gonococcal infections in MSM partnerships, and confirm that urethral gonorrhoea is contracted from both rectal and pharyngeal sites, and suggest that gonococci transmit between the rectum and pharynx. However, due to use of culture rather than NAAT, our analysis was not adequately powered to assess pharynx

  17. External beam radiotherapy of localized prostatic adenocarcinoma. Evaluation of conformal therapy, field number and target margins

    International Nuclear Information System (INIS)

    Lennernaes, B.; Rikner, G.; Letocha, H.; Nilsson, S.

    1995-01-01

    The purpose of the present study was to identify factors of importance in the planning of external beam radiotherapy of prostatic adenocarcinoma. Seven patients with urogenital cancers were planned for external radiotherapy of the prostate. Four different techniques were used, viz. a 4-field box technique and four-, five- or six-field conformal therapy set-ups combined with three different margins (1-3 cm). The evaluations were based on the doses delivered to the rectum and the urinary bladder. A normal tissue complication probability (NTCP) was calculated for each plan using Lyman's dose volume reduction method. The most important factors that resulted in a decrease of the dose delivered to the rectum and the bladder were the use of conformal therapy and smaller margins. Conformal therapy seemed more important for the dose distribution in the urinary bladder. Five- and six-field set-ups were not significantly better than those with four fields. NTCP calculations were in accordance with the evaluation of the dose volume histograms. To conclude, four-field conformal therapy utilizing reduced margins improves the dose distribution to the rectum and the urinary bladder in the radiotherapy of prostatic adenocarcinoma. (orig.)

  18. A knowledge-based approach to improving and homogenizing intensity modulated radiation therapy planning quality among treatment centers: an example application to prostate cancer planning.

    Science.gov (United States)

    Good, David; Lo, Joseph; Lee, W Robert; Wu, Q Jackie; Yin, Fang-Fang; Das, Shiva K

    2013-09-01

    Intensity modulated radiation therapy (IMRT) treatment planning can have wide variation among different treatment centers. We propose a system to leverage the IMRT planning experience of larger institutions to automatically create high-quality plans for outside clinics. We explore feasibility by generating plans for patient datasets from an outside institution by adapting plans from our institution. A knowledge database was created from 132 IMRT treatment plans for prostate cancer at our institution. The outside institution, a community hospital, provided the datasets for 55 prostate cancer cases, including their original treatment plans. For each "query" case from the outside institution, a similar "match" case was identified in the knowledge database, and the match case's plan parameters were then adapted and optimized to the query case by use of a semiautomated approach that required no expert planning knowledge. The plans generated with this knowledge-based approach were compared with the original treatment plans at several dose cutpoints. Compared with the original plan, the knowledge-based plan had a significantly more homogeneous dose to the planning target volume and a significantly lower maximum dose. The volumes of the rectum, bladder, and femoral heads above all cutpoints were nominally lower for the knowledge-based plan; the reductions were significantly lower for the rectum. In 40% of cases, the knowledge-based plan had overall superior (lower) dose-volume histograms for rectum and bladder; in 54% of cases, the comparison was equivocal; in 6% of cases, the knowledge-based plan was inferior for both bladder and rectum. Knowledge-based planning was superior or equivalent to the original plan in 95% of cases. The knowledge-based approach shows promise for homogenizing plan quality by transferring planning expertise from more experienced to less experienced institutions. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Dosimetric comparison of standard three-dimensional conformal radiotherapy followed by intensity-modulated radiotherapy boost schedule (sequential IMRT plan) with simultaneous integrated boost-IMRT (SIB IMRT) treatment plan in patients with localized carcinoma prostate.

    Science.gov (United States)

    Bansal, A; Kapoor, R; Singh, S K; Kumar, N; Oinam, A S; Sharma, S C

    2012-07-01

    DOSIMETERIC AND RADIOBIOLOGICAL COMPARISON OF TWO RADIATION SCHEDULES IN LOCALIZED CARCINOMA PROSTATE: Standard Three-Dimensional Conformal Radiotherapy (3DCRT) followed by Intensity Modulated Radiotherapy (IMRT) boost (sequential-IMRT) with Simultaneous Integrated Boost IMRT (SIB-IMRT). Thirty patients were enrolled. In all, the target consisted of PTV P + SV (Prostate and seminal vesicles) and PTV LN (lymph nodes) where PTV refers to planning target volume and the critical structures included: bladder, rectum and small bowel. All patients were treated with sequential-IMRT plan, but for dosimetric comparison, SIB-IMRT plan was also created. The prescription dose to PTV P + SV was 74 Gy in both strategies but with different dose per fraction, however, the dose to PTV LN was 50 Gy delivered in 25 fractions over 5 weeks for sequential-IMRT and 54 Gy delivered in 27 fractions over 5.5 weeks for SIB-IMRT. The treatment plans were compared in terms of dose-volume histograms. Also, Tumor Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) obtained with the two plans were compared. The volume of rectum receiving 70 Gy or more (V > 70 Gy) was reduced to 18.23% with SIB-IMRT from 22.81% with sequential-IMRT. SIB-IMRT reduced the mean doses to both bladder and rectum by 13% and 17%, respectively, as compared to sequential-IMRT. NTCP of 0.86 ± 0.75% and 0.01 ± 0.02% for the bladder, 5.87 ± 2.58% and 4.31 ± 2.61% for the rectum and 8.83 ± 7.08% and 8.25 ± 7.98% for the bowel was seen with sequential-IMRT and SIB-IMRT plans respectively. For equal PTV coverage, SIB-IMRT markedly reduced doses to critical structures, therefore should be considered as the strategy for dose escalation. SIB-IMRT achieves lesser NTCP than sequential-IMRT.

  20. Prostate position late in the course of external beam therapy: patterns and predictors

    International Nuclear Information System (INIS)

    Zellars, Richard C.; Roberson, Peter L.; Strawderman, Myla; Zhang Daowen; Sandler, Howard M.; Haken, Randall K. ten; Osher, David; McLaughlin, P. William

    2000-01-01

    Purpose: To examine prostate and seminal vesicles position late in the course of radiation therapy and to determine the effect and predictive value of the bladder and rectum on prostate and seminal vesicles positioning. Methods and Materials: Twenty-four patients with localized prostate cancer underwent a computerized tomography scan (CT1) before the start of radiation therapy. After 4-5 weeks of radiation therapy, a second CT scan (CT2) was obtained. All patients were scanned in the supine treatment position with instructions to maintain a full bladder. The prostate, seminal vesicles, bladder, and rectum were contoured. CT2 was aligned via fixed bony anatomy to CT1. The geometrical center and volume of each structure were obtained and directly compared. Results: The prostate shifted along a diagonal axis extending from an anterior-superior position to a posterior-inferior position. The dominant shift was to a more posterior-inferior position. On average, bladder and rectal volumes decreased to 51% (no. +-no. 29%) and 82% (no. +-no. 45%) of their pretreatment values, respectively. Multiple regression analysis (MRA) revealed that bladder movement and volume change and upper rectum movement were independently associated with prostate motion (p = 0.016, p = 0.003, and p = 0.052 respectively). Conclusion: Patients are often instructed to maintain a full bladder during a course of external beam radiation therapy, in the hopes of decreasing bladder and small bowel toxicity. However, our study shows that large bladder volumes late in therapy are strongly associated with posterior prostate displacement. This prostate displacement may result in marginal miss

  1. Metastatic Malignancy to the Colon and Rectum: A Report of 14 Cases from One Single Institute.

    Science.gov (United States)

    Lin, Chi-Chun; Lin, Chun-Chi; Chen, Wei-Shone; Lin, Tzu-Chen; Lin, Jen-Kou; Jiang, Jeng-Kai

    2017-10-31

    Metastatic malignancy occurs rarely in the colon or rectum. We presented 14 patients with colorectal metastasis (CRM). A retrospective review was conducted on a computerized colorectal tumor database at the Taipei Veterans General Hospital from January 2000 to June 2013. The incidence of CRM was 0.19% (14 in 7,524 patients). There were 6 males and 8 females with a mean age of 66.9 ± 13.6 years. Origins of the CRM included lung cancers (n = 3), prostate cancers (n = 2), and others (n = 1, respectively). Clinical presentations were not specific and colonoscopic pictures were indistinguishable from primary colorectal cancers; 5 of the 9 biopsies identified metastasis. Eight patients had extracolonic metastasis and 6 patients had CRM only. Significantly better survival was observed in the CRM-only group (p = 0.037). The mean interval from the treatment of primary tumor to the diagnosis of CRM was 30.2 ± 49.0 months. The mean survival time after CRM was 24.9 ± 30.8 months. Clinical features and colonoscopic findings of CRM were indistinguishable from primary colorectal cancer. Histopathological review of the biopsy could be helpful in identifying the primary lesion. Surgical resection with curative intent provided longer survival in CRM-only patients. © 2017 S. Karger AG, Basel.

  2. Dosimetric advantage and clinical implication of a micro-multileaf collimator in the treatment of prostate with intensity-modulated radiotherapy

    International Nuclear Information System (INIS)

    Wang Lu; Hoban, Peter; Paskalev, Kamen; Yang Jie; Li Jinsheng; Chen Lili; Xiong Weijun; Ma, Charlie

    2005-01-01

    This paper investigates the dosimetric benefits of a micro-multileaf (4-mm leaf width) collimator (mMLC) for intensity-modulated radiation therapy (IMRT) treatment planning of the prostate cancer and its potential application for dose escalation and hypofractionation. We compared treatment plans for IMRT delivery using 2 different multileaf collimator (MLC) leaf widths (4 vs. 10 mm) for 10 patients with prostate cancer. Treatment planning was performed on the XknifeRT2 treatment planning system. All beams and optimization parameters were identical for the mMLC and MLC plans. All of the plans were normalized to ensure that 95% of the planning target volume (PTV) received 100% of the prescribed dose (74 Gy). The differences in dose distribution between the 2 groups of plans using the mMLC and the MLC were assessed by dose-volume histogram (DVH) analysis of the target and critical organs. Significant reductions in the volume of rectum receiving medium to higher doses were achieved using the mMLC. The average decrease in the volume of the rectum receiving 40, 50, and 60 Gy using the mMLC plans was 40.2%, 33.4%, and 17.7%, respectively, with p-values less than 0.0001 for V 40 and V 50 and 0.012 for V 60 . The mean dose reductions for D 17 and D 35 for the rectum were 20.0% (p 0.78). Because of the reduction of rectal volume receiving medium to higher doses, dose to the prostate target can be escalated by about 20 Gy to over 74 Gy, while keeping the rectal dose (either denoted by D 17 or D 35 ) the same as those with the use of the MLC. The maximum achievable dose, derived when the rectum is allowed to reach the tolerance level, was found to be in the range of 113-172 Gy (using the tolerance value of D 17 ). We conclude that the use of the mMLC for IMRT of the prostate may facilitate dose hypofractionation due to its dosimetric advantage in significantly improving the DVH parameters of the prostate and critical organs. When used for conventional fractionation scheme, m

  3. Early toxicity from preoperative radiotherapy with continuous infusion 5-fluorouracil for resectable adenocarcinoma of the rectum: a Phase II trial for the Trans-Tasman Radiation Oncology Group

    International Nuclear Information System (INIS)

    Ngan, Samuel Y.K.; Burmeister, Bryan H.; Fisher, Richard; Rischin, Danny; Schache, David J.; Kneebone, Andrew; MacKay, John R.; Joseph, David; Bell, Andrew; Goldstein, David

    2001-01-01

    Purpose: To assess the toxicity and the efficacy of preoperative radiotherapy with continuous infusion 5-fluorouracil (5-FU) for locally advanced adenocarcinoma of the rectum. Methods and Materials: Eligible patients had newly diagnosed localized adenocarcinoma of the rectum within 12 cm of the anal verge, Stage T3-4, and were suitable for curative resection. Eighty-two patients were treated with radiotherapy--50.4 Gy in 28 fractions in 5.6 weeks, given concurrently with continuous infusion 5-FU, using either 96-h/week infusion at 300 mg/m 2 /day or 7-days/week infusion at 225 mg/m 2 /day. Results: The median age was 59 years (range, 27-87), and 67% of patients were male. Pretreatment stages of the rectal cancer were T3, 89% and resectable T4, 11%, with endorectal ultrasound confirmation in 67% of patients. Grade 3 acute toxicity occurred in 5 of 82 patients (6%; 95% confidence interval [CI], 2-14%). Types of surgical resection were anterior resection, 61%; abdominoperineal resection, 35%; and other procedures, 4%. There was no operative mortality. Anastomotic leakage after low anterior resection occurred in 3 of 50 patients (6%; 95% CI, 1-17%). The pathologic complete response rate was 16% (95% CI, 9-26%). Pathologic Stages T2 or less occurred in 51%. Conclusion: Preoperative radiotherapy with continuous infusion 5-FU for locally advanced rectal cancer is a safe regimen, with a significant downstaging effect. It does not seem to lead to a significant increase in serious surgical complications

  4. cExternal beam radiation results in minimal changes in post void residual urine volumes during the treatment of clinically localized prostate cancer

    International Nuclear Information System (INIS)

    Orio, Peter F III; Merrick, Gregory S; Allen, Zachariah A; Butler, Wayne M; Wallner, Kent E; Kurko, Brian S; Galbreath, Robert W

    2009-01-01

    To evaluate the impact of external beam radiation therapy (XRT) on weekly ultrasound determined post-void residual (PVR) urine volumes in patients with prostate cancer. 125 patients received XRT for clinically localized prostate cancer. XRT was delivered to the prostate only (n = 66) or if the risk of lymph node involvement was greater than 10% to the whole pelvis followed by a prostate boost (n = 59). All patients were irradiated in the prone position in a custom hip-fix mobilization device with an empty bladder and rectum. PVR was obtained at baseline and weekly. Multiple clinical and treatment parameters were evaluated as predictors for weekly PVR changes. The mean patient age was 73.9 years with a mean pre-treatment prostate volume of 53.3 cc, a mean IPSS of 11.3 and a mean baseline PVR of 57.6 cc. During treatment, PVR decreased from baseline in both cohorts with the absolute difference within the limits of accuracy of the bladder scanner. Alpha-blockers did not predict for a lower PVR during treatment. There was no significant difference in mean PVR urine volumes or differences from baseline in either the prostate only or pelvic radiation groups (p = 0.664 and p = 0.458, respectively). Patients with a larger baseline PVR (>40 cc) had a greater reduction in PVR, although the greatest reduction was seen between weeks one and three. Patients with a small PVR (<40 cc) had no demonstrable change throughout treatment. Prostate XRT results in clinically insignificant changes in weekly PVR volumes, suggesting that radiation induced bladder irritation does not substantially influence bladder residual urine volumes

  5. cExternal beam radiation results in minimal changes in post void residual urine volumes during the treatment of clinically localized prostate cancer

    Directory of Open Access Journals (Sweden)

    Wallner Kent E

    2009-07-01

    Full Text Available Abstract Background To evaluate the impact of external beam radiation therapy (XRT on weekly ultrasound determined post-void residual (PVR urine volumes in patients with prostate cancer. Methods 125 patients received XRT for clinically localized prostate cancer. XRT was delivered to the prostate only (n = 66 or if the risk of lymph node involvement was greater than 10% to the whole pelvis followed by a prostate boost (n = 59. All patients were irradiated in the prone position in a custom hip-fix mobilization device with an empty bladder and rectum. PVR was obtained at baseline and weekly. Multiple clinical and treatment parameters were evaluated as predictors for weekly PVR changes. Results The mean patient age was 73.9 years with a mean pre-treatment prostate volume of 53.3 cc, a mean IPSS of 11.3 and a mean baseline PVR of 57.6 cc. During treatment, PVR decreased from baseline in both cohorts with the absolute difference within the limits of accuracy of the bladder scanner. Alpha-blockers did not predict for a lower PVR during treatment. There was no significant difference in mean PVR urine volumes or differences from baseline in either the prostate only or pelvic radiation groups (p = 0.664 and p = 0.458, respectively. Patients with a larger baseline PVR (>40 cc had a greater reduction in PVR, although the greatest reduction was seen between weeks one and three. Patients with a small PVR ( Conclusion Prostate XRT results in clinically insignificant changes in weekly PVR volumes, suggesting that radiation induced bladder irritation does not substantially influence bladder residual urine volumes.

  6. Results of the Accord 12/0405- prodige 2 randomized test in the rectum cancers of stage T(2) 3-4 NX M0; Resultat de l'essai randomise Accord 12/0405-prodige 2 dans les cancers du rectum de stade T(2) 3-4 NX M0

    Energy Technology Data Exchange (ETDEWEB)

    Gerard, J.P.; Benezery, K. [Centre Antoine-Lacassagne, 06 - Nice (France); Azria, D.; Gourgou-Bourgade, S. [CRLCC Val d' Aurelle-Paul-Lamarque, 34 - Montpellier (France); Martel-Laffay, I. [Centre Leon-Berard, 69 - Lyon (France); Hennequin, C. [Hopital St-Louis, 75 - Paris (France); Etienne, P.L. [Clinique Armoricaine de Radiologie, 22 - Saint-Brieuc (France); Vendrely, V. [CHU, 33 - Bordeaux (France); Peiffert, D. [Centre Alexis-Vautrin, 54 - Nancy (France); Montoto-Grillot, C. [FNCLCC-BECT, 75 - Paris (France)

    2009-10-15

    The Capox 50 protocol increase the early toxicity without reducing the possibilities of surgery. It does not increase neither the sphincter conservation rate nor the surgery complications. It improves noticeably the histological tumor response (ypT) and the negative circumferential margin rate. The Star Italian protocol randomized for similar patients exclusively oxaliplatin, without increasing the histological tumor response rate and with 25% of grade 3 or 4 early toxicity. In comparison between the tests Accord 12 and Star it is possible to propose as neoadjuvant treatment of these rectum cancers (stage T3-4 Mo) a Cape 50 protocol associating a 50 Gy radiotherapy in 25 fractions and five weeks and a concomitant chemotherapy (capecitabine: 1600 mg/M{sup 2}/d). The oxaliplatin can be proposed out of radiotherapy to eradicate the infra clinical metastases. (N.C.)

  7. Dosimetric Consequences of Interobserver Variability in Delineating the Organs at Risk in Gynecologic Interstitial Brachytherapy

    International Nuclear Information System (INIS)

    Damato, Antonio L.; Townamchai, Kanopkis; Albert, Michele; Bair, Ryan J.; Cormack, Robert A.; Jang, Joanne; Kovacs, Arpad; Lee, Larissa J.; Mak, Kimberley S.; Mirabeau-Beale, Kristina L.; Mouw, Kent W.; Phillips, John G.; Pretz, Jennifer L.; Russo, Andrea L.; Lewis, John H.; Viswanathan, Akila N.

    2014-01-01

    Purpose: To investigate the dosimetric variability associated with interobserver organ-at-risk delineation differences on computed tomography in patients undergoing gynecologic interstitial brachytherapy. Methods and Materials: The rectum, bladder, and sigmoid of 14 patients treated with gynecologic interstitial brachytherapy were retrospectively contoured by 13 physicians. Geometric variability was calculated using κ statistics, conformity index (CI gen ), and coefficient of variation (CV) of volumes contoured across physicians. Dosimetric variability of the single-fraction D 0.1cc and D 2cc was assessed through CV across physicians, and the standard deviation of the total EQD2 (equivalent dose in 2 Gy per fraction) brachytherapy dose (SD TOT ) was calculated. Results: The population mean ± 1 standard deviation of κ, CI gen , and volume CV were, respectively: 0.77 ± 0.06, 0.70 ± 0.08, and 20% ± 6% for bladder; 0.74 ± 06, 0.67 ± 0.08, and 20% ± 5% for rectum; and 0.33 ± 0.20, 0.26 ± 0.17, and 82% ± 42% for sigmoid. Dosimetric variability was as follows: for bladder, CV = 31% ± 19% (SD TOT = 72 ± 64 Gy) for D 0.1cc and CV = 16% ± 10% (SD TOT = 9 ± 6 Gy) for D 2cc ; for rectum, CV = 11% ± 5% (SD TOT = 16 ± 17 Gy) for D 0.1cc and CV = 7% ± 2% (SD TOT = 4 ± 3 Gy) for D 2cc ; for sigmoid, CV = 39% ± 28% (SD TOT = 12 ± 18 Gy) for D 0.1cc and CV = 34% ± 19% (SD TOT = 4 ± 4 Gy) for D 2cc. Conclusions: Delineation of bladder and rectum by 13 physicians demonstrated substantial geometric agreement and resulted in good dosimetric agreement for all dose-volume histogram parameters except bladder D 0.1cc. Small delineation differences in high-dose regions by the posterior bladder wall may explain these results. The delineation of sigmoid showed fair geometric agreement. The higher dosimetric variability for sigmoid compared with rectum and bladder did not correlate with higher variability in the total brachytherapy dose but rather may be due to the

  8. Detecting sentinel lymph nodes in caner cases of lower and middle rectum following lymphoscintigraphy

    International Nuclear Information System (INIS)

    Dontshev, M.; Dimitrov, D.; Deliysky, T.; Tsarowska, T.; Slavova, M.; Dekova, M.

    2006-01-01

    Full text: The lymphoscintigraphy and the interoperative gamma probing for through detection of the marked with radiocolloid sentinel lymph nodes (SLN) in the cases of patients having cancer in the lower and middle third of the rectum (CLMTR) are with minimum clinical experience in Bulgaria. The aim of the study is to examine the elaboration on the subject and introduction of nuclear medical methods for preoperative marking and representation of SLN and their interoperative finding thanks to gamma probing in the cases of CLMTR. This research covers 14 patients having CLMTR (3 females and 11 males) at the age of 55 - 80 (average 76,5), of whom 17 - 20 hours before the operation was carried out lymphoscintigraphy of two-headed SPECT gamma camera Toshiba CGA7200UI with 99mTc colloid applied transanal submycotic. The interoperative finding of SLN was made by the means of detection with manual gamma probe Silicone instruments. The lymphoscintigraphy visualized in 13 patients 11 SLN, and in one patient the examination was negative. The interoperative gamma sounding established the presence of activity in 12 SLN, 8 of them mezenterial and 4 of them - extramezenterial. The immunohistological examination of the biopsied 12 SLN found metastasis in two mezenterial SLN. In the rest 10 SLN there were no indications for metastatic process. The preliminary results show that the used from us nuclear medical methods are applicable for marking and finding of SLN in the cases of CLMTR aiming improvement the staging of the illness

  9. The clinical value of 201Tl per rectum scintigraphy in the work-up of patients with alcoholic liver disease

    International Nuclear Information System (INIS)

    Urbain, D.; Reding, P.; Georges, B.; Thys, O.; Ham, H.R.; Vrije Univ., Brussels

    1986-01-01

    The clinical value of thallium 201 per rectum scintigraphy in the work-up of patients with alcoholic liver disease was evaluated using data obtained in 104 patients. The 25th min ratio of heart to liver activities was used as an index of portal systemic shunting. This ratio was found to be normal in alcoholic patients with normal liver biopsy and also in those presenting only steatosis. It was slightly higher in patients with liver fibrosis and significantly higher values were observed in patients with liver cirrhosis. High values of the ratio were associated with a higher risk of portal systemic encephalopathy and/or gastrointestinal bleeding. The prognostic value of the test was supported by the fact that good correlations were observed between the ratio and widely accepted prognostic scores such as the Child score or the Orrego index. Moreover, high ratios were associated with an increased mortality risk at one year. We conclude that this simple test is interesting in the screening of cirrhotics at risk of encephalopathy, gastrointestinal hemorrhage, or early death. (orig.)

  10. Increased Risk of Biochemical and Clinical Failure for Prostate Patients with a Large Rectum at Radiotherapy Planning: Results from the Dutch Trial of 68 GY Versus 78 Gy

    International Nuclear Information System (INIS)

    Heemsbergen, Wilma D.; Hoogeman, Mischa S.; Witte, Marnix G.; Peeters, Stephanie T.H.; Incrocci, Luca; Lebesque, Joos V.

    2007-01-01

    Purpose: To investigate whether a large rectum filling visible on the planning CT scan was associated with a decrease in freedom from any failure (FFF) and freedom from clinical failure (FFCF) for prostate cancer patients. Methods and Materials: Patients from the Dutch trial (78 Gy vs. 68 Gy) with available acute toxicity data were analyzed (n = 549). A 10-mm margin was applied for the first 68 Gy and 0-5 mm for the 10-Gy boost. The dose in the seminal vesicles (SVs) was prescribed within four treatment groups according to the estimated risk of SV involvement. Two potential risk factors (RFs) for a geometric miss were defined: (1) an anorectal volume ≥ 90 cm 3 and ≥ 25% of treatment-time diarrhea (RF1); and (2) the mean cross-sectional area of the anorectum (RF2). We tested whether these were significant predictors for FFF and FFCF within each treatment group. Results: Significant results were observed only for patients with a risk of SV involvement > 25% (dose of 68-78 Gy to the SVs, n = 349). We found a decrease in FFF (p = 0.001) and FFCF (p = 0.01) for the 87 patients with RF1 (for RF2, p = 0.02 and p = 0.01, respectively). The estimated decrease in the FFCF rate at 5 years was 15%. Conclusion: Tumor control was significantly decreased in patients with a risk of SV involvement > 25% and at risk of geometric miss. Current image guidance techniques offer several solutions to geometrically optimize the treatment. Additional research is needed to evaluate whether geometric misses can be prevented using these techniques

  11. 110 East and Central African Journal of Surgery Volume 12 Number ...

    African Journals Online (AJOL)

    Josephine Nakato

    Background: Anorectal malformations (ARM) are comprised of a wide spectrum of disease that involves congenital anomalies of the anus and rectum, as well as the urinary and genital tracts. They occur in approximately 1 in 5000 live births and affect males more than females. They may present as a single or as a ...

  12. EURECCA colorectal: multidisciplinary management: European consensus conference colon & rectum.

    Science.gov (United States)

    van de Velde, Cornelis J H; Boelens, Petra G; Borras, Josep M; Coebergh, Jan-Willem; Cervantes, Andres; Blomqvist, Lennart; Beets-Tan, Regina G H; van den Broek, Colette B M; Brown, Gina; Van Cutsem, Eric; Espin, Eloy; Haustermans, Karin; Glimelius, Bengt; Iversen, Lene H; van Krieken, J Han; Marijnen, Corrie A M; Henning, Geoffrey; Gore-Booth, Jola; Meldolesi, Elisa; Mroczkowski, Pawel; Nagtegaal, Iris; Naredi, Peter; Ortiz, Hector; Påhlman, Lars; Quirke, Philip; Rödel, Claus; Roth, Arnaud; Rutten, Harm; Schmoll, Hans J; Smith, Jason J; Tanis, Pieter J; Taylor, Claire; Wibe, Arne; Wiggers, Theo; Gambacorta, Maria A; Aristei, Cynthia; Valentini, Vincenzo

    2014-01-01

    Care for patients with colon and rectal cancer has improved in the last 20years; however considerable variation still exists in cancer management and outcome between European countries. Large variation is also apparent between national guidelines and patterns of cancer care in Europe. Therefore, EURECCA, which is the acronym of European Registration of Cancer Care, is aiming at defining core treatment strategies and developing a European audit structure in order to improve the quality of care for all patients with colon and rectal cancer. In December 2012, the first multidisciplinary consensus conference about cancer of the colon and rectum was held. The expert panel consisted of representatives of European scientific organisations involved in cancer care of patients with colon and rectal cancer and representatives of national colorectal registries. The expert panel had delegates of the European Society of Surgical Oncology (ESSO), European Society for Radiotherapy & Oncology (ESTRO), European Society of Pathology (ESP), European Society for Medical Oncology (ESMO), European Society of Radiology (ESR), European Society of Coloproctology (ESCP), European CanCer Organisation (ECCO), European Oncology Nursing Society (EONS) and the European Colorectal Cancer Patient Organisation (EuropaColon), as well as delegates from national registries or audits. Consensus was achieved using the Delphi method. For the Delphi process, multidisciplinary experts were invited to comment and vote three web-based online voting rounds and to lecture on the subjects during the meeting (13th-15th December 2012). The sentences in the consensus document were available during the meeting and a televoting round during the conference by all participants was performed. This manuscript covers all sentences of the consensus document with the result of the voting. The consensus document represents sections on diagnostics, pathology, surgery, medical oncology, radiotherapy, and follow-up where

  13. Endoscopic vacuum-assisted closure of anastomotic leakage following anterior resection of the rectum: a new method.

    Science.gov (United States)

    Weidenhagen, Rolf; Gruetzner, Klaus Uwe; Wiecken, Timm; Spelsberg, Fritz; Jauch, Karl-Walter

    2008-08-01

    Conservative treatment of anastomotic leakage after anterior resection of the rectum seems to be possible in patients who have no occurrence of generalized peritonitis. This report describes a new method of endoscopic management of large anastomotic leakage in these patients. The main feature of this new method is the endoscopically assisted placement of an open-cell sponge connected to a vacuum device into the abscess cavity via an introducer device. The sponge system is changed every 48-72 h. Twenty-nine patients with an anastomotic leakage after anterior resection were treated with the endoscopic vacuum therapy. The total duration of endovac therapy was 34.4 +/- 19.4 days. The total number of endoscopic sessions per patient was 11.4 +/- 6.3. In 21 of the 29 patients, a protecting stoma was created at the primary operation. Four patients were treated successfully without the need of a secondary stoma. Definitive healing was achieved in 28 of the 29 patients. Endoscopic vacuum-assisted closure is a new efficacious modality for treating anastomotic leakage following anterior resection due to an effective control of the septic focus. Further studies will show if it is possible to reduce the high mortality rate of patients with anastomotic leakage through the avoidance of surgical reinterventions while at the same time preserving the sphincter function.

  14. Utilization of cone-beam CT for offline evaluation of target volume coverage during prostate image-guided radiotherapy based on bony anatomy alignment.

    Science.gov (United States)

    Paluska, Petr; Hanus, Josef; Sefrova, Jana; Rouskova, Lucie; Grepl, Jakub; Jansa, Jan; Kasaova, Linda; Hodek, Miroslav; Zouhar, Milan; Vosmik, Milan; Petera, Jiri

    2012-01-01

    To assess target volume coverage during prostate image-guided radiotherapy based on bony anatomy alignment and to assess possibility of safety margin reduction. Implementation of IGRT should influence safety margins. Utilization of cone-beam CT provides current 3D anatomic information directly in irradiation position. Such information enables reconstruction of the actual dose distribution. Seventeen prostate patients were treated with daily bony anatomy image-guidance. Cone-beam CT (CBCT) scans were acquired once a week immediately after bony anatomy alignment. After the prostate, seminal vesicles, rectum and bladder were contoured, the delivered dose distribution was reconstructed. Target dose coverage was evaluated by the proportion of the CTV encompassed by the 95% isodose. Original plans employed a 1 cm safety margin. Alternative plans assuming a smaller 7 mm margin between CTV and PTV were evaluated in the same way. Rectal and bladder volumes were compared with the initial ones. Rectal and bladder volumes irradiated with doses higher than 75 Gy, 70 Gy, 60 Gy, 50 Gy and 40 Gy were analyzed. In 12% of reconstructed plans the prostate coverage was not sufficient. The prostate underdosage was observed in 5 patients. Coverage of seminal vesicles was not satisfactory in 3% of plans. Most of the target underdosage corresponded to excessive rectal or bladder filling. Evaluation of alternative plans assuming a smaller 7 mm margin revealed 22% and 11% of plans where prostate and seminal vesicles coverage, respectively, was compromised. These were distributed over 8 and 7 patients, respectively. Sufficient dose coverage of target volumes was not achieved for all patients. Reducing of safety margin is not acceptable. Initial rectal and bladder volumes cannot be considered representative for subsequent treatment.

  15. Role of image-guided patient repositioning and online planning in localized prostate cancer IMRT

    International Nuclear Information System (INIS)

    Lerma, Fritz A.; Liu, Bei; Wang, Zhendong; Yi, Byongyong; Amin, Pradip; Liu, Sandy; Feng Yuanming; Yu, Cedric X.

    2009-01-01

    Purpose: To determine the expected benefit of image-guided online replanning over image-guided repositioning of localized prostate cancer intensity-modulated radiotherapy (IMRT). Materials and methods: On 10 to 11 CT scans of each of 10 early-stage prostate cancer patients, the prostate, bladder and rectum are manually segmented. Using a 3-mm PTV margin expansion from the CTV, an IMRT plan is made on the first CT scan of each patient. Online repositioning is simulated by recalculating the IMRT plan from the initial CT scan on the subsequent CT scans of each patient. For online replanning, IMRT is replanned twice on all CT scans, using 0-mm and 3-mm margins. The doses from subsequent CT images of each patient are then deformed to the initial CT anatomy using a mesh-based thin-plate B-spline deformation method and are accumulated for DVH and isodose review. Results: Paired t-tests show that online replanning with 3-mm margins significantly increases the prostate volume receiving the prescribed dose over replanning with 0-mm margins (p-value 0.004); gives marginally better target coverage than repositioning with 3-mm margins(p-value 0.06-0.343), and reduces variations in target coverage over repositioning. Fractional volumes of rectum and bladder receiving 75%, 80%, 85%, 90%, and 95% (V75, V80, V85, V90, and V95) of the prescription dose are evaluated. V90 and V95 values for the rectum are 1.6% and 0.7 % for 3-mm margin replanning and 1% and 0.4 % for 0-mm margin replanning, with p-values of 0.010-0.011. No significant differences between repositioning and replanning with 3-mm margins are found for both the rectum and the bladder. Conclusions: Image-guided replanning using 3-mm margins reduces target coverage variations, and maintains comparable rectum and bladder sparing to patient repositioning in localized prostate cancer IMRT. Marginal reductions in doses to rectum and bladder are possible when planning margins are eliminated in the online replanning scenario

  16. IMRT: Improvement in treatment planning efficiency using NTCP calculation independent of the dose-volume-histogram

    International Nuclear Information System (INIS)

    Grigorov, Grigor N.; Chow, James C.L.; Grigorov, Lenko; Jiang, Runqing; Barnett, Rob B.

    2006-01-01

    The normal tissue complication probability (NTCP) is a predictor of radiobiological effect for organs at risk (OAR). The calculation of the NTCP is based on the dose-volume-histogram (DVH) which is generated by the treatment planning system after calculation of the 3D dose distribution. Including the NTCP in the objective function for intensity modulated radiation therapy (IMRT) plan optimization would make the planning more effective in reducing the postradiation effects. However, doing so would lengthen the total planning time. The purpose of this work is to establish a method for NTCP determination, independent of a DVH calculation, as a quality assurance check and also as a mean of improving the treatment planning efficiency. In the study, the CTs of ten randomly selected prostate patients were used. IMRT optimization was performed with a PINNACLE3 V 6.2b planning system, using planning target volume (PTV) with margins in the range of 2 to 10 mm. The DVH control points of the PTV and OAR were adapted from the prescriptions of Radiation Therapy Oncology Group protocol P-0126 for an escalated prescribed dose of 82 Gy. This paper presents a new model for the determination of the rectal NTCP ( R NTCP). The method uses a special function, named GVN (from Gy, Volume, NTCP), which describes the R NTCP if 1 cm 3 of the volume of intersection of the PTV and rectum (R int ) is irradiated uniformly by a dose of 1 Gy. The function was 'geometrically' normalized using a prostate-prostate ratio (PPR) of the patients' prostates. A correction of the R NTCP for different prescribed doses, ranging from 70 to 82 Gy, was employed in our model. The argument of the normalized function is the R int , and parameters are the prescribed dose, prostate volume, PTV margin, and PPR. The R NTCPs of another group of patients were calculated by the new method and the resulting difference was <±5% in comparison to the NTCP calculated by the PINNACLE3 software where Kutcher's dose

  17. Polarization of Bremsstrahlung; Polarisation du rayonnement de freinage

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The numerical results for the polarization of Bremsstrahlung are presented. The multiple scattering of electrons in the target is taken into account. The angular-and photon energy dependences are seen on the curves for an incident 25 MeV electron energy. (Author) [French] Le taux de polarisation d'un spectre de rayonnement de freinage est calcule pour une cible d'epaisseur finie en tenant compte de la diffusion multiple des electrons dans la cible. Les courbes sont tracees pour les electrons incidents d'energie 25 MeV, pour differentes energies de photons, et a differents angles. (auteur)

  18. Influence des conditions initiales sur l'évolution d'une onde de choc induite par impulsion laser

    OpenAIRE

    Cottet , F.; Romain , J.P.

    1983-01-01

    L'évolution d'un choc de forte amplitude induit par une impulsion laser dans une cible solide est décrite à l'aide d'un modèle hydrodynamique, précisant un modèle antérieur par la prise en compte du déplacement de la surface avant de la cible sous l'effet de la pression d'ablation. Ce modèle est également utilisé pour étudier l'influence du profil initial de pression sur l'amortissement de l'onde de choc au cours de sa propagation.

  19. Impact of catheter reconstruction error on dose distribution in high dose rate intracavitary brachytherapy and evaluation of OAR doses

    International Nuclear Information System (INIS)

    Thaper, Deepak; Shukla, Arvind; Rathore, Narendra; Oinam, Arun S.

    2016-01-01

    In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this study is to evaluate the impact of catheter reconstruction error on dose distribution in CT based intracavitary brachytherapy planning and evaluation of its effect on organ at risk (OAR) like bladder, rectum and sigmoid and target volume High risk clinical target volume (HR-CTV)

  20. Improved robotic stereotactic body radiation therapy plan quality and planning efficacy for organ-confined prostate cancer utilizing overlap-volume histogram-driven planning methodology

    International Nuclear Information System (INIS)

    Wu, Binbin; Pang, Dalong; Lei, Siyuan; Gatti, John; Tong, Michael; McNutt, Todd; Kole, Thomas; Dritschilo, Anatoly; Collins, Sean

    2014-01-01

    Background and purpose: This study is to determine if the overlap-volume histogram (OVH)-driven planning methodology can be adapted to robotic SBRT (CyberKnife Robotic Radiosurgery System) to further minimize the bladder and rectal doses achieved in plans manually-created by clinical planners. Methods and materials: A database containing clinically-delivered, robotic SBRT plans (7.25 Gy/fraction in 36.25 Gy) of 425 patients with localized prostate cancer was used as a cohort to establish an organ’s distance-to-dose model. The OVH-driven planning methodology was refined by adding the PTV volume factor to counter the target’s dose fall-off effect and incorporated into Multiplan to automate SBRT planning. For validation, automated plans (APs) for 12 new patients were generated, and their achieved dose/volume values were compared to the corresponding manually-created, clinically-delivered plans (CPs). A two-sided, Wilcoxon rank-sum test was used for statistical comparison with a significance level of p < 0.05. Results: PTV’s V(36.25 Gy) was comparable: 95.6% in CPs comparing to 95.1% in APs (p = 0.2). On average, the refined approach lowered V(18.12 Gy) to the bladder and rectum by 8.2% (p < 0.05) and 6.4% (p = 0.14). A physician confirmed APs were clinically acceptable. Conclusions: The improvements in APs could further reduce toxicities observed in SBRT for organ-confined prostate cancer

  1. Comparison of hypo-fractional irradiation protocols used in the treatment of prostate cancer by external radiotherapy; Porovnanie hypofrakcionacnych ozarovacich protokolov pouzivanych v liecbe karcinomu prostaty pomocou externej radioterapie

    Energy Technology Data Exchange (ETDEWEB)

    Petruskova, B. [Univerzita Pavla Jozefa Safarika, Ustav fyzikalnych vied, Katedra jadrovej a subjadrovej fyziky, 04001 Kosice (Slovakia); Matula, P.; Koncik, J.; Jasencak, M. [Vychodoslovensky onkologicky ustav, a.s., 04001 Kosice (Slovakia)

    2013-04-16

    The main aim of this study is to compare two hypo-fractionated protocols used in the radiotherapy of prostate cancer in terms of late complications in normal tissue. 50 patients in first protocol were irradiated with the dose of 52,8 Gy in 16 fractions. 52 patients included in the second protocol were irradiated with the dose of 62 Gy in 20 fractions. Protocols were compared through dose-volume histograms (DVH) of rectum and bladder and radiobiological calculations with the use of Lyman-Kutcher-Burman model for Normal Tissue Complication Probability (NTCP). Results of NTCP were compared with real incidence of late toxicity for normal tissue. DVH of rectum and bladder for patients from second protocol have a better behavior then DVHs for patients from first protocol. NTCPs for first protocol are (12,5{+-}3,3)% and (1,6{+-}1,3)% for rectum and bladder, respectively. NTCPs for second protocol are (6,8{+-}3,0)% and (0,53{+-}0,9)% for rectum and bladder, respectively. From comparison of results of radiobiological calculations and real incidence had arisen a need of refinement of parameters of LKB model. (authors)

  2. Comment on 'Deep convolutional neural network with transfer learning for rectum toxicity prediction in cervical cancer radiotherapy: a feasibility study'.

    Science.gov (United States)

    Valdes, Gilmer; Interian, Yannet

    2018-03-15

    The application of machine learning (ML) presents tremendous opportunities for the field of oncology, thus we read 'Deep convolutional neural network with transfer learning for rectum toxicity prediction in cervical cancer radiotherapy: a feasibility study' with great interest. In this article, the authors used state of the art techniques: a pre-trained convolutional neural network (VGG-16 CNN), transfer learning, data augmentation, drop out and early stopping, all of which are directly responsible for the success and the excitement that these algorithms have created in other fields. We believe that the use of these techniques can offer tremendous opportunities in the field of Medical Physics and as such we would like to praise the authors for their pioneering application to the field of Radiation Oncology. That being said, given that the field of Medical Physics has unique characteristics that differentiate us from those fields where these techniques have been applied successfully, we would like to raise some points for future discussion and follow up studies that could help the community understand the limitations and nuances of deep learning techniques.

  3. SU-E-J-228: MRI-Based Planning: Dosimetric Feasibility of Dose Painting for ADCDefined Intra-Prostatic Tumor

    Energy Technology Data Exchange (ETDEWEB)

    Chen, X; Dalah, E; Prior, P; Lawton, C; Li, X [Medical College of Wisconsin, Milwaukee, WI (United States)

    2015-06-15

    Purpose: Apparent diffusion coefficient (ADC) map may help to delineate the gross tumor volume (GTV) in prostate gland. Dose painting with external beam radiotherapy for GTV might increase the local tumor control. The purpose of this study is to explore the maximum boosting dose on GTV using VMAT without sacrificing sparing of organs at risk (OARs) in MRI based planning. Methods: VMAT plans for 5 prostate patients were generated following the commonly used dose volume (DV) criteria based on structures contoured on T2 weighted MRI with bulk electron density assignment using electron densities derived from ICRU46. GTV for each patient was manually delineated based on ADC maps and fused to T2-weighted image set for planning study. A research planning system with Monte Carlo dose engine (Monaco, Elekta) was used to generate the VMAT plans with boosting dose on GTV gradually increased from 85Gy to 100Gy. DV parameters, including V(boosting-dose) (volume covered by boosting dose) for GTV, V75.6Gy for PTV, V45Gy, V70Gy, V72Gy and D1cc (Maximum dose to 1cc volume) for rectum and bladder, were used to measure plan quality. Results: All cases achieve at least 99.0% coverage of V(boosting-dose) on GTV and 95% coverage of V75.6Gy to the PTV. All the DV criteria, V45Gy≤50% and V70Gy≤15% for bladder and rectum, D1cc ≤77Gy (Rectum) and ≤80Gy (Bladder), V72Gy≤5% (rectum and bladder) were maintained when boosting GTV to 95Gy for all cases studied. Except for two patients, all the criteria were also met when the boosting dose goes to 100Gy. Conclusion: It is dosimetrically feasible safe to boost the dose to at least 95Gy to ADC defined GTV in prostate cancer using MRI guided VMAT delivery. Conclusion: It is dosimetrically feasible safe to boost the dose to at least 95Gy to ADC defined GTV in prostate cancer using MRI guided VMAT delivery. This research is partially supported by Elekta Inc.

  4. A phantom production by using 3-dimensional printer and In-vivo dosimetry for a prostate cancer patient

    International Nuclear Information System (INIS)

    Seo, Jung Nam; Na, Jong Eok; Bae, Sun Myung; Jung, Dong Min; Yoon, In Ha; Bae, Jae Bum; Kwack, Jung Won; Baek, Geum Mun

    2015-01-01

    The purpose of this study is to evaluate the usefulness of a 3D printed phantom for in-vivo dosimetry of a prostate cancer patient. The phantom is produced to equally describe prostate and rectum based on a 3D volume contour of an actual prostate cancer patient who is treated in Asan Medical Center by using a 3D printer (3D EDISON+, Lokit, Korea). CT(Computed tomography) images of phantom are acquired by computed tomography (Lightspeed CT, GE, USA). By using treatment planning system (Eclipse version 10.0, Varian, USA), treatment planning is established after volume of a prostate cancer patient is compared with volume of the phantom. MOSFET(Metal OXIDE Silicon Field Effect Transistor) is estimated to identify precision and is located in 4 measuring points (bladder, prostate, rectal anterior wall and rectal posterior wall) to analyzed treatment planning and measured value. Prostate volume and rectum volume of prostate cancer patient represent 30.61 cc and 51.19 cc respectively. In case of a phantom, prostate volume and rectum volume represent 31.12 cc and 53.52 cc respectively. A variation of volume between a prostate cancer patient and a phantom is less than 3%. Precision of MOSFET represents less than 3%. It indicates linearity and correlation coefficient indicates from 0.99 - 1.00 depending on dose variation. Each accuracy of bladder, prostate, rectal anterior wall and rectal posterior wall represent 1.4%, 2.6%, 3.7% and 1.5% respectively. In- vivo dosimetry represents entirely less than 5% considering precision of MOSFET. By using a 3D printer, possibility of phantom production based on prostate is verified precision within 3%. effectiveness of In-vivo dosimetry is confirmed from a phantom which is produced by a 3D printer. In-vivo dosimetry is evaluated entirely less than 5% considering precision of MOSFET. Therefore, This study is confirmed the usefulness of a 3D printed phantom for in-vivo dosimetry of a prostate cancer patient. It is necessary to additional

  5. A phantom production by using 3-dimensional printer and In-vivo dosimetry for a prostate cancer patient

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jung Nam; Na, Jong Eok; Bae, Sun Myung; Jung, Dong Min; Yoon, In Ha; Bae, Jae Bum; Kwack, Jung Won; Baek, Geum Mun [Dept. of Radiation Oncology, ASAN Medical Center, Seoul (Korea, Republic of)

    2015-06-15

    The purpose of this study is to evaluate the usefulness of a 3D printed phantom for in-vivo dosimetry of a prostate cancer patient. The phantom is produced to equally describe prostate and rectum based on a 3D volume contour of an actual prostate cancer patient who is treated in Asan Medical Center by using a 3D printer (3D EDISON+, Lokit, Korea). CT(Computed tomography) images of phantom are acquired by computed tomography (Lightspeed CT, GE, USA). By using treatment planning system (Eclipse version 10.0, Varian, USA), treatment planning is established after volume of a prostate cancer patient is compared with volume of the phantom. MOSFET(Metal OXIDE Silicon Field Effect Transistor) is estimated to identify precision and is located in 4 measuring points (bladder, prostate, rectal anterior wall and rectal posterior wall) to analyzed treatment planning and measured value. Prostate volume and rectum volume of prostate cancer patient represent 30.61 cc and 51.19 cc respectively. In case of a phantom, prostate volume and rectum volume represent 31.12 cc and 53.52 cc respectively. A variation of volume between a prostate cancer patient and a phantom is less than 3%. Precision of MOSFET represents less than 3%. It indicates linearity and correlation coefficient indicates from 0.99 - 1.00 depending on dose variation. Each accuracy of bladder, prostate, rectal anterior wall and rectal posterior wall represent 1.4%, 2.6%, 3.7% and 1.5% respectively. In- vivo dosimetry represents entirely less than 5% considering precision of MOSFET. By using a 3D printer, possibility of phantom production based on prostate is verified precision within 3%. effectiveness of In-vivo dosimetry is confirmed from a phantom which is produced by a 3D printer. In-vivo dosimetry is evaluated entirely less than 5% considering precision of MOSFET. Therefore, This study is confirmed the usefulness of a 3D printed phantom for in-vivo dosimetry of a prostate cancer patient. It is necessary to additional

  6. An interactive tool for CT volume rendering and sagittal plane-picking of the prostate for radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Jani, Ashesh B.; Pelizzari, Charles A.; Chen, George T.Y.; Grzezcszuk, Robert P.; Vijayakumar, Srinivasan

    1997-01-01

    Objective: Accurate and precise target volume and critical structure definition is a basic necessity in radiotherapy. The prostate, particularly the apex (an important potential site of recurrence in prostate cancer patients), is a challenging structure to define using any modality, including conventional axial CT. Invasive or expensive techniques, such as retrograde urethrography or MRI, could be avoided if localization of the prostate were possible using information already available on the planning CT. Our primary objective was to build a software tool to determine whether volume rendering and sagittal plane-picking, which are CT-based, noninvasive visualization techniques, were of utility in radiotherapy treatment planning for the prostate. Methods: Using AVS (Application Visualization System) on a Silicon Graphics Indigo 2 High Impact workstation, we have developed a tool that enables the clinician to efficiently navigate a CT volume and to use volume rendering and sagittal plane-picking to better define structures at any anatomic site. We applied the tool to the specific example of the prostate to compare the two visualization techniques with the current standard of axial CT. The prostate was defined on 80-slice CT scans (scanning thickness 4mm, pixel size 2mm x 2mm) of prostate cancer patients using axial CT images, volume-rendered CT images, and sagittal plane-picked images. Results: The navigation of the prostate using the different visualization techniques qualitatively demonstrated that the sagittal plane-picked images, and even more so the volume-rendered images, revealed the prostate (particularly the lower border) better in relationship to the surrounding regional anatomy (bladder, rectum, pelvis, and penile structures) than did the axial images. A quantitative comparison of the target volumes obtained by navigating using the different visualization techniques demonstrated that, when compared to the prostate volume defined on axial CT, a larger volume

  7. Value of liver scan in the follow-up study of patients with adenocarcinoma of the colon and rectum

    International Nuclear Information System (INIS)

    Cedermark, B.J.; Schultz, S.S.; Bakshi, S.; Parthasarathy, K.L.; Mittelman, A.; Evans, J.T.

    1977-01-01

    Seventy consecutive patients with adenocarcinoma of the colon and rectum had a liver scan followed by surgical exploration of the liver. Preoperatively, blood chemistry studies were done in addition to palpation of the abdomen. Surgical findings were correlated to results of the liver scans, function tests and palpation of the liver. The overall concordance of liver scans with surgical findings was 78 percent. Thirty percent had false-positive results and 15 percent, false-negative results. The correlation of the liver scan with surgical findings was improved with increasing extent of metastases. When less than 25 percent of the liver was replaced by tumor, there was a random correlation of scan to surgical findings. By combining liver scans and liver function tests, metastases could be predicted with increased reliability only in patients who had severe metastatic disease of the liver. It is strongly recommended that patients with liver scans suggestive of metastatic disease and with most liver function tests within normal limits undergo exploration to establish the diagnosis. Exploratory laparotomy seems to be the only way to avoid chemotherapeutic treatment of patients with false-positive scans and still allow detection and treatment of metastases to the liver to occur at earlier stages

  8. Calculation of complication probability of pion treatment at PSI using dose-volume histograms

    International Nuclear Information System (INIS)

    Nakagawa, Keiichi; Akanuma, Atsuo; Aoki, Yukimasa

    1991-01-01

    In the conformation technique a target volume is irradiated uniformly as in conventional radiations, whereas surrounding tissue and organs are nonuniformly irradiated. Clinical data on radiation injuries that accumulate with conventional radiation are not applicable without appropriate compensation. Recently a putative solution of this problem was proposed by Lyman using dose-volume histograms. This histogram reduction method reduces a given dose-volume histogram of an organ to a single step which corresponds to the equivalent complication probability by interpolation. As a result it converts nonuniform radiation into a unique dose to the whole organ which has the equivalent likelihood of radiation injury. This method is based on low LET radiation with conventional fractionation schedules. When it is applied to high LET radiation such as negative pion treatment, a high LET dose should be converted to an equivalent photon dose using an appropriate value of RBE. In the present study the histogram reduction method was applied to actual patients treated by the negative pion conformation technique at the Paul Scherrer Institute. Out of evaluable 90 cases of pelvic tumors, 16 developed grade III-IV bladder injury, and 7 developed grade III-IV rectal injury. The 90 cases were divided into roughly equal groups according to the equivalent doses to the entire bladder and rectum. Complication rates and equivalent doses to the full organs in these groups could be represented by a sigmoid dose-effect relation. When RBE from a pion dose to a photon dose is assumed to be 2.1 for bladder injury, the rates of bladder complications fit best to the theoretical complication curve. When the RBE value was 2.3, the rates of rectal injury fit the theoretical curve best. These values are close to the conversion factor of 2.0 that is used in clinical practice at PSI. This agreement suggests the clinical feasibility of the histogram reduction method in conformation radiotherapy. (author)

  9. Rectum separation in patients with cervical cancer for treatment planning in primary chemo-radiation

    International Nuclear Information System (INIS)

    Marnitz, Simone; Budach, Volker; Weißer, Friederike; Burova, Elena; Gebauer, Bernhard; Vercellino, Filiberto Guiseppe; Köhler, Christhardt

    2012-01-01

    To proof feasibility of hydrogel application in patients with advanced cervical cancer undergoing chemo-radiation in order to reduce rectal toxicity from external beam radiation as well as brachytherapy. Under transrectal sonographic guidance five patients with proven cervical cancer underwent hydro gel (20 cc) instillation into the tip of rectovaginal septum adherent to posterior part of the visible cervical tumor. Five days after this procedure all patients underwent T2 weighted transversal and sagittal MRI for brachytherapy planning. MRI protocol included T2 weighted fast spin echo (FSE) imaging in sagittal, coronal and para-axial orientation using an 1.5 Tesla MRI. Separation of anterior rectal wall and cervix was documented. Hydrogel application was uneventful in all patients and no toxicity was reported. Separation ranged from 7 to 26 mm in width (median 10 mm). The length of the separation varied between 18 and 38 mm (median 32 mm). In all patients displacement was seen in the posterior vaginal fornix, and/or at the deepest part of uterine cervix depending on the extension of the cul-de-sac in correlation to the posterior wall of the uterus. In patients with bulky tumor and/or deep (vaginal) extend of peritoneal cavity tumour was seen mainly cranial from the rectovaginal space and therefore above the hydrogeI application. Only in the extra-peritoneal (lower) part of the cervix a good separation could be achieved between the rectum and cervix. Hydrgel instillation in patients with cervial cancer undergoing chemoradiation is safe and feasible. Because of the loose tissue of the cul-de-sac and its intra- and extraperitoneal part, hydrogel instillation of 20 cc did not result in a sufficient separation of the cervix from anterior wall

  10. Preoperative combination therapy of 5-fluorouracil suppository and radiation for carcinoma of the rectum

    International Nuclear Information System (INIS)

    Mizusawa, Hirokazu

    1986-01-01

    The effect of adjuvant preoperative treatments with radiation and 5-fluorouracil (5-FU) on rectal carcinomas was investigated. The radiation therapy was administered in the area including the rectum and regional lymph nodes up to the level of the promontorium with 10 doses of 300 rad in three-week periods (a total dose of 3,000 rad). The suppository containing 100 mg of 5-FU was given intrarectally twice daily in the same period (a total dose of 4,000 mg of 5-FU). The surgical procedure with either abdominoperineal excision or anterior resection was performed within 14 days after the last preoperative treatment. The resected specimens were examined microscopically. The mean thickness of excised tumor-free tissue around the rectal wall having the most extended tumor growth was 6.2 mm in 16 patients receiving the treatment with radiation and 5-FU, 3.9 mm in 31 patients with 5-FU alone and 3.7 mm in 19 patients without preoperative treatments. Lymph node metastases were detected in 3 of 17 patients (19 %) with radiation and 5-FU, in 18 of 33 patients (55 %) with 5-FU alone, and in 11 of 24 patients (46 %) without preoperative treatments. The extensive degenerative pictures of cancer cells such as nuclear picnosis, and the growth of collagen fibers in carcinoma foci were observed in resected specimens with radiation and 5-FU treatments. Those findings suggest that preoperative adjuvant therapy with moderate dose of radiation and 5-FU affected significantly rectal carcinomas. There were no adverse effects. It seems likely, thus, that this combined therapy could prevent postoperative local or intrapelvic recurrence, which was the most frequent form of recurrence after curative surgery in rectal cancer. (author)

  11. Different rectal toxicity tolerance with and without simultaneous conventionally-fractionated pelvic lymph node treatment in patients receiving hypofractionated prostate radiotherapy

    International Nuclear Information System (INIS)

    McDonald, Andrew M; Baker, Christopher B; Popple, Richard A; Shekar, Kiran; Yang, Eddy S; Jacob, Rojymon; Cardan, Rex; Kim, Robert Y; Fiveash, John B

    2014-01-01

    To investigate added morbidity associated with the addition of pelvic elective nodal irradiation (ENI) to hypofractionated radiotherapy to the prostate. Two-hundred twelve patients, treated with hypofractionated radiotherapy to the prostate between 2004 and 2011, met the inclusion criteria for the analysis. All patients received 70 Gy to the prostate delivered over 28 fractions and 103 (49%) received ENI consisting of 50.4 Gy to the pelvic lymphatics delivered simultaneously in 1.8 Gy fractions. The mean dose-volume histograms were compared between the two subgroups defined by use of ENI, and various dose-volume parameters were analyzed for effect on late lower gastrointestinal (GI) and genitourinary (GU) toxicity. Acute grade 2 lower GI toxicity occurred in 38 (37%) patients receiving ENI versus 19 (17%) in those who did not (p = 0.001). The Kaplan-Meier estimate of grade ≥ 2 lower GI toxicity at 3 years was 15.3% for patients receiving ENI versus 5.3% for those who did not (p = 0.026). Each rectal isodose volume was increased for patients receiving ENI up to 50 Gy (p ≤ 0.021 for each 5 Gy increment). Across all patients, the absolute V 70 of the rectum was the only predictor of late GI toxicity. When subgroups, defined by the use of ENI, were analyzed separately, rectal V 70 was only predictive of late GI toxicity for patients who received ENI. For patients receiving ENI, V 70 > 3 cc was associated with an increased risk of late GI events. Elective nodal irradiation increases the rates of acute and late GI toxicity when delivered simultaneously with hypofractioanted prostate radiotherapy. The use of ENI appears to sensitize the rectum to hot spots, therefore we recommend added caution to minimize the volume of rectum receiving 100% of the prescription dose in these patients

  12. Different rectal toxicity tolerance with and without simultaneous conventionally-fractionated pelvic lymph node treatment in patients receiving hypofractionated prostate radiotherapy.

    Science.gov (United States)

    McDonald, Andrew M; Baker, Christopher B; Popple, Richard A; Shekar, Kiran; Yang, Eddy S; Jacob, Rojymon; Cardan, Rex; Kim, Robert Y; Fiveash, John B

    2014-06-03

    To investigate added morbidity associated with the addition of pelvic elective nodal irradiation (ENI) to hypofractionated radiotherapy to the prostate. Two-hundred twelve patients, treated with hypofractionated radiotherapy to the prostate between 2004 and 2011, met the inclusion criteria for the analysis. All patients received 70 Gy to the prostate delivered over 28 fractions and 103 (49%) received ENI consisting of 50.4 Gy to the pelvic lymphatics delivered simultaneously in 1.8 Gy fractions. The mean dose-volume histograms were compared between the two subgroups defined by use of ENI, and various dose-volume parameters were analyzed for effect on late lower gastrointestinal (GI) and genitourinary (GU) toxicity. Acute grade 2 lower GI toxicity occurred in 38 (37%) patients receiving ENI versus 19 (17%) in those who did not (p = 0.001). The Kaplan-Meier estimate of grade ≥ 2 lower GI toxicity at 3 years was 15.3% for patients receiving ENI versus 5.3% for those who did not (p = 0.026). Each rectal isodose volume was increased for patients receiving ENI up to 50 Gy (p ≤ 0.021 for each 5 Gy increment). Across all patients, the absolute V70 of the rectum was the only predictor of late GI toxicity. When subgroups, defined by the use of ENI, were analyzed separately, rectal V70 was only predictive of late GI toxicity for patients who received ENI. For patients receiving ENI, V70 > 3 cc was associated with an increased risk of late GI events. Elective nodal irradiation increases the rates of acute and late GI toxicity when delivered simultaneously with hypofractioanted prostate radiotherapy. The use of ENI appears to sensitize the rectum to hot spots, therefore we recommend added caution to minimize the volume of rectum receiving 100% of the prescription dose in these patients.

  13. The normal tissue sparing obtained with simultaneous treatment of pelvic lymph nodes and bladder using intensity-modulated radiotherapy

    International Nuclear Information System (INIS)

    Soendergaard, Jimmi; Hoeyer, Morten; Wright, Pauliina; Grau, Cai; Muren, Ludvig Paul; Petersen, Joergen B.

    2009-01-01

    We have implemented an intensity-modulated radiotherapy (IMRT) protocol for simultaneous irradiation of bladder and lymph nodes. In this report, doses to normal tissue from IMRT and our previous conformal sequential boost technique are compared. Material and methods. Sixteen patients with urinary bladder cancer were treated using a six-field dynamic IMRT beam arrangement delivering 60 Gy to the bladder and 48 Gy to the pelvic lymph nodes. Dose-volume histogram (DVH) parameters for relevant normal tissues (bowel, bowel cavity, rectum and femoral heads) for the IMRT plans were compared with corresponding DVHs from our previous conformal sequential boost technique. Calculations of the generalized Equivalent Uniform Dose (gEUD) were performed for the bowel, with a reference volume of 200 cm 3 and a volume effect parameter k = 4, as well as for the rectum, using k = 12. Acute gastrointestinal (GI) and genitourinary (GU) RTOG toxicity was recorded. Results. Statistical significant normal tissue sparing was obtained by IMRT. For the bowel, a significant reduction was obtained at all dose levels between 20 and 50 Gy (p 3 at 50 Gy, while the gEUD was reduced from 58 to 53 Gy (p 3 at 50 Gy. The rectum gEUD was reduced from 55 to 53 Gy (p < 0.05). For the femoral heads, IMRT reduced the maximum dose as well as the volumes above all dose levels. The rate of acute peak Grade 2 GI RTOG complications was 38% after IMRT. Conclusion. IMRT to the urinary bladder and elective lymph nodes result in considerable normal tissue sparing compared to conformal sequential boost technique. This has paved the way for further studies combining IMRT with image-guided radiotherapy (IGRT) in bladder cancer

  14. Evaluation of atlas-based auto-segmentation software in prostate cancer patients

    International Nuclear Information System (INIS)

    Greenham, Stuart; Dean, Jenna; Fu, Cheuk Kuen Kenneth; Goman, Joanne; Mulligan, Jeremy; Tune, Deanna; Sampson, David; Westhuyzen, Justin; McKay, Michael

    2014-01-01

    The performance and limitations of an atlas-based auto-segmentation software package (ABAS; Elekta Inc.) was evaluated using male pelvic anatomy as the area of interest. Contours from 10 prostate patients were selected to create atlases in ABAS. The contoured regions of interest were created manually to align with published guidelines and included the prostate, bladder, rectum, femoral heads and external patient contour. Twenty-four clinically treated prostate patients were auto-contoured using a randomised selection of two, four, six, eight or ten atlases. The concordance between the manually drawn and computer-generated contours were evaluated statistically using Pearson's product–moment correlation coefficient (r) and clinically in a validated qualitative evaluation. In the latter evaluation, six radiation therapists classified the degree of agreement for each structure using seven clinically appropriate categories. The ABAS software generated clinically acceptable contours for the bladder, rectum, femoral heads and external patient contour. For these structures, ABAS-generated volumes were highly correlated with ‘as treated’ volumes, manually drawn; for four atlases, for example, bladder r = 0.988 (P < 0.001), rectum r = 0.739 (P < 0.001) and left femoral head r = 0.560 (P < 0.001). Poorest results were seen for the prostate (r = 0.401, P < 0.05) (four atlases); however this was attributed to the comparison prostate volume being contoured on magnetic resonance imaging (MRI) rather than computed tomography (CT) data. For all structures, increasing the number of atlases did not consistently improve accuracy. ABAS-generated contours are clinically useful for a range of structures in the male pelvis. Clinically appropriate volumes were created, but editing of some contours was inevitably required. The ideal number of atlases to improve generated automatic contours is yet to be determined

  15. Pelvic MRI application to the dosimetric analysis in Brachytherapy of Uterine Cervix Carcinoma

    International Nuclear Information System (INIS)

    Ahn, S. J.; Chung, W. K.; Nah, B. K.

    1997-01-01

    Before we report the results of curative radiotherapy in cervix cancer patients, we review the significance and safety of our dose specification methods in the brachytherapy system to have the insight of the potential predictive value of doses at specific points. We analyze the 45 cases of cervix cancer patients treated with intracavitary brachytherapy. In the lateral simulation film we draw the isodose curve and observe the absorbed dose rate of point A, the reference point of bladder(SBD) and rectum(SRD). In the sagittal view of pelvic MRI film we demarcate the tumor volume(TV) and determine whether the prescription dose curve of point A covers the tumor volume adequately by drawing the isodose curve as correctly as possible. Also we estimate the maximum point dose of bladder (MBD) and rectum (MRD) and calculate the inclusion area where the absorbed dose rate is higher than that of point A in the bladder (HBV) and rectum (HRV), respectively. Of forty-five cases, the isodose curve of point A seems to cover tumor volume optimally in only 24 (53%). The optimal tumor coverage seems to be associated not with the stage of the disease but with the tumor volume. There is no statistically significant association between SBD/SRD and MBD/MRD, respectively. SRD has statistically significant association with HBV and HRV. Our current treatment calculation methods seem to have the defect in the aspects of the nonoptimal coverage of the bulky tumor and the inappropriate estimation of bladder dose. We therefore need to modify the applicator geometry to optimize the dose distribution at the position of lower tandem source. Also it appears that the position of the bladder in relation to the applicators needs to be defined individually to define 'hot spots'. (author)

  16. MRI-assisted versus conventional treatment planning in brachytherapy of cervical and endometrial carcinoma: The impact of individual anatomy on dose distribution in target volume and organs at risk

    International Nuclear Information System (INIS)

    Wulf, Joern; Sauer, Otto A.; Herbolsheimer, Michael; Oppitz, Ulrich; Flentje, Michael

    1996-01-01

    endometrial carcinoma showed, that only 37.5% (min. 35%, max. 39%, volume range from 69cc to 250 cc) of target volume was covered by the reference isodose. The dose to organs at risk, identified with MRI-data, peaked generally higher compared to the estimated or measured dose in conventional treatment planning. MRI-assisted calculated maximum dose to the dorsal bladder wall was 10.35 Gy/fx at mean in cervical- and 6.67 Gy/fx in endometrial carcinoma, while the equivalent doses calculated as ICRU-reference point were 5.4 Gy/fx (cervical-ca.) resp. 5.1 Gy/fx (endometrial-ca). Mean irradiated bladder volume at 7 Gy isodose was 2.9 cc in cervical- and 5 cc in endometrial carcinoma. The mean of the maximum dose to the ventral rectum wall was 8.5 Gy/fx (MRI) vs. 5.1 Gy/fx (ICRU-point) in cervical- and 10.34 Gy/fx (MRI) vs. 2.4 Gy/fx (ICRU) in endometrial carcinoma. The irradiated volume at 7 Gy isodose was smaller than 1 cc in both entities. The irradiated volume and dose to small intestine was not relevant in most patients, however, the 7Gy isodose included 6 cc of small intestine in one patient. Conclusion: Pelvic anatomy differs widely among patients with cervical and endometrial cancer. Standard dose prescription fits only about 50% of patients and might be hazardous for patients with small and insufficient for patients with large uteri. Dose calculation to organs at risk in conventional treatment planning relies on the position of bladder and rectum catheters, where MRI identifies the organs at risk most adjacent to high dose isodose. MRI helps to identify those patients with small or large uteri, who could benefit from an individualized dose prescription. Furthermore, MRI information on dose to target and organs at risk might provide new insight in dose-volume relationships and could improve tumor control probability without compromise to normal tissue complication probability

  17. Dosimetric Consequences of Interobserver Variability in Delineating the Organs at Risk in Gynecologic Interstitial Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Damato, Antonio L., E-mail: adamato@lroc.harvard.edu [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, Massachusetts (United States); Townamchai, Kanopkis [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, Massachusetts (United States); Albert, Michele [Department of Radiation Oncology, Saint Anne' s Hospital Regional Cancer Center, Fall River, Massachusetts (United States); Bair, Ryan J. [Department of Radiology, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Cormack, Robert A. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, Massachusetts (United States); Jang, Joanne [Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, Massachusetts (United States); Kovacs, Arpad [Department of Radiology, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Lee, Larissa J. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, Massachusetts (United States); Mak, Kimberley S.; Mirabeau-Beale, Kristina L.; Mouw, Kent W.; Phillips, John G.; Pretz, Jennifer L.; Russo, Andrea L. [Harvard Radiation Oncology Program, Harvard Medical School, Boston, Massachusetts (United States); Lewis, John H.; Viswanathan, Akila N. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, Massachusetts (United States)

    2014-07-01

    Purpose: To investigate the dosimetric variability associated with interobserver organ-at-risk delineation differences on computed tomography in patients undergoing gynecologic interstitial brachytherapy. Methods and Materials: The rectum, bladder, and sigmoid of 14 patients treated with gynecologic interstitial brachytherapy were retrospectively contoured by 13 physicians. Geometric variability was calculated using κ statistics, conformity index (CI{sub gen}), and coefficient of variation (CV) of volumes contoured across physicians. Dosimetric variability of the single-fraction D{sub 0.1cc} and D{sub 2cc} was assessed through CV across physicians, and the standard deviation of the total EQD2 (equivalent dose in 2 Gy per fraction) brachytherapy dose (SD{sup TOT}) was calculated. Results: The population mean ± 1 standard deviation of κ, CI{sub gen}, and volume CV were, respectively: 0.77 ± 0.06, 0.70 ± 0.08, and 20% ± 6% for bladder; 0.74 ± 06, 0.67 ± 0.08, and 20% ± 5% for rectum; and 0.33 ± 0.20, 0.26 ± 0.17, and 82% ± 42% for sigmoid. Dosimetric variability was as follows: for bladder, CV = 31% ± 19% (SD{sup TOT} = 72 ± 64 Gy) for D{sub 0.1cc} and CV = 16% ± 10% (SD{sup TOT} = 9 ± 6 Gy) for D{sub 2cc}; for rectum, CV = 11% ± 5% (SD{sup TOT} = 16 ± 17 Gy) for D{sub 0.1cc} and CV = 7% ± 2% (SD{sup TOT} = 4 ± 3 Gy) for D{sub 2cc}; for sigmoid, CV = 39% ± 28% (SD{sup TOT} = 12 ± 18 Gy) for D{sub 0.1cc} and CV = 34% ± 19% (SD{sup TOT} = 4 ± 4 Gy) for D{sub 2cc.} Conclusions: Delineation of bladder and rectum by 13 physicians demonstrated substantial geometric agreement and resulted in good dosimetric agreement for all dose-volume histogram parameters except bladder D{sub 0.1cc.} Small delineation differences in high-dose regions by the posterior bladder wall may explain these results. The delineation of sigmoid showed fair geometric agreement. The higher dosimetric variability for sigmoid compared with rectum and bladder did not correlate with

  18. Evaluating efficiency of split VMAT plan for prostate cancer radiotherapy involving pelvic lymph nodes

    Energy Technology Data Exchange (ETDEWEB)

    Mun, Jun Ki; Son, Sang Jun; Kim, Dae Ho; Seo, Seok Jin [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2015-12-15

    The purpose of this study is to evaluate the efficiency of Split VMAT planning(Contouring rectum divided into an upper and a lower for reduce rectum dose) compare to Conventional VMAT planning(Contouring whole rectum) for prostate cancer radiotherapy involving pelvic lymph nodes. A total of 9 cases were enrolled. Each case received radiotherapy with Split VMAT planning to the prostate involving pelvic lymph nodes. Treatment was delivered using TrueBeam STX(Varian Medical Systems, USA) and planned on Eclipse(Ver. 10.0.42, Varian, USA), PRO3(Progressive Resolution Optimizer 10.0.28), AAA(Anisotropic Analytic Algorithm Ver. 10.0.28). Lower rectum contour was defined as starting 1 cm superior and ending 1 cm inferior to the prostate PTV, upper rectum is a part, except lower rectum from the whole rectum. Split VMAT plan parameters consisted of 10 MV coplanar 360° arcs. Each arc had 30° and 30° collimator angle, respectively. An SIB(Simultaneous Integrated Boost) treatment prescription was employed delivering 50.4 Gy to pelvic lymph nodes and 63- 70 Gy to the prostate in 28 fractions. D{sub mean} of whole rectum on Split VMAT plan was applied for DVC(Dose Volume Constraint) of the whole rectum for Conventional VMAT plan. In addition, all parameters were set to be the same of existing treatment plans. To minimize the dose difference that shows up randomly on optimizing, all plans were optimized and calculated twice respectively using a 0.2 cm grid. All plans were normalized to the prostate PTV{sub 100%} = 90% or 95%. A comparison of D{sub mean} of whole rectum, upperr ectum, lower rectum, and bladder, V{sub 50%} of upper rectum, total MU and H.I.(Homogeneity Index) and C.I.(Conformity Index) of the PTV was used for technique evaluation. All Split VMAT plans were verified by gamma test with portal dosimetry using EPID. Using DVH analysis, a difference between the Conventional and the Split VMAT plans was demonstrated. The Split VMAT plan demonstrated better in the D

  19. Bibliographical review of laparoscopic surgery in malignant pathology of the colon and rectum

    International Nuclear Information System (INIS)

    Peraza Solis, Yerald

    2010-01-01

    An exhaustive bibliographic review was performed on laparoscopic surgery in malignant pathology of the colon and rectum. Colorectal cancer has accounted for 13% of all human cancers and has accounted for 10% of deaths from malignant neoplasms. In Costa Rica it has had the fifth most frequent cancer in women and also in men. Mortality in Costa Rican women, contrary to the developed countries, has increased between 1985 and 2000. Mortality in Costa Rican men has remained stable. The incidence has begun to be high in patients aged 40-45 years and has increased incidence until age 75. Certain group has developed cancer at an early age due to a form of familial cancer. Rectal cancer has been a treatable and curable disease if it is managed in the early stages. Many of the features of colon cancer have been applicable to rectal cancer, it only changes the association of radiotherapy and the sequence of the same. Surgery has been the primary treatment and has resulted in healing in approximately 45% of all patients. Patients with rectal cancer usually have had a chronic history of bleeding or constipation, foreign body sensation and perianal or perineal pain, low weight only when has existed advanced or metastatic disease. The US endoscopy has been a precise method to evaluate the tumor stage and the status of the perirectal nodules. The treatment of rectal cancer has had as aim: 1. healing, 2. local control, 3. restoration of intestinal continuity and 4. prevention of urinary, sexual and anorectal sphincter function. Adjuvant treatment with radiotherapy and/or chemotherapy has been only necessary for tumors T3 and T4. The treatment by stage: Stage I: preoperative radiotherapy and one of the surgical modalities described according to the case; Stage II and III: preoperative radiotherapy and one of the surgical modalities according to the case; Stage IV: palliative extirpation of the tumor with restoration of the intestinal transit through anastomosis or definitive

  20. The co registration of initial PET on the CT-radiotherapy reduces significantly the variabilities of anatomo-clinical target volume in the child hodgkin disease; La coregistration de la TEP initiale sur la scanographie de radiotherapie diminue significativement les variabilites de volume cible anatomoclinique dans la maladie de Hodgkin de l'enfant

    Energy Technology Data Exchange (ETDEWEB)

    Metwally, H.; Blouet, A.; David, I.; Rives, M.; Izar, F.; Courbon, F.; Filleron, T.; Laprie, A. [Institut Claudius-Regaud, 31 - Toulouse (France); Plat, G.; Vial, J. [CHU-hopital des Enfants, 31 - Toulouse (France)

    2009-10-15

    It exists a great interobserver variability for the anatomo-clinical target volume (C.T.V.) definition in children suffering of Hodgkin disease. In this study, the co-registration of the PET with F.D.G. on the planning computed tomography has significantly lead to a greater coherence in the clinical target volume definition. (N.C.)

  1. Predicting objective function weights from patient anatomy in prostate IMRT treatment planning

    International Nuclear Information System (INIS)

    Lee, Taewoo; Hammad, Muhannad; Chan, Timothy C. Y.; Craig, Tim; Sharpe, Michael B.

    2013-01-01

    Purpose: Intensity-modulated radiation therapy (IMRT) treatment planning typically combines multiple criteria into a single objective function by taking a weighted sum. The authors propose a statistical model that predicts objective function weights from patient anatomy for prostate IMRT treatment planning. This study provides a proof of concept for geometry-driven weight determination. Methods: A previously developed inverse optimization method (IOM) was used to generate optimal objective function weights for 24 patients using their historical treatment plans (i.e., dose distributions). These IOM weights were around 1% for each of the femoral heads, while bladder and rectum weights varied greatly between patients. A regression model was developed to predict a patient's rectum weight using the ratio of the overlap volume of the rectum and bladder with the planning target volume at a 1 cm expansion as the independent variable. The femoral head weights were fixed to 1% each and the bladder weight was calculated as one minus the rectum and femoral head weights. The model was validated using leave-one-out cross validation. Objective values and dose distributions generated through inverse planning using the predicted weights were compared to those generated using the original IOM weights, as well as an average of the IOM weights across all patients. Results: The IOM weight vectors were on average six times closer to the predicted weight vectors than to the average weight vector, usingl 2 distance. Likewise, the bladder and rectum objective values achieved by the predicted weights were more similar to the objective values achieved by the IOM weights. The difference in objective value performance between the predicted and average weights was statistically significant according to a one-sided sign test. For all patients, the difference in rectum V54.3 Gy, rectum V70.0 Gy, bladder V54.3 Gy, and bladder V70.0 Gy values between the dose distributions generated by the

  2. Comment on ‘Deep convolutional neural network with transfer learning for rectum toxicity prediction in cervical cancer radiotherapy: a feasibility study’

    Science.gov (United States)

    Valdes, Gilmer; Interian, Yannet

    2018-03-01

    The application of machine learning (ML) presents tremendous opportunities for the field of oncology, thus we read ‘Deep convolutional neural network with transfer learning for rectum toxicity prediction in cervical cancer radiotherapy: a feasibility study’ with great interest. In this article, the authors used state of the art techniques: a pre-trained convolutional neural network (VGG-16 CNN), transfer learning, data augmentation, drop out and early stopping, all of which are directly responsible for the success and the excitement that these algorithms have created in other fields. We believe that the use of these techniques can offer tremendous opportunities in the field of Medical Physics and as such we would like to praise the authors for their pioneering application to the field of Radiation Oncology. That being said, given that the field of Medical Physics has unique characteristics that differentiate us from those fields where these techniques have been applied successfully, we would like to raise some points for future discussion and follow up studies that could help the community understand the limitations and nuances of deep learning techniques.

  3. Etude par calorimétrie à titrage isotherme (ITC) et spectroscopie de résonnance magnétique nucléaire (RMN) des effets de protonation liés à l'interaction entre l'alpha-chymotrypsine et la proflavine / Gilles Bruylants

    OpenAIRE

    Bruylants, Gilles

    2005-01-01

    Le nombre de cibles potentielles pour la conception de nouvelles molécules à activité thérapeutique ne cesse de croître. Pour chaque cible, il est nécessaire d’identifier des molécules actives et de les optimiser afin d’atteindre l’affinité et la sélectivité recherchées. Ces nouveaux défis accentuent la nécessité d’améliorer notre compréhension des facteurs qui mènent à la reconnaissance moléculaire entre une drogue potentielle et une macromolécule biologique, et particulièrement des facteurs...

  4. Postoperative digestive function after radical versus conservative surgical philosophy for deep endometriosis infiltrating the rectum.

    Science.gov (United States)

    Roman, Horace; Vassilieff, Maud; Tuech, Jean Jacques; Huet, Emmanuel; Savoye, Guillaume; Marpeau, Loïc; Puscasiu, Lucian

    2013-05-01

    To compare delayed digestive outcomes in women managed by two different surgical philosophies: a radical approach mainly related to colorectal resection, and a conservative approach involving rectal shaving and rectal nodule excision. "Before and after" comparative retrospective study. University tertiary referral center. Seventy-five patients managed by surgery for deep endometriosis infiltrating the rectum. Twenty-four women were managed during a period when surgeons pursued a radical philosophy toward treatment, and 51 women were managed during a period when a conservative philosophy was adopted. Standardized gastrointestinal questionnaires: the Gastrointestinal Quality of Life Index, the Knowles-Eccersley-Scott Symptom Questionnaire, the Bristol Stool Score, and the Fecal Incontinence Quality of Life Score. Preoperative patient characteristics, rectal nodule features, and associated localizations of the disease were comparable between the two groups. During the radical period, colorectal resection was carried out in 67% of patients, whereas during the second period only 20% of women underwent colorectal resection. Women managed according to the conservative philosophy had significantly improved results on the Knowles-Eccersley-Scott Symptom Questionnaire, Gastrointestinal Quality of Life Index, and depression/self-perception Fecal Incontinence Quality of Life Score, and significantly improved values for various items related to postoperative constipation: unsuccessful evacuatory attempts, feeling incomplete evacuation, abdominal pain, time taken to evacuate, difficulty evacuating causing a painful effort, and stool consistency. It seems that reducing the rate of colorectal resection leads to better functional outcomes in women presenting with rectal endometriosis, lending support to the conservative surgical philosophy over mandatory colorectal resection. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights

  5. A comparative dosimetric study of conventional, conformal and intensity-modulated radiotherapy in postoperative pelvic irradiation of cervical cancer

    International Nuclear Information System (INIS)

    Li Bin; An Jusheng; Wu Lingying; Huang Manni; Gao Juzhen; Xu Yingjie; Dai Jianrong

    2008-01-01

    Objective: To evaluate target-volume coverage and organ at risk (OAR) protection achieved with conventional radiotherapy (CRT), three dimensional conformal radiotherapy (3DCRT), and intensity-modulated radiotherapy(IMRT) through dosimetric comparison in patients with cervical cancer after hysterectomy. Methods: The planning CT scans of 10 patients treated with pelvic radiation after hysterectomy for cervical cancer were used to generate CRT, 3DCRT and IMRT plans for this study. Clinical target volume(CTV) was contoured on the individual axial CT slices of every patient. The CTV was then uniformly expanded by 1.0 cm to create the planning target volume (PTV). The small bowel, rectum, bladder, bone marrow, ovaries, and femoral heads were outlined for the organ at risk (OAR) evaluation. The CRT, 3DCRT and IMRT plans were generated using commercial planning software. CRT plan was prescribed to deliver 45 Gy to the reference point, while IMRT and 3DCRT plans were 45 Gy to 95% of the PTV. Isodose line and dose volume histograms(DVH) were used to evaluate the dose distribution in CTV and OAR. Results: For 10 patients, the average volume of CTV receiving the prescribed dose of CRT was significantly lower than 3DCRT(Q=8.27, P<0.01) and IMRT(Q=8.37, P<0.01), respectively. Comparing with the CRT plan, the 3DCRT and IMRT plans notably reduced the volume of bowel at 30 and 45 Gy levels. The IMRT plan significantly spared rectum and bladder at 30 and 45 Gy levels comparing with the CRT (P<0.01) and 3DCRT(P<0.05) plans, while the 3DCRT plan significantly spared rectum and bladder at 45 Gy level comparing with the CRT(P<0.01) plans. For 4 patients with ovarian transposition, the average doses of ovary over 3 Gy were 2 patients with the 3 DCRT and IMRT plans, and 2 with all three plans. Conclusions: IMRT and 3DCRT are superior to CRT in improving dose coverage of target volume and sparing of OAR, while IMRT being the best. The superiority of IMRT and 3DCRT is obvious in sparing

  6. [Historical overview and the current practice of intracavitary treatment of cervical and endometrial cancer in the Oncoradiology Center of Budapest].

    Science.gov (United States)

    Sinkó, Dániel; Nemeskéri, Csaba; Pallinger, Ágnes; Weisz, Csaba; Naszály, Attila; Landherr, László

    2015-06-01

    The aims of our study were to describe the history and development of intracavitary brachytherapy in the treatment of gynecological tumors, to introduce our current practice for intracavitary brachytherapy treatments based on CT planning. Gynecological intracavitary brachytherapy has been applied in our department since the early 1930s. After a long development it has been completely renewed by 2014. In our center definitive and/or preoperative gynecological HDR-AL brachytherapy treatments were given to 25 patients (13 corpus uterine cancer patients and 12 cervical cancer patients) during the period of 01. 01. 2014-31. 01. 2015. In each case, target volumes were planned by CT images, DVH (dose volume histogram) analysis was performed in order to calculate the radiation tolerance dose of rectum and urinary bladder. Evaluation was performed by the EclipseTM 11.0.47. brachytherapy treatment planning system. During the definitive treatments of the 13 uterine cancer patients the D2cc value related to rectum tolerance was 66.3 GyEQD2 (46-91 Gy). The average D2cc value of urinary bladder tolerance was 76.5 GyEQD2 (30-112 Gy). CI was 0.72 (0.6-0.95). Average value of COIN was 0.57 (0.35-0.78). Compared to the prescribed dose D100 and D90 values were given in ratios. Compared to the volume which receives 100% of reference dose V150 and V200 values were also given in ratios. D100 and D90 were calculated to be 0.66 (0.47-0.97) and 0.91 (0.8-1.25). V150 and V200 volumes were 0.11 (0.04-0.18) and 0.06 (0.02-0.1). During the definitive treatments of 12 cervical cancer patients the D2cc value related to rectum tolerance calculated by DVH was 75.2 GyEQD2 (60-82 Gy). The average D2cc value of urinary bladder tolerance was 85 GyEQD2 based on DVH. CI was 0.66 (0.42-0.76). Average value of COIN was 0.52 (0.32-0.78). Mean value of DHI was 0.46 (0.27-0.54). D100 and D90 were calculated to be 0.72 (0.57-0.89) and 0.91 (0.84-1.11). V150 and V200 volumes were 0.057 (0.02-0.13) and 0.02 (0

  7. Study of a bio-mechanical model of the movements and deformations of the pelvic organs and integration in the process of radiotherapy treatment for prostate cancer

    International Nuclear Information System (INIS)

    Azad, M.

    2011-01-01

    One of the goals of optimizing treatment planning of prostate cancer radiation therapy is to maintain the margins added to the clinical target volume (CTV) as small as possible to reduce the volumes of normal tissue irradiated. Several methods have been proposed to define these margins: 1) Methods based on the observation of movements obtained by different imaging systems, 2) The predictive methods of the movement of organs, from a model representing the motions of pelvis organs, a calculation of a margin can be made. We have developed and optimized a finite element bio-mechanical model of the prostate, bladder and rectum. This model describes the movement and deformation of the pelvic organs during the filling of certain organs such as the bladder and rectum. An evaluation of this model to predict the movement of the prostate during the various sessions of radiotherapy is shown using a series of CBCT images (Cone Beam Computerized Tomography). (author)

  8. Dosimetric comparison of intensity-modulated, conformal, and four-field pelvic radiotherapy boost plans for gynecologic cancer: a retrospective planning study

    International Nuclear Information System (INIS)

    Chan, Philip; Yeo, Inhwan; Perkins, Gregory; Fyles, Anthony; Milosevic, Michael

    2006-01-01

    To evaluate intensity-modulated radiation therapy (IMRT) as an alternative to conformal radiotherapy (CRT) or 4-field box boost (4FB) in women with gynecologic malignancies who are unsuitable for brachytherapy for technical or medical reasons. Dosimetric and toxicity information was analyzed for 12 patients with cervical (8), endometrial (2) or vaginal (2) cancer previously treated with external beam pelvic radiotherapy and a CRT boost. Optimized IMRT boost treatment plans were then developed for each of the 12 patients and compared to CRT and 4FB plans. The plans were compared in terms of dose conformality and critical normal tissue avoidance. The median planning target volume (PTV) was 151 cm 3 (range 58–512 cm 3 ). The median overlap of the contoured rectum with the PTV was 15 (1–56) %, and 11 (4–35) % for the bladder. Two of the 12 patients, both with large PTVs and large overlap of the contoured rectum and PTV, developed grade 3 rectal bleeding. The dose conformity was significantly improved with IMRT over CRT and 4FB (p ≤ 0.001 for both). IMRT also yielded an overall improvement in the rectal and bladder dose-volume distributions relative to CRT and 4FB. The volume of rectum that received the highest doses (>66% of the prescription) was reduced by 22% (p < 0.001) with IMRT relative to 4FB, and the bladder volume was reduced by 19% (p < 0.001). This was at the expense of an increase in the volume of these organs receiving doses in the lowest range (<33%). These results indicate that IMRT can improve target coverage and reduce dose to critical structures in gynecologic patients receiving an external beam radiotherapy boost. This dosimetric advantage will be integrated with other patient and treatment-specific factors, particularly internal tumor movement during fractionated radiotherapy, in the context of a future image-guided radiation therapy study

  9. Can we Save the rectum by watchful waiting or TransAnal microsurgery following (chemo) Radiotherapy versus Total mesorectal excision for early REctal Cancer (STAR-TREC study)?

    DEFF Research Database (Denmark)

    Rombouts, Anouk J M; Al-Najami, Issam; Abbott, Natalie L

    2017-01-01

    INTRODUCTION: Total mesorectal excision (TME) is the highly effective standard treatment for rectal cancer but is associated with significant morbidity and may be overtreatment for low-risk cancers. This study is designed to determine the feasibility of international recruitment in a study...... comparing organ-saving approaches versus standard TME surgery. METHODS AND ANALYSIS: STAR-TREC trial is a multicentre international randomised, three-arm parallel, phase II feasibility study in patients with biopsy-proven adenocarcinoma of the rectum. The trial is coordinated from Birmingham, UK...... endpoint of this phase II study is to demonstrate sufficient international recruitment in order to sustain a phase III study incorporating pelvic failure as the primary endpoint. Success in phase II is defined as randomisation of at least four cases per month internationally in year 1, rising to at least...

  10. Treatment planning evaluation of non-coplanar techniques for conformal radiotherapy of the prostate

    International Nuclear Information System (INIS)

    Bedford, James L.; Henrys, Anthony J.; Dearnaley, David P.; Khoo, Vincent S.

    2005-01-01

    Background and purpose: To evaluate the benefit of using non-coplanar treatment plans for irradiation of two different clinical treatment volumes: prostate only (PO) and the prostate plus seminal vesicles (PSV). Material and methods: An inverse planning algorithm was used to produce three-field, four-field, five-field and six-field non-coplanar treatment plans without intensity-modulation in ten patients. These were compared against a three-field coplanar plan. A dose of 74 Gy was prescribed to the isocentre. Plans were compared using the minimum dose to the planning target volume (PTV), maximum dose to the small bowel, and irradiated volumes of rectum, bladder and femoral head. Biological indices were also evaluated. Results: For the PO group, volume of rectum irradiated to 60 Gy (V 60 ) was 22.5±3.7% for the coplanar plan, and 21.5±5.3% for the five-field non-coplanar plan, which was the most beneficial (p=0.3). For the PSV group, the five-field non-coplanar plan was again the most beneficial. Rectal V 60 was in this case reduced from 41.5±10.4% for the coplanar plan to 35.2±9.3% for the non-coplanar plan (p=0.02). Conclusions: The use of non-coplanar beams in conformal prostate radiotherapy provides a small increase in rectal sparing, more significantly with PSV volumes than for PO volumes

  11. SU-F-T-26: A Study of the Consistency of Brachytherapy Treatments for Vaginal Cuff

    Energy Technology Data Exchange (ETDEWEB)

    Shojaei, M; Pella, S; Dumitru, N [21st Century Oncology, Boca Raton, FL (United States)

    2016-06-15

    Purpose: To evaluate to treatment consistency over the total number of fractions when treatment what HDR brachytherapy using the ML cylinders. At the same time the dosimetric impact on the critical organs is monitored over the total number of fractions. Methods: A retrospective analysis of 10 patients treated with Cylinder applicators, from 2015–2016 were considered for this study. The CT scans of these patients, taken before each treatment were separately imported in to the treatment planning system and paired with the initial CT scan after completing the contouring. Two sets of CT images were fused together with respective to the applicator, using landmark registration. The doses of each plan were imported as well and a cumulative dosimetric analysis was made for bladder, bowels, and rectum and PTV. Results: No contour of any of the OAR was exactly similar when CT images were fused on each other. The PTV volumes vary from fraction to fraction. There was always a difference between the doses received by the OARs between treatments. The maximum dose varied between 5% and 30% in rectum and bladder. The minimum dose varied between 5% and 8% in rectum and bladder. The average dose varied between 15% and 20% in rectum and bladder. Deviation in placement were noticed between fractions. Conclusion: The variation in volumes of OARs and isodoses near the OARs, indicate that the estimated doses to OARs on the planning system may not be the same dose delivered to the patient in all the fractions. There are no major differences between the prescribed dose and the delivered dose over the total number of fractions. In some cases the critical organs will benefit if the consecutive plans will made after the CT scans will be registered with the initial scan and then planned.

  12. Small-Volume Injections: Evaluation of Volume Administration Deviation From Intended Injection Volumes.

    Science.gov (United States)

    Muffly, Matthew K; Chen, Michael I; Claure, Rebecca E; Drover, David R; Efron, Bradley; Fitch, William L; Hammer, Gregory B

    2017-10-01

    In the perioperative period, anesthesiologists and postanesthesia care unit (PACU) nurses routinely prepare and administer small-volume IV injections, yet the accuracy of delivered medication volumes in this setting has not been described. In this ex vivo study, we sought to characterize the degree to which small-volume injections (≤0.5 mL) deviated from the intended injection volumes among a group of pediatric anesthesiologists and pediatric postanesthesia care unit (PACU) nurses. We hypothesized that as the intended injection volumes decreased, the deviation from those intended injection volumes would increase. Ten attending pediatric anesthesiologists and 10 pediatric PACU nurses each performed a series of 10 injections into a simulated patient IV setup. Practitioners used separate 1-mL tuberculin syringes with removable 18-gauge needles (Becton-Dickinson & Company, Franklin Lakes, NJ) to aspirate 5 different volumes (0.025, 0.05, 0.1, 0.25, and 0.5 mL) of 0.25 mM Lucifer Yellow (LY) fluorescent dye constituted in saline (Sigma Aldrich, St. Louis, MO) from a rubber-stoppered vial. Each participant then injected the specified volume of LY fluorescent dye via a 3-way stopcock into IV tubing with free-flowing 0.9% sodium chloride (10 mL/min). The injected volume of LY fluorescent dye and 0.9% sodium chloride then drained into a collection vial for laboratory analysis. Microplate fluorescence wavelength detection (Infinite M1000; Tecan, Mannedorf, Switzerland) was used to measure the fluorescence of the collected fluid. Administered injection volumes were calculated based on the fluorescence of the collected fluid using a calibration curve of known LY volumes and associated fluorescence.To determine whether deviation of the administered volumes from the intended injection volumes increased at lower injection volumes, we compared the proportional injection volume error (loge [administered volume/intended volume]) for each of the 5 injection volumes using a linear

  13. Comparison of target volumes in radiotherapy defined on scanner and on PET-T.D.M. with {sup 18}F-F.D.G. in the frame of head and neck cancers; Comparaison des volumes cibles en radiotherapie definis sur scanner et sur TEP-TDM au 18F FDG dans le cadre des cancers de la tete et du cou

    Energy Technology Data Exchange (ETDEWEB)

    Henriques De Figueiredo, B.; Barret, O.; Allard, M.; Fernandez, P. [Service de medecine nucleaire, CHU de Pellegrin, Bordeaux, (France); Demeaux, H.; Maire, J.P.; Lagarde, P. [service de radiotherapie, hopital Saint-Andre, Bordeaux, (France); Kantor, G.; Richau, P. [departement de radiotherapie, institut Bergonie, Bordeaux, (France); De Mones Del Pujol, E. [service d' ORL, hopital Pellegrin, Bordeaux, (France)

    2009-05-15

    The objective is to study in a prospective way, in the frame of head and neck cancers, the impact of the positron computed tomography with {sup 18}F fluorodeoxyglucose (PET-F.D.G.) on the limitation of target volumes in radiotherapy. In conclusions, the gross tumor volume (G.T.V.) defined on PET is smaller than this one defined on scanner, that could be interesting in radiotherapy, in the perspective of a dose escalation. In addition, areas of discordance exist between the clinical target volumes (C.T.V.70 and C.T.V.50) defined on PET and on scanner. These discordances, synonyms of under or over estimation of target volumes, could have important clinical consequences in term of local control and toxicity. (N.C.)

  14. Dosimetric analysis at ICRU reference points in HDR-brachytherapy of cervical carcinoma.

    Science.gov (United States)

    Eich, H T; Haverkamp, U; Micke, O; Prott, F J; Müller, R P

    2000-01-01

    In vivo dosimetry in bladder and rectum as well as determining doses on suggested reference points following the ICRU report 38 contribute to quality assurance in HDR-brachytherapy of cervical carcinoma, especially to minimize side effects. In order to gain information regarding the radiation exposure at ICRU reference points in rectum, bladder, ureter and regional lymph nodes those were calculated (digitalisation) by means of orthogonal radiographs of 11 applications in patients with cervical carcinoma, who received primary radiotherapy. In addition, the doses at the ICRU rectum reference point was compared to the results of in vivo measurements in the rectum. The in vivo measurements were by factor 1.5 below the doses determined for the ICRU rectum reference point (4.05 +/- 0.68 Gy versus 6.11 +/- 1.63 Gy). Reasons for this were: calibration errors, non-orthogonal radiographs, movement of applicator and probe in the time span between X-ray and application, missing connection of probe and anterior rectal wall. The standard deviation of calculations at ICRU reference points was on average +/- 30%. Possible reasons for the relatively large standard deviation were difficulties in defining the points, identifying them on radiographs and the different locations of the applicators. Although 3 D CT, US or MR based treatment planning using dose volume histogram analysis is more and more established, this simple procedure of marking and digitising the ICRU reference points lengthened treatment planning only by 5 to 10 minutes. The advantages of in vivo dosimetry are easy practicability and the possibility to determine rectum doses during radiation. The advantages of computer-aided planning at ICRU reference points are that calculations are available before radiation and that they can still be taken into account for treatment planning. Both methods should be applied in HDR-brachytherapy of cervical carcinoma.

  15. Grading-system-dependent volume effects for late radiation-induced rectal toxicity after curative radiotherapy for prostate cancer

    NARCIS (Netherlands)

    van der Laan, Hans Paul; van den Bergh, Alphons; Schilstra, C; Vlasman, Renske; Meertens, Harm; Langendijk, Johannes A

    2008-01-01

    PURPOSE: To assess the association between the dose distributions in the rectum and late Radiation Therapy Oncology Group and the European Organisation for Research and Treatment of Cancer (RTOG/EORTC), Late Effects of Normal Tissue SOMA, and Common Terminology Criteria for Adverse Events (CTCAE)

  16. [Target volume margins for lung cancer: internal target volume/clinical target volume].

    Science.gov (United States)

    Jouin, A; Pourel, N

    2013-10-01

    The aim of this study was to carry out a review of margins that should be used for the delineation of target volumes in lung cancer, with a focus on margins from gross tumour volume (GTV) to clinical target volume (CTV) and internal target volume (ITV) delineation. Our review was based on a PubMed literature search with, as a cornerstone, the 2010 European Organisation for Research and Treatment of Cancer (EORTC) recommandations by De Ruysscher et al. The keywords used for the search were: radiotherapy, lung cancer, clinical target volume, internal target volume. The relevant information was categorized under the following headings: gross tumour volume definition (GTV), CTV-GTV margin (first tumoural CTV then nodal CTV definition), in field versus elective nodal irradiation, metabolic imaging role through the input of the PET scanner for tumour target volume and limitations of PET-CT imaging for nodal target volume definition, postoperative radiotherapy target volume definition, delineation of target volumes after induction chemotherapy; then the internal target volume is specified as well as tumoural mobility for lung cancer and respiratory gating techniques. Finally, a chapter is dedicated to planning target volume definition and another to small cell lung cancer. For each heading, the most relevant and recent clinical trials and publications are mentioned. Copyright © 2013. Published by Elsevier SAS.

  17. Primary squamous cell carcinoma of the rectum: An update and implications for treatment

    Science.gov (United States)

    Guerra, Glen R; Kong, Cherng H; Warrier, Satish K; Lynch, Andrew C; Heriot, Alexander G; Ngan, Samuel Y

    2016-01-01

    AIM: To provide an update on the aetiology, pathogenesis, diagnosis, staging and management of rectal squamous cell carcinoma (SCC). METHODS: A systematic review was conducted according to the preferred reporting items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive search of Ovid MEDLINE was performed with the reference list of selected articles reviewed to ensure all relevant publications were captured. The search strategy was limited to the English language, spanning from 1946 to 2015. A qualitative analysis was undertaken examining patient demographics, clinical presentation, diagnosis, staging, treatment and outcome. The quantitaive analysis was limited to data extracted on treatment and outcomes including radiological, clinical and pathological complete response where available. The narrative and quantitative review were synthesised in concert. RESULTS: The search identified 487 articles in total with 79 included in the qualitative review. The quantitative analysis involved 63 articles, consisting of 43 case reports and 20 case series with a total of 142 individual cases. The underlying pathogenesis of rectal SCC while unclear, continues to be defined, with increasing evidence of a metaplasia-dysplasia-carcinoma sequence and a possible role for human papilloma virus in this progression. The presentation is similar to rectal adenocarcinoma, with a diagnosis confirmed by endoscopic biopsy. Many presumed rectal SCC’s are in fact an extension of an anal SCC, and cytokeratin markers are a useful adjunct in this distinction. Staging is most accurately reflected by the tumour-node-metastasis classification for rectal adenocarcinoma. It involves examining locoregional disease by way of magnetic resonance imaging and/or endorectal ultrasound, with systemic spread excluded by way of computed tomography. Positron emission tomography is integral in the workup to exclude an external site of primary SCC with metastasis to the rectum. While the

  18. SU-F-T-36: Dosimetric Comparison of Point Based Vs. Target Based Prescription for Intracavitary Brachytherapy in Cancer of the Cervix

    Energy Technology Data Exchange (ETDEWEB)

    Ashenafi, M; McDonald, D; Peng, J; Mart, C; Koch, N; Cooper, L; Vanek, K [Medical University of South Carolina, Charleston, SC (United States)

    2016-06-15

    Purpose: Improved patient imaging used for planning the treatment of cervical cancer with Tandem and Ovoid (T&O) Intracavitary high-dose-rate brachytherapy (HDR) now allows for 3D delineation of target volumes and organs-at-risk. However, historical data relies on the conventional point A-based planning technique. A comparative dosimetric study was performed by generating both target-based (TBP) and point-based (PBP) plans for ten clinical patients. Methods: Treatment plans created using Elekta Oncentra v. 4.3 for ten consecutive cervical cancer patients were analyzed. All patients were treated with HDR using the Utrecht T&O applicator. Both CT and MRI imaging modalities were utilized to delineate clinical target volume (CTV) and organs-at-risk (rectum, sigmoid, bladder, and small bowel). Point A (left and right), vaginal mucosa, and ICRU rectum and bladder points were defined on CT. Two plans were generated for each patient using two prescription methods (PBP and TBP). 7Gy was prescribed to each point A for each PBP plan and to the target D90% for each TBP plan. Target V90%, V100%, and V200% were evaluated. In addition, D0.1cc and D2cc were analyzed for each organ-at-risk. Differences were assessed for statistical significance (p<0.05) by use of Student’s t-test. Results: Target coverage was comparable for both planning methods, with each method providing adequate target coverage. TBP showed lower absolute dose to the target volume than PBP (D90% = 7.0Gy vs. 7.4Gy, p=0.028), (V200% = 10.9cc vs. 12.8cc, p=0.014), (ALeft = 6.4Gy vs. 7Gy, p=0.009), and (ARight = 6.4Gy vs. 7Gy, p=0.013). TBP also showed a statistically significant reduction in bladder, rectum, small bowel, and sigmoid doses compared to PBP. There was no statistically significant difference in vaginal mucosa or ICRU-defined rectum and bladder dose. Conclusion: Target based prescription resulted in substantially lower dose to delineated organs-at-risk compared to point based prescription, while

  19. Adjuvant radiation therapy for bladder cancer: A dosimetric comparison of techniques

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Brian C.; Noa, Kate [Department of Radiation Oncology at the University of Pennsylvania, Philadelphia, PA (United States); Wileyto, E. Paul [Department of Biostatistics and Epidemiology at the University of Pennsylvania, Philadelphia, PA (United States); Bekelman, Justin E. [Department of Radiation Oncology at the University of Pennsylvania, Philadelphia, PA (United States); Deville, Curtiland [Department of Radiation Oncology and Molecular Radiation Sciences at Johns Hopkins University School of Medicine, Baltimore, MD (United States); Vapiwala, Neha; Kirk, Maura; Both, Stefan; Dolney, Derek; Kassaee, Ali [Department of Radiation Oncology at the University of Pennsylvania, Philadelphia, PA (United States); Christodouleas, John P., E-mail: christojo@uphs.upenn.edu [Department of Radiation Oncology at the University of Pennsylvania, Philadelphia, PA (United States)

    2015-01-01

    Trials of adjuvant radiation after cystectomy are under development. There are no studies comparing radiation techniques to inform trial design. This study assesses the effect on bowel and rectal dose of 3 different modalities treating 2 proposed alternative clinical target volumes (CTVs). Contours of the bowel, rectum, CTV-pelvic sidewall (common/internal/external iliac and obturator nodes), and CTV-comprehensive (CTV-pelvic sidewall plus cystectomy bed and presacral regions) were drawn on simulation images of 7 post-cystectomy patients. We optimized 3-dimensional conformal radiation (3-D), intensity-modulated radiation (IMRT), and single-field uniform dose (SFUD) scanning proton plans for each CTV. Mixed models regression was used to compare plans for bowel and rectal volumes exposed to 35% (V{sub 35%}), 65% (V{sub 65%}), and 95% (V{sub 95%}) of the prescribed dose. For any given treatment modality, treating the larger CTV-comprehensive volume compared with treating only the CTV-pelvic sidewall nodes significantly increased rectal dose (V{sub 35%} {sub rectum}, V{sub 65%} {sub rectum}, and V{sub 95%} {sub rectum}; p < 0.001 for all comparisons), but it did not produce significant differences in bowel dose (V{sub 95%} {sub bowel}, V{sub 65%} {sub bowel}, or V{sub 35%} {sub bowel}). The 3-D plans, compared with both the IMRT and the SFUD plans, had a significantly greater V{sub 65%} {sub bowel} and V{sub 95%} {sub bowel} for each proposed CTV (p < 0.001 for all comparisons). The effect of treatment modality on rectal dosimetry differed by CTV, but it generally favored the IMRT and the SFUD plans over the 3-D plans. Comparison of the IMRT plan vs the SFUD plan yielded mixed results with no consistent advantage for the SFUD plan over the IMRT plan. Targeting a CTV that spares the cystectomy bed and presacral region may marginally improve rectal toxicity but would not be expected to improve the bowel toxicity associated with any given modality of adjuvant radiation

  20. A text-based data mining and toxicity prediction modeling system for a clinical decision support in radiation oncology: A preliminary study

    Science.gov (United States)

    Kim, Kwang Hyeon; Lee, Suk; Shim, Jang Bo; Chang, Kyung Hwan; Yang, Dae Sik; Yoon, Won Sup; Park, Young Je; Kim, Chul Yong; Cao, Yuan Jie

    2017-08-01

    The aim of this study is an integrated research for text-based data mining and toxicity prediction modeling system for clinical decision support system based on big data in radiation oncology as a preliminary research. The structured and unstructured data were prepared by treatment plans and the unstructured data were extracted by dose-volume data image pattern recognition of prostate cancer for research articles crawling through the internet. We modeled an artificial neural network to build a predictor model system for toxicity prediction of organs at risk. We used a text-based data mining approach to build the artificial neural network model for bladder and rectum complication predictions. The pattern recognition method was used to mine the unstructured toxicity data for dose-volume at the detection accuracy of 97.9%. The confusion matrix and training model of the neural network were achieved with 50 modeled plans (n = 50) for validation. The toxicity level was analyzed and the risk factors for 25% bladder, 50% bladder, 20% rectum, and 50% rectum were calculated by the artificial neural network algorithm. As a result, 32 plans could cause complication but 18 plans were designed as non-complication among 50 modeled plans. We integrated data mining and a toxicity modeling method for toxicity prediction using prostate cancer cases. It is shown that a preprocessing analysis using text-based data mining and prediction modeling can be expanded to personalized patient treatment decision support based on big data.

  1. Daily Isocenter Correction With Electromagnetic-Based Localization Improves Target Coverage and Rectal Sparing During Prostate Radiotherapy

    International Nuclear Information System (INIS)

    Rajendran, Ramji Ramaswamy; Plastaras, John P.; Mick, Rosemarie; McMichael Kohler, Diane; Kassaee, Alireza; Vapiwala, Neha

    2010-01-01

    Purpose: To evaluate dosimetric consequences of daily isocenter correction during prostate cancer radiation therapy using the Calypso 4D localization system. Methods and Materials: Data were analyzed from 28 patients with electromagnetic transponders implanted in their prostates for daily target localization and tracking. Treatment planning isocenters were recorded based on the values of the vertical, longitudinal, and lateral axes. Isocenter location obtained via alignment with skin tattoos was compared with that obtained via the electromagnetic localization system. Daily isocenter shifts, based on the isocenter location differences between the two alignment methods in each spatial axis, were calculated for each patient over their entire course. The mean isocenter shifts were used to determine dosimetric consequences of treatment based on skin tattoo alignments alone. Results: The mean += SD of the percentages of treatment days with shifts beyond += 0.5 cm for vertical, longitudinal and lateral shifts were 62% += 28%, 35% += 26%, and 38% +=21%, respectively. If daily electromagnetic localization was not used, the excess in prescribed dose delivered to 70% of the rectum was 10 Gy and the deficit in prescribed dose delivered to 95% of the planning target volume was 10 Gy. The mean isocenter shift was not associated with the volumes of the prostate, rectum, or bladder, or with patient body mass index. Conclusions: Daily isocenter localization can reduce the treatment dose to the rectum. Correcting for this variability could lead to improved dose delivery, reduced side effects, and potentially improved treatment outcomes.

  2. Comparative dosimetry of prostate brachytherapy with I-125 and Pd-103 seeds via SISCODES/MCNP

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, Bruno Machado; Falcao, Patricia Lima, E-mail: bmtrindade@yahoo.com [Nucleo de Radiacoes Ionizantes - Universidade Federal de Minas Gerais (NRI/UFMG), Belo Horizonte, MG (Brazil); Christovao, Marilia Tavares [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Trindade, Daniela de Fatima Maia [Centro Universitario Una, Belo Horizonte, MG (Brazil); Campos, Tarcisio Passos Ribeiro de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2012-09-15

    Objective: The present paper is aimed at presenting a comparative dosimetric study of prostate brachytherapy with I-125 and Pd-103 seeds. Materials and Methods: A protocol for both implants with 148 seeds was simulated on a heterogeneous three-dimensional pelvic phantom by means of the SISCODES/MCNP5 codes. Dose-volume histograms on prostate, rectum and bladder, dose indexes D10, D30, D90, D0.5cc, D2cc and D7cc, and representations of the spatial dose distribution were evaluated. Results: For a D90 index equivalent to the prescription dose, the initial activity of each I-125 seed was calculated as 0.42 mCi and of Pd-103 as 0.94 mCi. The maximum dose on the urethra was 90% and 108% of the prescription dose for I-125 and Pd-103, respectively. The D2cc for I-125 was 30 Gy on the rectum and 127 Gy on the bladder; for Pd-103 was 29 Gy on the rectum and 189 Gy on the bladder. The D10 on the pubic bone was 144 Gy for I-125 and 66 Gy for Pd-103. Conclusion: The results indicate that Pd-103 and I-125 implants could deposit the prescribed dose on the target volume. Among the findings of the present study, there is an excessive radiation exposure of the pelvic bones, particularly with the I-125 protocol. (author)

  3. Class solution to decrease rectal dose in prostate radiotherapy treatments 3D-CRT

    International Nuclear Information System (INIS)

    Andres Rodriguez, C.; Tortosa Oliver, R.; Alonso Hernandez, D.; Mari Palacios, A.; Castillo Belmonte, A. del

    2011-01-01

    This paper contains a method developed in our center with conventional 3D radiotherapy techniques to increase the dose conformation around the target volume in prostate cancer treatments significantly reduced the doses to the rectum. To evaluate the goodness of the method, the results are compared with two classical techniques of treatment.

  4. Class solution to decrease rectal dose in prostate radiotherapy treatments 3D-CRT; Solucion de clase para disminuir dosis en recto en tratamientos de prostata con radioterapia 3D-CRT

    Energy Technology Data Exchange (ETDEWEB)

    Andres Rodriguez, C.; Tortosa Oliver, R.; Alonso Hernandez, D.; Mari Palacios, A.; Castillo Belmonte, A. del

    2011-07-01

    This paper contains a method developed in our center with conventional 3D radiotherapy techniques to increase the dose conformation around the target volume in prostate cancer treatments significantly reduced the doses to the rectum. To evaluate the goodness of the method, the results are compared with two classical techniques of treatment.

  5. Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2016 for the treatment of colorectal cancer.

    Science.gov (United States)

    Watanabe, Toshiaki; Muro, Kei; Ajioka, Yoichi; Hashiguchi, Yojiro; Ito, Yoshinori; Saito, Yutaka; Hamaguchi, Tetsuya; Ishida, Hideyuki; Ishiguro, Megumi; Ishihara, Soichiro; Kanemitsu, Yukihide; Kawano, Hiroshi; Kinugasa, Yusuke; Kokudo, Norihiro; Murofushi, Keiko; Nakajima, Takako; Oka, Shiro; Sakai, Yoshiharu; Tsuji, Akihito; Uehara, Keisuke; Ueno, Hideki; Yamazaki, Kentaro; Yoshida, Masahiro; Yoshino, Takayuki; Boku, Narikazu; Fujimori, Takahiro; Itabashi, Michio; Koinuma, Nobuo; Morita, Takayuki; Nishimura, Genichi; Sakata, Yuh; Shimada, Yasuhiro; Takahashi, Keiichi; Tanaka, Shinji; Tsuruta, Osamu; Yamaguchi, Toshiharu; Yamaguchi, Naohiko; Tanaka, Toshiaki; Kotake, Kenjiro; Sugihara, Kenichi

    2018-02-01

    Japanese mortality due to colorectal cancer is on the rise, surpassing 49,000 in 2015. Many new treatment methods have been developed during recent decades. The Japanese Society for Cancer of the Colon and Rectum Guidelines 2016 for the treatment of colorectal cancer (JSCCR Guidelines 2016) were prepared to show standard treatment strategies for colorectal cancer, to eliminate disparities among institutions in terms of treatment, to eliminate unnecessary treatment and insufficient treatment, and to deepen mutual understanding between health-care professionals and patients by making these Guidelines available to the general public. These Guidelines were prepared by consensus reached by the JSCCR Guideline Committee, based on a careful review of the evidence retrieved by literature searches, and in view of the medical health insurance system and actual clinical practice settings in Japan. Therefore, these Guidelines can be used as a tool for treating colorectal cancer in actual clinical practice settings. More specifically, they can be used as a guide to obtaining informed consent from patients and choosing the method of treatment for each patient. As a result of the discussions held by the Guideline Committee, controversial issues were selected as Clinical Questions, and recommendations were made. Each recommendation is accompanied by a classification of the evidence and a classification of recommendation categories based on the consensus reached by the Guideline Committee members. Here we present the English version of the JSCCR Guidelines 2016.

  6. Dosimetric comparison of IMRT and modulated arc-therapy techniques in the treatment of cervical cancers; Comparaison dosimetrique des techniques de RCMI et d'arctherapie modulee dans le traitement des cancers du col uterin

    Energy Technology Data Exchange (ETDEWEB)

    Renard-Oldrini, S.; Charra-Brunaud, C.; Tournier-Rangeard, L.; Huger, S.; Marchesi, V.; Bouziz, D.; Peiffert, D. [Centre Alexis-Vautrin, Nancy (France)

    2011-10-15

    The authors report the dosimetric comparison of two techniques used for the treatment of cervical cancers: the intensity-modulated conformational radiotherapy (IMRT) with static beams and modulated arc-therapy with RapidArc. The treatment plans of 15 patients have been compared. The clinical target volume (CTV) comprises the gross target volume, the cervix, the upper third of the vagina, and ganglionary areas. The previsional target volume comprises the clinical target volume and a one centimetre margin. Organs at risk are rectum, bladder, intestine and bone marrow. Arc-therapy seems to provide a better sparing of intestine that IMRT, while maintaining a good coverage of the previsional target volume and decreasing treatment duration. Short communication

  7. Dynamics of rectal balloon implant shrinkage in prostate VMAT. Influence on anorectal dose and late rectal complication risk

    International Nuclear Information System (INIS)

    Vanneste, Ben G.L.; Wijk, Y. van; Lutgens, L.C.; Limbergen, E.J. van; Lambin, P.; Lin, E.N. van; Beek, K. van de; Hoffmann, A.L.

    2018-01-01

    To assess the effect of a shrinking rectal balloon implant (RBI) on the anorectal dose and complication risk during the course of moderately hypofractionated prostate radiotherapy. In 15 patients with localized prostate cancer, an RBI was implanted. A weekly kilovolt cone-beam computed tomography (CBCT) scan was acquired to measure the dynamics of RBI volume and prostate-rectum separation. The absolute anorectal volume encompassed by the 2 Gy equieffective 75 Gy isodose (V 75Gy ) was recalculated as well as the mean anorectal dose. The increase in estimated risk of grade 2-3 late rectal bleeding (LRB) between the start and end of treatment was predicted using nomograms. The observed acute and late toxicities were evaluated. A significant shrinkage of RBI volumes was observed, with an average volume of 70.4% of baseline at the end of the treatment. Although the prostate-rectum separation significantly decreased over time, it remained at least 1 cm. No significant increase in V 75Gy of the anorectum was observed, except in one patient whose RBI had completely deflated in the third week of treatment. No correlation between mean anorectal dose and balloon deflation was found. The increase in predicted LRB risk was not significant, except in the one patient whose RBI completely deflated. The observed toxicities confirmed these findings. Despite significant decrease in RBI volume the high-dose rectal volume and the predicted LRB risk were unaffected due to a persistent spacing between the prostate and the anterior rectal wall. (orig.) [de

  8. Automatically-generated rectal dose constraints in intensity-modulated radiation therapy for prostate cancer

    Science.gov (United States)

    Hwang, Taejin; Kim, Yong Nam; Kim, Soo Kon; Kang, Sei-Kwon; Cheong, Kwang-Ho; Park, Soah; Yoon, Jai-Woong; Han, Taejin; Kim, Haeyoung; Lee, Meyeon; Kim, Kyoung-Joo; Bae, Hoonsik; Suh, Tae-Suk

    2015-06-01

    The dose constraint during prostate intensity-modulated radiation therapy (IMRT) optimization should be patient-specific for better rectum sparing. The aims of this study are to suggest a novel method for automatically generating a patient-specific dose constraint by using an experience-based dose volume histogram (DVH) of the rectum and to evaluate the potential of such a dose constraint qualitatively. The normal tissue complication probabilities (NTCPs) of the rectum with respect to V %ratio in our study were divided into three groups, where V %ratio was defined as the percent ratio of the rectal volume overlapping the planning target volume (PTV) to the rectal volume: (1) the rectal NTCPs in the previous study (clinical data), (2) those statistically generated by using the standard normal distribution (calculated data), and (3) those generated by combining the calculated data and the clinical data (mixed data). In the calculated data, a random number whose mean value was on the fitted curve described in the clinical data and whose standard deviation was 1% was generated by using the `randn' function in the MATLAB program and was used. For each group, we validated whether the probability density function (PDF) of the rectal NTCP could be automatically generated with the density estimation method by using a Gaussian kernel. The results revealed that the rectal NTCP probability increased in proportion to V %ratio , that the predictive rectal NTCP was patient-specific, and that the starting point of IMRT optimization for the given patient might be different. The PDF of the rectal NTCP was obtained automatically for each group except that the smoothness of the probability distribution increased with increasing number of data and with increasing window width. We showed that during the prostate IMRT optimization, the patient-specific dose constraints could be automatically generated and that our method could reduce the IMRT optimization time as well as maintain the

  9. Daily variations in delivered doses in patients treated with radiotherapy for localized prostate cancer

    International Nuclear Information System (INIS)

    Kupelian, Patrick A.; Langen, Katja M.; Zeidan, Omar A.; Meeks, Sanford L.; Willoughby, Twyla R.; Wagner, Thomas H.; Jeswani, Sam; Ruchala, Kenneth J.; Haimerl, Jason; Olivera, Gustavo H.

    2006-01-01

    Purpose: The aim of this work was to study the variations in delivered doses to the prostate, rectum, and bladder during a full course of image-guided external beam radiotherapy. Methods and Materials: Ten patients with localized prostate cancer were treated with helical tomotherapy to 78 Gy at 2 Gy per fraction in 39 fractions. Daily target localization was performed using intraprostatic fiducials and daily megavoltage pelvic computed tomography (CT) scans, resulting in a total of 390 CT scans. The prostate, rectum, and bladder were manually contoured on each CT by a single physician. Daily dosimetric analysis was performed with dose recalculation. The study endpoints were D95 (dose to 95% of the prostate), rV2 (absolute rectal volume receiving 2 Gy), and bV2 (absolute bladder volume receiving 2 Gy). Results: For the entire cohort, the average D95 (±SD) was 2.02 ± 0.04 Gy (range, 1.79-2.20 Gy). The average rV2 (±SD) was 7.0 ± 8.1 cc (range, 0.1-67.3 cc). The average bV2 (±SD) was 8.7 ± 6.8 cc (range, 0.3-36.8 cc). Unlike doses for the prostate, there was significant daily variation in rectal and bladder doses, mostly because of variations in volume and shape of these organs. Conclusion: Large variations in delivered doses to the rectum and bladder can be documented with daily megavoltage CT scans. Image guidance for the targeting of the prostate, even with intraprostatic fiducials, does not take into account the variation in actual rectal and bladder doses. The clinical impact of techniques that take into account such dosimetric parameters in daily patient set-ups should be investigated

  10. Effects of organ motion on proton prostate treatments, as determined from analysis of daily CT imaging for patient positioning.

    Science.gov (United States)

    Maeda, Yoshikazu; Sato, Yoshitaka; Shibata, Satoshi; Bou, Sayuri; Yamamoto, Kazutaka; Tamamura, Hiroyasu; Fuwa, Nobukazu; Takamatsu, Shigeyuki; Sasaki, Makoto; Tameshige, Yuji; Kume, Kyo; Minami, Hiroki; Saga, Yusuke; Saito, Makoto

    2018-05-01

    We quantified interfractional movements of the prostate, seminal vesicles (SVs), and rectum during computed tomography (CT) image-guided proton therapy for prostate cancer and studied the range variation in opposed lateral proton beams. We analyzed 375 sets of daily CT images acquired throughout the proton therapy treatment of ten patients. We analyzed daily movements of the prostate, SVs, and rectum by simulating three image-matching strategies: bone matching, prostate center (PC) matching, and prostate-rectum boundary (PRB) matching. In the PC matching, translational movements of the prostate center were corrected after bone matching. In the PRB matching, we performed PC matching and correction along the anterior-posterior direction to match the boundary between the prostate and the rectum's anterior region. In each strategy, we evaluated systematic errors (Σ) and random errors (σ) by measuring the daily movements of certain points on each anatomic structure. The average positional deviations in millimeter of each point were determined by the Van Herk formula of 2.5Σ + 0.7σ. Using these positional deviations, we created planning target volumes of the prostate and SVs and analyzed the daily variation in the water equivalent length (WEL) from the skin surface to the target along the lateral beam directions using the density converted from the daily CT number. Based on this analysis, we designed prostate cancer treatment planning and evaluated the dose volume histograms (DVHs) for these strategies. The SVs' daily movements showed large variations over the superior-inferior direction, as did the rectum's anterior region. The average positional deviations of the prostate in the anterior, posterior, superior, inferior, and lateral sides (mm) in bone matching, PC matching, and PRB matching were (8.9, 9.8, 7.5, 3.6, 1.6), (5.6, 6.1, 3.5, 4.5, 1.9), and (8.6, 3.2, 3.5, 4.5, 1.9) (mm), respectively. Moreover, the ones of the SV tip were similarly (22.5, 15.5, 11

  11. Maximizing dosimetric benefits of IMRT in the treatment of localized prostate cancer through multicriteria optimization planning

    International Nuclear Information System (INIS)

    Wala, Jeremiah; Craft, David; Paly, Jon; Zietman, Anthony; Efstathiou, Jason

    2013-01-01

    We examine the quality of plans created using multicriteria optimization (MCO) treatment planning in intensity-modulated radiation therapy (IMRT) in treatment of localized prostate cancer. Nine random cases of patients receiving IMRT to the prostate were selected. Each case was associated with a clinically approved plan created using Corvus. The cases were replanned using MCO-based planning in RayStation. Dose-volume histogram data from both planning systems were presented to 2 radiation oncologists in a blinded evaluation, and were compared at a number of dose-volume points. Both physicians rated all 9 MCO plans as superior to the clinically approved plans (p −5 ). Target coverage was equivalent (p = 0.81). Maximum doses to the prostate and bladder and the V50 and V70 to the anterior rectum were reduced in all MCO plans (p<0.05). Treatment planning time with MCO took approximately 60 minutes per case. MCO-based planning for prostate IMRT is efficient and produces high-quality plans with good target homogeneity and sparing of the anterior rectum, bladder, and femoral heads, without sacrificing target coverage

  12. Maximizing dosimetric benefits of IMRT in the treatment of localized prostate cancer through multicriteria optimization planning

    Energy Technology Data Exchange (ETDEWEB)

    Wala, Jeremiah; Craft, David [Harvard Medical School, Boston, MA (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Paly, Jon [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Zietman, Anthony [Harvard Medical School, Boston, MA (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Efstathiou, Jason, E-mail: jefstathiou@partners.org [Harvard Medical School, Boston, MA (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States)

    2013-10-01

    We examine the quality of plans created using multicriteria optimization (MCO) treatment planning in intensity-modulated radiation therapy (IMRT) in treatment of localized prostate cancer. Nine random cases of patients receiving IMRT to the prostate were selected. Each case was associated with a clinically approved plan created using Corvus. The cases were replanned using MCO-based planning in RayStation. Dose-volume histogram data from both planning systems were presented to 2 radiation oncologists in a blinded evaluation, and were compared at a number of dose-volume points. Both physicians rated all 9 MCO plans as superior to the clinically approved plans (p<10{sup −5}). Target coverage was equivalent (p = 0.81). Maximum doses to the prostate and bladder and the V50 and V70 to the anterior rectum were reduced in all MCO plans (p<0.05). Treatment planning time with MCO took approximately 60 minutes per case. MCO-based planning for prostate IMRT is efficient and produces high-quality plans with good target homogeneity and sparing of the anterior rectum, bladder, and femoral heads, without sacrificing target coverage.

  13. Definition and grading of anastomotic leakage following anterior resection of the rectum: a proposal by the International Study Group of Rectal Cancer.

    Science.gov (United States)

    Rahbari, Nuh N; Weitz, Jürgen; Hohenberger, Werner; Heald, Richard J; Moran, Brendan; Ulrich, Alexis; Holm, Torbjörn; Wong, W Douglas; Tiret, Emmanuel; Moriya, Yoshihiro; Laurberg, Søren; den Dulk, Marcel; van de Velde, Cornelis; Büchler, Markus W

    2010-03-01

    Anastomotic leakage represents a major complication after anterior resection of the rectum. The incidence of anastomotic leakage varies considerably among clinical studies in part owing to the lack of a standardized definition of this complication. The aim of the present article was to propose a definition and severity grading of anastomotic leakage after anterior rectal resection. After a literature review a consensus definition and severity grading of anastomotic leakage was developed within the International Study Group of Rectal Cancer. Anastomotic leakage should be defined as a defect of the intestinal wall at the anastomotic site (including suture and staple lines of neorectal reservoirs) leading to a communication between the intra- and extraluminal compartments. Severity of anastomotic leakage should be graded according to the impact on clinical management. Grade A anastomotic leakage results in no change in patients' management, whereas grade B leakage requires active therapeutic intervention but is manageable without re-laparotomy. Grade C anastomotic leakage requires re-laparotomy. The proposed definition and clinical grading is applicable easily in the setting of clinical studies. It should be applied in future reports to facilitate valid comparison of the results of different studies. Copyright 2010 Mosby, Inc. All rights reserved.

  14. Proposal of a post-prostatectomy clinical target volume based on pre-operative MRI: volumetric and dosimetric comparison to the RTOG guidelines

    International Nuclear Information System (INIS)

    Croke, Jennifer; Maclean, Jillian; Nyiri, Balazs; Li, Yan; Malone, Kyle; Avruch, Leonard; Kayser, Cathleen; Malone, Shawn

    2014-01-01

    Recurrence rates following radiotherapy for prostate cancer in the post-operative adjuvant or salvage setting remain substantial. Previous work from our institution demonstrated that published prostate bed CTV guidelines frequently do not cover the pre-operative MRI defined prostate. Inadequate target delineation may contribute to the high recurrence rates, but increasing target volumes may increase dose to organs at risk. We propose guidelines for delineating post-prostatectomy target volumes based upon an individual’s co-registered pre-operative MRI. MRI-based CTVs and PTVs were compared to those created using the RTOG guidelines in 30 patients. Contours were analysed in terms of absolute volume, intersection volume (Jaccard Index) and the ability to meet the RADICALS and QUANTEC rectal and bladder constraints (tomotherapy IMRT plans with PTV coverage of V98% ≥98%). CTV MRI was a mean of 18.6% larger than CTV RTOG: CTV MRI mean 138 cc (range 72.3 - 222.2 cc), CTV RTOG mean 116.3 cc (range 62.1 - 176.6 cc), (p < 0.0001). The difference in mean PTV was only 4.6%: PTV MRI mean 386.9 cc (range 254.4 – 551.2), PTV RTOG mean 370 cc (range 232.3 - 501.6) (p = 0.05). The mean Jaccard Index representing intersection volume between CTVs was 0.72 and 0.84 for PTVs. Both criteria had a similar ability to meet rectal and bladder constraints. Rectal DVH: 77% of CTV RTOG cases passed all RADICALS criteria and 37% all QUANTEC criteria; versus 73% and 40% for CTV MRI (p = 1.0 for both). Bladder DVH; 47% of CTV RTOG cases passed all RADICALS criteria and 67% all QUANTEC criteria, versus 57% and 60% for CTV MRI (p = 0.61for RADICALS, p = 0.79 for QUANTEC). CTV MRI spares more of the lower anterior bladder wall than CTV RTOG but increases coverage of the superior lateral bladder walls. CTV contours based upon the patient’s co-registered pre-operative MRI in the post-prostatectomy setting may improve coverage of the individual’s prostate bed without substantially increasing

  15. Intensity modulated radiation therapy (IMRT: differences in target volumes and improvement in clinically relevant doses to small bowel in rectal carcinoma

    Directory of Open Access Journals (Sweden)

    Delclos Marc E

    2011-06-01

    Full Text Available Abstract Background A strong dose-volume relationship exists between the amount of small bowel receiving low- to intermediate-doses of radiation and the rates of acute, severe gastrointestinal toxicity, principally diarrhea. There is considerable interest in the application of highly conformal treatment approaches, such as intensity-modulated radiation therapy (IMRT, to reduce dose to adjacent organs-at-risk in the treatment of carcinoma of the rectum. Therefore, we performed a comprehensive dosimetric evaluation of IMRT compared to 3-dimensional conformal radiation therapy (3DCRT in standard, preoperative treatment for rectal cancer. Methods Using RTOG consensus anorectal contouring guidelines, treatment volumes were generated for ten patients treated preoperatively at our institution for rectal carcinoma, with IMRT plans compared to plans derived from classic anatomic landmarks, as well as 3DCRT plans treating the RTOG consensus volume. The patients were all T3, were node-negative (N = 1 or node-positive (N = 9, and were planned to a total dose of 45-Gy. Pairwise comparisons were made between IMRT and 3DCRT plans with respect to dose-volume histogram parameters. Results IMRT plans had superior PTV coverage, dose homogeneity, and conformality in treatment of the gross disease and at-risk nodal volume, in comparison to 3DCRT. Additionally, in comparison to the 3DCRT plans, IMRT achieved a concomitant reduction in doses to the bowel (small bowel mean dose: 18.6-Gy IMRT versus 25.2-Gy 3DCRT; p = 0.005, bladder (V40Gy: 56.8% IMRT versus 75.4% 3DCRT; p = 0.005, pelvic bones (V40Gy: 47.0% IMRT versus 56.9% 3DCRT; p = 0.005, and femoral heads (V40Gy: 3.4% IMRT versus 9.1% 3DCRT; p = 0.005, with an improvement in absolute volumes of small bowel receiving dose levels known to induce clinically-relevant acute toxicity (small bowel V15Gy: 138-cc IMRT versus 157-cc 3DCRT; p = 0.005. We found that the IMRT treatment volumes were typically larger than that

  16. The management of patients with T1 adenocarcinoma of the low rectum: a decision analysis.

    Science.gov (United States)

    Johnston, Calvin F; Tomlinson, George; Temple, Larissa K; Baxter, Nancy N

    2013-04-01

    Decision making for patients with T1 adenocarcinoma of the low rectum, when treatment options are limited to a transanal local excision or abdominoperineal resection, is challenging. The aim of this study was to develop a contemporary decision analysis to assist patients and clinicians in balancing the goals of maximizing life expectancy and quality of life in this situation. We constructed a Markov-type microsimulation in open-source software. Recurrence rates and quality-of-life parameters were elicited by systematic literature reviews. Sensitivity analyses were performed on key model parameters. Our base case for analysis was a 65-year-old man with low-lying T1N0 rectal cancer. We determined the sensitivity of our model for sex, age up to 80, and T stage. The main outcome measured was quality-adjusted life-years. In the base case, selecting transanal local excision over abdominoperineal resection resulted in a loss of 0.53 years of life expectancy but a gain of 0.97 quality-adjusted life-years. One-way sensitivity analysis demonstrated a health state utility value threshold for permanent colostomy of 0.93. This value ranged from 0.88 to 1.0 based on tumor recurrence risk. There were no other model sensitivities. Some model parameter estimates were based on weak data. In our model, transanal local excision was found to be the preferable approach for most patients. An abdominoperineal resection has a 3.5% longer life expectancy, but this advantage is lost when the quality-of-life reduction reported by stoma patients is weighed in. The minority group in whom abdominoperineal resection is preferred are those who are unwilling to sacrifice 7% of their life expectancy to avoid a permanent stoma. This is estimated to be approximately 25% of all patients. The threshold increases to 12% of life expectancy in high-risk tumors. No other factors are found to be relevant to the decision.

  17. Hypoxia-response plasmid vector producing bcl-2 shRNA enhances the apoptotic cell death of mouse rectum carcinoma.

    Science.gov (United States)

    Fujioka, Takashi; Matsunaga, Naoya; Okazaki, Hiroyuki; Koyanagi, Satoru; Ohdo, Shigehiro

    2010-01-01

    Hypoxia-induced gene expression frequently occurs in malignant solid tumors because they often have hypoxic areas in which circulation is compromised due to structurally disorganized blood vessels. Hypoxia-response elements (HREs) are responsible for activating gene transcription in response to hypoxia. In this study, we constructed a hypoxia-response plasmid vector producing short hairpin RNA (shRNA) against B-cell leukemia/lymphoma-2 (bcl-2), an anti-apoptotic factor. The hypoxia-response promoter was made by inserting tandem repeats of HREs upstream of cytomegalovirus (CMV) promoter (HRE-CMV). HRE-CMV shbcl-2 vector consisted of bcl-2 shRNA under the control of HRE-CMV promoter. In hypoxic mouse rectum carcinoma cells (colon-26), the production of bcl-2 shRNA driven by HRE-CMV promoter was approximately 2-fold greater than that driven by CMV promoter. A single intratumoral (i.t.) injection of 40 microg HRE-CMV shbcl-2 to colon-26 tumor-bearing mice caused apoptotic cell death, and repetitive treatment with HRE-CMV shbcl-2 (40 microg/mouse, i.t.) also significantly suppressed the growth of colon-26 tumor cells implanted in mice. Apoptotic and anti-tumor effects were not observed in tumor-bearing mice treated with CMV shbcl-2. These results reveal the ability of HRE-CMV shbcl-2 vector to suppress the expression of bcl-2 in hypoxic tumor cells and suggest the usefulness of our constructed hypoxia-response plasmid vector to treat malignant tumors. [Supplementary Figures: available only at http://dx.doi.org/10.1254/jphs.10054FP].

  18. Effect of rectal enemas on rectal dosimetric parameters during high-dose-rate vaginal cuff brachytherapy. A prospective trial

    International Nuclear Information System (INIS)

    Sabater, Sebastia; Andres, Ignacio; Sevillano, Marimar; Berenguer, Roberto; Aguayo, Manuel; Villas, Maria Victoria; Gascon, Marina; Arenas, Meritxell; Rovirosa, Angeles; Camacho-Lopez, Cristina

    2016-01-01

    To evaluate the effects of rectal enemas on rectal doses during postoperative high-dose-rate (HDR) vaginal cuff brachytherapy (VCB). This prospective trial included 59 patients. Two rectal cleansing enemas were self-administered before the second fraction, and fraction 1 was considered the basal status. Dose-volume histogram (DVH) values were generated for the rectum and correlated with rectal volume variation. Statistical analyses used paired and unpaired t-tests. Despite a significant 15 % reduction in mean rectal volume (44.07 vs. 52.15 cc, p = 0.0018), 35.6 % of patients had larger rectums after rectal enemas. No significant rectal enema-related DVH differences were observed compared to the basal data. Although not statistically significant, rectal cleansing-associated increases in mean rectal DVH values were observed: D 0.1 cc : 6.6 vs. 7.21 Gy; D 1 cc : 5.35 vs. 5.52 Gy; D 2 cc : 4.67 vs. 4.72 Gy, before and after rectal cleaning, respectively (where D x cc is the dose to the most exposed x cm 3 ). No differences were observed in DVH parameters according to rectal volume increase or decrease after the enema. Patients whose rectal volume increased also had significantly larger DVH parameters, except for D 5 % , D 25 % , and D 50 % . In contrast, in patients whose rectal volume decreased, significance was only seen for D 25 % and D 50 % (D x % dose covering x % of the volume). In the latter patients, nonsignificant reductions in D 2 cc , D 5 cc and V 5 Gy (volume receiving at least 5 Gy) were observed. The current rectal enemas protocol was ineffective in significantly modifying rectal DVH parameters for HDR-VCB. (orig.) [de

  19. Dosimetric impact of systematic MLC positional errors on step and shoot IMRT for prostate cancer: a planning study

    International Nuclear Information System (INIS)

    Ung, N.M.; Wee, L.; Harper, C.S.

    2010-01-01

    Full text: The positional accuracy of multi leaf collimators (MLC) is crucial in ensuring precise delivery of intensity-modulated radiotherapy (IMRT). The aim of this planning study was to investigate the dosimetric impact of systematic MLC errors on step and shoot IMRT of prostate cancer. Twelve MLC leaf banks perturbations were introduced to six prostate IMRT treatment plans to simulate MLC systematic errors. Dose volume histograms (OYHs) were generated for the extraction of dose endpoint parameters. Plans were evaluated in terms of changes to the defined endpoint dose parameters, conformity index (CI) and healthy tissue avoidance (HTA) to planning target volume (PTY), rectum and bladder. Negative perturbations of MLC had been found to produce greater changes to endpoint dose parameters than positive perturbations of MLC (p < 0.05). Negative and positive synchronized MLC perturbations of I mm resulted in median changes of -2.32 and 1.78%, respectively to 095% of PTY whereas asynchronized MLC perturbations of the same direction and magnitude resulted in median changes of 1.18 and 0.90%, respectively. Doses to rectum were generally more sensitive to systematic MLC errors compared to bladder. Synchronized MLC perturbations of I mm resulted in median changes of endpoint dose parameters to both rectum and bladder from about I to 3%. Maximum reduction of -4.44 and -7.29% were recorded for CI and HTA, respectively, due to synchronized MLC perturbation of I mm. In summary, MLC errors resulted in measurable amount of dose changes to PTY and surrounding critical structures in prostate LMRT. (author)

  20. Dosimetric impact of systematic MLC positional errors on step and shoot IMRT for prostate cancer: a planning study

    International Nuclear Information System (INIS)

    Ung, N.M.; Harper, C.S.; Wee, L.

    2011-01-01

    Full text: The positional accuracy of multileaf collimators (MLC) is crucial in ensuring precise delivery of intensity-modulated radiotherapy (IMRT). The aim of this planning study was to investigate the dosimetric impact of systematic MLC positional errors on step and shoot IMRT of prostate cancer. A total of 12 perturbations of MLC leaf banks were introduced to six prostate IMRT treatment plans to simulate MLC systematic positional errors. Dose volume histograms (DVHs) were generated for the extraction of dose endpoint parameters. Plans were evaluated in terms of changes to the defined endpoint dose parameters, conformity index (CI) and healthy tissue avoidance (HTA) to planning target volume (PTV), rectum and bladder. Negative perturbations of MLC had been found to produce greater changes to endpoint dose parameters than positive perturbations of MLC (p 9 5 of -1.2 and 0.9% respectively. Negative and positive synchronised MLC perturbations of I mm in one direction resulted in median changes in D 9 5 of -2.3 and 1.8% respectively. Doses to rectum were generally more sensitive to systematic MLC en-ors compared to bladder (p < 0.01). Negative and positive synchronised MLC perturbations of I mm in one direction resulted in median changes in endpoint dose parameters of rectum and bladder from 1.0 to 2.5%. Maximum reduction of -4.4 and -7.3% were recorded for conformity index (CI) and healthy tissue avoidance (HT A) respectively due to synchronised MLC perturbation of 1 mm. MLC errors resulted in dosimetric changes in IMRT plans for prostate. (author)

  1. Proposed Rectal Dose Constraints for Patients Undergoing Definitive Whole Pelvic Radiotherapy for Clinically Localized Prostate Cancer

    International Nuclear Information System (INIS)

    Chan, Linda W.; Xia Ping; Gottschalk, Alexander R.; Akazawa, Michelle; Scala, Matthew; Pickett, Barby M.S.; Hsu, I-C.; Speight, Joycelyn; Roach, Mack

    2008-01-01

    Purpose: Although several institutions have reported rectal dose constraints according to threshold toxicity, the plethora of trials has resulted in multiple, confusing dose-volume histogram recommendations. A set of standardized, literature-based constraints for patients undergoing whole pelvic radiotherapy (RT) for prostate cancer would help guide the practice of prostate RT. The purpose of this study was to develop these constraints, demonstrate that they are achievable, and assess the corresponding rectal toxicity. Methods and Materials: An extensive literature search identified eight key studies relating dose-volume histogram data to rectal toxicity. A correction factor was developed to address differences in the anatomic definition of the rectum across studies. The dose-volume histogram constraints recommended by each study were combined to generate the constraints. The data from all patients treated with definitive intensity-modulated RT were then compared against these constraints. Acute rectal toxicity was assessed. Results: A continuous, proposed rectal dose-constraint curve was generated. Intensity-modulated RT not only met this constraint curve, but also was able to achieve at least 30-40% lower dose to the rectum. The preliminary clinical results were also positive: 50% of patients reported no acute bowel toxicity, 33% reported Grade 1 toxicity, and 17% reported Grade 2 toxicity. No patients reported Grade 3-4 acute rectal toxicity. Conclusions: In this study, we developed a set of proposed rectal dose constraints. This allowed for volumetric assessment of the dose-volume relationship compared with single dose-volume histogram points. Additional research will be performed to validate this threshold as a class solution for rectal dose constraints

  2. Dosimetric Implications of an Injection of Hyaluronic Acid for Preserving the Rectal Wall in Prostate Stereotactic Body Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Chapet, Olivier, E-mail: olivier.chapet@chu-lyon.fr [Department of Radiation Oncology, Centre Hospitalier Lyon Sud, Pierre Benite (France); Udrescu, Corina [Department of Radiation Oncology, Centre Hospitalier Lyon Sud, Pierre Benite (France); Department of Medical Physics, Centre Hospitalier Lyon Sud, Pierre Benite (France); Tanguy, Ronan [Department of Radiation Oncology, Centre Hospitalier Lyon Sud, Pierre Benite (France); Ruffion, Alain [Department of Urology, Centre Hospitalier Lyon Sud, Pierre Benite (France); Fenoglietto, Pascal [Department of Radiation Oncology, Centre Val d' Aurelle, Montpellier (France); Sotton, Marie-Pierre [Department of Medical Physics, Centre Hospitalier Lyon Sud, Pierre Benite (France); Devonec, Marian [Department of Urology, Centre Hospitalier Lyon Sud, Pierre Benite (France); Colombel, Marc [Department of Urology, Hopital Edouard Herriot, Lyon (France); Jalade, Patrice [Department of Medical Physics, Centre Hospitalier Lyon Sud, Pierre Benite (France); Azria, David [Department of Radiation Oncology, Centre Val d' Aurelle, Montpellier (France)

    2014-02-01

    Purpose: This study assessed the contribution of ahyaluronic acid (HA) injection between the rectum and the prostate to reducing the dose to the rectal wall in stereotactic body radiation therapy (SBRT). Methods and Materials: As part of a phase 2 study of hypofractionated radiation therapy (62 Gy in 20 fractions), the patients received a transperineal injection of 10 cc HA between the rectum and the prostate. A dosimetric computed tomographic (CT) scan was systematically performed before (CT1) and after (CT2) the injection. Two 9-beam intensity modulated radiation therapy-SBRT plans were optimized for the first 10 patients on both CTs according to 2 dosage levels: 5 × 6.5 Gy (PlanA) and 5 × 8.5 Gy (PlanB). Rectal wall parameters were compared with a dose–volume histogram, and the prostate–rectum separation was measured at 7 levels of the prostate on the center line of the organ. Results: For both plans, the average volume of the rectal wall receiving the 90% isodose line (V90%) was reduced up to 90% after injection. There was no significant difference (P=.32) between doses received by the rectal wall on CT1 and CT2 at the base of the prostate. This variation became significant from the median plane to the apex of the prostate (P=.002). No significant differences were found between PlanA without HA and PlanB with HA for each level of the prostate (P=.77, at the isocenter of the prostate). Conclusions: HA injection significantly reduced the dose to the rectal wall and allowed a dose escalation from 6.5 Gy to 8.5 Gy without increasing the dose to the rectum. A phase 2 study is under way in our department to assess the rate of acute and late rectal toxicities when SBRT (5 × 8.5 Gy) is combined with an injection of HA.

  3. Dosimetric Implications of an Injection of Hyaluronic Acid for Preserving the Rectal Wall in Prostate Stereotactic Body Radiation Therapy

    International Nuclear Information System (INIS)

    Chapet, Olivier; Udrescu, Corina; Tanguy, Ronan; Ruffion, Alain; Fenoglietto, Pascal; Sotton, Marie-Pierre; Devonec, Marian; Colombel, Marc; Jalade, Patrice; Azria, David

    2014-01-01

    Purpose: This study assessed the contribution of ahyaluronic acid (HA) injection between the rectum and the prostate to reducing the dose to the rectal wall in stereotactic body radiation therapy (SBRT). Methods and Materials: As part of a phase 2 study of hypofractionated radiation therapy (62 Gy in 20 fractions), the patients received a transperineal injection of 10 cc HA between the rectum and the prostate. A dosimetric computed tomographic (CT) scan was systematically performed before (CT1) and after (CT2) the injection. Two 9-beam intensity modulated radiation therapy-SBRT plans were optimized for the first 10 patients on both CTs according to 2 dosage levels: 5 × 6.5 Gy (PlanA) and 5 × 8.5 Gy (PlanB). Rectal wall parameters were compared with a dose–volume histogram, and the prostate–rectum separation was measured at 7 levels of the prostate on the center line of the organ. Results: For both plans, the average volume of the rectal wall receiving the 90% isodose line (V90%) was reduced up to 90% after injection. There was no significant difference (P=.32) between doses received by the rectal wall on CT1 and CT2 at the base of the prostate. This variation became significant from the median plane to the apex of the prostate (P=.002). No significant differences were found between PlanA without HA and PlanB with HA for each level of the prostate (P=.77, at the isocenter of the prostate). Conclusions: HA injection significantly reduced the dose to the rectal wall and allowed a dose escalation from 6.5 Gy to 8.5 Gy without increasing the dose to the rectum. A phase 2 study is under way in our department to assess the rate of acute and late rectal toxicities when SBRT (5 × 8.5 Gy) is combined with an injection of HA

  4. A novel two-step optimization method for tandem and ovoid high-dose-rate brachytherapy treatment for locally advanced cervical cancer.

    Science.gov (United States)

    Sharma, Manju; Fields, Emma C; Todor, Dorin A

    2015-01-01

    To present a novel method allowing fast volumetric optimization of tandem and ovoid high-dose-rate treatments and to quantify its benefits. Twenty-seven CT-based treatment plans from 6 consecutive cervical cancer patients treated with four to five intracavitary tandem and ovoid insertions were used. Initial single-step optimized plans were manually optimized, approved, and delivered plans created with a goal to cover high-risk clinical target volume (HR-CTV) with D90 >90% and minimize rectum, bladder, and sigmoid D2cc. For the two-step optimized (TSO) plan, each single-step optimized plan was replanned adding a structure created from prescription isodose line to the existent physician delineated HR-CTV, rectum, bladder, and sigmoid. New, more rigorous dose-volume histogram constraints for the critical organs at risks (OARs) were used for the optimization. HR-CTV D90 and OAR D2ccs were evaluated in both plans. TSO plans had consistently smaller D2ccs for all three OARs while preserving HR-CTV D90. On plans with "excellent" CTV coverage, average D90 of 96% (91-102%), sigmoid, bladder, and rectum D2cc, respectively, reduced on average by 37% (16-73%), 28% (20-47%), and 27% (15-45%). Similar reductions were obtained on plans with "good" coverage, average D90 of 93% (90-99%). For plans with "inferior" coverage, average D90 of 81%, the coverage increased to 87% with concurrent D2cc reductions of 31%, 18%, and 11% for sigmoid, bladder, and rectum, respectively. The TSO can be added with minimal planning time increase but with the potential of dramatic and systematic reductions in OAR D2ccs and in some cases with concurrent increase in target dose coverage. These single-fraction modifications would be magnified over the course of four to five intracavitary insertions and may have real clinical implications in terms of decreasing both acute and late toxicities. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  5. Morphometric sexual maturity and allometric growth of the crab Sesarma rectum Randall, 1840 (Crustacea: Sesarmidae in an impacted tropical mangrove in northeast Brazil

    Directory of Open Access Journals (Sweden)

    Felipe Bezerra Ribeiro

    2013-04-01

    Full Text Available The size at sexual maturity and the allometric growth of the semi-terrestrial crab Sesarma rectum were studied in an impacted tropical mangrove in northeast Brazil. Crabs were monthly collected during spring low-tide periods, from October 2009 through September 2010. A catch-per-unit-effort (CPUE technique was used to sample the crab population, with two-hour sampling periods, by two people. A total of 492 crabs were obtained, being 262 males and 230 females. The specimens were measured at carapace width (CW, the left and right propodus length and height (RPL, RPH, LPL and LPH, and the gonopod length of males (GL, and abdomen width (AW of females. In males, the inflection point was at 27.14 mm CW in the relationship between CW and the length of right propodus (LRP, considering the morphological size at the onset of maturity. Based on the relationship between CW and AW, the size at sexual maturity in females was 22.97 mm. In spite of living in an impacted area, this population attained the maturity onset at a bigger size than other localities.

  6. Tumor de reto e cárdia sincrônicos: relato de caso e revisão da literatura Rectum and cardia cynchronous tumor: case report and literature review

    Directory of Open Access Journals (Sweden)

    Robson Luis Silveira Jara

    2007-03-01

    Full Text Available Os autores relatam um caso raro de um paciente de 77 anos, que desenvolveu dois tumores sincrônicos do trato gastrintestinal, localizados em topografia de reto e cárdia. Feito o diagnóstico de ambos simultaneamente. Foi submetido à cirurgia em dois tempos e evoluiu bem, realizando a reconstrução do trato gastrintestinal três meses após a primeira intervenção. Não encontramos na literatura nenhum outro relato desta combinação de tumores.We discuss a 77-year-old man who developed two cancers: adenocarcinoma of the stomach and adenocarcinoma of the rectum. He was submitted at the surgery developed for two interventions and evolved aright. To the best of our knowledge, no other patient with the combination of these two cancers has been reported in the literature.

  7. Développement | Page 12 | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... climate change adaptation, and sustainable management of fragile ecosystems. ... An IDRC-sponsored symposium exploring the impact of the Internet on ... Les domaines de collaboration ciblés comprennent le commerce, la sécurité ...

  8. La reputation scientifique contestee des freres Bogdanov

    CERN Multimedia

    Morin, H

    2002-01-01

    "Les celebres jumeaux sont revenus a la television apres avoir obtenu des theses en mathematiques et physique theorique. Depuis, ils sont la cible de virulentes critiques portant sur la qualite reelle de leurs travaux" (1 page).

  9. Dosimetric study of permanent prostate brachytherapy utilizing 131Cs, 125I and 103Pd seeds

    International Nuclear Information System (INIS)

    Yang Ruijie; Wang Junjie; Zhang Hongzhi

    2009-01-01

    Objective: To compare the dosimetric differences of permanent prostate brachytherapy utilizing 131 Cs, 125 I and 103 Pd seeds. Methods: Twenty-five patients with T 1 -T 2 c prostate cancer who had previously implanted with 125 I seeds were randomly selected in our study. The patients were re-planned with 131 Cs, 125 I and 103 Pd seeds by using the Prowess Brachytherapy 3.1 planning system to the prescription doses of 115 Gy, 145 Gy and 125 Gy, respectively. The seed strengths were 1.8 U,0.5 U and 1.8 U, respectively. The prostate, prostatic urethra and anterior wall of the rectum were contoured on trans-rectal ultrasound images. PTV was outlined based on the prostate volume with no margin applied. The attempted planning goals were that V 100 (the percentage volume of the prostate receiving at least 100% of the prescription doses)= 95%, D 90 (the minimum percentage dose covering 90% of the prostate volume) ≥100%, and prostatic urethra UD 10 (the maximum percentage dose receiving by 10% of the contoured urethra) ≤150%. For the plan comparison, we also computed prostate V 150 , prostatic urethra UV 120 , rectum RV 100 , and the number of implanted seeds and needles. The significance of the differences was tested using one way analysis of variance. Results: The average V 200 in the 103 Pd, 125 I and 131 Cs plans were 28.7%, 20.9% and 19.6% (F=42.50, P=0.000); the average V 150 were 51.9%, 42.1% and 39.4% (F=26.15, P=0.000); the average UV 120 were 26.9%, 29.5% and 23.8% (F=0.37, P=0.691); and the average rectum RV 100 were 0.31 cm 3 , 0.22 cm 3 and 0.19 cm 3 (F=0.43, P=0.652). For 103 Pd, 125 I and 131 Cs, the average number of implanted seeds per cm 3 prostate were 2.02, 2.01 and 1.87 (F=1.92, P=0.154), and the average number of needles were 33.6, 32.9 and 31.6 (F=0.26,P=0.772). Conclusions: Comparing to 125 I and 103 Pd seeds used in permanent prostate brachytherapy, 131 Cs seeds has better dose homogeneity, and possible better sparing of the urethra and rectum

  10. A randomised trial of preoperative radiotherapy for stage T3 adenocarcinoma of rectum (TROG 01.04): a progress report

    International Nuclear Information System (INIS)

    Ngan, S.; Fisher, R.; McKay, M.J.; McClure, B.; Burmeister, B.H.; Schache, D.; Joseph, D.; Solomon, M.; Ackland, S.P.; Goldstein, D.; McLachlan, S.; Dhillon, H.; Thompson, P.

    2003-01-01

    To provide a progress report of the conduct of the randomised trial TROG 01.04. This is a randomised Australian and New Zealand multi-centre trial of preoperative radiotherapy for rectal cancer currently being conducted under the auspices of Trans-Tasman Radiation Oncology Group, Australasian Gastrointestinal Trials Group, Colorectal Surgical Society of Australasia, and Royal Australasian College of Surgeons. The trial comprises two studies, each with its own main objective. These objectives are, in patients with T3 clinically resectable carcinoma of the rectum, to demonstrate that (Study 1) the local recurrence rate in patients treated with a long course (LC) of pre-operative radiotherapy with continuous infusion 5-FU is lower than that in patients treated with a short course (SC) of pre-operative radiotherapy with early surgery; and (Study 2) the local recurrence rate in patients given pre-operative radiotherapy and chemotherapy is lower than that in patients treated with initial surgery. Over 150 patients have been accrued from 21 centres in the first 21 months. All patients were enrolled on Study 1, SC versus LC pre-operative radiotherapy. Study 2 has enrolled no patients in 15 months and has been discontinued. There was no obvious difference in rates of serious adverse events of SC and LC. An Independent Data Monitoring Committee is monitoring these and other aspects of the trial. The trial of SC versus LC is progressing well: such a trial is clearly feasible in Australia and New Zealand. It is however not feasible to compare initial surgery with preoperative radiotherapy

  11. When high-volume PCI operators in high-volume hospitals move to lower volume hospitals-Do they still maintain high volume and quality of outcomes?

    Science.gov (United States)

    Lu, Tsung-Hsueh; Li, Sheng-Tun; Liang, Fu-Wen; Lee, Jo-Chi; Yin, Wei-Hsian

    2017-10-31

    The aim of this quasi-experimental study was to examine whether high-volume percutaneous coronary intervention (PCI) operators still maintain high volume and quality of outcomes when they moved to lower volume hospitals. Systematic reviews have indicated that high-volume PCI operators and hospitals have higher quality outcomes. However, little is known on whether high PCI volume and high quality outcomes are mainly due to operator characteristics (i.e., skill and experience) and is portable across organizations or whether it is due to hospital characteristics (i.e., equipment, team, and management system) and is less portable. We used Taiwan National Health Insurance claims data 2000-2012 to identify 98 high-volume PCI operators, 10 of whom moved from one hospital to another during the study period. We compared the PCI volume, risk-adjusted mortality ratio, and major adverse cardiovascular event (MACE) ratio before and after moving. Of the 10 high-volume operators who moved, 6 moved from high- to moderate- or low-volume hospitals, with median annual PCI volumes (interquartile range) of 130 (117-165) in prior hospitals and 54 (46-84) in subsequent hospitals (the hospital the operator moved to), and the remaining 4 moved from high to high-volume hospitals, with median annual PCI volumes (interquartile range) of 151 (133-162) in prior hospitals and 193 (178-239) in subsequent hospitals. No significant differences were observed in the risk-adjusted mortality ratios and MACE ratios between high-volume operators and matched controls before and after moving. High-volume operators cannot maintain high volume when they moved from high to moderate or low-volume hospitals; however, the quality of care is maintained. High PCI volume and high-quality outcomes are less portable and more hospital bound. © 2017 Wiley Periodicals, Inc.

  12. Postoperative HDR afterloading brachytherapy: Vaginal tumor recurrence rates in patients with endometrial carcinoma dependent on treatment volumes

    International Nuclear Information System (INIS)

    Kloetzer, K.H.; Guenther, R.; Wendt, T.

    1997-01-01

    Patients and Method: At Jena University, Department of Radiotherapy, from 1981 to 1990 108 patients with endometrical carcinoma were postoperatively treated with high dose radiation brachytherapy of the vagina without additional percutaneous radiotherapy. Histology showed more or less differenciated adenocarcinoma in 90% of all patients, all patients were postoperatively stage I or II without proven lymphatic metastases. Dependent on individual figures patients were distributed to 3 different gorups: group A: 4 x 10 Gy, tissue-thickness of 1 cm (vaginal apex) respectively 0.5 cm (lower vaginal walls); group B: 4 x 10 Gy, tissue thickness of 1 cm (upper vaginal wall); group C: 4 x 10 Gy, tissue-thickness of 0.5 cm (both excluding the lower vaginal walls). Results: Both 3-year survival rates (group A: 96.6%, group B: 96.9%, group C: 97.7%) and tumor relapse rates of the vaginal apex (group A: 0, group B: 3.1%, group C: 2.2%) don't show significant differences. No case of local tumor recurrence was seen in the upper 2/3 of the vagina and the pelvic walls. Late side effects concerning bladder and rectum (grade III to IV, EORTC/RTOG) could be minimized by reducing the treatment volume (group A: 6.8%/12.6%, group B: 6,2%/3.1%, group C: 2.2%/0). (orig./AJ) [de

  13. Development | Page 12 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... (RMR) project, IDID staff undertook an ambitious set of organizational changes. They: ... An IDRC-sponsored symposium exploring the impact of the Internet on ... Les domaines de collaboration ciblés comprennent le commerce, la sécurité ...

  14. SU-F-T-15: Evaluation of 192Ir, 60Co and 169Yb Sources for High Dose Rate Prostate Brachytherapy Inverse Planning Using An Interior Point Constraint Generation Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Mok Tsze Chung, E; Aleman, D [University of Toronto, Toronto, Ontario (Canada); Safigholi, H; Nicolae, A; Davidson, M; Ravi, A; Song, W [Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada)

    2016-06-15

    Purpose: The effectiveness of using a combination of three sources, {sup 60}Co, {sup 192}Ir and {sup 169}Yb, is analyzed. Different combinations are compared against a single {sup 192}Ir source on prostate cancer cases. A novel inverse planning interior point algorithm is developed in-house to generate the treatment plans. Methods: Thirteen prostate cancer patients are separated into two groups: Group A includes eight patients with the prostate as target volume, while group B consists of four patients with a boost nodule inside the prostate that is assigned 150% of the prescription dose. The mean target volume is 35.7±9.3cc and 30.6±8.5cc for groups A and B, respectively. All patients are treated with each source individually, then with paired sources, and finally with all three sources. To compare the results, boost volume V150 and D90, urethra Dmax and D10, and rectum Dmax and V80 are evaluated. For fair comparison, all plans are normalized to a uniform V100=100. Results: Overall, double- and triple-source plans were better than single-source plans. The triple-source plans resulted in an average decrease of 21.7% and 1.5% in urethra Dmax and D10, respectively, and 8.0% and 0.8% in rectum Dmax and V80, respectively, for group A. For group B, boost volume V150 and D90 increased by 4.7% and 3.0%, respectively, while keeping similar dose delivered to the urethra and rectum. {sup 60}Co and {sup 192}Ir produced better plans than their counterparts in the double-source category, whereas {sup 60}Co produced more favorable results than the remaining individual sources. Conclusion: This study demonstrates the potential advantage of using a combination of two or three sources, reflected in dose reduction to organs-at-risk and more conformal dose to the target. three sources, reflected in dose reduction to organs-at-risk and more conformal dose to the target. Our results show that {sup 60}Co, {sup 192}Ir and {sup 169}Yb produce the best plans when used simultaneously and

  15. Ion therapy of prostate cancer: daily rectal dose reduction by application of spacer gel

    International Nuclear Information System (INIS)

    Rucinski, Antoni; Brons, Stephan; Richter, Daniel; Habl, Gregor; Debus, Jürgen; Bert, Christoph; Haberer, Thomas; Jäkel, Oliver

    2015-01-01

    Ion beam therapy represents a promising approach to treat prostate cancer, mainly due to its high conformity and radiobiological effectiveness. However, the presence of prostate motion, patient positioning and range uncertainties may deteriorate target dose and increase exposure of organs at risk. Spacer gel injected between prostate and rectum may increase the safety of prostate cancer (PC) radiation therapy by separating the rectum from the target dose field. The dosimetric impact of the application of spacer gel for scanned carbon ion therapy of PC has been analyzed at Heidelberg Ion-Beam Therapy Center (HIT). The robustness of ion therapy treatment plans was investigated by comparison of two data sets of patients treated with and without spacer gel. A research treatment planning system for ion therapy was used for treatment plan optimization and calculation of daily dose distributions on 2 to 9 Computed Tomography (CT) studies available for each of the 19 patients. Planning and daily dose distributions were analyzed with respect to target coverage, maximal dose to the rectum (excluding 1 ml of the greatest dose; Dmax-1 ml) and the rectal volume receiving dose greater than 90% of prescribed target dose (V90 Rectum ), respectively. The application of spacer gel did substantially diminish rectum dose. Dmax-1 ml on the treatment planning CT was on average reduced from 100.0 ± 1.0% to 90.2 ± 4.8%, when spacer gel was applied. The robustness analysis performed with daily CT studies demonstrated for all analyzed patient cases that application of spacer gel results in a decrease of the daily V90 Rectum index, which calculated over all patient cases and CT studies was 10.2 ± 10.4 [ml] and 1.1 ± 2.1 [ml] for patients without and with spacer gel, respectively. The dosimetric benefit of increasing the distance between prostate and rectum using spacer gel for PC treatment with carbon ion beams has been quantified. Application of spacer gel substantially reduced rectal

  16. Multivariate analysis of factors predicting prostate dose in intensity-modulated radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Tsuneyuki [Division of Radiology, Osaka Red Cross Hospital, Osaka (Japan); Nakamura, Mitsuhiro, E-mail: m_nkmr@kuhp.kyoto-u.ac.jp [Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Hirose, Yoshinori; Kitsuda, Kenji; Notogawa, Takuya; Miki, Katsuhito [Division of Radiology, Osaka Red Cross Hospital, Osaka (Japan); Nakamura, Kiyonao; Ishigaki, Takashi [Department of Radiation Oncology, Osaka Red Cross Hospital, Osaka (Japan)

    2014-01-01

    We conducted a multivariate analysis to determine relationships between prostate radiation dose and the state of surrounding organs, including organ volumes and the internal angle of the levator ani muscle (LAM), based on cone-beam computed tomography (CBCT) images after bone matching. We analyzed 270 CBCT data sets from 30 consecutive patients receiving intensity-modulated radiation therapy for prostate cancer. With patients in the supine position on a couch with the HipFix system, data for center of mass (COM) displacement of the prostate and the state of individual organs were acquired and compared between planning CT and CBCT scans. Dose distributions were then recalculated based on CBCT images. The relative effects of factors on the variance in COM, dose covering 95% of the prostate volume (D{sub 95%}), and percentage of prostate volume covered by the 100% isodose line (V{sub 100%}) were evaluated by a backward stepwise multiple regression analysis. COM displacement in the anterior-posterior direction (COM{sub AP}) correlated significantly with the rectum volume (δVr) and the internal LAM angle (δθ; R = 0.63). Weak correlations were seen for COM in the left-right (R = 0.18) and superior-inferior directions (R = 0.31). Strong correlations between COM{sub AP} and prostate D{sub 95%} and V{sub 100%} were observed (R ≥ 0.69). Additionally, the change ratios in δVr and δθ remained as predictors of prostate D{sub 95%} and V{sub 100%}. This study shows statistically that maintaining the same rectum volume and LAM state for both the planning CT simulation and treatment is important to ensure the correct prostate dose in the supine position with bone matching.

  17. Rectal dose variation during the course of image-guided radiation therapy of prostate cancer

    International Nuclear Information System (INIS)

    Chen Lili; Paskalev, Kamen; Xu Xiu; Zhu, Jennifer; Wang Lu; Price, Robert A.; Hu Wei; Feigenberg, Steven J.; Horwitz, Eric M.; Pollack, Alan; Charlie Ma, C.M.

    2010-01-01

    Background and purpose: To investigate the change in rectal dose during the treatment course for intensity-modulated radiotherapy (IMRT) of prostate cancer with image-guidance. Materials and methods: Twenty prostate cancer patients were recruited for this retrospective study. All patients have been treated with IMRT. For each patient, MR and CT images were fused for target and critical structure delineation. IMRT treatment planning was performed on the simulation CT images. Inter-fractional motion during the course of treatment was corrected using a CT-on-rails system. The rectum was outlined on both the original treatment plan and the subsequent daily CT images from the CT-on-rails by the same investigator. Dose distributions on these daily CT images were recalculated with the isocenter shifts relative to the simulation CT images using the leaf sequences/MUs based on the original treatment plan. The rectal doses from the subsequent daily CTs were compared with the original doses planned on the simulation CT using our clinical acceptance criteria. Results: Based on 20 patients with 139 daily CT sets, 28% of the subsequent treatment dose distributions did not meet our criterion of V 40 65 < 17%. The inter-fractional rectal volume variation is significant for some patients. Conclusions: Due to the large inter-fractional variation of the rectal volume, it is more favorable to plan prostate IMRT based on an empty rectum and deliver treatment to patients with an empty rectum. Over 70% of actual treatments showed better rectal doses than our clinical acceptance criteria. A significant fraction (27%) of the actual treatments would benefit from adaptive image-guided radiotherapy based on daily CT images.

  18. Preliminary analysis of risk factors for late rectal toxicity after helical tomotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Tomita, Natsuo; Soga, Norihito; Ogura, Yuji

    2013-01-01

    The purpose of this study is to examine risk factors for late rectal toxicity for localized prostate cancer patients treated with helical tomotherapy (HT). The patient cohort of this retrospective study was composed of 241 patients treated with HT and followed up regularly. Toxicity levels were scored according to the Radiation Therapy Oncology Group grading scale. The clinical and dosimetric potential factors increasing the risk of late rectal toxicity, such as age, diabetes, anticoagulants, prior abdominal surgery, prescribed dose, maximum dose of the rectum, and the percentage of the rectum covered by 70 Gy (V70), 60 Gy (V60), 40 Gy (V40) and 20 Gy (V20) were compared between ≤ Grade 1 and ≥ Grade 2 toxicity groups using the Student's t-test. Multivariable logistic regression analysis of the factors that appeared to be associated with the risk of late rectal toxicity (as determined by the Student's t-test) was performed. The median follow-up time was 35 months. Late Grade 2-3 rectal toxicity was observed in 18 patients (7.4%). Age, the maximum dose of the rectum, V70 and V60 of the ≥ Grade 2 toxicity group were significantly higher than in those of the ≤ Grade 1 toxicity group (P=0.00093, 0.048, 0.0030 and 0.0021, respectively). No factor was significant in the multivariable analysis. The result of this study indicates that the risk of late rectal toxicity correlates with the rectal volume exposed to high doses of HT for localized prostate cancer. Further follow-up and data accumulation may establish dose-volume modeling to predict rectal complications after HT. (author)

  19. Altitude Acclimatization and Blood Volume: Effects of Exogenous Erythrocyte Volume Expansion

    National Research Council Canada - National Science Library

    Sawka, M

    1996-01-01

    ...: (a) altitude acclimatization effects on erythrocyte volume and plasma volume; (b) if exogenous erythrocyte volume expansion alters subsequent erythrocyte volume and plasma volume adaptations; (c...

  20. linear-quadratic-linear model

    Directory of Open Access Journals (Sweden)

    Tanwiwat Jaikuna

    2017-02-01

    Full Text Available Purpose: To develop an in-house software program that is able to calculate and generate the biological dose distribution and biological dose volume histogram by physical dose conversion using the linear-quadratic-linear (LQL model. Material and methods : The Isobio software was developed using MATLAB version 2014b to calculate and generate the biological dose distribution and biological dose volume histograms. The physical dose from each voxel in treatment planning was extracted through Computational Environment for Radiotherapy Research (CERR, and the accuracy was verified by the differentiation between the dose volume histogram from CERR and the treatment planning system. An equivalent dose in 2 Gy fraction (EQD2 was calculated using biological effective dose (BED based on the LQL model. The software calculation and the manual calculation were compared for EQD2 verification with pair t-test statistical analysis using IBM SPSS Statistics version 22 (64-bit. Results: Two and three-dimensional biological dose distribution and biological dose volume histogram were displayed correctly by the Isobio software. Different physical doses were found between CERR and treatment planning system (TPS in Oncentra, with 3.33% in high-risk clinical target volume (HR-CTV determined by D90%, 0.56% in the bladder, 1.74% in the rectum when determined by D2cc, and less than 1% in Pinnacle. The difference in the EQD2 between the software calculation and the manual calculation was not significantly different with 0.00% at p-values 0.820, 0.095, and 0.593 for external beam radiation therapy (EBRT and 0.240, 0.320, and 0.849 for brachytherapy (BT in HR-CTV, bladder, and rectum, respectively. Conclusions : The Isobio software is a feasible tool to generate the biological dose distribution and biological dose volume histogram for treatment plan evaluation in both EBRT and BT.

  1. Is it always possible to respect dose constraints for target volumes and organs at risk within the frame of breast radiotherapy after conservative treatment?; Le respect des contraintes de dose aux volumes cibles et aux organes a risque est-il toujours possible dans le cadre d'une radiotherapie du sein apres traitement conservateur?

    Energy Technology Data Exchange (ETDEWEB)

    Renoult, F.; Faivre, J.C.; Charra Brunaud, C.; Tournier-Rangeard, L.; Lostette, J.; Huger, S.; Marchesi, V.; Peiffert, D.; Marchal, C. [Centre Alexis-Vautrin, 54 - Nancy (France); Xemard, S. [Centre hospitalier Jean-Monnet, 88 - Epinal (France)

    2010-10-15

    The use of three-dimensional breast radiotherapy after a conservative treatment allowed cardiotoxicity as well as the dose delivered to lungs to be significantly reduced. However several bibliographic references give different dose constraints. Based on the constraints given by the Oncological radiotherapy French Society (SFRO), the authors analysed whether these recommendations could be actually respected within a daily practice. Based on a sample of 91 patients, the authors collected the following data: mammary gland volumes receiving respectively 95 and 107% of the dose before the boost calculation, heart and pulmonary volumes receiving different dose levels. Coverage constraints are indicated. It appears that the present technique does not allow the constraints to be respected in a majority of cases. Short communication

  2. Risques d'exposition aux résidus de pesticides via les produits ...

    African Journals Online (AJOL)

    NGOM

    peut également affecter les organismes non ciblés. Ainsi beaucoup d'insectes .... Pour les produits agricoles, une micro- extraction de ..... sont les principaux facteurs de la .... Contrôle des pesticides organochlors dans le lait et produits laitiers.

  3. A feature alignment score for online cone-beam CT-based image-guided radiotherapy for prostate cancer.

    Science.gov (United States)

    Hargrave, Catriona; Deegan, Timothy; Poulsen, Michael; Bednarz, Tomasz; Harden, Fiona; Mengersen, Kerrie

    2018-05-17

    To develop a method for scoring online cone-beam CT (CBCT)-to-planning CT image feature alignment to inform prostate image-guided radiotherapy (IGRT) decision-making. The feasibility of incorporating volume variation metric thresholds predictive of delivering planned dose into weighted functions, was investigated. Radiation therapists and radiation oncologists participated in workshops where they reviewed prostate CBCT-IGRT case examples and completed a paper-based survey of image feature matching practices. For 36 prostate cancer patients, one daily CBCT was retrospectively contoured then registered with their plan to simulate delivered dose if (a) no online setup corrections and (b) online image alignment and setup corrections, were performed. Survey results were used to select variables for inclusion in classification and regression tree (CART) and boosted regression trees (BRT) modeling of volume variation metric thresholds predictive of delivering planned dose to the prostate, proximal seminal vesicles (PSV), bladder, and rectum. Weighted functions incorporating the CART and BRT results were used to calculate a score of individual tumor and organ at risk image feature alignment (FAS TV _ OAR ). Scaled and weighted FAS TV _ OAR were then used to calculate a score of overall treatment compliance (FAS global ) for a given CBCT-planning CT registration. The FAS TV _ OAR were assessed for sensitivity, specificity, and predictive power. FAS global thresholds indicative of high, medium, or low overall treatment plan compliance were determined using coefficients from multiple linear regression analysis. Thirty-two participants completed the prostate CBCT-IGRT survey. While responses demonstrated consensus of practice for preferential ranking of planning CT and CBCT match features in the presence of deformation and rotation, variation existed in the specified thresholds for observed volume differences requiring patient repositioning or repeat bladder and bowel

  4. Influence of image slice thickness on rectal dose–response relationships following radiotherapy of prostate cancer

    International Nuclear Information System (INIS)

    Olsson, C; Thor, M; Apte, A; Deasy, J O; Liu, M; Moissenko, V; Petersen, S E; Høyer, M

    2014-01-01

    When pooling retrospective data from different cohorts, slice thicknesses of acquired computed tomography (CT) images used for treatment planning may vary between cohorts. It is, however, not known if varying slice thickness influences derived dose–response relationships. We investigated this for rectal bleeding using dose–volume histograms (DVHs) of the rectum and rectal wall for dose distributions superimposed on images with varying CT slice thicknesses. We used dose and endpoint data from two prostate cancer cohorts treated with three-dimensional conformal radiotherapy to either 74 Gy (N = 159) or 78 Gy (N = 159) at 2 Gy per fraction. The rectum was defined as the whole organ with content, and the morbidity cut-off was Grade ≥2 late rectal bleeding. Rectal walls were defined as 3 mm inner margins added to the rectum. DVHs for simulated slice thicknesses from 3 to 13 mm were compared to DVHs for the originally acquired slice thicknesses at 3 and 5 mm. Volumes, mean, and maximum doses were assessed from the DVHs, and generalized equivalent uniform dose (gEUD) values were calculated. For each organ and each of the simulated slice thicknesses, we performed predictive modeling of late rectal bleeding using the Lyman–Kutcher–Burman (LKB) model. For the most coarse slice thickness, rectal volumes increased (≤18%), whereas maximum and mean doses decreased (≤0.8 and ≤4.2 Gy, respectively). For all a values, the gEUD for the simulated DVHs were ≤1.9 Gy different than the gEUD for the original DVHs. The best-fitting LKB model parameter values with 95% CIs were consistent between all DVHs. In conclusion, we found that the investigated slice thickness variations had minimal impact on rectal dose–response estimations. From the perspective of predictive modeling, our results suggest that variations within 10 mm in slice thickness between cohorts are unlikely to be a limiting factor when pooling multi-institutional rectal dose data that include slice

  5. Locoregional recurrence of rectal carcinoma. A CT-analysis and a target volume concept in adjuvant radiotherapy

    International Nuclear Information System (INIS)

    Bagatzounis, A.; Koelbl, O.; Mueller, G.; Oppitz, U.; Willner, J.; Flentje, M.

    1997-01-01

    Patients and method: 155 patients with the diagnosis of rectal carcinoma recurrences were treated in our institution between 1980 and 1995. To determine the extension of the recurrent tumor within the pelvic levels (praesacral levels S1-S5, precoccygeal-, pelvic floor level and perineal level) and the tumor infiltration of pelvic organs and muscles we analysed the pretherapeutic CT-images. The lymphnode recurrences were classified as: Pararectal-, presacral-, iliac internal-, iliac external-, iliac communis- and paraaortal recurrences. Results: Sixty-one percent of the patients with rectum exstirpation and 66% with anterior resection showed a combined local and nodal recurrence. Isolated lymph node recurrences were rare (4% and 5%). The local recurrence was mostly situated in the presacral pelvis, predominantly there was an infiltration of the presacral space at the level of S4, S5 and os coccygis regardless of the operating method and the primary tumor location. The anastomosis was involved in the tumor recurrence in 93% of the anteriorly resected patients. In 9 out of 96 patients after rectum exstirpation the pelvic region caudal of the tip of the coccyx was the origin of the recurrent tumor. Primarily all 9 patients had a deep-seated carcinoma ( [de

  6. SU-E-T-310: Dosimetric Comparison of Tandem and Ovoid (TO) Vs. Tandem and Ring (TR) Applicators in High-Dose Rate (HDR) Brachytherapy (BT) for the Treatment of Locally-Advanced Cervical-Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, L; Viswanathan, A; Damato, A [Brigham and Women’s Hospital, Boston, MA (United States)

    2015-06-15

    Purpose: To investigate the dosimetric differences associated with the use of TO or TR applicators for cervical-cancer HDR BT. Methods: The records of all cervical-cancer patients treated with image-guided HDR BT in 2013 were reviewed. Image-based planning based on isodose line and DVH metrics inspections was performed following the GEC-ESTRO recommendations. CTV volume, CTV D90, and rectum, bladder and sigmoid D2cc were collected as % of the prescription dose (80Gy EQD2). Patients receiving both TO and TR were identified and plans were compared (paired analysis). A Student T-test was used to evaluate statistical significance (p ≤ 0.05). Results: Twenty-eight patients were identified (20 TR only, 4 TO only, 4 TO and TR), associated with 116 plans (109 TR, 7 TO). Overall metrics: CTV volume, 26.5±10.4 cm3 (TR) and 39.1±14.0 cm3 (TO, p < 0.01); CTV D90, 126±28% (TR) and 110±15% (TO, p = 0.15); rectum D2cc, 56±11% (TR) and 58±19% (TO, p = 0.91); bladder D2cc, 74±20% (TR) and 88±19% (TO, p = 0.09); sigmoid D2cc, 52±17% (TR) and 49±20% (TO, p = 0.63). The paired analysis results were: CTV volume, 37.3±11.9 cm3 (TR) and 51.0±23.1 cm3 (TO, p = 0.23); CTV D90, 111±12% (TR) and 101±17% (TO, p = 0.50); rectum D2cc, 56±12% (TR) and 53±16% (TO, p = 0.71); bladder D2cc, 73±14% (TR) and 90±20% (TO, p = 0.22); sigmoid D2cc, 59±10% (TR) and 59±22% (TO, p = 0.98). Conclusion: TR and TO were both used with good dosimetric results. TO were used for patients with larger CTV volumes than TR, although paired analysis suggest that tissue distortion and contouring bias may partially explain this Result. CTV D90 on average > 80 Gy EQD2 were achieved in both groups despite the different CTV volume. Higher bladder D2cc for TO than TR was observed.

  7. Pelvic Normal Tissue Contouring Guidelines for Radiation Therapy: A Radiation Therapy Oncology Group Consensus Panel Atlas

    Energy Technology Data Exchange (ETDEWEB)

    Gay, Hiram A., E-mail: hgay@radonc.wustl.edu [Washington University School of Medicine, St Louis, MO (United States); Barthold, H. Joseph [Commonwealth Hematology and Oncology, Weymouth, MA (United States); Beth Israel Deaconess Medical Center, Boston, MA (Israel); O' Meara, Elizabeth [Radiation Therapy Oncology Group, Philadelphia, PA (United States); Bosch, Walter R. [Washington University School of Medicine, St Louis, MO (United States); El Naqa, Issam [Department of Radiation Oncology, McGill University Health Center, Montreal, Quebec (Canada); Al-Lozi, Rawan [Washington University School of Medicine, St Louis, MO (United States); Rosenthal, Seth A. [Radiation Oncology Centers, Radiological Associates of Sacramento, Sacramento, CA (United States); Lawton, Colleen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Lee, W. Robert [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Sandler, Howard [Cedars-Sinai Medical Center, Los Angeles, CA (United States); Zietman, Anthony [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Myerson, Robert [Washington University School of Medicine, St Louis, MO (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Willett, Christopher [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Kachnic, Lisa A. [Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, MA (United States); Jhingran, Anuja [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Portelance, Lorraine [University of Miami, Miami, FL (United States); Ryu, Janice [Radiation Oncology Centers, Radiological Associates of Sacramento, Sacramento, CA (United States); and others

    2012-07-01

    Purpose: To define a male and female pelvic normal tissue contouring atlas for Radiation Therapy Oncology Group (RTOG) trials. Methods and Materials: One male pelvis computed tomography (CT) data set and one female pelvis CT data set were shared via the Image-Guided Therapy QA Center. A total of 16 radiation oncologists participated. The following organs at risk were contoured in both CT sets: anus, anorectum, rectum (gastrointestinal and genitourinary definitions), bowel NOS (not otherwise specified), small bowel, large bowel, and proximal femurs. The following were contoured in the male set only: bladder, prostate, seminal vesicles, and penile bulb. The following were contoured in the female set only: uterus, cervix, and ovaries. A computer program used the binomial distribution to generate 95% group consensus contours. These contours and definitions were then reviewed by the group and modified. Results: The panel achieved consensus definitions for pelvic normal tissue contouring in RTOG trials with these standardized names: Rectum, AnoRectum, SmallBowel, Colon, BowelBag, Bladder, UteroCervix, Adnexa{sub R}, Adnexa{sub L}, Prostate, SeminalVesc, PenileBulb, Femur{sub R}, and Femur{sub L}. Two additional normal structures whose purpose is to serve as targets in anal and rectal cancer were defined: AnoRectumSig and Mesorectum. Detailed target volume contouring guidelines and images are discussed. Conclusions: Consensus guidelines for pelvic normal tissue contouring were reached and are available as a CT image atlas on the RTOG Web site. This will allow uniformity in defining normal tissues for clinical trials delivering pelvic radiation and will facilitate future normal tissue complication research.

  8. Treatment of Locally Advanced Vaginal Cancer With Radiochemotherapy and Magnetic Resonance Image-Guided Adaptive Brachytherapy: Dose–Volume Parameters and First Clinical Results

    International Nuclear Information System (INIS)

    Dimopoulos, Johannes C.A.; Schmid, Maximilian P.; Fidarova, Elena; Berger, Daniel; Kirisits, Christian; Pötter, Richard

    2012-01-01

    Purpose: To investigate the clinical feasibility of magnetic resonance image-guided adaptive brachytherapy (IGABT) for patients with locally advanced vaginal cancer and to report treatment outcomes. Methods and Materials: Thirteen patients with vaginal cancer were treated with external beam radiotherapy (45–50.4 Gy) plus IGABT with or without chemotherapy. Distribution of International Federation of Gynecology and Obstetrics stages among patients were as follows: 4 patients had Stage II cancer, 5 patients had Stage III cancer, and 4 patients had Stage IV cancer. The concept of IGABT as developed for cervix cancer was transferred and adapted for vaginal cancer, with corresponding treatment planning and reporting. Doses were converted to the equivalent dose in 2 Gy, applying the linear quadratic model (α/β = 10 Gy for tumor; α/β = 3 for organs at risk). Endpoints studied were gross tumor volume (GTV), dose-volume parameters for high-risk clinical target volume (HRCTV), and organs at risk, local control (LC), adverse side effects, and survival. Results: The mean GTV (± 1 standard deviation) at diagnosis was 45.3 (±30) cm 3 , and the mean GTV at brachytherapy was 10 (±14) cm 3 . The mean D90 for the HRCTV was 86 (±13) Gy. The mean D2cc for bladder, urethra, rectum, and sigmoid colon were 80 (±20) Gy, 76 (±16) Gy, 70 (±9) Gy, and 60 (±9) Gy, respectively. After a median follow-up of 43 months (range, 19–87 months), one local recurrence and two distant metastases cases were observed. Actuarial LC and overall survival rates at 3 years were 92% and 85%. One patient with Stage IVA and 1 patient with Stage III disease experienced fistulas (one vesicovaginal, one rectovaginal), and 1 patient developed periurethral necrosis. Conclusions: The concept of IGABT, originally developed for treating cervix cancer, appears to be applicable to vaginal cancer treatment with only minor adaptations. Dose-volume parameters for HRCTV and organs at risk are in a comparable

  9. Treatment of Locally Advanced Vaginal Cancer With Radiochemotherapy and Magnetic Resonance Image-Guided Adaptive Brachytherapy: Dose-Volume Parameters and First Clinical Results

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, Johannes C.A. [Department of Radiation Oncology, Metropolitan Hospital, Athens (Greece); Schmid, Maximilian P., E-mail: maximilian.schmid@akhwien.at [Department of Radiotherapy, Medical University of Vienna, Vienna (Austria); Fidarova, Elena; Berger, Daniel; Kirisits, Christian; Poetter, Richard [Department of Radiotherapy, Medical University of Vienna, Vienna (Austria)

    2012-04-01

    Purpose: To investigate the clinical feasibility of magnetic resonance image-guided adaptive brachytherapy (IGABT) for patients with locally advanced vaginal cancer and to report treatment outcomes. Methods and Materials: Thirteen patients with vaginal cancer were treated with external beam radiotherapy (45-50.4 Gy) plus IGABT with or without chemotherapy. Distribution of International Federation of Gynecology and Obstetrics stages among patients were as follows: 4 patients had Stage II cancer, 5 patients had Stage III cancer, and 4 patients had Stage IV cancer. The concept of IGABT as developed for cervix cancer was transferred and adapted for vaginal cancer, with corresponding treatment planning and reporting. Doses were converted to the equivalent dose in 2 Gy, applying the linear quadratic model ({alpha}/{beta} = 10 Gy for tumor; {alpha}/{beta} = 3 for organs at risk). Endpoints studied were gross tumor volume (GTV), dose-volume parameters for high-risk clinical target volume (HRCTV), and organs at risk, local control (LC), adverse side effects, and survival. Results: The mean GTV ({+-} 1 standard deviation) at diagnosis was 45.3 ({+-}30) cm{sup 3}, and the mean GTV at brachytherapy was 10 ({+-}14) cm{sup 3}. The mean D90 for the HRCTV was 86 ({+-}13) Gy. The mean D2cc for bladder, urethra, rectum, and sigmoid colon were 80 ({+-}20) Gy, 76 ({+-}16) Gy, 70 ({+-}9) Gy, and 60 ({+-}9) Gy, respectively. After a median follow-up of 43 months (range, 19-87 months), one local recurrence and two distant metastases cases were observed. Actuarial LC and overall survival rates at 3 years were 92% and 85%. One patient with Stage IVA and 1 patient with Stage III disease experienced fistulas (one vesicovaginal, one rectovaginal), and 1 patient developed periurethral necrosis. Conclusions: The concept of IGABT, originally developed for treating cervix cancer, appears to be applicable to vaginal cancer treatment with only minor adaptations. Dose-volume parameters for HRCTV and

  10. SFRO booklets - The radiotherapy of cancers: of anal canal (Anus), brain, mediastinum, pancreas, lung, prostate, rectum, breast, upper aero-digestive tract (ENT cancers), cervix, endometrium (cervical cancers), and bladder for a better understanding of radiotherapy, sarcoma radiotherapy - To better understand your treatment

    International Nuclear Information System (INIS)

    Leroy, Thomas; Mornex, Francoise; Peiffert, Didier; Thariat, Juliette; Faivre, Jean-Christophe; Huguet, Florence; Vendrely, Veronique; Barillot, Isabelle; Janoray, Guillaume; Bibault, Jean-Emmanuel; Antoni, Delphine; Crehange, Gilles; Meillan, Nicolas; Pichon, Baptiste; Biau, Julian; Pointreau, Yoann; Mirabel, Xavier; Leysalle, Axel; Claren, Audrey; Cartier, Lysian; Chand, Mari-Eve; Jacob, Julian; Renard-Oldrini, Sophie; Le Pechoux, Cecile; Ducassou, Anne; Moureau-Zabotto, Laurence; Lagrange, Jean Leon; Molina, Sarah

    2016-07-01

    This document gathers several booklets which, for different types of cancers, propose information regarding the anatomy and location of the cancer, its diagnosis, possible treatments, secondary effects during treatment, some practical advices, issues related to the post-treatment period, associations and other resources which can be useful for patient information, and a glossary of the main terms used for this cancer and its treatment. Cancer types are anal canal (Anus), brain, mediastinum, pancreas, lung, prostate, rectum, breast, upper aero-digestive tract (ENT cancers), cervix, endometrium (cervical cancers), and bladder cancers

  11. Preoperative assessment of intestinal endometriosis: A comparison of transvaginal sonography with water-contrast in the rectum, transrectal sonography, and barium enema.

    Science.gov (United States)

    Bergamini, Valentino; Ghezzi, Fabio; Scarperi, Stefano; Raffaelli, Ricciarda; Cromi, Antonella; Franchi, Massimo

    2010-12-01

    To evaluate the accuracy of Transrectal Sonography (TRS) and a new technique, Transvaginal Sonography with Water-Contrast in the Rectum (RWC-TVS), in the diagnosis of rectosigmoid endometriosis, and the accuracy of Barium Enema (BE) and RWC-TVS in the detection of intestinal stenosis due to endometriosis. In a prospective study, we compared the findings of TRS and RWC-TVS performed before surgery with the operative and pathologic findings in 61 consecutive patients who underwent laparoscopy or laparotomy for suspected rectosigmoid endometriosis. The accuracy of BE and RWC-TVS in the detection of intestinal stenosis was evaluated comparing the radiologic and ultrasonographic results with the macroscopic findings at surgery and pathology. RWC-TVS diagnosed rectosigmoid endometriosis with the same accuracy of TRS and was equally efficient as BE in the detection of a significant intestinal lumen stenosis. For the diagnosis of rectosigmoid endometriosis the sensitivity, specificity, positive and negative predictive values of TRS and RWC-TVS were 88.2% and 96%, 80%, and 90%, 95.7%, and 98%, and 57.1% and 81.8%, respectively. For the detection of intestinal stenosis the sensitivity, specificity, positive and negative predictive values of BE and RWC-TVS were 93.7% and 87.5%, 94.2% and 91.4%, 88.2% and 82.3%, and 97% and 94.1%, respectively. RWC-TVS is a new, simple technique for a single-step and accurate preoperative assessment of rectosigmoid endometriosis.

  12. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    KAUST Repository

    Sicat, Ronell Barrera

    2014-12-31

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  13. Impact of collimator leaf width on stereotactic radiosurgery and 3D conformal radiotherapy treatment plans

    International Nuclear Information System (INIS)

    Kubo, H. Dale; Wilder, Richard B.; Pappas, Conrad T.E.

    1999-01-01

    rectum within the prescription isodose surface by 26% and 17%, respectively, compared to the multileaf collimator with a leaf width of 10 mm. Use of the 1.7 mm leaf width micro-multileaf collimator allowed one to decrease the median volume of bladder and rectum within the prescription isodose surface by 48% and 39%, respectively, compared to the multileaf collimator with a leaf width of 10 mm. Conclusions: For most lesions treated with radiosurgery, the use of a micro-multileaf collimator with a leaf width of 1.7-3.0 mm at isocenter and 3-5 static fields allows one to meet the Radiation Therapy Oncology Group guidelines for treatment planning. Both planning and treatment are relatively straightforward with a micro-multileaf collimator, allowing for efficient treatment of non-spherical targets with either stereotactic radiosurgery or fractionated stereotactic radiotherapy. When the clinical target volume consists of the prostate gland, micro-multileaf collimators with a minimum leaf width of 1.7-3.0 mm allow one to spare more bladder and rectum than one can with a multileaf collimator that has a 10-mm leaf width based on an analysis of PITV ratios, isodose distributions, and dose volume histograms

  14. Elastic and inelastic {alpha}-scattering cross-sections obtained with the 44 MeV fixed energy Saclay cyclotron on separated targets of {sup 24}Mg, {sup 25}Mg, {sup 26}Mg, {sup 40}Ca, {sup 46}Ti, {sup 48}Ti, {sup 50}Ti, {sup 52}Cr, {sup 54}Fe, {sup 56}Fe, {sup 58}Fe, {sup 58}Ni, {sup 60}Ni, {sup 62}Ni, {sup 64}Ni, {sup 63}Cu, {sup 65}Cu, {sup 64}Zn, {sup 112}Sn, {sup 114}Sn, {sup 116}Sn, {sup 118}Sn, {sup 120}Sn, {sup 122}Sn, {sup 124}Sn and {sup 208}Pb using the Saclay fixed-energy cyclotron; Sections efficaces differentielles elastiques et inelastiques obtenues par diffusion de particules {alpha} de 44 MeV sur des cibles de {sup 24}Mg, {sup 25}Mg, {sup 26}Mg, {sup 40}Ca, {sup 46}Ti, {sup 48}Ti, {sup 50}Ti, {sup 52}Cr, {sup 54}Fe, {sup 56}Fe, {sup 58}Fe, {sup 58}Ni, {sup 60}Ni, {sup 62}Ni, {sup 64}Ni, {sup 63}Cu, {sup 65}Cu, {sup 64}Zn, {sup 112}Sn, {sup 114}Sn, {sup 116}Sn, {sup 118}Sn, {sup 120}Sn, {sup 122}Sn, {sup 124}Sn et {sup 208}Pb au cyclotron a energie fixe de saclay

    Energy Technology Data Exchange (ETDEWEB)

    Bruge, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Departement de physique nucleaire, service de physique nucleaire a moyenne energie

    1967-01-01

    This report contains elastic and inelastic {alpha}-scattering cross-sections obtained with the 44 MeV fixed energy Saclay cyclotron on Mg, Ca, Ti, Cr, Fe, Ni, Co, Zn, Sn and Pb enriched targets. (author) [French] Ce rapport contient les tableaux des sections efficaces differentielles obtenues par diffusion elastique et inelastique des particules {alpha} de 44 MeV, fournies par le cyclotron a energie fixe de Saclay, sur des cibles d'isotopes separes de Mg, Ca, Ti, Cr, Fe, Ni, Co, Zn, Sn et Pb. (auteur)

  15. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    KAUST Repository

    Sicat, Ronell Barrera; Kruger, Jens; Moller, Torsten; Hadwiger, Markus

    2014-01-01

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined

  16. SU-E-J-14: A Novel Approach to Evaluate the Dosimetric Effect of Rectal Variation During Image Guided Prostate Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Murray, J [The Institute of Cancer Research, London (United Kingdom); McQuaid, D; Dunlop, A; Nill, S; Gulliford, S [Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden, London (United Kingdom); Buettner, F [Helmholtz Zentrum Munchen - German Research Center for Environmental Healt, Neuherberg (Germany); Hall, E [Clinical Trials and Statistics Unit, The Institute of Cancer Research, London (United Kingdom); Dearnaley, D [The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London (United Kingdom)

    2014-06-01

    Purpose: Deformable registration establishes the spatial correspondence back to the reference image in order to accumulate dose. However, in prostate radiotherapy the changing shape and volume of the rectum present a challenge to accurate deformable registration and consequently calculation of delivered dose. We explored an alternative approach to calculating accumulated dose to the rectum, independent of deformable registration. Methods: This study was performed on three patients who received online image-guided radiotherapy (IGRT) with daily CBCT (XVI-system,Elekta) and target localization using intraprostatic fiducials. On each CBCT, the rectum was manually contoured and bulk density assignments were made allowing dose to be calculated for each fraction. Dose-surface maps (DSM) were generated (MATLAB,Mathworks,Natick,MA) by considering the rectum as a cylinder and sampling the dose at 21-equispaced points on each CT slice. The cylinder was “cut” at the posterior-most position on each CT and unfolded to generate a DSM. These were normalised in the longitudinal direction by interpolation creating maps of 21×21 pixels. A DSM was produced for each CBCT and the dose was accumulated. Results: The mean accumulated delivered rectal surface dose was on average 7.5(+/−3.5)% lower than the planned dose. The dose difference maps consistently show that the greatest variation in dose between planned and delivered dose is away from where the rectal surface is adjacent to the prostate. Conclusion: Estimation of dose accumulation using DSM provides an alternative method for determining actual delivered dose to the rectum. The dose difference is greatest in areas away from the region where the rectal surface abuts the prostate, the region where set-up is verified. The change in size and shape of the rectum was shown to resultin a change in the accumulated dose compared to the planned dose and this will have an impact on determining the relationships between dose delivered

  17. Strengthening Environmental Economics Capacity in Research on ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Strengthening Environmental Economics Capacity in Research on Climate Change Adaptation ... They will develop environmental economics methods to address specific climate change challenges caused by extreme weather stressors. ... Initiative Villes ciblées : gestion des déchets urbains à Cochabamba, en Bolivie.

  18. guide du participant atelier sur le suivi-evaluation pour les projets

    International Development Research Centre (IDRC) Digital Library (Canada)

    acer

    ..................... ..... Observation ou mesure des indicateurs d'état ;. • Recueil de .... point de départ que l'on peut comparer à la cible de performance. ... au hasard, pour permettre d'avoir un groupe de contrôle identique. C'est ce ...

  19. A clinical study of 14 patients with radiation colitis; A case of radiation colitis treated by abdominoperineal resection of the rectum and lumbar plasty

    Energy Technology Data Exchange (ETDEWEB)

    Futamura, Manabu; Tanaka, Sengai; Oshita, Hiroo; Nagao, Naritoshi (Gifu City Hospital (Japan))

    1991-12-01

    Clinical study of 14 patients with radiation colitis who were treated surgically at our clinic in the past 16-year period and a patient whose treatment was very difficult are reported. Primary lesions included 13 cervical carcinomas and one ovarian cancer. Ten cases received surgery combined with radiation and 4 did radiation. Radiation dose was 6055 rad on average. Latent time ranged from 6 months to 25 years with the average of 8 years and 9 months. No significant correlation between radiation dose and latent time was noted. Symptoms included obstruction and stenosis in 56% (8/14), hematoemesis in 46% (5/14), and fistula in 46% (5/14). All lesions presented as remarkably adhesion and stenosis, and resection with anastomosis was performed in 9 (64%), colostomy in 5 (46%), and urostomy in 2 (14%). Lumbar plasty was added in one case. A 65-year-old female patient who had undergone radiation therapy 13 years before had a rectal perforation and pelvic fistula. Abdominoperineal resection of the rectum and closure of the fistula by transferring the major gluteal muscle pedicle were performed. The patient is followed on ambulant basis for more than one year, and no evidence of recurrence has been observed. (author).

  20. Development and clinical use of a software for the analysis of the diagnosis and the features of polypoid lesions of the colon and rectum

    International Nuclear Information System (INIS)

    Bellomi, M.; Pestalozza, M.A.; Bellegotti, L.; Gardani, G.S.; Graziano, M.

    1987-01-01

    Double contrast enema and endoscopy are very important in the diagnosis of adenomas and early cancer of the colon and rectum. These exams can not only detect the presence, but also suggest the histologic diagnosis, of polypoid lesions of the colon. An Olivetti M24 Personal Computer was used to create a software to study the results obtained by double contrast enema, and to compare them with endoscopy and pathology. The data base is formed by 7 files: one anagraphic, 3 collecting the characteristics of the diagnosis - namely the radiologic, the endoscopic and the pathologic one - and 3 multiple files featuring each lesion, as defined by the three diagnostic techniques. The software allows to evaluate the different lesions that can be detected by three techniques in the same patient and to compare the diagnosis of presence to the morphologic features of each lesion. False negatives and false positive of each technique are easily recognized. It is also possible to characterize the single morphological feature leading the radiologist and/or the endoscopist to express an opinion about the histologic diagnosis of each lesion and to compare them with pathological features. The first experience in clinical use of the software, in the analysis of the characters of 336 lesions in 218 patients, is described

  1. Is ad-hoc plan adaptation based on 2-Step IMRT feasible?

    International Nuclear Information System (INIS)

    Bratengeier, Klaus; Polat, Buelent; Gainey, Mark; Grewenig, Patricia; Meyer, Juergen; Flentje, Michael

    2009-01-01

    Background: The ability of a geometry-based method to expeditiously adapt a '2-Step' step and shoot IMRT plan was explored. Both changes of the geometry of target and organ at risk have to be balanced. A retrospective prostate planning study was performed to investigate the relative benefits of beam segment adaptation to the changes in target and organ at risk coverage. Methods: Four patients with six planning cases with extraordinarily large deformations of rectum and prostate were chosen for the study. A 9-field IMRT plan (A) using 2-Step IMRT segments was planned on an initial CT study. The plan had to fulfil all the requirements of a conventional high-quality step and shoot IMRT plan. To adapt to changes of the anatomy in a further CT data set, three approaches were considered: the original plan with optimized isocentre position (B), a newly optimized plan (C) and the original plan, adapted using the 2-Step IMRT optimization rules (D). DVH parameters were utilized for quantification of plan quality: D 99 for the CTV and the central planning target volume (PTV), D 95 for an outer PTV, V 95 , V 80 and V 50 for rectum and bladder. Results: The adapted plan (D) achieved almost the same target coverage as the newly optimized plan (C). Target coverage for plan B was poor and for the organs at risk, the rectum V 80 was slightly increased. The volume with more than 95% of the target dose (V 95 ) was 1.5 ± 1.5 cm 3 for the newly optimized plan (C), compared to 2.2 ± 1.3 cm 3 for the original plan (A) and 7.2 ± 4.8 cm 3 (B) on the first and the second CT, respectively. The adapted plan resulted in 4.3 ± 2.1 cm 3 (D), an intermediate dose load to the rectum. All other parameters were comparable for the newly optimized and the adapted plan. Conclusions: The first results for adaptation of interfractional changes using the 2-Step IMRT algorithm are encouraging. The plans were superior to plans with optimized isocentre position and only marginally inferior to a newly

  2. SU-E-T-202: Impact of Monte Carlo Dose Calculation Algorithm On Prostate SBRT Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Venencia, C; Garrigo, E; Cardenas, J; Castro Pena, P [Instituto de Radioterapia - Fundacion Marie Curie, Cordoba (Argentina)

    2014-06-01

    Purpose: The purpose of this work was to quantify the dosimetric impact of using Monte Carlo algorithm on pre calculated SBRT prostate treatment with pencil beam dose calculation algorithm. Methods: A 6MV photon beam produced by a Novalis TX (BrainLAB-Varian) linear accelerator equipped with HDMLC was used. Treatment plans were done using 9 fields with Iplanv4.5 (BrainLAB) and dynamic IMRT modality. Institutional SBRT protocol uses a total dose to the prostate of 40Gy in 5 fractions, every other day. Dose calculation is done by pencil beam (2mm dose resolution), heterogeneity correction and dose volume constraint (UCLA) for PTV D95%=40Gy and D98%>39.2Gy, Rectum V20Gy<50%, V32Gy<20%, V36Gy<10% and V40Gy<5%, Bladder V20Gy<40% and V40Gy<10%, femoral heads V16Gy<5%, penile bulb V25Gy<3cc, urethra and overlap region between PTV and PRV Rectum Dmax<42Gy. 10 SBRT treatments plans were selected and recalculated using Monte Carlo with 2mm spatial resolution and mean variance of 2%. DVH comparisons between plans were done. Results: The average difference between PTV doses constraints were within 2%. However 3 plans have differences higher than 3% which does not meet the D98% criteria (>39.2Gy) and should have been renormalized. Dose volume constraint differences for rectum, bladder, femoral heads and penile bulb were les than 2% and within tolerances. Urethra region and overlapping between PTV and PRV Rectum shows increment of dose in all plans. The average difference for urethra region was 2.1% with a maximum of 7.8% and for the overlapping region 2.5% with a maximum of 8.7%. Conclusion: Monte Carlo dose calculation on dynamic IMRT treatments could affects on plan normalization. Dose increment in critical region of urethra and PTV overlapping region with PTV could have clinical consequences which need to be studied. The use of Monte Carlo dose calculation algorithm is limited because inverse planning dose optimization use only pencil beam.

  3. The Voronoi volume and molecular representation of molar volume: equilibrium simple fluids.

    Science.gov (United States)

    Hunjan, Jagtar Singh; Eu, Byung Chan

    2010-04-07

    The Voronoi volume of simple fluids was previously made use of in connection with volume transport phenomena in nonequilibrium simple fluids. To investigate volume transport phenomena, it is important to develop a method to compute the Voronoi volume of fluids in nonequilibrium. In this work, as a first step to this goal, we investigate the equilibrium limit of the nonequilibrium Voronoi volume together with its attendant related molar (molal) and specific volumes. It is proved that the equilibrium Voronoi volume is equivalent to the molar (molal) volume. The latter, in turn, is proved equivalent to the specific volume. This chain of equivalences provides an alternative procedure of computing the equilibrium Voronoi volume from the molar volume/specific volume. We also show approximate methods of computing the Voronoi and molar volumes from the information on the pair correlation function. These methods may be employed for their quick estimation, but also provide some aspects of the fluid structure and its relation to the Voronoi volume. The Voronoi volume obtained from computer simulations is fitted to a function of temperature and pressure in the region above the triple point but below the critical point. Since the fitting function is given in terms of reduced variables for the Lennard-Jones (LJ) model and the kindred volumes (i.e., specific and molar volumes) are in essence equivalent to the equation of state, the formula obtained is a reduced equation state for simple fluids obeying the LJ model potential in the range of temperature and pressure examined and hence can be used for other simple fluids.

  4. Structural characterization of electrodeposited boron

    Indian Academy of Sciences (India)

    high temperature reaction between elemental boron and car- bon to form B4C is .... cible was used as the container for the electrolyte and also acted as an anode. ... chosen as cathode due to its availability, low cost, ease of fabrication and ...

  5. Transformation des découvertes en génomique pour soigner les ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... des composés préventifs et thérapeutiques ciblés pour des essais précliniques ... IDRC is pleased to announce the results of its 2017 call for proposals to establish Cyber ... IDRC invites applications for the IDRC Doctoral Research Awards.

  6. Prehospital tidal volume influences hospital tidal volume: A cohort study.

    Science.gov (United States)

    Stoltze, Andrew J; Wong, Terrence S; Harland, Karisa K; Ahmed, Azeemuddin; Fuller, Brian M; Mohr, Nicholas M

    2015-06-01

    The purposes of the study are to describe current practice of ventilation in a modern air medical system and to measure the association of ventilation strategy with subsequent ventilator care and acute respiratory distress syndrome (ARDS). Retrospective observational cohort study of intubated adult patients (n = 235) transported by a university-affiliated air medical transport service to a 711-bed tertiary academic center between July 2011 and May 2013. Low tidal volume ventilation was defined as tidal volumes less than or equal to 8 mL/kg predicted body weight. Multivariable regression was used to measure the association between prehospital tidal volume, hospital ventilation strategy, and ARDS. Most patients (57%) were ventilated solely with bag valve ventilation during transport. Mean tidal volume of mechanically ventilated patients was 8.6 mL/kg predicted body weight (SD, 0.2 mL/kg). Low tidal volume ventilation was used in 13% of patients. Patients receiving low tidal volume ventilation during air medical transport were more likely to receive low tidal volume ventilation in the emergency department (P tidal volume (P = .840). Low tidal volume ventilation was rare during air medical transport. Air transport ventilation strategy influenced subsequent ventilation but was not associated with ARDS. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Influence of source batch S{sub K} dispersion on dosimetry for prostate cancer treatment with permanent implants

    Energy Technology Data Exchange (ETDEWEB)

    Nuñez-Cumplido, E., E-mail: ejnc-mccg@hotmail.com; Hernandez-Armas, J. [Medical Physics Department, University Hospital of the Canary Island, La Cuesta – Ofra, 38003 La Laguna (Spain); Perez-Calatayud, J. [Radiotherapy Department, La Fe University Hospital, Bulevar Sur, 46026 Valencia (Spain); Casares-Magaz, O. [Medical Physics Department, University Hospital of the Canary Island, La Cuesta – Ofra, 38003 La Laguna, Spain and Medical Physics Department, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus (Denmark)

    2015-08-15

    Purpose: In clinical practice, specific air kerma strength (S{sub K}) value is used in treatment planning system (TPS) permanent brachytherapy implant calculations with {sup 125}I and {sup 103}Pd sources; in fact, commercial TPS provide only one S{sub K} input value for all implanted sources and the certified shipment average is typically used. However, the value for S{sub K} is dispersed: this dispersion is not only due to the manufacturing process and variation between different source batches but also due to the classification of sources into different classes according to their S{sub K} values. The purpose of this work is to examine the impact of S{sub K} dispersion on typical implant parameters that are used to evaluate the dose volume histogram (DVH) for both planning target volume (PTV) and organs at risk (OARs). Methods: The authors have developed a new algorithm to compute dose distributions with different S{sub K} values for each source. Three different prostate volumes (20, 30, and 40 cm{sup 3}) were considered and two typical commercial sources of different radionuclides were used. Using a conventional TPS, clinically accepted calculations were made for {sup 125}I sources; for the palladium, typical implants were simulated. To assess the many different possible S{sub K} values for each source belonging to a class, the authors assigned an S{sub K} value to each source in a randomized process 1000 times for each source and volume. All the dose distributions generated for each set of simulations were assessed through the DVH distributions comparing with dose distributions obtained using a uniform S{sub K} value for all the implanted sources. The authors analyzed several dose coverage (V{sub 100} and D{sub 90}) and overdosage parameters for prostate and PTV and also the limiting and overdosage parameters for OARs, urethra and rectum. Results: The parameters analyzed followed a Gaussian distribution for the entire set of computed dosimetries. PTV and

  8. [Evaluation of tidal volume delivered by ventilators during volume-controlled ventilation].

    Science.gov (United States)

    Zhou, Juan; Yan, Yong; Cao, Desen

    2014-12-01

    To study the ways which ensure the delivery of enough tidal volume to patients under various conditions close to the demand of the physician. The volume control ventilation model was chosen, and the simulation lung type was active servo lung ASL 5000 or Michigan lung 1601. The air resistance, air compliance and lung type in simulation lungs were set. The tidal volume was obtained from flow analyzer PF 300. At the same tidal volume, the displaying values of tidal volume of E5, Servo i, Evital 4, and Evital XL ventilators with different lung types of patient, compliance of gas piping, leakage, gas types, etc. were evaluated. With the same setting tidal volume of a same ventilator, the tidal volume delivered to patients was different with different lung types of patient, compliance of gas piping, leakage, gas types, etc. Reducing compliance and increasing resistance of the patient lungs caused high peak airway pressure, the tidal volume was lost in gas piping, and the tidal volume be delivered to the patient lungs was decreased. If the ventilator did not compensate to leakage, the tidal volume delivered to the patient lungs was decreased. When the setting gas type of ventilator did not coincide with that applying to the patient, the tidal volume be delivered to the patient lungs might be different with the setting tidal volume of ventilator. To ensure the delivery of enough tidal volume to patients close to the demand of the physician, containable factors such as the compliance of gas piping, leakage, and gas types should be controlled.

  9. Intraoperative real-time planned conformal prostate brachytherapy: Post-implantation dosimetric outcome and clinical implications

    International Nuclear Information System (INIS)

    Zelefsky, Michael J.; Yamada, Yoshiya; Cohen, Gil'ad N.; Sharma, Neha; Shippy, Alison M.; Fridman, David; Zaider, Marco

    2007-01-01

    Purpose: To report the dosimetric outcome of patients with clinically localized prostate cancer treated with I-125 permanent implantation using an intraoperative real-time conformal planning technique. Methods and materials: Five hundred and sixty-two patients with prostate cancer were treated with I-125 permanent interstitial implantation using a transrectal ultrasound-guided approach. Real-time intraoperative treatment planning software that incorporates inverse planning optimization was used. Dose-volume constraints for this inverse-planning system included: prostate V100 ≥95%, maximal urethral dose ≤120%, and average rectal dose 3 of the rectum was exposed to the prescription dose, the incidence of late grade 2 toxicity rectal toxicity was 9% compared to 4% for smaller volumes of the rectum exposed to similar doses (p = 0.003). No dosimetric parameter in these patients with tight dose confines for the urethra influenced acute or late urinary toxicity. Conclusion: Real-time intraoperative planning was associated with a 90% consistency of achieving the planned intraoperative dose constraints for target coverage and maintaining planned urethral and rectal constraints in a high percentage of implants. Rectal volumes of ≥2.5 cm 3 exposed to the prescription doses were associated with an increased incidence of grade 2 rectal bleeding. Further enhancements in imaging guidance for optimal seed deposition are needed to guarantee optimal dose distribution for all patients. Whether such improvements lead to further reduction in acute and late morbidities associated with therapy requires further study

  10. Volume and Surface-Enhanced Volume Negative Ion Sources

    International Nuclear Information System (INIS)

    Stockli, M P

    2013-01-01

    H - volume sources and, especially, caesiated H - volume sources are important ion sources for generating high-intensity proton beams, which then in turn generate large quantities of other particles. This chapter discusses the physics and technology of the volume production and the caesium-enhanced (surface) production of H - ions. Starting with Bacal's discovery of the H - volume production, the chapter briefly recounts the development of some H - sources, which capitalized on this process to significantly increase the production of H - beams. Another significant increase was achieved in the 1990s by adding caesiated surfaces to supplement the volume-produced ions with surface-produced ions, as illustrated with other H - sources. Finally, the focus turns to some of the experience gained when such a source was successfully ramped up in H - output and in duty factor to support the generation of 1 MW proton beams for the Spallation Neutron Source. (author)

  11. Calculation of rectal dose surface histograms in the presence of time varying deformations

    International Nuclear Information System (INIS)

    Roeske, John C.; Spelbring, Danny R.; Vijayakumar, S.; Forman, Jeffrey D.; Chen, George T.Y.

    1996-01-01

    Purpose: Dose volume (DVH) and dose surface histograms (DSH) of the bladder and rectum are usually calculated from a single treatment planning scan. These DVHs and DSHs will eventually be correlated with complications to determine parameters for normal tissue complication probabilities (NTCP). However, from day to day, the size and shape of the rectum and bladder may vary. The purpose of this study is to compare a more accurate estimate of the time integrated DVHs and DSHs of the rectum (in the presence of daily variations in rectal shape) to initial DVHs/DSHs. Methods: 10 patients were scanned once per week during the course of fractionated radiotherapy, typically accumulating a total of six scans. The rectum and bladder were contoured on each of the studies. The model used to assess effects of rectal contour deformation is as follows: the contour on a given axial slice (see figure) is boxed within a rectangle. A line drawn parallel to the AP axis through the rectangle equally partitions the box. Starting at the intersection of the vertical line and the rectal contour, points on the contour are marked off representing the same rectal dose point, even in the presence of distortion. Corresponding numbered points are used to sample the dose matrix and create a composite DSH. The model assumes uniform stretching of the rectal contour for any given axial cut, and no twist of the structure or vertical displacement. A similar model is developed for the bladder with spherical symmetry. Results: Normalized DSHs (nDSH) for each CT scan were calculated as well as the time averaged nDSH over all scans. These were compared with the nDSH from the initial planning scan. Individual nDSHs differed by 8% surface area irradiated at the 80% dose level, to as much as 20% surface area in the 70-100% dose range. DSH variations are due to position and shape changes in the rectum during different CT scans. The spatial distribution of dose is highly variable, and depends on the field

  12. Development of Automatic Visceral Fat Volume Calculation Software for CT Volume Data

    Directory of Open Access Journals (Sweden)

    Mitsutaka Nemoto

    2014-01-01

    Full Text Available Objective. To develop automatic visceral fat volume calculation software for computed tomography (CT volume data and to evaluate its feasibility. Methods. A total of 24 sets of whole-body CT volume data and anthropometric measurements were obtained, with three sets for each of four BMI categories (under 20, 20 to 25, 25 to 30, and over 30 in both sexes. True visceral fat volumes were defined on the basis of manual segmentation of the whole-body CT volume data by an experienced radiologist. Software to automatically calculate visceral fat volumes was developed using a region segmentation technique based on morphological analysis with CT value threshold. Automatically calculated visceral fat volumes were evaluated in terms of the correlation coefficient with the true volumes and the error relative to the true volume. Results. Automatic visceral fat volume calculation results of all 24 data sets were obtained successfully and the average calculation time was 252.7 seconds/case. The correlation coefficients between the true visceral fat volume and the automatically calculated visceral fat volume were over 0.999. Conclusions. The newly developed software is feasible for calculating visceral fat volumes in a reasonable time and was proved to have high accuracy.

  13. SU-E-T-604: Dosimetric Dependence On the Collimator Angle in Prostate Volumetric Modulated Arc Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Khan, M; Rehman, J; Khan, M [The Islaimia University of Bahawalpur, Bahawalpur, Punjab (Pakistan); Chow, J [Princess Margaret Cancer Center, Toronto, ON (Canada)

    2014-06-01

    Purpose: The purpose of this study is to investigate the dose-volume variations of planning target volume (PTV) and organs-at-risk (OARs) in prostate volumetric modulated arc therapy (VMAT) when using different collimator angles. It is because collimator angle awareness is essential for planner to produce an optimal prostate VMAT plan in a rational time. Methods: Single-arc VMAT plans at different collimator angles (0o, 15o, 30o, 45o, 60o, 75o and 90o) were created systematically using a Harold heterogeneous pelvis phantom. For each change of collimator angle, a new plan was re-optimized for that angle. The prescription dose was 78 Gy per 39 fractions. Conformity index (CI), homogeneity index (HI), gradient index, machine monitor unit, dose-volume histogram, the mean and maximum doses of the PTV were calculated and analyzed. On the other hand, dose-volume histogram, the mean and maximum doses of the OARs such as bladder, rectum and femoral heads for different collimator angles were determined from the plans. Results: There was no significance difference, based on the plan dose-volume evaluation criteria, found in the VMAT optimizations for all studied collimator angles. Higher CI and lower HI were found for the 45o collimator angle. In addition, the 15o collimator angle provided lower HI similar to the 45o collimator angle. The 75o and 90o collimator angle were found good for the rectum sparing, and the 75o and 30o collimator angle were found good for the right and left femur sparing, respectively. The PTV dose coverage for each plan was comparatively independent of the collimator angle. Conclusion: The dosimetric results in this study are useful to the planner to select different collimator angles to improve the PTV coverage and OAR sparing in prostate VMAT.

  14. SU-E-T-604: Dosimetric Dependence On the Collimator Angle in Prostate Volumetric Modulated Arc Therapy

    International Nuclear Information System (INIS)

    Khan, M; Rehman, J; Khan, M; Chow, J

    2014-01-01

    Purpose: The purpose of this study is to investigate the dose-volume variations of planning target volume (PTV) and organs-at-risk (OARs) in prostate volumetric modulated arc therapy (VMAT) when using different collimator angles. It is because collimator angle awareness is essential for planner to produce an optimal prostate VMAT plan in a rational time. Methods: Single-arc VMAT plans at different collimator angles (0o, 15o, 30o, 45o, 60o, 75o and 90o) were created systematically using a Harold heterogeneous pelvis phantom. For each change of collimator angle, a new plan was re-optimized for that angle. The prescription dose was 78 Gy per 39 fractions. Conformity index (CI), homogeneity index (HI), gradient index, machine monitor unit, dose-volume histogram, the mean and maximum doses of the PTV were calculated and analyzed. On the other hand, dose-volume histogram, the mean and maximum doses of the OARs such as bladder, rectum and femoral heads for different collimator angles were determined from the plans. Results: There was no significance difference, based on the plan dose-volume evaluation criteria, found in the VMAT optimizations for all studied collimator angles. Higher CI and lower HI were found for the 45o collimator angle. In addition, the 15o collimator angle provided lower HI similar to the 45o collimator angle. The 75o and 90o collimator angle were found good for the rectum sparing, and the 75o and 30o collimator angle were found good for the right and left femur sparing, respectively. The PTV dose coverage for each plan was comparatively independent of the collimator angle. Conclusion: The dosimetric results in this study are useful to the planner to select different collimator angles to improve the PTV coverage and OAR sparing in prostate VMAT

  15. 3D inverse treatment planning for the tandem and ovoid applicator in cervical cancer

    International Nuclear Information System (INIS)

    DeWitt, Kelly D.; Hsu, I. Chow Joe; Speight, Joycelyn; Weinberg, Vivian K.; Lessard, Etienne; Pouliot, Jean

    2005-01-01

    Purpose: Three-dimensional treatment planning systems and inverse planning optimization for brachytherapy are becoming commercially available. Guidelines for target delineation and dose constrictions have not been established using this new software. In this study we describe a method of target delineation for the tandem and ovoids applicator. We then compare inverse planning dose distributions with the traditional methods of prescribing dose. Methods and Materials: Target and organ-at-risk volumes were defined using systematic guidelines on 15 patients treated in our department with high-dose-rate brachytherapy for cervical cancer using tandem and ovoids. High-dose-rate distributions were created according to three different dose optimization protocols: inverse planning simulated annealing (IPSA), point A, and point A with a normalization of 2 cc of the bladder receiving 80% of the dose (bladder-sparing method). An uniform cost function for dose constraints was applied to all IPSA generated plans, and no manual optimization was allowed for any planning method. Results: Guidelines for target and structure-at-risk volumes, as well as dose constraint cost functions, were established. Dose-volume histogram analysis showed that the IPSA algorithm indicated no difference in tumor coverage compared with point A optimization while decreasing dose to the bladder and rectum. The IPSA algorithm provided better target volume coverage compared with bladder-sparing method with equivalent doses to the bladder and rectum. Conclusion: This study uses a systematic approach for delineating target and organ-at-risk volumes and a uniform cost function for generating IPSA plans for cervical cancer using tandem and ovoids. Compared with conventional dose prescription methods, IPSA provides a consistent method of optimization that maintains or improves target coverage while decreasing dose to normal structures. Image-guided brachytherapy and inverse planning improve brachytherapy

  16. Dosimetric Changes Resulting From Patient Rotational Setup Errors in Proton Therapy Prostate Plans

    International Nuclear Information System (INIS)

    Sejpal, Samir V.; Amos, Richard A.; Bluett, Jaques B.; Levy, Lawrence B.; Kudchadker, Rajat J.; Johnson, Jennifer; Choi, Seungtaek; Lee, Andrew K.

    2009-01-01

    Purpose: To evaluate the dose changes to the target and critical structures from rotational setup errors in prostate cancer patients treated with proton therapy. Methods and Materials: A total of 70 plans were analyzed for 10 patients treated with parallel-opposed proton beams to a dose of 7,600 60 Co-cGy-equivalent (CcGE) in 200 CcGE fractions to the clinical target volume (i.e., prostate and proximal seminal vesicles). Rotational setup errors of +3 o , -3 deg., +5 deg., and -5 deg. (to simulate pelvic tilt) were generated by adjusting the gantry. Horizontal couch shifts of +3 deg. and -3 deg. (to simulate longitudinal setup variability) were also generated. Verification plans were recomputed, keeping the same treatment parameters as the control. Results: All changes shown are for 38 fractions. The mean clinical target volume dose was 7,780 CcGE. The mean change in the clinical target volume dose in the worse case scenario for all shifts was 2 CcGE (absolute range in worst case scenario, 7,729-7,848 CcGE). The mean changes in the critical organ dose in the worst case scenario was 6 CcGE (bladder), 18 CcGE (rectum), 36 CcGE (anterior rectal wall), and 141 CcGE (femoral heads) for all plans. In general, the percentage of change in the worse case scenario for all shifts to the critical structures was <5%. Deviations in the absolute percentage of volume of organ receiving 45 and 70 Gy for the bladder and rectum were <2% for all plans. Conclusion: Patient rotational movements of 3 deg. and 5 deg. and horizontal couch shifts of 3 deg. in prostate proton planning did not confer clinically significant dose changes to the target volumes or critical structures.

  17. The effect of bowel preparation regime on interfraction rectal filling variation during image guided radiotherapy for prostate cancer.

    Science.gov (United States)

    Hosni, Ali; Rosewall, Tara; Craig, Timothy; Kong, Vickie; Bayley, Andrew; Berlin, Alejandro; Bristow, Robert; Catton, Charles; Warde, Padraig; Chung, Peter

    2017-03-09

    This study aimed to investigate the tolerability and impact of milk of magnesia (MoM) on interfraction rectal filling during prostate cancer radiotherapy. Two groups were retrospectively identified, each consisting of 40 patients with prostate cancer treated with radiotherapy to prostate+/-seminal vesicles, with daily image-guidance in 78Gy/39fractions/8 weeks. The first-group followed anti-flatulence diet with MoM started 3-days prior to planning-CT and continued during radiotherapy, while the second-group followed the same anti-flatulence diet only. The rectum between upper and lower limit of the clinical target volume (CTV) was delineated on planning-CT and on weekly cone-beam-CT (CBCT). Rectal filling was assessed by measurement of anterio-posterior diameter of the rectum at the superior and mid levels of CTV, rectal volume (RV), and average cross-sectional rectal area (CSA; RV/length). Overall 720 images (80 planning-CT and 640 CBCT images) from 80 patients were analyzed. Using linear mixed models, and after adjusting for baseline values at the time of planning-CT to test the differences in rectal dimensions between both groups over the 8-week treatment period, there were no significant differences in RV (p = 0.4), CSA (p = 0.5), anterio-posterior diameter of rectum at superior (p = 0.4) or mid level of CTV (p = 0.4). In the non-MoM group; 22.5% of patients had diarrhea compared to 60% in the MoM group, while 40% discontinued use of MoM by end of radiotherapy. The addition of MoM to antiflatulence diet did not reduce the interfraction variation in rectal filling but caused diarrhea in a substantial proportion of patients who then discontinued its use.

  18. Rectal dexmedetomidine in rats: evaluation of sedative and mucosal effects

    Directory of Open Access Journals (Sweden)

    Volkan Hanci

    2015-02-01

    Full Text Available BACKGROUND AND OBJECTIVES: In this study, we investigated the anesthetic and mucosal effects of the rectal application of dexmedetomidine to rats. METHODS: Male Wistar albino rats weighing 250-300 g were divided into four groups: Group S (n = 8 was a sham group that served as a baseline for the normal basal values; Group C (n = 8 consisted of rats that received the rectal application of saline alone; Group IPDex (n = 8 included rats that received the intraperitoneal application of dexmedetomidine (100 µg kg-1; and Group RecDex (n = 8 included rats that received the rectal application of dexmedetomidine (100 µg kg-1. For the rectal drug administration, we used 22 G intravenous cannulas with the stylets removed. We administered the drugs by advancing the cannula 1 cm into the rectum, and the rectal administration volume was 1 mL for all the rats. The latency and anesthesia time (min were measured. Two hours after rectal administration, 75 mg kg-1 ketamine was administered for intraperitoneal anesthesia in all the groups, followed by the removal of the rats' rectums to a distal distance of 3 cm via an abdominoperineal surgical procedure. We histopathologically examined and scored the rectums. RESULTS: Anesthesia was achieved in all the rats in the Group RecDex following the administration of dexmedetomidine. The onset of anesthesia in the Group RecDex was significantly later and of a shorter duration than in the Group IPDEx (p < 0.05. In the Group RecDex, the administration of dexmedetomidine induced mild-moderate losses of mucosal architecture in the colon and rectum, 2 h after rectal inoculation. CONCLUSION: Although 100 µg kg-1 dexmedetomidine administered rectally to rats achieved a significantly longer duration of anesthesia compared with the rectal administration of saline, our histopathological evaluations showed that the rectal administration of 100 µg kg-1 dexmedetomidine led to mild-moderate damage to the mucosal structure of the

  19. Comparison of Real-Time Intraoperative Ultrasound-Based Dosimetry With Postoperative Computed Tomography-Based Dosimetry for Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Nag, Subir; Shi Peipei; Liu Bingren; Gupta, Nilendu; Bahnson, Robert R.; Wang, Jian Z.

    2008-01-01

    Purpose: To evaluate whether real-time intraoperative ultrasound (US)-based dosimetry can replace conventional postoperative computed tomography (CT)-based dosimetry in prostate brachytherapy. Methods and Materials: Between December 2001 and November 2002, 82 patients underwent 103 Pd prostate brachytherapy. An interplant treatment planning system was used for real-time intraoperative transrectal US-guided treatment planning. The dose distribution was updated according to the estimated seed position to obtain the dose-volume histograms. Postoperative CT-based dosimetry was performed a few hours later using the Theraplan-Plus treatment planning system. The dosimetric parameters obtained from the two imaging modalities were compared. Results: The results of this study revealed correlations between the US- and CT-based dosimetry. However, large variations were found in the implant-quality parameters of the two modalities, including the doses covering 100%, 90%, and 80% of the prostate volume and prostate volumes covered by 100%, 150%, and 200% of the prescription dose. The mean relative difference was 38% and 16% for doses covering 100% and 90% of the prostate volume and 10% and 21% for prostate volumes covered by 100% and 150% of the prescription dose, respectively. The CT-based volume covered by 200% of the prescription dose was about 30% greater than the US-based one. Compared with CT-based dosimetry, US-based dosimetry significantly underestimated the dose to normal organs, especially for the rectum. The average US-based maximal dose and volume covered by 100% of the prescription dose for the rectum was 72 Gy and 0.01 cm 3 , respectively, much lower than the 159 Gy and 0.65 cm 3 obtained using CT-based dosimetry. Conclusion: Although dosimetry using intraoperative US-based planning provides preliminary real-time information, it does not accurately reflect the postoperative CT-based dosimetry. Until studies have determined whether US-based dosimetry or

  20. Étude des impacts écologiques du dynamisme spatio-temporel des ...

    African Journals Online (AJOL)

    transformer radicalement les occupations du sol. Toutefois, le recul des .... également de cette protection (Roberge et Angelstam 2004). L'objectif est de ... distribution des espèces cibles a ensuite été cartographiée sur la couche d'unités de ...

  1. Estimation of lung volume and pulmonary blood volume from radioisotopic images

    International Nuclear Information System (INIS)

    Kanazawa, Minoru

    1989-01-01

    Lung volume and pulmonary blood volume in man were estimated from the radioisotopic image using single photon emission computed tomography (SPECT). Six healthy volunteers were studied in a supine position with normal and altered lung volumes by applying continuous negative body-surface pressure (CNP) and by positive end-expiratory pressure (PEEP). 99m Tc labeled human serum albumin was administered as an aerosol to image the lungs. The CNP caused the diaphragm to be lowered and it increased the mean lung tissue volume obtained by SPECT from 3.09±0.49 l for baseline to 3.67±0.62 l for 10 cmH 2 O (p 2 O (p 2 O), respectively. The PEEP also increased the lung tissue volume to 3.68±0.68 l for 10 cmH 2 O as compared with the baseline (p 2 O PEEP. The lung tissue volume obtained by SPECT showed a positive correlation with functional residual capacity measured by the He dilution method (r=0.91, p 99m Tc-labeled red blood cells. The L/H ratio decreased after either the CNP or PEEP, suggesting a decrease in the blood volume per unit lung volume. However, it was suggested that the total pulmonary blood volume increased slightly either on the CNP (+7.4% for 10 cmH 2 O, p 2 O,p<0.05) when we extrapolated the L/H ratio to the whole lungs by multiplying the lung tissue volume obtained by SPECT. We concluded that SPECT could offer access to the estimation of lung volume and pulmonary blood volume in vivo. (author)

  2. ВОССОЗДАНИЕ СЛОВ-РЕАЛИЙ В КОНТЕКСТЕ МЕЖКУЛЬТУРНОЙ КОММУНИКАЦИИ (ПАРЫ ЯЗЫКОВ: ФРАНЦУЗCКИЙ ↔ УКРАИНСКИЙ

    Directory of Open Access Journals (Sweden)

    Olga Mokra

    2014-06-01

    Full Text Available Les termes fortement ancrés dans la culture de la nation existent dans chaque langue. Ils constituent un système de signes marqués par la connotation ethnique dont le transfert linguistique adéquat permet à deux civilisations différentes de communiquer. Les realia ne connaissent pas d’équivalent dans la langue-cible. De surcroît, une forte hétérogénéité lexicale de leur corpus ne se prête pas facilement à la traduction. Médiateur entre les usagers de la langue source et ceux de la langue cible, le traducteur est appelé à traduire ces mots mais également des concepts propres à une civilisation possédant sa propre façon de penser. Le choix correct des méthodes de traduction permet de préserver l’identité du terme à fort contenu culturel et de satisfaire les attentes des destinataires de son message.

  3. Cross-correlations in volume space: Differences between buy and sell volumes

    Science.gov (United States)

    Lee, Sun Young; Hwang, Dong Il; Kim, Min Jae; Koh, In Gyu; Kim, Soo Yong

    2011-03-01

    We study the cross-correlations of buy and sell volumes on the Korean stock market in high frequency. We observe that the pulling effects of volumes are as small as that of returns. The properties of the correlations of buy and sell volumes differ. They are explained by the degree of synchronization of stock volumes. Further, the pulling effects on the minimal spanning tree are studied. In minimal spanning trees with directed links, the large pulling effects are clustered at the center, not uniformly distributed. The Epps effect of buy and sell volumes are observed. The reversal of the cross-correlations of buy and sell volumes is also detected.

  4. An image-guided radiotherapy decision support framework incorporating a Bayesian network and visualization tool.

    Science.gov (United States)

    Hargrave, Catriona; Deegan, Timothy; Bednarz, Tomasz; Poulsen, Michael; Harden, Fiona; Mengersen, Kerrie

    2018-05-17

    To describe a Bayesian network (BN) and complementary visualization tool that aim to support decision-making during online cone-beam computed tomography (CBCT)-based image-guided radiotherapy (IGRT) for prostate cancer patients. The BN was created to represent relationships between observed prostate, proximal seminal vesicle (PSV), bladder and rectum volume variations, an image feature alignment score (FAS TV _ OAR ), delivered dose, and treatment plan compliance (TPC). Variables influencing tumor volume (TV) targeting accuracy such as intrafraction motion, and contouring and couch shift errors were also represented. A score of overall TPC (FAS global ) and factors such as image quality were used to inform the BN output node providing advice about proceeding with treatment. The BN was quantified using conditional probabilities generated from published studies, FAS TV _ OAR /global modeling, and a survey of IGRT decision-making practices. A new IGRT visualization tool (IGRT REV ), in the form of Mollweide projection plots, was developed to provide a global summary of residual errors after online CBCT-planning CT registration. Sensitivity and scenario analyses were undertaken to evaluate the performance of the BN and the relative influence of the network variables on TPC and the decision to proceed with treatment. The IGRT REV plots were evaluated in conjunction with the BN scenario testing, using additional test data generated from retrospective CBCT-planning CT soft-tissue registrations for 13/36 patients whose data were used in the FAS TV _ OAR /global modeling. Modeling of the TV targeting errors resulted in a very low probability of corrected distances between the CBCT and planning CT prostate or PSV volumes being within their thresholds. Strength of influence evaluation with and without the BN TV targeting error nodes indicated that rectum- and bladder-related network variables had the highest relative importance. When the TV targeting error nodes were excluded

  5. Importância da dieta na epidemiologia do câncer de colon e reto The importance of diet in the epidemiology of cancer of the colon and rectum

    Directory of Open Access Journals (Sweden)

    Eliza da Conceição da Fonseca Lopes

    1984-10-01

    Full Text Available Foi feita atualização de estudos realizados com o objetivo de verificar a relação entre o fator ambiental, destacando-se a alimentação caracterizada por uma dieta pobre em fibra e rica em gordura e a distribuição epidemiológica do câncer de colon e reto. São enfatizadas as diferenças apresentadas pelas dietas dos países industrializados e dos países em desenvolvimento e a influência da religião e do fluxo migratório no hábito alimentar, associadas com as taxas de incidência da doença.Studies have been made to verify the relation between the environmental factor, diet rich in fat and deficient in fibre, and the epidemiologic distribution of cancer of the colon and rectum. The research emphasizes the differences between the diets of the industrialized and the developing countries, and the influence of religion and migratory movements on the diet usualy associated with incidence of the disease.

  6. Blood volume studies

    International Nuclear Information System (INIS)

    Lewis, S.M.; Yin, J.A.L.

    1986-01-01

    The use of dilution analysis with such radioisotopes as 51 Cr, 32 P, sup(99m)Tc and sup(113m)In for measuring red cell volume is reviewed briefly. The use of 125 I and 131 I for plasma volume studies is also considered and the subsequent determination of total blood volume discussed, together with the role of the splenic red cell volume. Substantial bibliography. (UK)

  7. Is orbital volume associated with eyeball and visual cortex volume in humans?

    Science.gov (United States)

    Pearce, Eiluned; Bridge, Holly

    2013-01-01

    In humans orbital volume increases linearly with absolute latitude. Scaling across mammals between visual system components suggests that these larger orbits should translate into larger eyes and visual cortices in high latitude humans. Larger eyes at high latitudes may be required to maintain adequate visual acuity and enhance visual sensitivity under lower light levels. To test the assumption that orbital volume can accurately index eyeball and visual cortex volumes specifically in humans. Structural Magnetic Resonance Imaging (MRI) techniques are employed to measure eye and orbit (n = 88) and brain and visual cortex (n = 99) volumes in living humans. Facial dimensions and foramen magnum area (a proxy for body mass) were also measured. A significant positive linear relationship was found between (i) orbital and eyeball volumes, (ii) eyeball and visual cortex grey matter volumes and (iii) different visual cortical areas, independently of overall brain volume. In humans the components of the visual system scale from orbit to eye to visual cortex volume independently of overall brain size. These findings indicate that orbit volume can index eye and visual cortex volume in humans, suggesting that larger high latitude orbits do translate into larger visual cortices.

  8. Décentralisation,pouvoir local et droits des femmes

    International Development Research Centre (IDRC) Digital Library (Canada)

    user

    transfert de compétences aux collectivités locales, la loi 96-09 ... dans trois dispositions à propos des organes des collectivités locales que le. Code fait allusion aux ... les élus locaux, Les secteurs cibles d'intervention prioritaires sont l'accès ...

  9. Significant correlation between rectal DVH and late bleeding in patients treated after radical prostatectomy with conformal or conventional radiotherapy (66.6-70.2 Gy)

    International Nuclear Information System (INIS)

    Cozzarini, Cesare; Fiorino, Claudio; Ceresoli, Giovanni Luca; Cattaneo, Giovanni Mauro; Bolognesi, Angelo; Calandrino, Riccardo; Villa, Eugenio

    2003-01-01

    Purpose: Investigating the correlation between dosimetric/clinical parameters and late rectal bleeding in patients treated with adjuvant or salvage radiotherapy after radical prostatectomy. Methods and Materials: Data of 154 consecutive patients, including three-dimensional treatment planning and dose-volume histograms (DVHs) of the rectum (including filling), were retrospectively analyzed. Twenty-six of 154 patients presenting a (full) rectal volume >100 cc were excluded from the analysis. All patients considered for the analysis (n=128) were treated at a nominal dose equal to 66.6-70.2 Gy (ICRU dose 68-72.5 Gy; median 70 Gy) with conformal (n=76) or conventional (n=52) four-field technique (1.8 Gy/fr). Clinical parameters such as diabetes mellitus, acute rectal bleeding, hypertension, age, and hormonal therapy were considered. Late rectal bleeding was scored using a modified Radiation Therapy Oncology Group scale, and patients experiencing ≥Grade 2 were considered bleeders. Median follow-up was 36 months (range 12-72). Mean and median rectal dose were considered, together with rectal volume and the % fraction of rectum receiving more than 50, 55, 60, and 65 Gy (V50, V55, V60, V65, respectively). Median and quartile values of all parameters were taken as cutoff for statistical analysis. Univariate (log-rank) and multivariate (Cox hazard model) analyses were performed. Results: Fourteen of 128 patients experienced ≥Grade 2 late bleeding (3-year actuarial incidence 10.5%). A significant correlation between a number of cutoff values and late rectal bleeding was found. In particular, a mean dose ≥54 Gy, V50 ≥63%, V55 ≥57%, and V60 ≥50% was highly predictive of late bleeding (p≤0.01). A rectal volume <60 cc and type of treatment (conventional vs. conformal) were also significantly predictive of late bleeding (p=0.05). Concerning clinical variables, acute bleeding (p < 0.001) was significantly related to late bleeding, and a trend was found for

  10. Equivalence of Gyn GEC-ESTRO guidelines for image guided cervical brachytherapy with EUD-based dose prescription

    International Nuclear Information System (INIS)

    Shaw, William; Rae, William ID; Alber, Markus L

    2013-01-01

    To establish a generalized equivalent uniform dose (gEUD) -based prescription method for Image Guided Brachytherapy (IGBT) that reproduces the Gyn GEC-ESTRO WG (GGE) prescription for cervix carcinoma patients on CT images with limited soft tissue resolution. The equivalence of two IGBT planning approaches was investigated in 20 patients who received external beam radiotherapy (EBT) and 5 concomitant high dose rate IGBT treatments. The GGE planning strategy based on dose to the most exposed 2 cm 3 (D2cc) was used to derive criteria for the gEUD-based planning of the bladder and rectum. The safety of gEUD constraints in terms of GGE criteria was tested by maximizing dose to the gEUD constraints for individual fractions. The gEUD constraints of 3.55 Gy for the rectum and 5.19 Gy for the bladder were derived. Rectum and bladder gEUD-maximized plans resulted in D2cc averages very similar to the initial GGE criteria. Average D2ccs and EUDs from the full treatment course were comparable for the two techniques within both sets of normal tissue constraints. The same was found for the tumor doses. The derived gEUD criteria for normal organs result in GGE-equivalent IGBT treatment plans. The gEUD-based planning considers the entire dose distribution of organs in contrast to a single dose-volume-histogram point

  11. McKittrick-Wheelock syndrome - a rare cause of acute renal failure.

    Science.gov (United States)

    Popescu, Alina; Orban-Schiopu, Ana-Maria; Becheanu, Gabriel; Diculescu, Mircea

    2005-03-01

    Fluid and electrolyte hypersecretion in the villous adenoma of the rectum is presented in the case of a 74 year old man presenting with a severe fluid imbalance. The patient had a 2-year history of mucous diarrhea and, on admission, presented prerenal uremia, hyponatremia and severe hypokalemia. At sigmoidoscopy, a 6/4 cm villous adenoma of the rectum was found. The increased loss of volume, followed by exhaustion of the physiological compensation mechanisms, led to a life-threatening hypokalemia, as well as to acute renal failure. Conservative treatment was followed by a temporary improvement of the renal function. Alternative treatment was: endocavitary irradiation, endoscopic resection and radical tumor surgery. The surgical removal of the adenoma led to complete recovery of the symptoms. The McKittrick-Wheelock syndrome can be a problem of difficult diagnosis, both for the gastroenterologist and also for the nephrologist. The patient may develop severe complications, which require a sustained treatment.

  12. Radiation dose delivery verification in the treatment of carcinoma-cervix

    International Nuclear Information System (INIS)

    Shrotriya, D.; Srivastava, R. N. L.; Kumar, S.

    2015-01-01

    The accurate dose delivery to the clinical target volume in radiotherapy can be affected by various pelvic tissues heterogeneities. An in-house heterogeneous woman pelvic phantom was designed and used to verify the consistency and computational capability of treatment planning system of radiation dose delivery in the treatment of cancer cervix. Oncentra 3D-TPS with collapsed cone convolution (CCC) dose calculation algorithm was used to generate AP/PA and box field technique plan. the radiation dose was delivered by Primus Linac (Siemens make) employing high energy 15 MV photon beam by isocenter technique. A PTW make, 0.125cc ionization chamber was used for direct measurements at various reference points in cervix, bladder and rectum. The study revealed that maximum variation between computed and measured dose at cervix reference point was 1% in both the techniques and 3% and 4% variation in AP/PA field and 5% and 4.5% in box technique at bladder and rectum points respectively

  13. Radiation dose delivery verification in the treatment of carcinoma-cervix

    Science.gov (United States)

    Shrotriya, D.; Kumar, S.; Srivastava, R. N. L.

    2015-06-01

    The accurate dose delivery to the clinical target volume in radiotherapy can be affected by various pelvic tissues heterogeneities. An in-house heterogeneous woman pelvic phantom was designed and used to verify the consistency and computational capability of treatment planning system of radiation dose delivery in the treatment of cancer cervix. Oncentra 3D-TPS with collapsed cone convolution (CCC) dose calculation algorithm was used to generate AP/PA and box field technique plan. the radiation dose was delivered by Primus Linac (Siemens make) employing high energy 15 MV photon beam by isocenter technique. A PTW make, 0.125cc ionization chamber was used for direct measurements at various reference points in cervix, bladder and rectum. The study revealed that maximum variation between computed and measured dose at cervix reference point was 1% in both the techniques and 3% and 4% variation in AP/PA field and 5% and 4.5% in box technique at bladder and rectum points respectively.

  14. Radiation dose delivery verification in the treatment of carcinoma-cervix

    Energy Technology Data Exchange (ETDEWEB)

    Shrotriya, D., E-mail: shrotriya2007@gmail.com; Srivastava, R. N. L. [Department of Radiotherapy, J.K. Cancer Institute Kanpur-208019 (India); Kumar, S. [Department of Physics, Christ Church College, Kanpur-208001 (India)

    2015-06-24

    The accurate dose delivery to the clinical target volume in radiotherapy can be affected by various pelvic tissues heterogeneities. An in-house heterogeneous woman pelvic phantom was designed and used to verify the consistency and computational capability of treatment planning system of radiation dose delivery in the treatment of cancer cervix. Oncentra 3D-TPS with collapsed cone convolution (CCC) dose calculation algorithm was used to generate AP/PA and box field technique plan. the radiation dose was delivered by Primus Linac (Siemens make) employing high energy 15 MV photon beam by isocenter technique. A PTW make, 0.125cc ionization chamber was used for direct measurements at various reference points in cervix, bladder and rectum. The study revealed that maximum variation between computed and measured dose at cervix reference point was 1% in both the techniques and 3% and 4% variation in AP/PA field and 5% and 4.5% in box technique at bladder and rectum points respectively.

  15. The evolution of rectal and urinary toxicity and immune response in prostate cancer patients treated with two three-dimensional conformal radiotherapy techniques

    International Nuclear Information System (INIS)

    Vranova, Jana; Vinakurau, Stepan; Richter, Jan; Starec, Miroslav; Fiserova, Anna; Rosina, Jozef

    2011-01-01

    Our research compared whole pelvic (WP) and prostate-only (PO) 3-dimensional conformal radiotherapy (3DCRT) techniques in terms of the incidence and evolution of acute and late toxicity of the rectum and urinary bladder, and identified the PTV-parameters influencing these damages and changes in antitumor immune response. We analyzed 197 prostate cancer patients undergoing 3DCRT for gastrointestinal (GI) and genitourinary (GU) toxicities, and conducted a pilot immunological study including flow cytometry and an NK cell cytotoxicity assay. Acute and late toxicities were recorded according to the RTOG and the LENT-SOMA scales, respectively. Univariate and multivariate analyses were conducted for factors associated with toxicity. In the WP group, an increase of acute rectal toxicity was observed. A higher incidence of late GI/GU toxicity appeared in the PO group. Only 18 patients (WP-7.76% and PO-11.11%) suffered severe late GI toxicity, and 26 patients (WP-11.21% and PO-16.05%) severe late GU toxicity. In the majority of acute toxicity suffering patients, the diminution of late GI/GU toxicity to grade 1 or to no toxicity after radiotherapy was observed. The 3DCRT technique itself, patient age, T stage of TNM classification, surgical intervention, and some dose-volume parameters emerged as important factors in the probability of developing acute and late GI/GU toxicity. The proportion and differentiation of NK cells positively correlated during 3DCRT and negatively so after its completion with dose-volumes of the rectum and urinary bladder. T and NKT cells were down-regulated throughout the whole period. We found a negative correlation between leukocyte numbers and bone marrow irradiated by 44-54 Gy and a positive one for NK cell proportion and doses of 5-25 Gy. The acute GU, late GU, and GI toxicities up-regulated the T cell (CTL) numbers and NK cytotoxicity. Our study demonstrates the association of acute and late damage of the urinary bladder and rectum, with

  16. Influence of image slice thickness on rectal dose-response relationships following radiotherapy of prostate cancer

    Science.gov (United States)

    Olsson, C.; Thor, M.; Liu, M.; Moissenko, V.; Petersen, S. E.; Høyer, M.; Apte, A.; Deasy, J. O.

    2014-07-01

    When pooling retrospective data from different cohorts, slice thicknesses of acquired computed tomography (CT) images used for treatment planning may vary between cohorts. It is, however, not known if varying slice thickness influences derived dose-response relationships. We investigated this for rectal bleeding using dose-volume histograms (DVHs) of the rectum and rectal wall for dose distributions superimposed on images with varying CT slice thicknesses. We used dose and endpoint data from two prostate cancer cohorts treated with three-dimensional conformal radiotherapy to either 74 Gy (N = 159) or 78 Gy (N = 159) at 2 Gy per fraction. The rectum was defined as the whole organ with content, and the morbidity cut-off was Grade ≥2 late rectal bleeding. Rectal walls were defined as 3 mm inner margins added to the rectum. DVHs for simulated slice thicknesses from 3 to 13 mm were compared to DVHs for the originally acquired slice thicknesses at 3 and 5 mm. Volumes, mean, and maximum doses were assessed from the DVHs, and generalized equivalent uniform dose (gEUD) values were calculated. For each organ and each of the simulated slice thicknesses, we performed predictive modeling of late rectal bleeding using the Lyman-Kutcher-Burman (LKB) model. For the most coarse slice thickness, rectal volumes increased (≤18%), whereas maximum and mean doses decreased (≤0.8 and ≤4.2 Gy, respectively). For all a values, the gEUD for the simulated DVHs were ≤1.9 Gy different than the gEUD for the original DVHs. The best-fitting LKB model parameter values with 95% CIs were consistent between all DVHs. In conclusion, we found that the investigated slice thickness variations had minimal impact on rectal dose-response estimations. From the perspective of predictive modeling, our results suggest that variations within 10 mm in slice thickness between cohorts are unlikely to be a limiting factor when pooling multi-institutional rectal dose data that include slice thickness

  17. SU-F-T-338: Flattening Filter Free Photon Beams Can Achieve the Same Plan Quality as Conventional Flattened Beams for Prostate Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kolar, M; Szwedowski, R; Greskovich, J; Xia, P [Cleveland Clinic, Cleveland, OH (United States)

    2016-06-15

    Purpose: Some modern linear accelerators are equipped with one low energy flat beam and two flattening filter free (FFF) beams at high and low energies. The purpose of this study is to investigate whether the high energy FFF beam can produce the same plan quality as the conventional low energy flat beam, using a volumetric modulated arc (VMAT) technique for prostate patients. Methods: Ten prostate cancer patients were selected with a prescription of 78Gy. For each patient, three plans were created: (a) double arc flat 6MV plan used clinically; (b) double arc 10MV FFF plan; (c) single arc 10MV FFF plan. Each plan was prescribed so that at least 95% of the PTV received the prescription dose. The following dosimetric endpoints were evaluated: volume receiving 78Gy (V78) of the CTV and PTV, PTV conformality index (CI, ratio of prescription isodose volume to the PTV volume), bladder volume receiving 70Gy (V70) and 60Gy (V60), rectum volume receiving 70Gy (V70) and 50Gy (V50), dose to 10cc of the rectum, and volume of both femoral heads receiving 50Gy (V50). Total monitor units for each plan were recorded. Results: No significant difference was found for all dosimetric endpoints between all plans (p>0.05). Compared to the 6MV plans, monitor units were higher with the double arc 10MV FFF plans and lower with the single arc 10MV FFF plans, 29% and 4% respectively. Conclusion: Both single arc and double arc 10MV FFF VMAT can achieve equivalent plan quality as 6MV flat beam double arc treatment plans. With the gantry speed restriction, a high dose rate of 2400MU/min may allow the optimizer to use more MUs than actually needed. Single arc 10MV FFF VMAT plans are a reasonable alternative to double arc 6MV flat beam VMAT plans.

  18. SU-F-T-338: Flattening Filter Free Photon Beams Can Achieve the Same Plan Quality as Conventional Flattened Beams for Prostate Radiotherapy

    International Nuclear Information System (INIS)

    Kolar, M; Szwedowski, R; Greskovich, J; Xia, P

    2016-01-01

    Purpose: Some modern linear accelerators are equipped with one low energy flat beam and two flattening filter free (FFF) beams at high and low energies. The purpose of this study is to investigate whether the high energy FFF beam can produce the same plan quality as the conventional low energy flat beam, using a volumetric modulated arc (VMAT) technique for prostate patients. Methods: Ten prostate cancer patients were selected with a prescription of 78Gy. For each patient, three plans were created: (a) double arc flat 6MV plan used clinically; (b) double arc 10MV FFF plan; (c) single arc 10MV FFF plan. Each plan was prescribed so that at least 95% of the PTV received the prescription dose. The following dosimetric endpoints were evaluated: volume receiving 78Gy (V78) of the CTV and PTV, PTV conformality index (CI, ratio of prescription isodose volume to the PTV volume), bladder volume receiving 70Gy (V70) and 60Gy (V60), rectum volume receiving 70Gy (V70) and 50Gy (V50), dose to 10cc of the rectum, and volume of both femoral heads receiving 50Gy (V50). Total monitor units for each plan were recorded. Results: No significant difference was found for all dosimetric endpoints between all plans (p>0.05). Compared to the 6MV plans, monitor units were higher with the double arc 10MV FFF plans and lower with the single arc 10MV FFF plans, 29% and 4% respectively. Conclusion: Both single arc and double arc 10MV FFF VMAT can achieve equivalent plan quality as 6MV flat beam double arc treatment plans. With the gantry speed restriction, a high dose rate of 2400MU/min may allow the optimizer to use more MUs than actually needed. Single arc 10MV FFF VMAT plans are a reasonable alternative to double arc 6MV flat beam VMAT plans.

  19. 2547-IJBCS-Article-Dr Koffi Marcelin yao

    African Journals Online (AJOL)

    hp

    cible biologique, les pesticides sont classés en plusieurs familles parmi lesquels figurent les insecticides, les nématicides (contre les nématodes), les herbicides, les fongicides. (contre les champignons) et les rodenticides. Selon leurs structures chimiques ou groupes fonctionnels, l'on distingue aussi plusieurs familles dont ...

  20. Établissement d'une plateforme commune de recherche sur le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    épidémie se caractérise par la complexité des sous-types de VIH, est une cible capitale pour la recherche visant à évaluer le vaccin contre le VIH. Cette subvention appuiera l'établissement d'un partenariat réunissant l'Institute of Human ...

  1. Correlation of ultrasound estimated placental volume and umbilical cord blood volume in term pregnancy.

    Science.gov (United States)

    Pannopnut, Papinwit; Kitporntheranunt, Maethaphan; Paritakul, Panwara; Kongsomboon, Kittipong

    2015-01-01

    To investigate the correlation between ultrasound measured placental volume and collected umbilical cord blood (UCB) volume in term pregnancy. An observational cross-sectional study of term singleton pregnant women in the labor ward at Maha Chakri Sirindhorn Medical Center was conducted. Placental thickness, height, and width were measured using two-dimensional (2D) ultrasound and calculated for placental volume using the volumetric mathematic model. After the delivery of the baby, UCB was collected and measured for its volume immediately. Then, birth weight, placental weight, and the actual placental volume were analyzed. The Pearson's correlation was used to determine the correlation between each two variables. A total of 35 pregnant women were eligible for the study. The mean and standard deviation of estimated placental volume and actual placental volume were 534±180 mL and 575±118 mL, respectively. The median UCB volume was 140 mL (range 98-220 mL). The UCB volume did not have a statistically significant correlation with the estimated placental volume (correlation coefficient 0.15; p=0.37). However, the UCB volume was significantly correlated with the actual placental volume (correlation coefficient 0.62; pcorrelation coefficient 0.38; p=0.02). The estimated placental volume by 2D ultrasound was not significantly correlated with the UCB volume. Further studies to establish the correlation between the UCB volume and the estimated placental volume using other types of placental imaging may be needed.

  2. Electronic device for measuring the polarization parameter in the {pi}{sup -}p {yields} {pi}{sup 0}n charge exchange reaction on a polarized proton target; Un appareillage electronique destine a la mesure du parametre de polarisation dans la reaction d'echange de charge {pi}{sup -}p {yields} {pi}{sup 0}n sur cible de protons polarises

    Energy Technology Data Exchange (ETDEWEB)

    Brehin, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-12-15

    An electronic apparatus has been constructed to measure the polarization parameter P{sub 0}(t) in {pi}{sup -}p {yields} {pi}{sup 0}n charge exchange scattering at 5.9 GeV/c and 11,2 GeV/c on polarized proton target. This device insures triggering of a heavy plate spark chamber, allowing visualisation of {gamma} rays from the {pi}{sup 0} decays when the associated neutron offers suitable characteristics in direction and energy. The neutron is detected by an array of 32 counters and his energy is measured by a time of flight method. Electronic circuits of this apparatus are described as test and calibration methods used. (author) [French] Un appareillage electronique a ete realise pour mesurer le parametre de polarisation P{sub 0}(t) dans la reaction d'echange de charge {pi}{sup -}p {yields} {pi}{sup 0}n a 5,9 GeV/c et 11,2 GeV/c sur une cible de protons polarises. Ce dispositif assure le declenchement d'une chambre a etincelles a plaques lourdes, permettant de visualiser les {gamma} de desitegration du {pi}{sup 0}, lorsque le neutron associe presente les caracteristiques convenables en direction et en energie. Le neutron est detecte par un ensemble de 32 compteurs et son energie est mesuree par une methode de temps de vol. Les circuits composant cet appareillage sont decrits ainsi que les methodes d'etalonnage et de verification utilisees. (auteur)

  3. Electronic device for measuring the polarization parameter in the {pi}{sup -}p {yields} {pi}{sup 0}n charge exchange reaction on a polarized proton target; Un appareillage electronique destine a la mesure du parametre de polarisation dans la reaction d'echange de charge {pi}{sup -}p {yields} {pi}{sup 0}n sur cible de protons polarises

    Energy Technology Data Exchange (ETDEWEB)

    Brehin, S. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-12-15

    An electronic apparatus has been constructed to measure the polarization parameter P{sub 0}(t) in {pi}{sup -}p {yields} {pi}{sup 0}n charge exchange scattering at 5.9 GeV/c and 11,2 GeV/c on polarized proton target. This device insures triggering of a heavy plate spark chamber, allowing visualisation of {gamma} rays from the {pi}{sup 0} decays when the associated neutron offers suitable characteristics in direction and energy. The neutron is detected by an array of 32 counters and his energy is measured by a time of flight method. Electronic circuits of this apparatus are described as test and calibration methods used. (author) [French] Un appareillage electronique a ete realise pour mesurer le parametre de polarisation P{sub 0}(t) dans la reaction d'echange de charge {pi}{sup -}p {yields} {pi}{sup 0}n a 5,9 GeV/c et 11,2 GeV/c sur une cible de protons polarises. Ce dispositif assure le declenchement d'une chambre a etincelles a plaques lourdes, permettant de visualiser les {gamma} de desitegration du {pi}{sup 0}, lorsque le neutron associe presente les caracteristiques convenables en direction et en energie. Le neutron est detecte par un ensemble de 32 compteurs et son energie est mesuree par une methode de temps de vol. Les circuits composant cet appareillage sont decrits ainsi que les methodes d'etalonnage et de verification utilisees. (auteur)

  4. Bare-Hand Volume Cracker for Raw Volume Data Analysis

    Directory of Open Access Journals (Sweden)

    Bireswar Laha

    2016-09-01

    Full Text Available Analysis of raw volume data generated from different scanning technologies faces a variety of challenges, related to search, pattern recognition, spatial understanding, quantitative estimation, and shape description. In a previous study, we found that the Volume Cracker (VC 3D interaction (3DI technique mitigated some of these problems, but this result was from a tethered glove-based system with users analyzing simulated data. Here, we redesigned the VC by using untethered bare-hand interaction with real volume datasets, with a broader aim of adoption of this technique in research labs. We developed symmetric and asymmetric interfaces for the Bare-Hand Volume Cracker (BHVC through design iterations with a biomechanics scientist. We evaluated our asymmetric BHVC technique against standard 2D and widely used 3D interaction techniques with experts analyzing scanned beetle datasets. We found that our BHVC design significantly outperformed the other two techniques. This study contributes a practical 3DI design for scientists, documents lessons learned while redesigning for bare-hand trackers, and provides evidence suggesting that 3D interaction could improve volume data analysis for a variety of visual analysis tasks. Our contribution is in the realm of 3D user interfaces tightly integrated with visualization, for improving the effectiveness of visual analysis of volume datasets. Based on our experience, we also provide some insights into hardware-agnostic principles for design of effective interaction techniques.

  5. Volume Regulated Channels

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjær

    of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume...... but are also essential for a number of physiological processes such as proliferation, controlled cell death, migration and endocrinology. The thesis have been focusing on two Channels, namely the swelling activated Cl- channel (ICl, swell) and the transient receptor potential Vanilloid (TRPV4) channel. I: Cl......- serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...

  6. Volume-Dependent Overestimation of Spontaneous Intracerebral Hematoma Volume by the ABC/2 Formula

    International Nuclear Information System (INIS)

    Chih-Wei Wang; Chun-Jung Juan; Hsian-He Hsu; Hua-Shan Liu; Cheng-Yu Chen; Chun-Jen Hsueh; Hung-Wen Kao; Guo-Shu Huang; Yi-Jui Liu; Chung-Ping Lo

    2009-01-01

    Background: Although the ABC/2 formula has been widely used to estimate the volume of intracerebral hematoma (ICH), the formula tends to overestimate hematoma volume. The volume-related imprecision of the ABC/2 formula has not been documented quantitatively. Purpose: To investigate the volume-dependent overestimation of the ABC/2 formula by comparing it with computer-assisted volumetric analysis (CAVA). Material and Methods: Forty patients who had suffered spontaneous ICH and who had undergone non-enhanced brain computed tomography scans were enrolled in this study. The ICH volume was estimated based on the ABC/2 formula and also calculated by CAVA. Based on the ICH volume calculated by the CAVA method, the patients were divided into three groups: group 1 consisted of 17 patients with an ICH volume of less than 20 ml; group 2 comprised 13 patients with an ICH volume of 20 to 40 ml; and group 3 was composed of 10 patients with an ICH volume larger than 40 ml. Results: The mean estimated hematoma volume was 43.6 ml when using the ABC/2 formula, compared with 33.8 ml when using the CAVA method. The mean estimated difference was 1.3 ml, 4.4 ml, and 31.4 ml for groups 1, 2, and 3, respectively, corresponding to an estimation error of 9.9%, 16.7%, and 37.1% by the ABC/2 formula (P<0.05). Conclusion: The ABC/2 formula significantly overestimates the volume of ICH. A positive association between the estimation error and the volume of ICH is demonstrated

  7. Mobilisation du financement privé aux fins de l'adaptation | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le Private Financing Advisory Network (PFAN) de la Climate Technology Initiative (CTI) réalisera la recherche en collaboration avec la Frankfurt Business School et le réseau actuel du PFAN de la CTI dans les pays d'Afrique subsaharienne ciblés. Les équipes ... International Center for Environmental Technology Transfer.

  8. Do new anesthesia ventilators deliver small tidal volumes accurately during volume-controlled ventilation?

    Science.gov (United States)

    Bachiller, Patricia R; McDonough, Joseph M; Feldman, Jeffrey M

    2008-05-01

    During mechanical ventilation of infants and neonates, small changes in tidal volume may lead to hypo- or hyperventilation, barotrauma, or volutrauma. Partly because breathing circuit compliance and fresh gas flow affect tidal volume delivery by traditional anesthesia ventilators in volume-controlled ventilation (VCV) mode, pressure-controlled ventilation (PCV) using a circle breathing system has become a common approach to minimizing the risk of mechanical ventilation for small patients, although delivered tidal volume is not assured during PCV. A new generation of anesthesia machine ventilators addresses the problems of VCV by adjusting for fresh gas flow and for the compliance of the breathing circuit. In this study, we evaluated the accuracy of new anesthesia ventilators to deliver small tidal volumes. Four anesthesia ventilator systems were evaluated to determine the accuracy of volume delivery to the airway during VCV at tidal volume settings of 100, 200, and 500 mL under different conditions of breathing circuit compliance (fully extended and fully contracted circuits) and lung compliance. A mechanical test lung (adult and infant) was used to simulate lung compliances ranging from 0.0025 to 0.03 L/cm H(2)O. Volumes and pressures were measured using a calibrated screen pneumotachograph and custom software. We tested the Smartvent 7900, Avance, and Aisys anesthesia ventilator systems (GE Healthcare, Madison, WI) and the Apollo anesthesia ventilator (Draeger Medical, Telford, PA). The Smartvent 7900 and Avance ventilators use inspiratory flow sensors to control the volume delivered, whereas the Aisys and Apollo ventilators compensate for the compliance of the circuit. We found that the anesthesia ventilators that use compliance compensation (Aisys and Apollo) accurately delivered both large and small tidal volumes to the airway of the test lung under conditions of normal and low lung compliance during VCV (ranging from 95.5% to 106.2% of the set tidal volume

  9. Gastrointestinal Dose-Histogram Effects in the Context of Dose-Volume–Constrained Prostate Radiation Therapy: Analysis of Data From the RADAR Prostate Radiation Therapy Trial

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Martin A., E-mail: Martin.Ebert@health.wa.gov.au [Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Western Australia (Australia); School of Physics, University of Western Australia, Perth, Western Australia (Australia); Foo, Kerwyn [Sydney Medical School, University of Sydney, Sydney, New South Wales (Australia); Haworth, Annette [Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria (Australia); Gulliford, Sarah L. [Joint Department of Physics, Institute of Cancer Research and Royal Marsden National Health Service Foundation Trust, Sutton, Surrey (United Kingdom); Kennedy, Angel [Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Western Australia (Australia); Joseph, David J. [Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Western Australia (Australia); School of Surgery, University of Western Australia, Perth, Western Australia (Australia); Denham, James W. [School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales (Australia)

    2015-03-01

    Purpose: To use a high-quality multicenter trial dataset to determine dose-volume effects for gastrointestinal (GI) toxicity following radiation therapy for prostate carcinoma. Influential dose-volume histogram regions were to be determined as functions of dose, anatomical location, toxicity, and clinical endpoint. Methods and Materials: Planning datasets for 754 participants in the TROG 03.04 RADAR trial were available, with Late Effects of Normal Tissues (LENT) Subjective, Objective, Management, and Analytic (SOMA) toxicity assessment to a median of 72 months. A rank sum method was used to define dose-volume cut-points as near-continuous functions of dose to 3 GI anatomical regions, together with a comprehensive assessment of significance. Univariate and multivariate ordinal regression was used to assess the importance of cut-points at each dose. Results: Dose ranges providing significant cut-points tended to be consistent with those showing significant univariate regression odds-ratios (representing the probability of a unitary increase in toxicity grade per percent relative volume). Ranges of significant cut-points for rectal bleeding validated previously published results. Separation of the lower GI anatomy into complete anorectum, rectum, and anal canal showed the impact of mid-low doses to the anal canal on urgency and tenesmus, completeness of evacuation and stool frequency, and mid-high doses to the anorectum on bleeding and stool frequency. Derived multivariate models emphasized the importance of the high-dose region of the anorectum and rectum for rectal bleeding and mid- to low-dose regions for diarrhea and urgency and tenesmus, and low-to-mid doses to the anal canal for stool frequency, diarrhea, evacuation, and bleeding. Conclusions: Results confirm anatomical dependence of specific GI toxicities. They provide an atlas summarizing dose-histogram effects and derived constraints as functions of anatomical region, dose, toxicity, and endpoint for

  10. Gastrointestinal Dose-Histogram Effects in the Context of Dose-Volume–Constrained Prostate Radiation Therapy: Analysis of Data From the RADAR Prostate Radiation Therapy Trial

    International Nuclear Information System (INIS)

    Ebert, Martin A.; Foo, Kerwyn; Haworth, Annette; Gulliford, Sarah L.; Kennedy, Angel; Joseph, David J.; Denham, James W.

    2015-01-01

    Purpose: To use a high-quality multicenter trial dataset to determine dose-volume effects for gastrointestinal (GI) toxicity following radiation therapy for prostate carcinoma. Influential dose-volume histogram regions were to be determined as functions of dose, anatomical location, toxicity, and clinical endpoint. Methods and Materials: Planning datasets for 754 participants in the TROG 03.04 RADAR trial were available, with Late Effects of Normal Tissues (LENT) Subjective, Objective, Management, and Analytic (SOMA) toxicity assessment to a median of 72 months. A rank sum method was used to define dose-volume cut-points as near-continuous functions of dose to 3 GI anatomical regions, together with a comprehensive assessment of significance. Univariate and multivariate ordinal regression was used to assess the importance of cut-points at each dose. Results: Dose ranges providing significant cut-points tended to be consistent with those showing significant univariate regression odds-ratios (representing the probability of a unitary increase in toxicity grade per percent relative volume). Ranges of significant cut-points for rectal bleeding validated previously published results. Separation of the lower GI anatomy into complete anorectum, rectum, and anal canal showed the impact of mid-low doses to the anal canal on urgency and tenesmus, completeness of evacuation and stool frequency, and mid-high doses to the anorectum on bleeding and stool frequency. Derived multivariate models emphasized the importance of the high-dose region of the anorectum and rectum for rectal bleeding and mid- to low-dose regions for diarrhea and urgency and tenesmus, and low-to-mid doses to the anal canal for stool frequency, diarrhea, evacuation, and bleeding. Conclusions: Results confirm anatomical dependence of specific GI toxicities. They provide an atlas summarizing dose-histogram effects and derived constraints as functions of anatomical region, dose, toxicity, and endpoint for

  11. Role of the parameters involved in the plan optimization based on the generalized equivalent uniform dose and radiobiological implications

    International Nuclear Information System (INIS)

    Widesott, L; Strigari, L; Pressello, M C; Landoni, V; Benassi, M

    2008-01-01

    We investigated the role and the weight of the parameters involved in the intensity modulated radiation therapy (IMRT) optimization based on the generalized equivalent uniform dose (gEUD) method, for prostate and head-and-neck plans. We systematically varied the parameters (gEUD max and weight) involved in the gEUD-based optimization of rectal wall and parotid glands. We found that the proper value of weight factor, still guaranteeing planning treatment volumes coverage, produced similar organs at risks dose-volume (DV) histograms for different gEUD max with fixed a = 1. Most of all, we formulated a simple relation that links the reference gEUD max and the associated weight factor. As secondary objective, we evaluated plans obtained with the gEUD-based optimization and ones based on DV criteria, using the normal tissue complication probability (NTCP) models. gEUD criteria seemed to improve sparing of rectum and parotid glands with respect to DV-based optimization: the mean dose, the V 40 and V 50 values to the rectal wall were decreased of about 10%, the mean dose to parotids decreased of about 20-30%. But more than the OARs sparing, we underlined the halving of the OARs optimization time with the implementation of the gEUD-based cost function. Using NTCP models we enhanced differences between the two optimization criteria for parotid glands, but no for rectum wall

  12. A cost-effectiveness analysis of adjuvant therapies for resected adenocarcinoma of the rectum

    International Nuclear Information System (INIS)

    Lee, Jason H.

    1997-01-01

    PURPOSE: Several prospective randomized trials have shown a significant survival advantage with adjuvant chemotherapy and radiation therapy following surgical resection of adenocarcinoma of the rectum. Recent and ongoing trials are evaluating the role of modulated and/or protracted venous infusion [PVI] chemotherapy with pelvic irradiation [PRT]. The economic implications of additional therapies compared with their incremental benefits have not been rigorously analyzed. This study attempts to assess the incremental cost effectiveness of adjuvant therapy over surgery alone, and secondly, adjuvant therapy with PVI delivery systems versus rapid infusion. METHODS: A Markov model was constructed to describe the natural history of rectal carcinoma [stage B2, C] following surgical resection in a hypothetical cohort of 60 year old patients. This model was used to perform two sets of comparisons: [1] surgery alone versus adjuvant bolus fluorouracil [5-FU] with PRT, and [2] bolus 5-FU with PRT versus PVI 5-FU with PRT. Relapse rates and overall survival were derived from an early GITSG trial for the first comparison and from the NCCTG 86-47-51 trial for the second comparison. Medicare reimbursement rates and reports from health maintenance organizations were used to obtain net medical costs of adjuvant treatments, routine follow-up, advanced recurrent disease, and terminal illness as a result of rectal carcinoma. Total years of life and medical costs were projected over an 8-year time horizon for the first comparison [GITSG data] and over a 5-year time horizon for the second comparison [NCCTG data]. Monetary and nonmonetary benefits were discounted at 5% per year. Adjustments for quality of life, costs of adverse effects from treatment, and indirect costs of disease or treatment were not included in this current analysis. RESULTS: The main survival and economic outcomes for each treatment arm in the two comparisons are reported in the table below. For the first comparison

  13. Oncological strategies for locally advanced rectal cancer with synchronous liver metastases, interval strategy versus rectum first strategy: a comparison of short-term outcomes.

    Science.gov (United States)

    Salvador-Rosés, H; López-Ben, S; Casellas-Robert, M; Planellas, P; Gómez-Romeu, N; Farrés, R; Ramos, E; Codina-Cazador, A; Figueras, J

    2017-12-22

    The goal of treatment for patients with synchronous liver metastases (SLM) from rectal cancer is to achieve a complete resection of both tumor locations. For patients with symptomatic locally advanced rectal cancer with resectable SLM at diagnosis, our usual strategy has been the rectum first approach (RF). However, since 2014, we advocate for the interval approach (IS) that involves the administration of chemo-radiotherapy followed by the resection of the SLM in the interval of time between rectal cancer radiation and rectal surgery. From 2010 to 2016, 16 patients were treated according to this new strategy and 19 were treated according RF strategy. Data were collected prospectively and analyzed with an intention-to-treat perspective. Complete resection rate, duration of the treatment and morbi-mortality were the main outcomes. The complete resection rate in the IS was higher (100%, n = 16) compared to the RF (74%, n = 14, p = 0.049) and the duration of the strategy was shorter (6 vs. 9 months, respectively, p = 0.006). The incidence of severe complications after liver surgery was 14% (n = 2) in the RF and 0% in the IS (p = 1.000), and after rectal surgery was 24% (n = 4) and 12% (n = 2), respectively (p = 1.000). The IS is a feasible and safe strategy that procures higher level of complete resection rate in a shorter period of time compared to RF strategy.

  14. Reachable volume RRT

    KAUST Repository

    McMahon, Troy

    2015-05-01

    © 2015 IEEE. Reachable volumes are a new technique that allows one to efficiently restrict sampling to feasible/reachable regions of the planning space even for high degree of freedom and highly constrained problems. However, they have so far only been applied to graph-based sampling-based planners. In this paper we develop the methodology to apply reachable volumes to tree-based planners such as Rapidly-Exploring Random Trees (RRTs). In particular, we propose a reachable volume RRT called RVRRT that can solve high degree of freedom problems and problems with constraints. To do so, we develop a reachable volume stepping function, a reachable volume expand function, and a distance metric based on these operations. We also present a reachable volume local planner to ensure that local paths satisfy constraints for methods such as PRMs. We show experimentally that RVRRTs can solve constrained problems with as many as 64 degrees of freedom and unconstrained problems with as many as 134 degrees of freedom. RVRRTs can solve problems more efficiently than existing methods, requiring fewer nodes and collision detection calls. We also show that it is capable of solving difficult problems that existing methods cannot.

  15. Reachable volume RRT

    KAUST Repository

    McMahon, Troy; Thomas, Shawna; Amato, Nancy M.

    2015-01-01

    © 2015 IEEE. Reachable volumes are a new technique that allows one to efficiently restrict sampling to feasible/reachable regions of the planning space even for high degree of freedom and highly constrained problems. However, they have so far only been applied to graph-based sampling-based planners. In this paper we develop the methodology to apply reachable volumes to tree-based planners such as Rapidly-Exploring Random Trees (RRTs). In particular, we propose a reachable volume RRT called RVRRT that can solve high degree of freedom problems and problems with constraints. To do so, we develop a reachable volume stepping function, a reachable volume expand function, and a distance metric based on these operations. We also present a reachable volume local planner to ensure that local paths satisfy constraints for methods such as PRMs. We show experimentally that RVRRTs can solve constrained problems with as many as 64 degrees of freedom and unconstrained problems with as many as 134 degrees of freedom. RVRRTs can solve problems more efficiently than existing methods, requiring fewer nodes and collision detection calls. We also show that it is capable of solving difficult problems that existing methods cannot.

  16. Frequently Asked Questions - GHRI Calls

    International Development Research Centre (IDRC) Digital Library (Canada)

    Genevieve Prud'homme

    16 mai 2014 ... ... des pays d'Afrique subsaharienne ciblés par le Plan d'action pour accroître ... Les définitions utilisées pour ces rôles sont celles des Instituts de ..... Une personne ayant rang de directeur au sein du ministère de la Santé ...

  17. MRI volume measurement of basal ganglia volumes in patients with Tourette's syndrome

    International Nuclear Information System (INIS)

    Lu Jie; Li Kuncheng; Cao Yanxiang; Zhang Miao; Sui Xin; Zhang Xiaohua

    2009-01-01

    Objective: To evaluate MRI measurement of basal ganglia volumes in patients with Tourette's syndrome. Methods: Ten patients with Tourette's syndrome (TS) and 10 healthy volunteers were studied. Volumes of bilateral caudate, putamen and pallidum were measured, and the results were analyzed using paired t test. The basal ganglia volume was normalized according to individual brain volume. The basal ganglia volumes of TS patients were compared with normal control group using independent-sample t test. Results: In 10 healthy volunteers, volumes of the left caudate, putamen, pallidum were significantly larger compared with those of the right side (P 0.05) in TS patients. After normalized processing, the volumes of the left caudate (7.06 ± 0.48) cm 3 , putamen (8.81±1.01) cm 3 , pallidum (2.64± 0.38) cm 3 were smaller than those of control group [caudate (11.05±1.86) cm 3 , putamen (9.97± 1.11) cm 3 , pallidum (3.04±0.37) cm 3 ] (t=-6.577, -2.457, -2.376, P 3 in TS patients was significantly smaller compared with the control group (9.81±1.83) cm 3 (t=-4.258, P 0.05). Conclusion: The basal ganglia volumes were significantly decreased in patients with TS. MRI volumetric measurement was an important tool for evaluating pathologic changes of TS. (authors)

  18. Volume regulation in epithelia

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Hoffmann, Else Kay

    2016-01-01

    to amphibian skin and mammalian cortical collecting tubule of low and intermediate osmotic permeability. Crosstalk between entrance and exit mechanisms interferes with volume regulation both at aniso-osmotic and iso-osmotic volume perturbations. It has been proposed that cell volume regulation is an intrinsic...... regulation are cloned. The volume-regulated anion channel (VRAC) exhibiting specific electrophysiological characteristics seems exclusive to serve cell volume regulation. This is contrary to K+ channels as well as cotransporters and exchange mechanisms that may serve both transepithelial transport and cell...... volume regulation. In the same cell, these functions may be maintained by different ion pathways that are separately regulated. RVD is often preceded by increase in cytosolic free Ca2+, probably via influx through TRP channels, but Ca2+ release from intracellular stores has also been observed. Cell...

  19. Feasibility of CBCT-based target and normal structure delineation in prostate cancer radiotherapy: Multi-observer and image multi-modality study

    International Nuclear Information System (INIS)

    Luetgendorf-Caucig, Carola; Fotina, Irina; Stock, Markus; Poetter, Richard; Goldner, Gregor; Georg, Dietmar

    2011-01-01

    Background and purpose: In-room cone-beam CT (CBCT) imaging and adaptive treatment strategies are promising methods to decrease target volumes and to spare organs at risk. The aim of this work was to analyze the inter-observer contouring uncertainties of target volumes and organs at risks (oars) in localized prostate cancer radiotherapy using CBCT images. Furthermore, CBCT contouring was benchmarked against other image modalities (CT, MR) and the influence of subjective image quality perception on inter-observer variability was assessed. Methods and materials: Eight prostate cancer patients were selected. Seven radiation oncologists contoured target volumes and oars on CT, MRI and CBCT. Volumes, coefficient of variation (COV), conformity index (cigen), and coordinates of center-of-mass (COM) were calculated for each patient and image modality. Reliability analysis was performed for the support of the reported findings. Subjective perception of image quality was assessed via a ten-scored visual analog scale (VAS). Results: The median volume for prostate was larger on CT compared to MRI and CBCT images. The inter-observer variation for prostate was larger on CBCT (CIgen = 0.57 ± 0.09, 0.61 reliability) compared to CT (CIgen = 0.72 ± 0.07, 0.83 reliability) and MRI (CIgen = 0.66 ± 0.12, 0.87 reliability). On all image modalities values of the intra-observer reliability coefficient (0.97 for CT, 0.99 for MR and 0.94 for CBCT) indicated high reproducibility of results. For all patients the root mean square (RMS) of the inter-observer standard deviation (σ) of the COM was largest on CBCT with σ(x) = 0.4 mm, σ(y) = 1.1 mm, and σ(z) = 1.7 mm. The concordance in delineating OARs was much stronger than for target volumes, with average CIgen > 0.70 for rectum and CIgen > 0.80 for bladder. Positive correlations between CIgen and VAS score of the image quality were observed for the prostate, seminal vesicles and rectum. Conclusions: Inter-observer variability for target

  20. Three-dimensional reconstruction volume: a novel method for volume measurement in kidney cancer.

    Science.gov (United States)

    Durso, Timothy A; Carnell, Jonathan; Turk, Thomas T; Gupta, Gopal N

    2014-06-01

    The role of volumetric estimation is becoming increasingly important in the staging, management, and prognostication of benign and cancerous conditions of the kidney. We evaluated the use of three-dimensional reconstruction volume (3DV) in determining renal parenchymal volumes (RPV) and renal tumor volumes (RTV). We compared 3DV with the currently available methods of volume assessment and determined its interuser reliability. RPV and RTV were assessed in 28 patients who underwent robot-assisted laparoscopic partial nephrectomy for kidney cancer. Patients with a preoperative creatinine level of kidney pre- and postsurgery overestimated 3D reconstruction volumes by 15% to 102% and 12% to 101%, respectively. In addition, volumes obtained from 3DV displayed high interuser reliability regardless of experience. 3DV provides a highly reliable way of assessing kidney volumes. Given that 3DV takes into account visible anatomy, the differences observed using previously published methods can be attributed to the failure of geometry to accurately approximate kidney or tumor shape. 3DV provides a more accurate, reproducible, and clinically useful tool for urologists looking to improve patient care using analysis related to volume.

  1. Prostate Hypofractionated Radiation Therapy: Injection of Hyaluronic Acid to Better Preserve The Rectal Wall

    International Nuclear Information System (INIS)

    Chapet, Olivier; Udrescu, Corina; Devonec, Marian; Tanguy, Ronan; Sotton, Marie-Pierre; Enachescu, Ciprian; Colombel, Marc; Azria, David; Jalade, Patrice; Ruffion, Alain

    2013-01-01

    Purpose: The aim of this study was to evaluate the contribution of an injection of hyaluronic acid (HA) between the rectum and the prostate for reducing the dose to the rectal wall in a hypofractionated irradiation for prostate cancer. Methods and Materials: In a phase 2 study, 10 cc of HA was injected between the rectum and prostate. For 16 patients, the same intensity modulated radiation therapy plan (62 Gy in 20 fractions) was optimized on 2 computed tomography scans: CT1 (before injection) and CT2 (after injection). Rectal parameters were compared: dose to 2.5 cc (D2.5), 5 cc (D5), 10 cc (D10), 15 cc (D15), and 20 cc (D20) of rectal wall and volume of rectum covered by the 90% isodose line (V90), 80% (V80), 70% (V70), 60% (V60), and 50% (V50). Results: The mean V90, V80, V70, V60, and V50 values were reduced by 73.8% (P<.0001), 55.7% (P=.0003), 43.0% (P=.007), 34% (P=.002), and 25% (P=.036), respectively. The average values of D2.5, D5, D10, D15, and D20 were reduced by 8.5 Gy (P<.0001), 12.3 Gy (P<.0001), 8.4 Gy (P=.005), 3.7 Gy (P=.026), and 1.2 Gy (P=.25), respectively. Conclusions: The injection of HA significantly limited radiation doses to the rectal wall

  2. Prostate Hypofractionated Radiation Therapy: Injection of Hyaluronic Acid to Better Preserve The Rectal Wall

    Energy Technology Data Exchange (ETDEWEB)

    Chapet, Olivier, E-mail: olivier.chapet@chu-lyon.fr [Department of Radiation Oncology, Centre Hospitalier Lyon Sud, Pierre Benite (France); Udrescu, Corina [Department of Radiation Oncology, Centre Hospitalier Lyon Sud, Pierre Benite (France); Department of Medical Physics, Centre Hospitalier Lyon Sud, Pierre Benite (France); Devonec, Marian [Department of Urology, Centre Hospitalier Lyon Sud, Pierre Benite (France); Tanguy, Ronan [Department of Radiation Oncology, Centre Hospitalier Lyon Sud, Pierre Benite (France); Sotton, Marie-Pierre [Department of Medical Physics, Centre Hospitalier Lyon Sud, Pierre Benite (France); Enachescu, Ciprian [Department of Radiation Oncology, Centre Hospitalier Lyon Sud, Pierre Benite (France); Colombel, Marc [Department of Urology, Hopital Edouard Herriot, Lyon (France); Azria, David [Department of Radiation Oncology, Centre Val d' Aurelle, Montpellier (France); Jalade, Patrice [Department of Medical Physics, Centre Hospitalier Lyon Sud, Pierre Benite (France); Ruffion, Alain [Department of Urology, Centre Hospitalier Lyon Sud, Pierre Benite (France)

    2013-05-01

    Purpose: The aim of this study was to evaluate the contribution of an injection of hyaluronic acid (HA) between the rectum and the prostate for reducing the dose to the rectal wall in a hypofractionated irradiation for prostate cancer. Methods and Materials: In a phase 2 study, 10 cc of HA was injected between the rectum and prostate. For 16 patients, the same intensity modulated radiation therapy plan (62 Gy in 20 fractions) was optimized on 2 computed tomography scans: CT1 (before injection) and CT2 (after injection). Rectal parameters were compared: dose to 2.5 cc (D2.5), 5 cc (D5), 10 cc (D10), 15 cc (D15), and 20 cc (D20) of rectal wall and volume of rectum covered by the 90% isodose line (V90), 80% (V80), 70% (V70), 60% (V60), and 50% (V50). Results: The mean V90, V80, V70, V60, and V50 values were reduced by 73.8% (P<.0001), 55.7% (P=.0003), 43.0% (P=.007), 34% (P=.002), and 25% (P=.036), respectively. The average values of D2.5, D5, D10, D15, and D20 were reduced by 8.5 Gy (P<.0001), 12.3 Gy (P<.0001), 8.4 Gy (P=.005), 3.7 Gy (P=.026), and 1.2 Gy (P=.25), respectively. Conclusions: The injection of HA significantly limited radiation doses to the rectal wall.

  3. Modelling the variation in rectal dose due to inter-fraction rectal wall deformation in external beam prostate treatments

    International Nuclear Information System (INIS)

    Booth, Jeremy; Zavgorodni, Sergei

    2005-01-01

    Prostate radiotherapy inevitably deposits radiation dose in the rectal wall, and the dose delivered to prostate is limited by the expected rectal complications. Accurate evaluation of the rectal dose is non-trivial due to a number of factors. One of these is variation of the shape and position of the rectal wall (with respect to the clinical target volume (CTV)), which may differ daily from that taken during planning CT acquisition. This study uses data currently available in the literature on rectal wall motion to provide estimates of mean population rectal wall dose. The rectal wall geometry is characterized by a population mean radius of the rectum as well as inter-patient and inter-fraction standard deviations in rectum radius. The model is used to evaluate the range of inter-fraction and inter-patient rectal dose variations. The simulation of individual patients with full and empty rectum in the planning CT scan showed that large variations in rectal dose (>15 Gy) are possible. Mean calculated dose accounting for treatment and planning uncertainties in the rectal wall surface was calculated as well as the map of planning dose over/underpredictions. It was found that accuracy of planning dose is dependent on the CTV-PTV margin size with larger margins producing more accurate estimates. Over a patient population, the variation in rectal dose is reduced by increasing the number of pre-treatment CT scans

  4. Assessment of accuracy and efficiency of atlas-based autosegmentation for prostate radiotherapy in a variety of clinical conditions.

    Science.gov (United States)

    Simmat, I; Georg, P; Georg, D; Birkfellner, W; Goldner, G; Stock, M

    2012-09-01

    The goal of the current study was to evaluate the commercially available atlas-based autosegmentation software for clinical use in prostate radiotherapy. The accuracy was benchmarked against interobserver variability. A total of 20 planning computed tomographs (CTs) and 10 cone-beam CTs (CBCTs) were selected for prostate, rectum, and bladder delineation. The images varied regarding to individual (age, body mass index) and setup parameters (contrast agent, rectal balloon, implanted markers). Automatically created contours with ABAS(®) and iPlan(®) were compared to an expert's delineation by calculating the Dice similarity coefficient (DSC) and conformity index. Demo-atlases of both systems showed different results for bladder (DSC(ABAS) 0.86 ± 0.17, DSC(iPlan) 0.51 ± 0.30) and prostate (DSC(ABAS) 0.71 ± 0.14, DSC(iPlan) 0.57 ± 0.19). Rectum delineation (DSC(ABAS) 0.78 ± 0.11, DSC(iPlan) 0.84 ± 0.08) demonstrated differences between the systems but better correlation of the automatically drawn volumes. ABAS(®) was closest to the interobserver benchmark. Autosegmentation with iPlan(®), ABAS(®) and manual segmentation took 0.5, 4 and 15-20 min, respectively. Automatic contouring on CBCT showed high dependence on image quality (DSC bladder 0.54, rectum 0.42, prostate 0.34). For clinical routine, efforts are still necessary to either redesign algorithms implemented in autosegmentation or to optimize image quality for CBCT to guarantee required accuracy and time savings for adaptive radiotherapy.

  5. Dynamic contrast-enhanced MR imaging of the rectum: Correlations between single-section and whole-tumor histogram analyses.

    Science.gov (United States)

    Choi, M H; Oh, S N; Park, G E; Yeo, D-M; Jung, S E

    2018-05-10

    To evaluate the interobserver and intermethod correlations of histogram metrics of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters acquired by multiple readers using the single-section and whole-tumor volume methods. Four DCE parameters (K trans , K ep , V e , V p ) were evaluated in 45 patients (31 men and 14 women; mean age, 61±11 years [range, 29-83 years]) with locally advanced rectal cancer using pre-chemoradiotherapy (CRT) MRI. Ten histogram metrics were extracted using two methods of lesion selection performed by three radiologists: the whole-tumor volume method for the whole tumor on axial section-by-section images and the single-section method for the entire area of the tumor on one axial image. The interobserver and intermethod correlations were evaluated using the intraclass correlation coefficients (ICCs). The ICCs showed excellent interobserver and intermethod correlations in most of histogram metrics of the DCE parameters. The ICCs among the three readers were > 0.7 (Phistogram metrics, except for the minimum and maximum. The intermethod correlations for most of the histogram metrics were excellent for each radiologist, regardless of the differences in the radiologists' experience. The interobserver and intermethod correlations for most of the histogram metrics of the DCE parameters are excellent in rectal cancer. Therefore, the single-section method may be a potential alternative to the whole-tumor volume method using pre-CRT MRI, despite the fact that the high agreement between the two methods cannot be extrapolated to post-CRT MRI. Copyright © 2018 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  6. Molecular representation of molar domain (volume), evolution equations, and linear constitutive relations for volume transport.

    Science.gov (United States)

    Eu, Byung Chan

    2008-09-07

    In the traditional theories of irreversible thermodynamics and fluid mechanics, the specific volume and molar volume have been interchangeably used for pure fluids, but in this work we show that they should be distinguished from each other and given distinctive statistical mechanical representations. In this paper, we present a general formula for the statistical mechanical representation of molecular domain (volume or space) by using the Voronoi volume and its mean value that may be regarded as molar domain (volume) and also the statistical mechanical representation of volume flux. By using their statistical mechanical formulas, the evolution equations of volume transport are derived from the generalized Boltzmann equation of fluids. Approximate solutions of the evolution equations of volume transport provides kinetic theory formulas for the molecular domain, the constitutive equations for molar domain (volume) and volume flux, and the dissipation of energy associated with volume transport. Together with the constitutive equation for the mean velocity of the fluid obtained in a previous paper, the evolution equations for volume transport not only shed a fresh light on, and insight into, irreversible phenomena in fluids but also can be applied to study fluid flow problems in a manner hitherto unavailable in fluid dynamics and irreversible thermodynamics. Their roles in the generalized hydrodynamics will be considered in the sequel.

  7. Limiting volume with modern ventilators.

    Science.gov (United States)

    Wing, Thomas J; Haan, Lutana; Ashworth, Lonny J; Anderson, Jeff

    2015-06-01

    The acute respiratory distress syndrome (ARDS) network low tidal-volume study comparing tidal volumes of 12 ml/kg versus 6 ml/kg was published in 2000. The study was stopped early as data revealed a 22% relative reduction in mortality rate when using 6 ml/kg tidal volume. The current generation of critical care ventilators allows the tidal volume to be set during volume-targeted, assist/control (volume A/C); however, some ventilators include options that may prevent the tidal volume from being controlled. The purpose of this bench study was to evaluate the delivered tidal volume, when these options are active, in a spontaneously breathing lung model using an electronic breathing simulator. Four ventilators were evaluated: CareFusion AVEA (AVEA), Dräger Evita® XL (Evita XL), Covidien Puritan Bennett® 840(TM) (PB 840), and Maquet SERVO-i (SERVO-i). Each ventilator was connected to the Hans Rudolph Electronic Breathing Simulator at an amplitude of 0 cm H2O and then 10 cm H2O. All four ventilators were set to deliver volume A/C, tidal volume 400 ml, respiratory rate 20 bpm, positive end-expiratory pressure 5 cm H2O, peak flowrate 60 L/min. The displayed tidal volume was recorded for each ventilator at the above settings with additional options OFF and then ON. The AVEA has two options in volume A/C: demand breaths and V-sync. When activated, these options allow the patient to exceed the set tidal volume. When using the Evita XL, the option AutoFlow can be turned ON or OFF, and when this option is ON, the tidal volume may vary. The PB 840 does not have any additional options that affect volume delivery, and it maintains the set tidal volume regardless of patient effort. The SERVO-i's demand valve allows additional flow if the patient's inspiratory flowrate exceeds the set flowrate, increasing the delivered tidal volume; this option can be turned OFF with the latest software upgrade. Modern ventilators have an increasing number of optional settings. These settings may

  8. Dosimetric comparison of single-beam multi-arc and 2-beam multi-arc VMAT optimization in the Monaco treatment planning system

    Energy Technology Data Exchange (ETDEWEB)

    Kalet, Alan M., E-mail: amkalet@uw.edu [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Seattle Cancer Care Alliance, Seattle, Washington (United States); Richardson, Hannah L.; Nikolaisen, Darrin A. [Seattle Cancer Care Alliance, Seattle, Washington (United States); Cao, Ning [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Seattle Cancer Care Alliance, Seattle, Washington (United States); Lavilla, Myra A. [Seattle Cancer Care Alliance, Seattle, Washington (United States); Dempsey, Claire; Meyer, Juergen; Koh, Wui-Jin; Russell, Kenneth J. [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Seattle Cancer Care Alliance, Seattle, Washington (United States)

    2017-07-01

    The purpose of this study was to evaluate the dosimetric and practical effects of the Monaco treatment planning system “max arcs-per-beam” optimization parameter in pelvic radiotherapy treatments. We selected for this study a total of 17 previously treated patients with a range of pelvic disease sites including prostate (9), bladder (1), uterus (3), rectum (3), and cervix (1). For each patient, 2 plans were generated, one using an arc-per-beam setting of “1” and another with an arc-per-beam setting of “2” using the volumes and constraints established from the initial clinical treatments. All constraints and dose coverage objects were kept the same between plans, and all plans were normalized to 99.7% to ensure 100% of the planning target volume (PTV) received 95% of the prescription dose. Plans were evaluated for PTV conformity, homogeneity, number of monitor units, number of control points, and overall plan acceptability. Treatment delivery time, patient-specific quality assurance procedures, and the impact on clinical workflow were also assessed. We found that for complex-shaped target volumes (small central volumes with extending arms to cover nodal regions), the use of 2 arc-per-beam (2APB) parameter setting achieved significantly lower average dose-volume histogram values for the rectum V{sub 20} (p = 0.0012) and bladder V{sub 30} (p = 0.0036) while meeting the high dose target constraints. For simple PTV shapes, we found reduced monitor units (13.47%, p = 0.0009) and control points (8.77%, p = 0.0004) using 2APB planning. In addition, we found a beam delivery time reduction of approximately 25%. In summary, the dosimetric benefit, although moderate, was improved over a 1APB setting for complex PTV, and equivalent in other cases. The overall reduced delivery time suggests that the use of mulitple arcs per beam could lead to reduced patient-on-table time, increased clinical throughput, and reduced medical physics quality assurance

  9. SU-G-JeP3-05: Geometry Based Transperineal Ultrasound Probe Positioning for Image Guided Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Camps, S; With, P de [University of Technology Eindhoven, Eindhoven (Netherlands); Verhaegen, F [Maastro Clinic, Maastricht (Netherlands); Fontanarosa, D [Philips Research, Eindhoven (Netherlands)

    2016-06-15

    Purpose: The use of ultrasound (US) imaging in radiotherapy is not widespread, primarily due to the need for skilled operators performing the scans. Automation of probe positioning has the potential to remove this need and minimize operator dependence. We introduce an algorithm for obtaining a US probe position that allows good anatomical structure visualization based on clinical requirements. The first application is on 4D transperineal US images of prostate cancer patients. Methods: The algorithm calculates the probe position and orientation using anatomical information provided by a reference CT scan, always available in radiotherapy workflows. As initial test, we apply the algorithm on a CIRS pelvic US phantom to obtain a set of possible probe positions. Subsequently, five of these positions are randomly chosen and used to acquire actual US volumes of the phantom. Visual inspection of these volumes reveal if the whole prostate, and adjacent edges of bladder and rectum are fully visualized, as clinically required. In addition, structure positions on the acquired US volumes are compared to predictions of the algorithm. Results: All acquired volumes fulfill the clinical requirements as specified in the previous section. Preliminary quantitative evaluation was performed on thirty consecutive slices of two volumes, on which the structures are easily recognizable. The mean absolute distances (MAD) between actual anatomical structure positions and positions predicted by the algorithm were calculated. This resulted in MAD of 2.4±0.4 mm for prostate, 3.2±0.9 mm for bladder and 3.3±1.3 mm for rectum. Conclusion: Visual inspection and quantitative evaluation show that the algorithm is able to propose probe positions that fulfill all clinical requirements. The obtained MAD is on average 2.9 mm. However, during evaluation we assumed no errors in structure segmentation and probe positioning. In future steps, accurate estimation of these errors will allow for better

  10. Comparison of Automated Atlas Based Segmentation Software for postoperative prostate cancer radiotherapy

    Directory of Open Access Journals (Sweden)

    Grégory Delpon

    2016-08-01

    Full Text Available Automated atlas-based segmentation algorithms present the potential to reduce the variability in volume delineation. Several vendors offer software that are mainly used for cranial, head and neck and prostate cases. The present study will compare the contours produced by a radiation oncologist to the contours computed by different automated atlas-based segmentation algorithms for prostate bed cases, including femoral heads, bladder and rectum. Contour comparison was evaluated by different metrics such as volume ratio, Dice coefficient and Hausdorff distance. Results depended on the volume of interest and showed some discrepancies between the different software. Automatic contours could be a good starting point for the delineation of organs since efficient editing tools are provided by different vendors. It should become an important help in the next few years for organ at risk delineation.

  11. Growth of lead molybdate crystals by vertical Bridgman method

    Indian Academy of Sciences (India)

    Unknown

    The seeds were put in the seed wells, then the feed materials were filled in the cylinder of crucibles. The assembled crucible was sealed in order to prevent the volatilization of the melt during crystal growth. The cru- cible was installed in a refractory tube filled with Al2O3 powder to isolate it from external temperature fluctua-.

  12. Données probantes empiriques et promotion du leadership en ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Données probantes empiriques et promotion du leadership en appui aux programmes de mise à niveau. Ce projet appuiera le passage à grande échelle d'interventions mises à l'essai localement visant à améliorer les moyens de subsistance des femmes et des jeunes en Afrique subsaharienne et en Asie. Il cible des ...

  13. INTERNET5 : Favoriser l'autonomisation des femmes au moyen d ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    8 déc. 2017 ... Photo : Visual News Associates / World Bank. Dans de bonnes conditions, les technologies numériques peuvent favoriser l'atteinte des cibles prévues dans les objectifs de développement durable (ODD) d'ici 2030 en stimulant la croissance économique, et en permettant d'améliorer la gouvernance et ...

  14. Implementation of Family Life and HIV/AIDS Education in Nigerian ...

    African Journals Online (AJOL)

    Keywords: FLHE implementation, reproductive health, young people, youth corpers, sexual attitude. Résumé. Cette étude a utilisé des données provenant des groupes de discussion à cible et des entrevues en profondeur entre élèves et enseignants des écoles secondaires afin d'examiner la portée, l'actualisation et la ...

  15. Renforcement des capacités en vue de l'édification d'une société ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    L'Association pour le progrès des communications (APC) est en train de réorienter sa position en matière de recherche sur les politiques relatives aux technologies de l'information et de la communication (TIC). Elle a ciblé quatre domaines thématiques dans lesquels elle souhaite approfondir la recherche, et voudrait ...

  16. DRDC Starfish Acoustic Sentinel and Phase Gradient Histogram Tracking

    Science.gov (United States)

    2015-04-01

    filtres exponentiels parallèles ; dans le domaine fréquentiel, l’algorithme utilise des filtres parallèles dans chaque cellule de fréquences. Un... cellule de fréquences. Une procé- dure de poursuite par histogramme sert à déterminer et à afficher les angles de route des cibles acoustiques à large

  17. Intrafraction Prostate Translations and Rotations During Hypofractionated Robotic Radiation Surgery: Dosimetric Impact of Correction Strategies and Margins

    Energy Technology Data Exchange (ETDEWEB)

    Water, Steven van de, E-mail: s.vandewater@erasmusmc.nl [Erasmus MC Cancer Institute, Department of Radiation Oncology, Rotterdam (Netherlands); Valli, Lorella [Erasmus MC Cancer Institute, Department of Radiation Oncology, Rotterdam (Netherlands); Alma Mater Studiorum, Department of Physics and Astronomy, Bologna University, Bologna (Italy); Aluwini, Shafak [Erasmus MC Cancer Institute, Department of Radiation Oncology, Rotterdam (Netherlands); Lanconelli, Nico [Alma Mater Studiorum, Department of Physics and Astronomy, Bologna University, Bologna (Italy); Heijmen, Ben; Hoogeman, Mischa [Erasmus MC Cancer Institute, Department of Radiation Oncology, Rotterdam (Netherlands)

    2014-04-01

    Purpose: To investigate the dosimetric impact of intrafraction prostate motion and the effect of robot correction strategies for hypofractionated CyberKnife treatments with a simultaneously integrated boost. Methods and Materials: A total of 548 real-time prostate motion tracks from 17 patients were available for dosimetric simulations of CyberKnife treatments, in which various correction strategies were included. Fixed time intervals between imaging/correction (15, 60, 180, and 360 seconds) were simulated, as well as adaptive timing (ie, the time interval reduced from 60 to 15 seconds in case prostate motion exceeded 3 mm or 2° in consecutive images). The simulated extent of robot corrections was also varied: no corrections, translational corrections only, and translational corrections combined with rotational corrections up to 5°, 10°, and perfect rotational correction. The correction strategies were evaluated for treatment plans with a 0-mm or 3-mm margin around the clinical target volume (CTV). We recorded CTV coverage (V{sub 100%}) and dose-volume parameters of the peripheral zone (boost), rectum, bladder, and urethra. Results: Planned dose parameters were increasingly preserved with larger extents of robot corrections. A time interval between corrections of 60 to 180 seconds provided optimal preservation of CTV coverage. To achieve 98% CTV coverage in 98% of the treatments, translational and rotational corrections up to 10° were required for the 0-mm margin plans, whereas translational and rotational corrections up to 5° were required for the 3-mm margin plans. Rectum and bladder were spared considerably better in the 0-mm margin plans. Adaptive timing did not improve delivered dose. Conclusions: Intrafraction prostate motion substantially affected the delivered dose but was compensated for effectively by robot corrections using a time interval of 60 to 180 seconds. A 0-mm margin required larger extents of additional rotational corrections than a 3

  18. Intrafraction Prostate Translations and Rotations During Hypofractionated Robotic Radiation Surgery: Dosimetric Impact of Correction Strategies and Margins

    International Nuclear Information System (INIS)

    Water, Steven van de; Valli, Lorella; Aluwini, Shafak; Lanconelli, Nico; Heijmen, Ben; Hoogeman, Mischa

    2014-01-01

    Purpose: To investigate the dosimetric impact of intrafraction prostate motion and the effect of robot correction strategies for hypofractionated CyberKnife treatments with a simultaneously integrated boost. Methods and Materials: A total of 548 real-time prostate motion tracks from 17 patients were available for dosimetric simulations of CyberKnife treatments, in which various correction strategies were included. Fixed time intervals between imaging/correction (15, 60, 180, and 360 seconds) were simulated, as well as adaptive timing (ie, the time interval reduced from 60 to 15 seconds in case prostate motion exceeded 3 mm or 2° in consecutive images). The simulated extent of robot corrections was also varied: no corrections, translational corrections only, and translational corrections combined with rotational corrections up to 5°, 10°, and perfect rotational correction. The correction strategies were evaluated for treatment plans with a 0-mm or 3-mm margin around the clinical target volume (CTV). We recorded CTV coverage (V 100% ) and dose-volume parameters of the peripheral zone (boost), rectum, bladder, and urethra. Results: Planned dose parameters were increasingly preserved with larger extents of robot corrections. A time interval between corrections of 60 to 180 seconds provided optimal preservation of CTV coverage. To achieve 98% CTV coverage in 98% of the treatments, translational and rotational corrections up to 10° were required for the 0-mm margin plans, whereas translational and rotational corrections up to 5° were required for the 3-mm margin plans. Rectum and bladder were spared considerably better in the 0-mm margin plans. Adaptive timing did not improve delivered dose. Conclusions: Intrafraction prostate motion substantially affected the delivered dose but was compensated for effectively by robot corrections using a time interval of 60 to 180 seconds. A 0-mm margin required larger extents of additional rotational corrections than a 3-mm

  19. Violence interpersonnelle au travail : typologie des acteurs, agresseurs et cibles Interpersonal Violence in the Workplace: Typology of the Actors - Aggressors and Targets Violencia interpersonal en el trabajo : tipología de los actores, agresores y víctimas

    Directory of Open Access Journals (Sweden)

    Michel Vézina

    2011-11-01

    Full Text Available Le phénomène de violence interpersonnelle au travail a été largement étudié au cours des dix dernières années, mais rares sont les auteurs qui l’ont abordé dans une optique compréhensive, en prenant appui sur le témoignage des travailleurs. Le sens que revêt la violence pour les travailleurs demeure, lui, très peu exploré. Les auteurs présentent les résultats d’une étude compréhensive qui a permis de dégager une typologie des agresseurs et des cibles de la violence interpersonnelle et d’ouvrir la voie au développement d’un modèle compréhensif plus large ainsi qu’à une réflexion sur les interventions à développer pour agir sur ce phénomène.Interpersonal violence in the workplace is a phenomenon that has been widely studied over the last ten years. However, very few authors have examined it from a comprehensive perspective (based on the accounts of workers. Violence in terms of what it means for workers has hardly been explored. The authors present the results of a comprehensive study that has identified a typology of both the aggressors and the targets of interpersonal violence, and that has led to the development of a broader comprehensive model and the consideration of interventions that could be developed to deal with this phenomenon.El fenómeno de violencia interpersonal en el trabajo fue ampliamente estudiado en el curso de los últimos diez años, pero son raros los autores que lo abordaron dentro de una óptica comprensiva, apoyándose en el testimonio de los trabajadores. El sentido que reviste esta violencia para los trabajadores queda muy poco explorado. Los autores presentan los resultados de un estudio comprensivo que ha permitido extraer una tipología de los agresores y de las víctimas de la violencia interpersonal y abrir la vía al desarrollo de un modelo comprensivo más amplio, así como una reflexión sobre las intervenciones a desarrollar para actuar sobre este fenómeno.

  20. Surgery for Pelvic Organ Prolapse

    Science.gov (United States)

    ... Rectum Close-up of posterior vaginal wall The posterior wall of the vagina is strengthened with stitches so that it once again supports the rectum. Sacrohysteropexy Mesh Rectum Bladder Urethra Vagina Surgical mesh is attached to the cervix ...