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Sample records for high-dose-rate interactively irradiation

  1. Comparable cell survival between high dose rate flattening filter free and conventional dose rate irradiation.

    Science.gov (United States)

    Verbakel, Wilko F A R; van den Berg, Jaap; Slotman, Ben J; Sminia, Peter

    2013-04-01

    Investigation of clonogenic cell survival and cell proliferation following single dose and fractionated delivery of high dose rate flattening filter free (FFF) irradiation compared to conventional dose rates. The human astrocytoma D384, glioma T98 and lung carcinoma SW1573 cell lines were irradiated using either a single dose (0-12 Gy) or a fractionated protocol of 5 daily fractions of 2 Gy (D384) or 3 Gy (SW1573). Cells were irradiated inside a phantom using fixed gantry beams of a linear accelerator. A sliding window technique created homogeneous dose distributions over the surface of the cell cultures. Irradiations using standard beams (6 MV, 600 MU/min.) and high dose rate FFF beams (10 MV, 2400 MU/min.) were compared. Cell survival was determined by clonogenic assay. In the fractionated irradiation set-up, the number of clonogenic cells was estimated by including tumor cell proliferation during the overall treatment time in the analysis. All cell lines showed equal cell survival following irradiation using either the FFF beams or conventional flattened (FF) beams. This was observed after single dose exposure (0-12 Gy) as well as after fractionated irradiation (p = 0.08 for D384 and 0.20 for SW1373 cell lines). FFF irradiation with a dose rate of 2400 MU/min and four times higher dose per pulse compared to irradiation with FF beams did not change cell survival for three human cancer cell lines up to a fraction dose of 12 Gy compared to irradiation using FF beams.

  2. Development of computerized dose planning system and applicator for high dose rate remote afterloading irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, T. J. [Keimyung Univ., Taegu (Korea); Kim, S. W. [Fatima Hospital, Taegu (Korea); Kim, O. B.; Lee, H. J.; Won, C. H. [Keimyung Univ., Taegu (Korea); Yoon, S. M. [Dong-a Univ., Pusan (Korea)

    2000-04-01

    To design and fabricate of the high dose rate source and applicators which are tandem, ovoids and colpostat for OB/Gyn brachytherapy includes the computerized dose planning system. Designed the high dose rate Ir-192 source with nuclide atomic power irradiation and investigated the dose characteristics of fabricated brachysource. We performed the effect of self-absorption and determining the gamma constant and output factor and determined the apparent activity of designed source. he automated computer planning system provided the 2D distribution and 3D includes analysis programs. Created the high dose rate source Ir-192, 10 Ci(370GBq). The effective attenuation factor from the self-absorption and source wall was examined to 0.55 of the activity of bare source and this factor is useful for determination of the apparent activity and gamma constant 4.69 Rcm{sup 2}/mCi-hr. Fabricated the colpostat was investigated the dose distributions of frontal, axial and sagittal plane in intra-cavitary radiation therapy for cervical cancer. The reduce dose at bladder and rectum area was found about 20 % of original dose. The computerized brachytherapy planning system provides the 2-dimensional isodose and 3-D include the dose-volume histogram(DVH) with graphic-user-interface mode. emoted afterloading device was built for experiment of created Ir-192 source with film dosimetry within {+-}1 mm discrepancy. 34 refs., 25 figs., 11 tabs. (Author)

  3. Salvage high-dose-rate brachytherapy for esophageal cancer in previously irradiated patients: A retrospective analysis.

    Science.gov (United States)

    Wong Hee Kam, Stéphanie; Rivera, Sofia; Hennequin, Christophe; Lourenço, Nelson; Chirica, Mircea; Munoz-Bongrand, Nicolas; Gornet, Jean-Marc; Quéro, Laurent

    2015-01-01

    To evaluate outcomes after exclusive salvage high-dose-rate (HDR) intraluminal esophageal brachytherapy given to previously irradiated patients with recurrent esophageal cancer. We reviewed medical records of 30 patients who were treated by salvage HDR brachytherapy for local esophageal cancer. Brachytherapy delivered four to six fractions of 5-7 Gy at 5 mm from the applicator surface and 20 mm above and below the macroscopic tumor volume. Eighty percentage of patients received treatment as initially planned. Complete response rate, evaluated 1 month after brachytherapy by endoscopy and biopsy, was 53%. Squamous histology and complete endoscopic tumor response at 1 month were significantly associated with better local tumor control. Median local progression-free survival was 9.8 months. Overall survival was 31.5% and 17.5% at 1 and 2 years, respectively. On univariate analysis, preserved performance status and limited weight loss (brachytherapy were associated with better overall survival. Severe toxicity (Grade ≥3) occurred in 7 patients (23%). Although esophageal cancer in previously irradiated patients is associated with poor outcomes, HDR brachytherapy may be a valuable salvage treatment for inoperable patients with locally limited esophageal cancer, particularly in the subset of patients with preserved performance status and limited weight loss (≤10%) before salvage brachytherapy. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  4. A Performance Evaluation of a Notebook PC under a High Dose-Rate Gamma Ray Irradiation Test

    Directory of Open Access Journals (Sweden)

    Jai Wan Cho

    2014-01-01

    Full Text Available We describe the performance of a notebook PC under a high dose-rate gamma ray irradiation test. A notebook PC, which is small and light weight, is generally used as the control unit of a robot system and loaded onto the robot body. Using TEPCO’s CAMS (containment atmospheric monitoring system data, the gamma ray dose rate before and after a hydrogen explosion in reactor units 1–3 of the Fukushima nuclear power plant was more than 150 Gy/h. To use a notebook PC as the control unit of a robot system entering a reactor building to mitigate the severe accident situation of a nuclear power plant, the performance of the notebook PC under such intense gamma-irradiation fields should be evaluated. Under a similar dose-rate (150 Gy/h gamma ray environment, the performances of different notebook PCs were evaluated. In addition, a simple method for a performance evaluation of a notebook PC under a high dose-rate gamma ray irradiation test is proposed. Three notebook PCs were tested to verify the method proposed in this paper.

  5. Total skin electron irradiation therapy in mycosis fungoides using high-dose rate mode: a preliminary experience.

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    Parida, Dillip K; Verma, Kaushal K; Chander, Subhash; Joshi, R C; Rath, Goura K

    2005-10-01

    Total skin electron irradiation (TSEI) therapy is the treatment of choice for mycosis fungoides. However, conventional TSEI therapy is time consuming as well as patient unfriendly. Therefore we used high-dose rate (HDR) mode TSEI in these patients. High-dose rate mode of TSEI is a technological innovation attached to a Linear Accelerator (Philips, SL-20, Netherlands), which can deliver an electron beam of 30 Gy/min at the iso-center. The iso-center faces the patient, 100 cm away from the target of the linear accelerator. The patient is treated at a distance of 10 feet from the iso-center of the linear accelerator. The dose delivered to the skin was 1.13 Gy/min, making the treatment execution much easier and patient compliance much better. Seven male patients between 40 and 64 years in age having mycosis fungoides for 9-18 months were treated by TSEI using high-dose rate mode between 1998 and 2000. The TSEI was performed according to the Stanford technique, delivering a total dose of 36 Gy. Each patient received a dose of 1.2 Gy/field/day. There were six fields, i.e. anterior, posterior, left and right anterior obliques, and left and right posterior obliques in both the upper and lower parts of the body. The eyes and nails were shielded at each session of radiotherapy. The times taken at each session of the therapy and radiation-associated side-effects were determined in each patient. The patients were followed up to 26 months (median 9 months) to look for any relapse. Three patients had early stage disease (IB) whereas four patients had advanced disease (IIB). Six patients out of these had complete remission following TSEI while one patient died as a result of progression of the disease during treatment. The treatment time taken at each treatment session in each individual patient was approximately 15 min. Radiation-associated morbidity was seen in all patients. Cutaneous lesions relapsed in two patients after 4 and 10 months, respectively, while four patients were

  6. On-Line High Dose-Rate Gamma Ray Irradiation Test of the CCD/CMOS Cameras

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    Cho, Jai Wan; Jeong, Kyung Min [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    In this paper, test results of gamma ray irradiation to CCD/CMOS cameras are described. From the CAMS (containment atmospheric monitoring system) data of Fukushima Dai-ichi nuclear power plant station, we found out that the gamma ray dose-rate when the hydrogen explosion occurred in nuclear reactors 1{approx}3 is about 160 Gy/h. If assumed that the emergency response robot for the management of severe accident of the nuclear power plant has been sent into the reactor area to grasp the inside situation of reactor building and to take precautionary measures against releasing radioactive materials, the CCD/CMOS cameras, which are loaded with the robot, serve as eye of the emergency response robot. In the case of the Japanese Quince robot system, which was sent to carry out investigating the unit 2 reactor building refueling floor situation, 7 CCD/CMOS cameras are used. 2 CCD cameras of Quince robot are used for the forward and backward monitoring of the surroundings during navigation. And 2 CCD (or CMOS) cameras are used for monitoring the status of front-end and back-end motion mechanics such as flippers and crawlers. A CCD camera with wide field of view optics is used for monitoring the status of the communication (VDSL) cable reel. And another 2 CCD cameras are assigned for reading the indication value of the radiation dosimeter and the instrument. In the preceding assumptions, a major problem which arises when dealing with CCD/CMOS cameras in the severe accident situations of the nuclear power plant is the presence of high dose-rate gamma irradiation fields. In the case of the DBA (design basis accident) situations of the nuclear power plant, in order to use a CCD/CMOS camera as an ad-hoc monitoring unit in the vicinity of high radioactivity structures and components of the nuclear reactor area, a robust survivability of this camera in such intense gamma-radiation fields therefore should be verified. The CCD/CMOS cameras of various types were gamma irradiated at a

  7. Experimental Platform for Ultra-high Dose Rate FLASH Irradiation of Small Animals Using a Clinical Linear Accelerator

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    Schüler, Emil; Trovati, Stefania; King, Gregory; Lartey, Frederick; Rafat, Marjan; Villegas, Manuel; Praxel, A. Joe [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Loo, Billy W., E-mail: BWLoo@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Maxim, Peter G., E-mail: PMaxim@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States)

    2017-01-01

    Purpose: A key factor limiting the effectiveness of radiation therapy is normal tissue toxicity, and recent preclinical data have shown that ultra-high dose rate irradiation (>50 Gy/s, “FLASH”) potentially mitigates this effect. However, research in this field has been strongly limited by the availability of FLASH irradiators suitable for small animal experiments. We present a simple methodologic approach for FLASH electron small animal irradiation with a clinically available linear accelerator (LINAC). Methods and Materials: We investigated the FLASH irradiation potential of a Varian Clinac 21EX in both clinical mode and after tuning of the LINAC. We performed detailed FLUKA Monte Carlo and experimental dosimetric characterization at multiple experimental locations within the LINAC head. Results: Average dose rates of ≤74 Gy/s were achieved in clinical mode, and the dose rate after tuning exceeded 900 Gy/s. We obtained 220 Gy/s at 1-cm depth for a >4-cm field size with 90% homogeneity throughout a 2-cm-thick volume. Conclusions: We present an approach for using a clinical LINAC for FLASH irradiation. We obtained dose rates exceeding 200 Gy/s after simple tuning of the LINAC, with excellent dosimetric properties for small animal experiments. This will allow for increased availability of FLASH irradiation to the general research community.

  8. High-dose-rate afterloading intracavitary irradiation and expandable metallic biliary endoprosthesis for malignant biliary obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Hitoshi; Ohishi, Hajime; Yoshioka, Tetsuya (Nara Medical Univ., Kashihara (Japan)) (and others)

    1989-04-01

    A double lumen catheter was developed as an applicator for the remote afterloading system (RALS) of {sup 60}Co for the intracavitary irradiation of an obstructed common bile duct due to gallbladder cancer in 1 case and by cholangiocarcinoma in 7 cases. This was followed by the biliary endoprosthesis with expandable metallic stents to maintain patency. The mean survival period after treatment was not long (14 weeks). However, removal of the external drainage tube was possible in 7 of the 8 cases, and none of the 8 cases showed dislodgement or deformity of the stent, or obstruction of the bile duct in the stent-inserted area. This combination effectively provided palliation, and has considerable potential for malignant biliary obstruction. (author).

  9. A dose verification tool for high-dose-rate interstitial brachytherapy treatment planning in accelerated partial breast irradiation.

    Science.gov (United States)

    Marqa, Mohamad Feras; Caudrelier, Jean-Michel; Betrouni, Nacim

    2012-01-01

    To develop a dose verification tool for high-dose-rate interstitial brachytherapy treatment planning in accelerated partial breast irradiation. We have developed a software tool for interstitial brachytherapy treatment planning assessment. The software contains a database of seven (192)Ir source models and is able to estimate the dose distribution using the Task Group 43 and the Sievert integral algorithms. Dose-volume histogram analysis and dose quality assurance (QA) criteria including conformity (COnformal INdex [COIN] and conformation number [CN]), homogeneity (homogeneity index [HI]) parameters were implemented in the software to evaluate and to compare between the doses estimated by the two algorithms and a dose extracted from an external treatment planning system (TPS). The tool was evaluated and validated on four clinical cases treated by high-dose-rate interstitial brachytherapy. The doses provided by the Task Group 43 and the Sievert integral algorithms were evaluated by establishing the dose-volume histogram analysis and then by calculating the QA criteria. The algorithms were validated by comparing the dose at different anatomic points with their corresponding dose points provided from TPS. The differences were considered in good agreement (within 5%). Pretreatment dose verification is an important step in the QA of brachytherapy accelerated partial breast irradiation. A simple, fast, and accurate method of dose verification is therefore needed. The software proposed in this study could fulfill these requirements. In addition, it is freely available for using by anyone wishing to do a QA on any TPS. Copyright © 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  10. Preoperative radiotherapy for advanced lower rectal cancer. Combination of external and high-dose-rate intraluminal irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Horikawa, Noriko; Yoshimura, Hitoshi; Tamamoto, Tetsuro; Tsuji, Yoshihiko; Uto, Fumiaki; Ohishi, Hajime; Uchida, Hideo; Fujii, Hisao; Nakano, Hiroshige [Nara Medical Univ., Kashihara (Japan)

    1999-01-01

    This paper reports the therapeutic results of preoperative irradiation using a combination of external irradiation and high dose rate intraluminal irradiation using {sup 60}Co aimed at enhancing postoperative local control of advanced rectal cancer. The subjects comprised 38 patients (RT group) in whom {>=} A{sub 1}` lower rectal cancer was suspected and who underwent preoperative irradiation at this hospital. A control group (N-RT group) consisted of 16 patients subjected to operation alone in whom clinical {>=} A{sub 1}` and postoperative histological study revealed {>=} a{sub 1}. Intraluminal irradiation was performed using a balloon applicator. The external irradiation was performed with a 10 MVX delivering 30-40 Gy/15-20 Fr to the entire pelvic cavity. Using the criteria of Ohboshi and Shimozato to judge the histopathological effect, no cases showed Grade I, while of Grade II, 15 cases showed IIA and 19 cases IIB, Grade III in 4 cases. Grade IIB or above was noted in 23 of 38 (61%). Five and 8-year survival rates were 82.5 and 82.5% in the RT group, and were 79.5 and 79.5% in the N-RT group. Although these differences were not significant, a trend to better survival was found in the RT group. The local recurrence rate was 8% (3/38 cases) in the RT group in contrast to 25% (4/16 cases) in the N-RT group. The following complications developed during radiation therapy: diarrhea 19 (50%), anal pain 18 (47%), and others. Postoperative complications consisted of perineal fluid collection 4 (10%), bowel obstruction 3 cases (8%), an anastomotic insufficiency 3 (8%), fistula formation of bladder 2 (5%), ureteral narrowing 1 (3%), and thrombosis of vein 1 cases (3%) of the RT group, while perineal fluid collection 1 (6%), bowel obstruction 1 (6%), an anastomotic insufficiency 4 (25%) of the N-RT group, only one case of RT group (3%) required surgical treatment for the fistula formation of bladder. (K.H.)

  11. High-dose-rate interstitial brachytherapy for accelerated partial breast irradiation – trial results of Azerbaijan National Center of Oncology

    Directory of Open Access Journals (Sweden)

    Jamil A. Aliyev

    2017-04-01

    Full Text Available Purpose : To describe early results of two cohorts of patients with low and intermediate risk of early breast cancer treated with accelerated partial breast irradiation (APBI using different schedules of multicatheter brachytherapy. Material and methods: Patients with early stage breast cancer after breast conserving surgery were enrolled for a prospective analysis. The APBI, using multicatheter brachytherapy, was delivered either eight times 4 Gy in five days with a planned total dose of 32 Gy, or seven times 5 Gy in four days with a planned total dose of 35 Gy. Primary endpoints were side effects. Results : Forty-eight patients were enrolled between 2012 and 2014. Patients characteristics were as follow: median age of patients was 55 years, early breast cancer was defined according GEC-ESTRO recommendations. With a median follow-up period of 37 months, no significant differences regarding late side effects and cosmesis between two cohorts of patients were documented. In total, cosmesis was excellent in 13/48 (27.1% patients, good in 34/48 (70.8% patients, and moderate in 1/48 patient (2.1%. Conclusions : Accelerated partial breast irradiation using multicatheter brachytherapy with 32 Gy/8 fractions and 35 Gy/7 fractions for early breast cancer seems to be similar in terms of late side effects. According to our findings, APBI was also feasible for intermediate-risk of early breast cancer patients.

  12. Analysis of Chromosomal Aberrations after Low and High Dose Rate Gamma Irradiation in ATM or NBS Suppressed Human Fibroblast Cells

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    Hada, M.; Huff, J. L.; Patel, Z.; Pluth, J. M.; George, K. A.; Cucinotta, F. A.

    2009-01-01

    A detailed understanding of the biological effects of heavy nuclei is needed for space radiation protection and for cancer therapy. High-LET radiation produces more complex DNA lesions that may be non-repairable or that may require additional processing steps compared to endogenous DSBs, increasing the possibility of misrepair. Interplay between radiation sensitivity, dose, and radiation quality has not been studied extensively. Previously we studied chromosome aberrations induced by low- and high- LET radiation in several cell lines deficient in ATM (ataxia telangactasia mutated; product of the gene that is mutated in ataxia telangiectasia patients) or NBS (nibrin; product of the gene mutated in the Nijmegen breakage syndrome), and gliomablastoma cells that are proficient or lacking in DNA-dependent protein kinase (DNA-PK) activity. We found that the yields of both simple and complex chromosomal aberrations were significantly increased in the DSB repair defective cells compared to normal cells. The increased aberrations observed for the ATM and NBS defective lines was due to a significantly larger quadratic dose-response term compared to normal fibroblasts for both simple and complex aberrations, while the linear dose-response term was significantly higher in NBS cells only for simple exchanges. These results point to the importance of the functions of ATM and NBS in chromatin modifications that function to facilitate correct DSB repair and minimize aberration formation. To further understand the sensitivity differences that were observed in ATM and NBS deficient cells, in this study, chromosomal aberration analysis was performed in normal lung fibroblast cells treated with KU-55933, a specific ATM kinase inhibitor, or Mirin, an MRN complex inhibitor involved in activation of ATM. We are also testing siRNA knockdown of these proteins. Normal and ATM or NBS suppressed cells were irradiated with gamma-rays and chromosomes were collected with a premature chromosome

  13. NOTE: Clinical application of a OneDose™ MOSFET for skin dose measurements during internal mammary chain irradiation with high dose rate brachytherapy in carcinoma of the breast

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    Kinhikar, Rajesh A.; Sharma, Pramod K.; Tambe, Chandrashekhar M.; Mahantshetty, Umesh M.; Sarin, Rajiv; Deshpande, Deepak D.; Shrivastava, Shyam K.

    2006-07-01

    In our earlier study, we experimentally evaluated the characteristics of a newly designed metal oxide semiconductor field effect transistor (MOSFET) OneDose™ in-vivo dosimetry system for Ir-192 (380 keV) energy and the results were compared with thermoluminescent dosimeters (TLDs). We have now extended the same study to the clinical application of this MOSFET as an in-vivo dosimetry system. The MOSFET was used during high dose rate brachytherapy (HDRBT) of internal mammary chain (IMC) irradiation for a carcinoma of the breast. The aim of this study was to measure the skin dose during IMC irradiation with a MOSFET and a TLD and compare it with the calculated dose with a treatment planning system (TPS). The skin dose was measured for ten patients. All the patients' treatment was planned on a PLATO treatment planning system. TLD measurements were performed to compare the accuracy of the measured results from the MOSFET. The mean doses measured with the MOSFET and the TLD were identical (0.5392 Gy, 15.85% of the prescribed dose). The mean dose was overestimated by the TPS and was 0.5923 Gy (17.42% of the prescribed dose). The TPS overestimated the skin dose by 9% as verified by the MOSFET and TLD. The MOSFET provides adequate in-vivo dosimetry for HDRBT. Immediate readout after irradiation, small size, permanent storage of dose and ease of use make the MOSFET a viable alternative for TLDs.

  14. Clinical application of a OneDose MOSFET for skin dose measurements during internal mammary chain irradiation with high dose rate brachytherapy in carcinoma of the breast.

    Science.gov (United States)

    Kinhikar, Rajesh A; Sharma, Pramod K; Tambe, Chandrashekhar M; Mahantshetty, Umesh M; Sarin, Rajiv; Deshpande, Deepak D; Shrivastava, Shyam K

    2006-07-21

    In our earlier study, we experimentally evaluated the characteristics of a newly designed metal oxide semiconductor field effect transistor (MOSFET) OneDose in-vivo dosimetry system for Ir-192 (380 keV) energy and the results were compared with thermoluminescent dosimeters (TLDs). We have now extended the same study to the clinical application of this MOSFET as an in-vivo dosimetry system. The MOSFET was used during high dose rate brachytherapy (HDRBT) of internal mammary chain (IMC) irradiation for a carcinoma of the breast. The aim of this study was to measure the skin dose during IMC irradiation with a MOSFET and a TLD and compare it with the calculated dose with a treatment planning system (TPS). The skin dose was measured for ten patients. All the patients' treatment was planned on a PLATO treatment planning system. TLD measurements were performed to compare the accuracy of the measured results from the MOSFET. The mean doses measured with the MOSFET and the TLD were identical (0.5392 Gy, 15.85% of the prescribed dose). The mean dose was overestimated by the TPS and was 0.5923 Gy (17.42% of the prescribed dose). The TPS overestimated the skin dose by 9% as verified by the MOSFET and TLD. The MOSFET provides adequate in-vivo dosimetry for HDRBT. Immediate readout after irradiation, small size, permanent storage of dose and ease of use make the MOSFET a viable alternative for TLDs.

  15. Temporo-spatial cell-cycle kinetics in HeLa cells irradiated by Ir-192 high dose-rate remote afterloading system (HDR-RALS).

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    Asahina, Taito; Kaida, Atsushi; Goto, Tatsuaki; Yoshimura, Ryo-Ichi; Sasai, Keisuke; Miura, Masahiko

    2016-07-29

    Intracavitary irradiation plays a pivotal role in definitive radiotherapy for cervical cancer, and the Ir-192 high dose-rate remote afterloading system (HDR-RALS) is often used for this purpose. Under this condition, tumor tissues receive remarkably different absorption doses, with a steep gradient, depending on distance from the radiation source. To obtain temporo-spatial information regarding cell-cycle kinetics in cervical cancer following irradiation by Ir-192 HDR-RALS, we examined HeLa cells expressing the fluorescence ubiquitination-based cell cycle indicator (Fucci), which allowed us to visualize cell-cycle progression. HeLa-Fucci cells, which emit red and green fluorescence in G1 and S/G2/M phases, respectively, were grown on 35-mm dishes and irradiated by Ir-192 HDR-RALS under normoxic and hypoxic conditions. A 6 French (Fr) catheter was used as an applicator. A radiation dose of 6 Gy was prescribed at hypothetical treatment point A, located 20 mm from the radiation source. Changes in Fucci fluorescence after irradiation were visualized for cells from 5 to 20 mm from the Ir-192 source. Several indices, including first green phase duration after irradiation (FGPD), were measured by analysis of time-lapse images. Cells located 5 to 20 mm from the Ir-192 source became green, reflecting arrest in G2, in a similar manner up to 12 h after irradiation; at more distant positions, however, cells were gradually released from the G2 arrest and became red. This could be explained by the observation that the FGPD was longer for cells closer to the radiation source. Detailed observation revealed that FGPD was significantly longer in cells irradiated in the green phase than in the red phase at positions closer to the Ir-192 source. Unexpectedly, the FGPD was significantly longer after irradiation under hypoxia than normoxia, due in large part to the elongation of FGPD in cells irradiated in the red phase. Using HeLa-Fucci cells, we obtained the first temporo

  16. Salvage prostate re-irradiation using high-dose-rate brachytherapy or focal stereotactic body radiotherapy for local recurrence after definitive radiation therapy.

    Science.gov (United States)

    Mbeutcha, Aurélie; Chauveinc, Laurent; Bondiau, Pierre-Yves; Chand, Marie-Eve; Durand, Matthieu; Chevallier, Daniel; Amiel, Jean; Kee, Daniel Lam Cham; Hannoun-Lévi, Jean-Michel

    2017-03-09

    Optimal management of locally recurrent prostate cancer after definitive radiation therapy is still challenging. With the development of highly accurate radiotherapy devices, prostate salvage re-irradiation might generate lower toxicity rates than classical salvage therapies. We retrospectively evaluated the toxicity and the feasibility of a prostate re-irradiation after definitive radiation therapy failure. Two modalities were investigated: high-dose-rate brachytherapy (HDRB) on whole prostate gland and focal stereotactic radiotherapy (SBRT) using CyberKnife® linac. Between 2011 and 2015, 28 patients with imaged and/or biopsy-proven intra-prostatic recurrence of cancer after definitive radiation therapy underwent a salvage re-irradiation using HDRB (n = 10) or focal SBRT (n = 18). The schedule of re-irradiation was 35 Gy in 5 fractions. Biological response (defined as post-salvage radiation PSA variation) and biochemical no-evidence of disease (bNED) were evaluated in the whole cohort. For patients who had a positive biological response after salvage radiation, biochemical recurrence (BCR) and survival after salvage radiotherapy were evaluated. Post-salvage toxicities were assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v4.03 and were compared to baseline status. Within a median follow-up of 22.5 months (IQR = 8-42), 9 (90%) patients experienced a positive biological response after salvage HDRB and 5 (50%) remained bNED at the end of the follow-up. Among patients who initially responded to salvage HDRB, the BCR rate was 44.4% after a median interval of 19.5 months (IQR = 11.5-26). Only one patient experienced a transient grade 3 urinary complication. In the SBRT group, the median follow-up was 14.5 months (IQR = 7-23) and 10 (55.6%) out of the 18 patients remained bNED. Among the 15 patients who initially responded to salvage SBRT, 5 (33.3%) experienced a BCR. One patient experienced a transient grade 4

  17. Advantages and implications of high dose rate (HDR) total skin electron irradiation (TSEI) for the management of Mycosis Fungoides. Indian experience.

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    Parida, Dillip Kumar; Rath, Goura Kishore

    2014-03-01

    Mycosis Fungoides (MF) is an indolent lymphoproliferative disorder affecting dermis caused by abnormal proliferation of CD4+ T-cells. Radiation therapy is the most effective modality of treatment for MF which offers cure in limited stage disease and desirable palliation in advance stage disease. Treating entire skin having many curved surfaces and folds with radiation is the real challenge for the radiation oncologist. Many techniques, dose schedules and modifications in total skin electron irradiation (TSEI) have been tried since 1950s. TSEI treatment is a very time consuming, inconvenient and physically challenging to both patient as well as oncologist. At our center TSEI was performed since 1983 with conventional linear accelerator where the treatment time was prolonged beyond two hours, which was very difficult or the patient, oncologist, technical officer and eating away the machine time hampering the treatment of other patients. From 1998 we shifted to high dose rate (HDR) mode, in order to bring down the treatment time of a single patient every day from two and half hour to 15 min. The reduction of treatment time increases patient compliance and at the same time saved machine time. Between 1998 and 2003, eleven pathological diagnosed MF patients were treated using HDR TSEI. All the patients were male between 40 and 70 years of age, who had the history of having the disease for 7-22 months. Four patients had T2 and seven patients had T3 stage disease with more than 90% skin surface involvement. TSEI was performed with 4 MeV electrons with a daily fraction size of 120 cGy to a total dose of 36 Gy. At the end of 36 Gy, boost dose of 10 Gy was delivered to self shielding regions like sole, scalp and perineum. Considering the treatment related toxicities and consequent treatment interruptions, in the first seven patients, the last four patients were treated using similar HDR TSEI technique with modified treatment schedule, where the treatment was given on

  18. Tolerance of the vaginal vault to high-dose rate brachytherapy and concomitant chemo-pelvic irradiation: Long-term perspective.

    Science.gov (United States)

    Kaidar-Person, Orit; Abdah-Bortnyak, Roxolyana; Amit, Amnon; Nevelsky, Alexander; Berniger, Alison; Bar-Deroma, Raquel; Ben-Yosef, Rahamim; Kuten, Abraham

    2014-01-01

    We sought to determine the tolerance level and complication rates of the vaginal vault to combined high-dose-rate intra-cavitary brachytherapy with concomitant chemo-radiotherapy. A retrospective review of medical records of all the patients who received definitive chemo-radiotherapy for cervical cancer between 1998 and 2002 was undertaken. The records were reviewed for doses and for radiation-associated early and late sequelae of the vagina, rectum and bladder. Cumulative biological effective dose was calculated for two reference vaginal surface points. Fifty patients were included. Average age at diagnosis was 54 years. Median follow-up was 59 months. There were no recorded instances of acute grade IV toxicity. Maximal high-dose-rate vaginal surface dose (upper central point) was 103 Gy, and maximal brachytherapy lateral surface dose was 70 Gy. Maximal cumulative biological effective dose for the lateral surface reference point was 465.5 Gy3, and the maximal cumulative biological effective dose for the superior reference point was 878.6 Gy3. There were no cases of vaginal necrosis or fistulas, and no cases of grade IV late vaginal, rectal or bladder toxicity. No correlation was found between the maximal vaginal surface dose and vaginal, rectal or bladder toxicity. The maximal surface HDR brachytherapy dose of 103 Gy and the maximal cBED of 878.6 Gy3 were not associated with fistula or necrosis or other grade 3-4 vaginal complications. Concomitant chemo-radiotherapy, including pelvic radiotherapy and high-dose-rate intracavitary brachytherapy, is relatively safe for cervical cancer patients.

  19. Treatment of squamous cell carcinomas of the floor of the mouth and tongue by interstitial high-dose-rate irradiation using iridium-192

    Energy Technology Data Exchange (ETDEWEB)

    Klein, M.; Menneking, H.; Langford, A. [Humboldt Univ. of Berlin, Clinic for Maxillofacial Surgery, Berlin (Germany); Koch, K. [Clinic Ernst von Bergman, Clinic for Radiation Therapy, Potsdam (Germany); Stahl, H. [Humboldt Univ. of Berlin, Dept. of Radiation Oncology, Berlin (Germany)

    1998-02-01

    The results are presented of afterloading high-dose-rate-radiation with iridium-192 in 34 patients with squamous cell carcinomas of the floor of the mouth and tongue. Some patients were also treated surgically or given percutaneous radio- or chemotherapy. At the time of diagnosis, 28.0% had a T2 tumour, 41.9% a T3 tumour and 30.1% a T4 tumour. 41.2% had positive lymph nodes and 2.9% distant metastases. The response rate was 64.7%, 26.5% of which were complete remissions and 38.2% partial remissions. In 61.8% of cases, the tumour was recurrent and responded with a rate as high as 57.2%, 23.9% of which were complete remissions and 33.3% partial remissions. Survival times were dependent upon therapy results. The mean survival of patients with complete remission was 40.3 months, with partial remission 16.1 months as opposed to 7.2 and 3.5 months respectively in patients showing no change or progressive disease. It can be concluded that afterloading therapy using high-dose-rate-radiation with iridium-192 achieves good palliative results and should be looked at as a supplementary treatment modality for squamous cell carcinomas of the floor of the mouth and tongue. (au). 12 refs.

  20. Systemic response of Korean dark-striped field mice, Apodenmus agrarius coreae after high-dose- rate γ-irradiation: Organ weights, hemato-chemistry, apoptosis of splenocytes and sperm

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Kwang Hee; Choi, Hoon; Joo, Hyun Jin; Kim, Hee Sun [Radiation Health Research Institute, KHNP, Gyeongju (Korea, Republic of); Keum, Dong Kwon [Nuclear Environment Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-11-15

    Since the territory of the radio-contaminated area is in homeogenous in radiation level and spectrum, investigation of the genetical mutation process in the natural animal populations inhabiting the radioontaminated areas will be provide a realistic picture of genetic effects for radiation exposure. However, little is known about the basic data such as systemic responses after ionizing radiation exposures in wild small rodents. Taking into account different radio-sensitivity of dark-striped field mice (A. a. coreae, THOMAS), the objective of the study is focus on investigate the level of systemic responses, included organ weights, hemato-chemistry and apoptosis in splenocytes and sperm of caudal epididymis after high-dose-rate irradiation especially as a potential biological dosimeter in radio-ecology. Figure 1 summarizes the results of the apoptotic events in spleen (data not shown at here) and in sperm of caudal epididymis at 24hrs after a single high-dose-rate γ-irradiation. The results of apoptosis in spleen and sperm caused by exposure to different doses of γ-irradiation are displayed. The data show that the field striped mice after irradiated with more than high dose of 0.5 Gy induces an significantly increased apoptosis. Results also shown that for exposure to 0.5 Gy, the apoptosis of both organs ware decreased compared to those of other γ-irradiated mice.

  1. Dose volume histogram analysis of normal structures associated with accelerated partial breast irradiation delivered by high dose rate brachytherapy and comparison with whole breast external beam radiotherapy fields.

    Science.gov (United States)

    Stewart, Alexandra J; O'Farrell, Desmond A; Cormack, Robert A; Hansen, Jorgen L; Khan, Atif J; Mutyala, Subhakar; Devlin, Phillip M

    2008-11-19

    To assess the radiation dose delivered to the heart and ipsilateral lung during accelerated partial breast brachytherapy using a MammoSite applicator and compare to those produced by whole breast external beam radiotherapy (WBRT). Dosimetric analysis was conducted on patients receiving MammoSite breast brachytherapy following conservative surgery for invasive ductal carcinoma. Cardiac dose was evaluated for patients with left breast tumors with a CT scan encompassing the entire heart. Lung dose was evaluated for patients in whom the entire lung was scanned. The prescription dose of 3400 cGy was 1 cm from the balloon surface. MammoSite dosimetry was compared to simulated WBRT fields with and without radiobiological correction for the effects of dose and fractionation. Dose parameters such as the volume of the structure receiving 10 Gy or more (V10) and the dose received by 20 cc of the structure (D20), were calculated as well as the maximum and mean doses received. Fifteen patients were studied, five had complete lung data and six had left-sided tumors with complete cardiac data. Ipsilateral lung volumes ranged from 925-1380 cc. Cardiac volumes ranged from 337-551 cc. MammoSite resulted in a significantly lower percentage lung V30 and lung and cardiac V20 than the WBRT fields, with and without radiobiological correction. This study gives low values for incidental radiation received by the heart and ipsilateral lung using the MammoSite applicator. The volume of heart and lung irradiated to clinically significant levels was significantly lower with the MammoSite applicator than using simulated WBRT fields of the same CT data sets.

  2. Dose volume histogram analysis of normal structures associated with accelerated partial breast irradiation delivered by high dose rate brachytherapy and comparison with whole breast external beam radiotherapy fields

    Directory of Open Access Journals (Sweden)

    Mutyala Subhakar

    2008-11-01

    Full Text Available Abstract Purpose To assess the radiation dose delivered to the heart and ipsilateral lung during accelerated partial breast brachytherapy using a MammoSite™ applicator and compare to those produced by whole breast external beam radiotherapy (WBRT. Materials and methods Dosimetric analysis was conducted on patients receiving MammoSite breast brachytherapy following conservative surgery for invasive ductal carcinoma. Cardiac dose was evaluated for patients with left breast tumors with a CT scan encompassing the entire heart. Lung dose was evaluated for patients in whom the entire lung was scanned. The prescription dose of 3400 cGy was 1 cm from the balloon surface. MammoSite dosimetry was compared to simulated WBRT fields with and without radiobiological correction for the effects of dose and fractionation. Dose parameters such as the volume of the structure receiving 10 Gy or more (V10 and the dose received by 20 cc of the structure (D20, were calculated as well as the maximum and mean doses received. Results Fifteen patients were studied, five had complete lung data and six had left-sided tumors with complete cardiac data. Ipsilateral lung volumes ranged from 925–1380 cc. Cardiac volumes ranged from 337–551 cc. MammoSite resulted in a significantly lower percentage lung V30 and lung and cardiac V20 than the WBRT fields, with and without radiobiological correction. Conclusion This study gives low values for incidental radiation received by the heart and ipsilateral lung using the MammoSite applicator. The volume of heart and lung irradiated to clinically significant levels was significantly lower with the MammoSite applicator than using simulated WBRT fields of the same CT data sets. Trial registration Dana Farber Trial Registry number 03-179

  3. Objective and Longitudinal Assessment of Dermatitis After Postoperative Accelerated Partial Breast Irradiation Using High-Dose-Rate Interstitial Brachytherapy in Patients With Breast Cancer Treated With Breast Conserving Therapy: Reduction of Moisture Deterioration by APBI

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Eiichi [Department of Radiation Oncology, National Hospital Organization, Osaka National Hospital, Osaka (Japan); Yamazaki, Hideya, E-mail: hideya10@hotmail.com [Department of Radiology, Kyoto Prefectural University of Medicine, Kyoto (Japan); Yoshida, Ken; Takenaka, Tadashi [Department of Radiation Oncology, National Hospital Organization, Osaka National Hospital, Osaka (Japan); Masuda, Norikazu [Department of Surgery and Breast Oncology, National Hospital Organization, Osaka National Hospital, Osaka (Japan); Kotsuma, Tadayuki; Yoshioka, Yasuo; Inoue, Takehiro [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita (Japan)

    2011-11-15

    Purpose: To objectively evaluate the radiation dermatitis caused by accelerated partial breast irradiation (APBI) using high-dose-rate interstitial brachytherapy. Patients and Methods: The skin color and moisture changes were examined using a newly installed spectrophotometer and corneometer in 22 patients who had undergone APBI using open cavity implant high-dose-rate interstitial brachytherapy (36 Gy in six fractions) and compared with the corresponding values for 44 patients in an external beam radiotherapy (EBRT) control group (50-60 Gy in 25-30 fractions within 5-6 weeks) after breast conserving surgery. Results: All values changed significantly as a result of APBI. The extent of elevation in a Asterisk-Operator (reddish) and reduction in L Asterisk-Operator (black) values caused by APBI were similar to those for EBRT, with slightly delayed recovery for 6-12 months after treatment owing to the surgical procedure. In contrast, only APBI caused a change in the b Asterisk-Operator values, and EBRT did not, demonstrating that the reduction in b Asterisk-Operator values (yellowish) depends largely on the surgical procedure. The changes in moisture were less severe after APBI than after EBRT, and the recovery was more rapid. The toxicity assessment using the Common Toxicity Criteria, version 3, showed that all dermatitis caused by APBI was Grade 2 or less. Conclusion: An objective analysis can quantify the effects of APBI procedures on color and moisture cosmesis. The radiation dermatitis caused by APBI using the present schedule showed an equivalent effect on skin color and a less severe effect on moisture than the effects caused by standard EBRT.

  4. Concomitant chemoradiotherapy with high dose rate brachytherapy ...

    African Journals Online (AJOL)

    Purpose: This study aims to report the incidence of treatment-induced acute toxicities, local control and survival of patients with cervix cancer treated by external beam radiotherapy (EBR) and high-dose-rate (HDR) brachytherapy concomitant with weekly Cisplatin chemotherapy. Methods: Forty patients with FIGO Stages IB2 ...

  5. Attenuation measurements show that the presence of a TachoSil surgical patch will not compromise target irradiation in intra-operative electron radiation therapy or high-dose-rate brachytherapy.

    Science.gov (United States)

    Sarmento, Sandra; Costa, Filipa; Pereira, Alexandre; Lencart, Joana; Dias, Anabela; Cunha, Luís; Sousa, Olga; Silva, José Pedro; Santos, Lúcio

    2015-01-09

    Surgery of locally advanced and/or recurrent rectal cancer can be complemented with intra-operative electron radiation therapy (IOERT) to deliver a single dose of radiation directly to the unresectable margins, while sparing nearby sensitive organs/structures. Haemorrhages may occur and can affect the dose distribution, leading to an incorrect target irradiation. The TachoSil (TS) surgical patch, when activated, creates a fibrin clot at the surgical site to achieve haemostasis. The aim of this work was to determine the effect of TS on the dose distribution, and ascertain whether it could be used in combination with IOERT. This characterization was extended to include high dose rate (HDR) intraoperative brachytherapy, which is sometimes used at other institutions instead of IOERT. CT images of the TS patch were acquired for initial characterization. Dosimetric measurements were performed in a water tank phantom, using a conventional LINAC with a hard-docking system of cylindrical applicators. Percentage Depth Dose (PDD) curves were obtained, and measurements made at the depth of dose maximum for the three clinically used electron energies (6, 9 and 12MeV), first without any attenuator and then with the activated patch of TS completely covering the tip of the IOERT applicator. For HDR brachytherapy, a measurement setup was improvised using a solid water phantom and a Farmer ionization chamber. Our measurements show that the attenuation of a TachoSil patch is negligible, both for high energy electron beams (6 to 12MeV), and for a HDR (192)Ir brachytherapy source. Our results cannot be extrapolated to lower beam energies such as 50 kVp X-rays, which are sometimes used for breast IORT. The TachoSil surgical patch can be used in IORT procedures using 6MeV electron energies or higher, or HDR (192)Ir brachytherapy.

  6. Braquiterapia intersticial de alta tasa de rescate en cáncer cabeza cuello previamente radiado High-dose-rate (HDR brachytherapy in previously irradiated recurrent head and neck cancer

    Directory of Open Access Journals (Sweden)

    Lucía Gutiérrez-Bayard

    2011-09-01

    Full Text Available A pesar de los avances en el tratamiento de cáncer de cabeza y cuello (CCC, el 15-50% de los pacientes presentan recurrencia locorregional. Para los pacientes que presentan enfermedad localmente recurrente o un segundo tumor primario en un campo previamente irradiado, las opciones terapéuticas de rescate son limitadas, siendo la resección quirúrgica con intención curativa la opción de elección para los pacientes con enfermedad limitada. Reirradiación con o sin la adición de quimioterapia puede ser una buena opción, obteniendo en pacientes seleccionados supervivencia a largo plazo. La braquiterapia de alta tasa de dosis (HDRBT puede jugar un papel importante en el tratamiento de rescate en tumores de cabeza y cuello recurrentes. Presentamos un paciente de 56 años diagnosticado de cáncer de lengua sometido a cirugía y radioterapia externa adyuvante, y recurrencia metastásica ganglionar cervical contralateral a los 18 meses. Recibió tratamiento multidisciplinar con quimioterapia, cirugía y braquiterapia intersticial.Despite advances in the treatment of head and neck cancer (HNC, 15-50% of patients present locoregional disease recurrence. The therapeutic options are limited for patients who present locally recurrent disease or a second primary tumor in a previously irradiated field. Surgical salvage with curative intent is the preferred option for patients with limited-volume disease. Re-irradiation with or without the addition of chemotherapy may hold promise for long-term survival for selected patients. High-dose-rate (HDR brachytherapy can play an important role in the salvage treatment of previously irradiated recurrent head and neck cancer. The case reported was a 56-year old man diagnosed of tongue cancer who presented recurrent metastatic contralateral cervical node 1.5 years after radical treatment with surgery and adjuvant external radiotherapy. He received multidisciplinary treatment with chemotherapy, surgery and HDR

  7. Partial breast irradiation: high dose rate per-operative brachytherapy technique using the MammoSite; Irradiation partielle du sein: technique de curietherapie de haut debit de dose apres l'implantation peroperatoire du dispositif MammoSite

    Energy Technology Data Exchange (ETDEWEB)

    Belkacemi, Y.; Poupon, L.; Castellanos, M.E.; Villette, S.; Lartigau, E. [Centre de Lutte Contre le Cancer Oscar-Lambret, Dept. de Radiotherapie, 59 - Lille (France); Chauvet, M.P.; Giard, S. [Centre de Lutte Contre le Cancer Oscar-Lambret, Dept. de Chirurgie Senologique, 59 - Lille (France); Bonodeau, F. [de Lutte Contre le Cancer Oscar-Lambret, Dept. de Radiologie, 59 - Lille (France); Cabaret, V. [de Lutte Contre le Cancer Oscar-Lambret, Dept. d' Anatomopathologie, 59 - Lille (France)

    2003-11-01

    In the conservative management of breast cancer, radiation therapy delivering 45 to 50 Gy to the whole breast, in 4.5 to 5 weeks, followed by a booster dose of 10 to 20 Gy is the standard of care. Based on the numerous studies which have reported that the local recurrences occurs within and surrounding the primary tumor site and in order to decrease the treatment duration and its morbidity, partial breast irradiation using several techniques has been developed. Partial irradiation may be considered as an alternative local adjuvant treatment for selected patients with favorable prognostic factors. Using external beam radiation therapy, the 3D-conformal technique is appropriate to deliver the whole dose to a limited volume. In UK, an intraoperative technique using a miniature beam of low energy of X-ray (50 kV) has been developed (Targit). Milan's team have developed an intraoperative electrons beam radiotherapy using a dedicated linear accelerator in the operative room. In USA and Canada the MammoSite has been advised for clinical use in per-operative brachytherapy of the breast. These two last techniques are currently compared in phase III randomized studies to the standard whole breast irradiation followed by a tumour bed booster dose. In this review we will focus on the MammoSite technique and will describe the per-operative implantation procedure. radiological controls ad dosimetric aspects. (author)

  8. High dose rate brachytherapy for oral cancer

    Science.gov (United States)

    YamazakI, Hideya; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Furukawa, Souhei; Koizumi, Masahiko; Ogawa, Kazuhiko

    2013-01-01

    Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer. PMID:23179377

  9. Dose determination in high dose-rate brachytherapy.

    Science.gov (United States)

    Houdek, P V; Schwade, J G; Wu, X; Pisciotta, V; Fiedler, J A; Serago, C F; Markoe, A M; Abitbol, A A; Lewin, A A; Braunschweiger, P G

    1992-01-01

    Although high dose-rate brachytherapy with a single, rapidly moving radiation source is becoming a common treatment modality, a suitable formalism for determination of the dose delivered by a moving radiation source has not yet been developed. At present, brachytherapy software simulates high dose-rate treatments using only a series of stationary sources, and consequently fails to account for the dose component delivered while the source is in motion. We now describe a practical model for determination of the true, total dose administered. The algorithm calculates both the dose delivered while the source is in motion within and outside of the implanted volume (dynamic component), and the dose delivered while the source is stationary at a series of fixed dwell points. It is shown that the dynamic dose element cannot be ignored because it always increases the dose at the prescription points and, in addition, distorts the dose distribution within and outside of the irradiated volume. Failure to account for the dynamic dose component results in dosimetric errors that range from significant (> 10%) to negligible (source activity, and source speed as defined by the implant geometry.

  10. SU-F-T-70: A High Dose Rate Total Skin Electron Irradiation Technique with A Specific Inter-Film Variation Correction Method for Very Large Electron Beam Fields

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X; Rosenfield, J; Dong, X; Elder, E; Dhabaan, A [Emory University, Atlanta, GA (United States)

    2016-06-15

    Purpose: Rotational total skin electron irradiation (RTSEI) is used in the treatment of cutaneous T-cell lymphoma. Due to inter-film uniformity variations the dosimetry measurement of a large electron beam of a very low energy is challenging. This work provides a method to improve the accuracy of flatness and symmetry for a very large treatment field of low electron energy used in dual beam RTSEI. Methods: RTSEI is delivered by dual angles field a gantry of ±20 degrees of 270 to cover the upper and the lower halves of the patient body with acceptable beam uniformity. The field size is in the order of 230cm in vertical height and 120 cm in horizontal width and beam energy is a degraded 6 MeV (6 mm of PMMA spoiler). We utilized parallel plate chambers, Gafchromic films and OSLDs as a measuring devices for absolute dose, B-Factor, stationary and rotational percent depth dose and beam uniformity. To reduce inter-film dosimetric variation we introduced a new specific correction method to analyze beam uniformity. This correction method uses some image processing techniques combining film value before and after radiation dose to compensate the inter-variation dose response differences among films. Results: Stationary and rotational depth of dose demonstrated that the Rp is 2 cm for rotational and the maximum dose is shifted toward the surface (3mm). The dosimetry for the phantom showed that dose uniformity reduced to 3.01% for the vertical flatness and 2.35% for horizontal flatness after correction thus achieving better flatness and uniformity. The absolute dose readings of calibrated films after our correction matched with the readings from OSLD. Conclusion: The proposed correction method for Gafchromic films will be a useful tool to correct inter-film dosimetric variation for the future clinical film dosimetry verification in very large fields, allowing the optimizations of other parameters.

  11. Transit dose calculation in high dose rate brachytherapy (HDR ...

    African Journals Online (AJOL)

    Transit doses around a high dose rate 192Ir brachytherapy source were calculated using Sievert Integral at positions where the moving source was located exactly between two adjacent dwell positions. The correspond-ing transit dose rates were obtained by using energy absorption coefficients. Discrete step sizes of 0.25 ...

  12. Salvage high-dose-rate interstitial brachytherapy for locally recurrent rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pellizzon, Antonio Cassio Assis, E-mail: acapellizzon@hcancer.org.br [A.C. Camargo Cancer Center, Sao Paulo, SP (Brazil). Departamento de Radioterapia

    2016-05-15

    For tumors of the lower third of the rectum, the only safe surgical procedure is abdominal-perineal resection. High-dose-rate interstitial brachytherapy is a promising treatment for local recurrence of previously irradiated lower rectal cancer, due to the extremely high concentrated dose delivered to the tumor and the sparing of normal tissue, when compared with a course of external beam radiation therapy. (author)

  13. A model for low dose effects of low-LET radiation delivered at high dose rates

    Science.gov (United States)

    Schöllnberger, H.; Stewart, R.D.; Mitchel, R.E.J.

    2011-01-01

    In vitro studies show that protective tumour-reducing effects occur for low dose rates (mGy per minute). To account for these phenomena, we have previously developed stochastic and deterministic multi-stage cancer models that include radiation-induced adaptations in DNA repair processes and radical scavenging. Here, these models are extended to account for the induction of radioprotective mechanisms for low doses of low LET radiation delivered at high dose rates. Cellular adaptations in DNA repair are related to temporal changes in the amount of DNA damage in a cell. The combined effects of endogenous DNA damage, background radiation and artificial irradiation are considered. PMID:22318364

  14. Effects of high dose rate gamma radiation on survival and reproduction of Biomphalaria glabrata

    Energy Technology Data Exchange (ETDEWEB)

    Cantinha, Rebeca S.; Nakano, Eliana [Instituto Butantan, Sao Paulo, SP (Brazil). Lab. de Parasitologia], e-mail: rebecanuclear@gmail.com, e-mail: eliananakano@butantan.gov.br; Borrely, Sueli I. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes], e-mail: sborrely@ipen.br; Amaral, Ademir; Melo, Ana M.M.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia (GERAR)], e-mail: amaral@ufpe.br; Silva, Luanna R.S. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia. Lab. de Radiobiologia], e-mail: amdemelo@hotmail.com, e-mail: luannaribeiro_lua@hotmail.com

    2009-07-01

    Ionizing radiations are known as mutagenic agents, causing lethality and infertility. This characteristic has motivated its application on animal biological control. In this context, the freshwater snail Biomphalaria glabrata can be considered an excellent experimental model to study effects of ionizing radiations on lethality and reproduction. This work was designed to evaluate effects of {sup 60}Co gamma radiation at high dose rate (10.04 kGy/h) on B. glabrata. For this purpose, adult snails were selected and exposed to doses ranging from 20 to 100 Gy, with 10 Gy intervals; one group was kept as control. There was not effect of dose rate in the lethality of gamma radiation; the value of 64,3 Gy of LD{sub 50} obtained in our study was similar to that obtained by other authors with low dose rates. Nevertheless, our data suggest that there was a dose rate effect in the reproduction. On all dose levels, radiation improved the production of embryos for all exposed individuals. However, viability indexes were below 6% and, even 65 days after irradiation, fertility was not recovered. These results are not in agreement with other studies using low dose rates. Lethality was obtained in all groups irradiated, and the highest doses presented percentiles of dead animals above 50%. The results demonstrated that doses of 20 and 30 Gy were ideal for population control of B. glabrata. Further studies are needed; nevertheless, this research evidenced great potential of high dose rate gamma radiation on B. glabrata reproductive control. (author)

  15. Interstitial high-dose-rate brachytherapy in eyelid cancer.

    Science.gov (United States)

    Mareco, Virgínia; Bujor, Laurentiu; Abrunhosa-Branquinho, André N; Ferreira, Miguel Reis; Ribeiro, Tiago; Vasconcelos, Ana Luisa; Ferreira, Cidalina Reis; Jorge, Marília

    2015-01-01

    To report the experience and the outcomes of interstitial high-dose-rate (HDR) brachytherapy (BT) of eyelid skin cancer at the Department of Radiotherapy of Hospital de Santa Maria in Lisbon. Seventeen patients (pts; mean age, 73.75 years) who underwent eyelid interstitial HDR BT with an (192)Ir source between January 2011 and February 2013 were analyzed. Lesions were basal (94%) and squamous (6%) cell carcinomas, on lower (88%) or upper (6%) eyelids, and on inner canthus (6%). T-stage was Tis (6%), T1 (46%), T2 (36%), and T3a (12%). The purpose of BT was radical (12%), adjuvant to surgery (71%), or salvage after surgery (18%). The BT implant and treatment planning were based on the Stepping Source Dosimetry System. The median total dose was 42.75 Gy (range, 32-50 Gy), with a median of 10 fractions (range, 9-11 fractions), twice daily, 6 h apart. The median V100 was 2.38 cm(3) (range, 0.83-5.59 cm(3)), and the median V150 was 1.05 cm(3) (range, 0.24-3.12 cm(3)). At a median followup of 40 months (range, 7-43 months), the local control was 94.1%. There was one local recurrence and one non-related death. The BT was well tolerated. Madarosis was the most common late effect (65% of pts) and was related with higher values of V100 (p = 0.027). Cosmetic outcomes were good and excellent in 70% of pts. Interstitial HDR BT is a feasible and safe technique for eyelid skin cancers, with good local control. Recurrent lesions and higher volumes receiving the prescribed dose were associated with worse outcomes. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  16. High-dose rate Ir-192 interstitial brachytherapy for recurrent pelvic tumors

    Energy Technology Data Exchange (ETDEWEB)

    Tsukiyama, Iwao; Katano, Susumu; Kotake, Kenjiro; Yamamoto, Seiichiro; Kamata, Hiroyuki; Sekiguchi, Isao [Tochigi Cancer Center, (Japan); Furuta, Masaya; Ohno, Tatsuya

    1999-06-01

    Recurrent pelvic tumors are difficult to control with external irradiation alone. We have conducted phase I and II clinical trials against recurrent pelvic tumors. From January 1995 through March 1997, 13 recurrent pelvic tumors in 10 patients were treated with high-dose rate Ir-192 interstitial brachytherapy. Complete responses were achieved for 2 tumors, partial responses for 5 tumors, and no response for 6 tumors; therefore, the response rate was 61% (8 of 13 tumors). Treatment-related morbidity was noted in 5 patients and included one case each of skin ulcer, rectovaginal fistula, sacral abscess, rectal bleeding, and vesicovaginal fistula. In January 1999, four patients were alive and had survived for 17, 18, 28, and 46 months. Six patients had died but had survived 4, 13, 15, 16, and 27 months. (author)

  17. Radiolysis of confined water: hydrogen production at a high dose rate.

    Science.gov (United States)

    Le Caër, Sophie; Rotureau, Patricia; Brunet, Francine; Charpentier, Thibault; Blain, Guillaume; Renault, Jean Philippe; Mialocq, Jean-Claude

    2005-12-09

    The production of molecular hydrogen in the radiolysis of dried or hydrated nanoporous controlled-pore glasses (CPG) has been carefully studied using 10 MeV electron irradiation at high dose rate. In all cases, the H2 yield increases when the pore size decreases. Moreover, the yields measured in dried materials are two orders of magnitude smaller than those obtained in hydrated glasses. This proves that the part of the H2 coming from the surface of the material is negligible in the hydrated case. Thus, the measured yields correspond to those of nanoconfined water. Moreover, these yields are not modified by the presence of potassium bromide, which is a hydroxyl radical scavenger. This experimental observation shows that the back reaction between H2 and HO* does not take place in such confined environments. These porous materials have been characterized before and after irradiation by means of Fourier-transform infrared (FT-IR) spectroscopy, electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) techniques, which helps to understand the elementary processes taking place in this type of environment, especially the protective effect of water on the surface in the case of hydrated glasses.

  18. Novel Use of the Contura for High Dose Rate Cranial Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Scanderbeg, Daniel J., E-mail: dscanderbeg@ucsd.edu [Department of Radiation Oncology, University of California at San Diego, La Jolla, CA (United States); Center for Advanced Radiotherapy Technologies, Rebecca and John Moores Comprehensive Cancer Center, University of California at San Diego, La Jolla, CA (United States); Alksne, John F. [Division of Neurological Surgery, University of California at San Diego, La Jolla, CA (United States); Lawson, Joshua D. [Department of Radiation Oncology, University of California at San Diego, La Jolla, CA (United States); Center for Advanced Radiotherapy Technologies, Rebecca and John Moores Comprehensive Cancer Center, University of California at San Diego, La Jolla, CA (United States); Murphy, Kevin T. [Department of Radiation Oncology, University of California at San Diego, La Jolla, CA (United States)

    2011-01-01

    A popular choice for treatment of recurrent gliomas was cranial brachytherapy using the GliaSite Radiation Therapy System. However, this device was taken off the market in late 2008, thus leaving a treatment void. This case study presents our experience treating a cranial lesion for the first time using a Contura multilumen, high-dose-rate (HDR) brachytherapy balloon applicator. The patient was a 47-year-old male who was diagnosed with a recurrent right frontal anaplastic oligodendroglioma. Previous radiosurgery made him a good candidate for brachytherapy. An intracavitary HDR balloon brachytherapy device (Contura) was placed in the resection cavity and treated with a single fraction of 20 Gy. The implant, treatment, and removal of the device were all completed without incident. Dosimetry of the device was excellent because the dose conformed very well to the target. V90, V100, V150, and V200 were 98.9%, 95.7%, 27.2, and 8.8 cc, respectively. This patient was treated successfully using the Contura multilumen balloon. Contura was originally designed for deployment in a postlumpectomy breast for treatment by accelerated partial breast irradiation. Being an intracavitary balloon device, its similarity to the GliaSite system makes it a viable replacement candidate. Multiple lumens in the device also make it possible to shape the dose delivered to the target, something not possible before with the GliaSite applicator.

  19. On the use of particle filters for electromagnetic tracking in high dose rate brachytherapy

    Science.gov (United States)

    Götz, Th I.; Lahmer, G.; Brandt, T.; Kallis, K.; Strnad, V.; Bert, Ch; Hensel, B.; Tomé, A. M.; Lang, E. W.

    2017-10-01

    Modern radiotherapy of female breast cancers often employs high dose rate brachytherapy, where a radioactive source is moved inside catheters, implanted in the female breast, according to a prescribed treatment plan. Source localization relative to the patient’s anatomy is determined with solenoid sensors whose spatial positions are measured with an electromagnetic tracking system. Precise sensor dwell position determination is of utmost importance to assure irradiation of the cancerous tissue according to the treatment plan. We present a hybrid data analysis system which combines multi-dimensional scaling with particle filters to precisely determine sensor dwell positions in the catheters during subsequent radiation treatment sessions. Both techniques are complemented with empirical mode decomposition for the removal of superimposed breathing artifacts. We show that the hybrid model robustly and reliably determines the spatial positions of all catheters used during the treatment and precisely determines any deviations of actual sensor dwell positions from the treatment plan. The hybrid system only relies on sensor positions measured with an EMT system and relates them to the spatial positions of the implanted catheters as initially determined with a computed x-ray tomography.

  20. Online pretreatment verification of high-dose rate brachytherapy using an imaging panel

    Science.gov (United States)

    Fonseca, Gabriel P.; Podesta, Mark; Bellezzo, Murillo; Van den Bosch, Michiel R.; Lutgens, Ludy; Vanneste, Ben G. L.; Voncken, Robert; Van Limbergen, Evert J.; Reniers, Brigitte; Verhaegen, Frank

    2017-07-01

    Brachytherapy is employed to treat a wide variety of cancers. However, an accurate treatment verification method is currently not available. This study describes a pre-treatment verification system that uses an imaging panel (IP) to verify important aspects of the treatment plan. A detailed modelling of the IP was only possible with an extensive calibration performed using a robotic arm. Irradiations were performed with a high dose rate (HDR) 192Ir source within a water phantom. An empirical fit was applied to measure the distance between the source and the detector so 3D Cartesian coordinates of the dwell positions can be obtained using a single panel. The IP acquires 7.14 fps to verify the dwell times, dwell positions and air kerma strength (Sk). A gynecological applicator was used to create a treatment plan that was registered with a CT image of the water phantom used during the experiments for verification purposes. Errors (shifts, exchanged connections and wrong dwell times) were simulated to verify the proposed verification system. Cartesian source positions (panel measurement plane) have a standard deviation of about 0.02 cm. The measured distance between the source and the panel (z-coordinate) have a standard deviation up to 0.16 cm and maximum absolute error of  ≈0.6 cm if the signal is close to sensitive limit of the panel. The average response of the panel is very linear with Sk. Therefore, Sk measurements can be performed with relatively small errors. The measured dwell times show a maximum error of 0.2 s which is consistent with the acquisition rate of the panel. All simulated errors were clearly identified by the proposed system. The use of IPs is not common in brachytherapy, however, it provides considerable advantages. It was demonstrated that the IP can accurately measure Sk, dwell times and dwell positions.

  1. 3D-printed surface mould applicator for high-dose-rate brachytherapy

    Science.gov (United States)

    Schumacher, Mark; Lasso, Andras; Cumming, Ian; Rankin, Adam; Falkson, Conrad B.; Schreiner, L. John; Joshi, Chandra; Fichtinger, Gabor

    2015-03-01

    In contemporary high-dose-rate brachytherapy treatment of superficial tumors, catheters are placed in a wax mould. The creation of current wax models is a difficult and time consuming proces.The irradiation plan can only be computed post-construction and requires a second CT scan. In case no satisfactory dose plan can be created, the mould is discarded and the process is repeated. The objective of this work was to develop an automated method to replace suboptimal wax moulding. We developed a method to design and manufacture moulds that guarantee to yield satisfactory dosimetry. A 3D-printed mould with channels for the catheters designed from the patient's CT and mounted on a patient-specific thermoplastic mesh mask. The mould planner was implemented as an open-source module in the 3D Slicer platform. Series of test moulds were created to accommodate standard brachytherapy catheters of 1.70mm diameter. A calibration object was used to conclude that tunnels with a diameter of 2.25mm, minimum 12mm radius of curvature, and 1.0mm open channel gave the best fit for this printer/catheter combination. Moulds were created from the CT scan of thermoplastic mesh masks of actual patients. The patient-specific moulds have been visually verified to fit on the thermoplastic meshes. The masks were visually shown to fit onto the thermoplastic meshes, next the resulting dosimetry will have to be compared with treatment plans and dosimetry achieved with conventional wax moulds in order to validate our 3D printed moulds.

  2. Dosimetric verification of a high dose rate brachytherapy treatment planning system in homogeneous and heterogeneous media.

    Science.gov (United States)

    Uniyal, S C; Sharma, S D; Naithani, U C

    2013-03-01

    To verify the dosimetric accuracy of treatment plans in high dose rate (HDR) brachytherapy by using Gafchromic EBT2 film and to demonstrate the adequacy of dose calculations of a commercial treatment planning system (TPS) in a heterogeneous medium. Absorbed doses at chosen points in anatomically different tissue equivalent phantoms were measured using Gafchromic EBT2 film. In one case, tandem ovoid brachytherapy was performed in a homogeneous cervix phantom, whereas in the other, organ heterogeneities were introduced in a phantom to replicate the upper thorax for esophageal brachytherapy treatment. A commercially available TPS was used to perform treatment planning in each case and the EBT2 films were irradiated with the HDR Ir-192 brachytherapy source. Film measurements in the cervix phantom were found to agree with the TPS calculated values within 3% in the clinically relevant volume. In the thorax phantom, the presence of surrounding heterogeneities was not seen to affect the dose distribution in the volume being treated, whereas, a little dose perturbation was observed at the lung surface. Doses to the spinal cord and to the sternum bone were overestimated and underestimated by 14.6% and 16.5% respectively by the TPS relative to the film measurements. At the trachea wall facing the esophagus, a dose reduction of 10% was noticed in the measurements. The dose calculation accuracy of the TPS was confirmed in homogeneous medium, whereas, it was proved inadequate to produce correct dosimetric results in conditions of tissue heterogeneity. Copyright © 2012 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  3. Salvage high-dose-rate brachytherapy for local prostate cancer recurrence after radical radiotherapy

    Directory of Open Access Journals (Sweden)

    V. A. Solodkiy

    2016-01-01

    Full Text Available Studies salvage interstitial radiation therapy for recurrent prostate cancer, launched at the end of the XX century. In recent years, more and more attention is paid to high-dose-rate brachytherapy (HDR-BT as a method of treating local recurrence.The purpose of research – preliminary clinical results of salvage high-dose-rate brachytherapy applied in cases of suspected local recurrence or of residual tumour after radiotherapy.Preliminary findings indicate the possibility of using HDR-BT, achieving local tumor control with low genitourinary toxicity.

  4. High-dose-rate brachytherapy for uterine cervical cancer: the results of different fractionation regimen

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Won Sup; Kim, Tae Hyun; Yang, Dae Sik; Choi, Myung Sun; Kim, Chul Yong [College of Medicine, Korea University, Seoul (Korea, Republic of)

    2002-09-15

    Although high-dose-rate (HDR) brachytherapy regimens have been practiced with a variety of modalities and various degrees of success, few studies on the subject have been conducted. The purpose of this study was to compare the results of local control and late complication rate according to different HDR brachytherapy fractionation regimens in uterine cervical cancer patients. From November 1992 to March 1998, 224 patients with uterine cervical cancer were treated with external beam irradiation and HDR brachytherapy. In external pelvic radiation therapy, the radiation dose was 45 {approx} 54 Gy (median dose 54 Gy) with daily fraction size 1.8 Gy, five times per week. In HDR brachytherapy, 122 patients (Group A) were treated with three times weekly with 3 Gy to line-A (isodose line of 2 cm radius from source) and 102 patients (Group B) underwent the HDR brachytherapy twice weekly with 4 or 4.5 Gy to line-A after external beam irradiation. Iridium-192 was used as the source of HDR brachytherapy. Late complication was assessed from grade 1 to 5 using the RTOG morbidity grading system. The local control rate (LCR) at 5 years was 80% in group A and 84% in group B ({rho} = 0.4523). In the patients treated with radiation therapy alone, LCR at 5 years was 60.9% in group A and 76.9% in group B ({rho} = 0.2557). In post-operative radiation therapy patients, LCR at 5 years was 92.6% in group A and 91.6% in group B ({rho} 0.8867). The incidence of late complication was 18% (22 patients) and 29.4% (30 patients), of bladder complication was 9.8% (12 patients) and 14.7% (15 patients), and of rectal complication was 9.8% (12 patients) and 21.6% (22 patients), in group A and B, respectively. Lower fraction sized HDR brachytherapy was associated with decrease in late complication ({rho} =0.0405) (rectal complication, {rho} = 0.0147; bladder complication, {rho} =0.115). The same result was observed in postoperative radiation therapy patients ({rho} = 0.0860) and radiation only

  5. Postoperative high-dose-rate brachytherapy in the prevention of keloids

    NARCIS (Netherlands)

    Veen, Ronald E.; Kal, Henk B.

    2007-01-01

    Background: The aim of this study is to show the efficiency of keloidectomy and postoperative interstitial high-dose-rate (HDR) brachytherapy in the prevention of keloids. Methods and Materials: Between 1998 and 2004, 35 patients with 54 keloids were treated postoperatively with HDR brachytherapy.

  6. Learning curve of MRI-based planning for high-dose-rate brachytherapy for prostate cancer

    DEFF Research Database (Denmark)

    Buus, Simon; Rylander, Susanne; Hokland, Steffen

    2016-01-01

    Purpose To evaluate introduction of MRI-based high-dose-rate brachytherapy (HDRBT), including procedure times, dose-volume parameters, and perioperative morbidity. Methods and Materials Study included 42 high-risk prostate cancer patients enrolled in a clinical protocol, offering external beam...

  7. An automated optimization tool for high-dose-rate (HDR) prostate brachytherapy with divergent needle pattern

    NARCIS (Netherlands)

    Borot, Maxence; Maenhout, M.; de Senneville, B. Denis; Hautvast, G.; Binnekamp, D.; Lagendijk, J. J. W.; van Vulpen, M.; Moerland, M. A.

    2015-01-01

    Focal high-dose-rate (HDR) for prostate cancer has gained increasing interest as an alternative to whole gland therapy as it may contribute to the reduction of treatment related toxicity. For focal treatment, optimal needle guidance and placement is warranted. This can be achieved under MR guidance.

  8. In vivo measurements for high dose rate brachytherapy with optically stimulated luminescent dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Renu; Jursinic, Paul A. [Department of Radiation Oncology, West Michigan Cancer Center, 200 North Park Street, Kalamazoo, Michigan 49007 (United States)

    2013-07-15

    Purpose: To show the feasibility of clinical implementation of OSLDs for high dose-rate (HDR) in vivo dosimetry for gynecological and breast patients. To discuss how the OSLDs were characterized for an Ir-192 source, taking into account low gamma energy and high dose gradients. To describe differences caused by the dose calculation formalism of treatment planning systems.Methods: OSLD irradiations were made using the GammaMedplus iX Ir-192 HDR, Varian Medical Systems, Milpitas, CA. BrachyVision versions 8.9 and 10.0, Varian Medical Systems, Milpitas, CA, were used for calculations. Version 8.9 used the TG-43 algorithm and version 10.0 used the Acuros algorithm. The OSLDs (InLight Nanodots) were characterized for Ir-192. Various phantoms were created to assess calculated and measured doses and the angular dependence and self-absorption of the Nanodots. Following successful phantom measurements, patient measurements for gynecological patients and breast cancer patients were made and compared to calculated doses.Results: The OSLD sensitivity to Ir-192 compared to 6 MV is between 1.10 and 1.25, is unique to each detector, and changes with accumulated dose. The measured doses were compared to those predicted by the treatment planning system and found to be in agreement for the gynecological patients to within measurement uncertainty. The range of differences between the measured and Acuros calculated doses was -10%-14%. For the breast patients, there was a discrepancy of -4.4% to +6.5% between the measured and calculated doses at the skin surface when the Acuros algorithm was used. These differences were within experimental uncertainty due to (random) error in the location of the detector with respect to the treatment catheter.Conclusions: OSLDs can be successfully used for HDR in vivo dosimetry. However, for the measurements to be meaningful one must account for the angular dependence, volume-averaging, and the greater sensitivity to Ir-192 gamma rays than to 6 MV x

  9. Applicator Attenuation Effect on Dose Calculations of Esophageal High-Dose Rate Brachytherapy Using EDR2 Film

    Directory of Open Access Journals (Sweden)

    Seyed Mohsen Hosseini Daghigh

    2012-03-01

    Full Text Available Introduction Interaluminal brachytherapy is one of the important methods of esophageal cancer treatment. The effect of applicator attenuation is not considered in dose calculation method released by AAPM-TG43. In this study, the effect of High-Dose Rate (HDR brachytherapy esophageal applicator on dose distribution was surveyed in HDR brachytherapy. Materials and Methods A cylindrical PMMA phantom was built in order to be inserted by various sizes of esophageal applicators. EDR2 films were placed at 33 mm from Ir-192 source and irradiated with 1.5 Gy after planning using treatment planning system for all applicators. Results The results of film dosimetry in reference point for 6, 8, 10, and 20 mm applicators were 1.54, 1.53, 1.48, and 1.50 Gy, respectively. The difference between practical and treatment planning system results was 0.023 Gy (

  10. Interstitial brachytherapy for carcinoma of the base of tongue using a high dose rate {sup 192}Ir remote afterloader

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Tetsuo; Imai, Michiko; Iijima, Mitsuharu; Suzuki, Kazunori; Nozue, Masashi; Kaneko, Masao; Mukodaka, Hiroyuki; Asai, Yoshihiro [Hamamatsu Univ., Shizuoka (Japan). School of Medicine

    1996-11-01

    We have applied an interstitial brachytherapy employing a high dose rate {sup 192}Ir remote afterloader to five patients with cancer of the base of tongue since December 1994. Insertion of applicators was carried out with tracheotomy under general anesthesia. Brachytherapy was delivered twice a day with a 6-hour interval. Irradiation dose was estimated at the point of 5 mm from outer applicators. HDR brachytherapy was well tolerated for 4-5 days in all patients and acute radiation reaction was minimal. Local control were observed in two cases. In conclusion, our preliminary experience suggests that HDR brachytherapy may be an option in the radiotherapy for carcinoma of the base of tongue. Optimal dose-fractionation protocol should be established. (author)

  11. Assessment for effects and adverse effects of preoperative high-dose-rate intraluminal brachytherapy for lower rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Terauchi, Kazuo (Hyogo College of Medicine, Nishinomiya (Japan))

    1993-11-01

    Endoscopic and histological effects and perianal dermal side effects after high-dose-rate intraluminal brachytherapy (HDRIBT) using [sup 60]Co for preoperative irradiation were assessed in thirty-five patients with low-lying rectal cancers. In more than half of the patients irradiated with 30 Gy or more, marked effective change was observed under endoscopy. In the histological assessment, while the resected lesions irradiated with 16-20 Gy showed no effective change, 68.8%, 75.0%, and 76.9% respectively, of those in the groups given 30 Gy, 40-60 Gy, and 80 Gy showed marked destruction. While 23. 1% of the patients irradiated with 80 Gy developed severe perianal dermal lesions requiring surgical removal of the anus, 18.8% of the 30 Gy group and 25% of the 40-60 Gy group suffered from dermal side effects which were mild and reversible. Consequently, it has been concluded that the proper regimen for preoperative HDRIBT for rectal cancer was 30 Gy followed by surgery within two weeks. During the follow up period from 35 to 70 months, one patient (2.9%) who received 16 Gy HDRIBT developed local recurrence within 3 years after resection, and the other one developed hepatic metastasis. The 3-year local recurrence rate after resection for lower rectal cancer in the previous series at our department was 19.6%. We, therefore, concluded that HDRIBT was a promising adjuvant therapy for rectal cancer. (author).

  12. Remote afterloading high dose-rate intracavity radiotherapy for advanced maxillary cancer. Treatment with individual appliances

    Energy Technology Data Exchange (ETDEWEB)

    Horimoto, Susumu; Kakei, Masaki; Saito, Tomokatsu [Yokohama City Univ. (Japan). School of Medicine] [and others

    1998-08-01

    Seven advanced maxillary cancers, 5 squamous cell carcinomas, and 2 adenoid cystic carcinomas were treated with remote afterloading high dose-rate intracavity radiotherapy. For treatment, we fabricated individual dental acrylic appliances for the postoperative area of the oral cavity. Because the appliance was specially matched to the remaining maxillary structures, radiation doses to the treated area were easily reproduced without distress to the patient. However, minor or major complications (moderate or severe mucositis and osteoradionecrosis) were observed in all patients. In this study, the number of patients was too small to assess the significance of this treatment. Nevertheless, with improvements, we think that remote afterloading high dose-rate intracavity radiotherapy with a dental acrylic appliance will soon be used to treat advanced maxillary carcinoma. (author)

  13. Perioperative Interstitial High-Dose-Rate Brachytherapy for the Treatment of Recurrent Keloids

    DEFF Research Database (Denmark)

    Jiang, Ping; Baumann, René; Dunst, Jürgen

    2016-01-01

    PURPOSE: To prospectively evaluate high-dose-rate brachytherapy in the treatment of therapy-resistant keloids and report first results, with emphasis on feasibility and early treatment outcome. METHODS AND MATERIALS: From 2009 to 2014, 24 patients with 32 recurrent keloids were treated...... with immediate perioperative high-dose-rate brachytherapy; 3 patients had been previously treated with adjuvant external beam radiation therapy and presented with recurrences in the pretreated areas. Two or more different treatment modalities had been tried in all patients and had failed to achieve remission....... After (re-)excision of the keloids, a single brachytherapy tube was placed subcutaneously before closing the wound. The target volume covered the scar in total length. Brachytherapy was given in 3 fractions with a single dose of 6 Gy in 5 mm tissue depth. The first fraction was given within 6 hours...

  14. High dose-rate irradiation of materials with pulsed ion beams at NDCX-II

    Science.gov (United States)

    Seidl, Peter; Treffert, F.; Ji, Q.; Ludewigt, B.; Persaud, A.; Kong, X.; de Leon, S. J.; Dowling, E.; Waldron, W. L.; Schenkel, T.; Barnard, J. J.; Friedman, A.; Grote, D. P.; Stepanov, A.; Gilson, E. P.; Kaganovich, I. D.

    2017-10-01

    Charged particle radiation effects in materials is important for the design of fusion plasma facing components. Also, radiation effects in semiconductor devices are of interest for many applications such as detectors and space electronics. We present results from radiation effects studies with intense pulses of helium ions that impinged on thin samples at the induction linac at Berkeley Lab (Neutralized Drift Compression Experiment-II). Intense bunches of 1.2 MeV He+ ions with peak currents of 2 A, 1-mm beam spot radius and 2-30 ns FWHM duration create controlled high instantaneous dose rates enabling the exploration of collective damage effects. We use in-situ diagnostics to monitor transient effects due to rapid heating and the ionization and damage cascade dynamics. For tin, single pulses deposit sufficient energy in the foil to drive phase transitions. A new Thomson parabola to measures ion energy loss and charge state distributions following transmission of a few micron thick samples. In silicon, ion pulses induce free electron densities of order 1021 cm-3. Supported by the Office of Science of the US DOE under contracts DE-AC0205CH11231, DE-AC52-07NA27344 and DE-AC02-09CH11466 and by the China Scholarship Council.

  15. Ureteral stent insertion for gynecologic interstitial high-dose-rate brachytherapy.

    Science.gov (United States)

    Demanes, D Jeffrey; Banerjee, Robyn; Cahan, Benjamin L; Lee, Steve P; Park, Sang-June; Fallon, Julia M; Reyes, Paula; Van, Thanh Q; Steinberg, Michael L; Kamrava, Mitchell R

    2015-01-01

    To determine the utility of ureteral stents in interstitial gynecological brachytherapy. We reviewed 289 patients with cervix cancer treated with high-dose-rate interstitial brachytherapy who did not have pretreatment hydronephrosis to determine the relative incidence of benign ureteral strictures after treatment. We also did comparative dosimetry analysis in five cases of high-dose-rate brachytherapy. Bilateral ureteral stents were placed during the procedure. Three dosimetry plans were created to determine the impact of modifying clinical target volume (CTV) and applying ureteral dose constraints. In Plan 1, the ureters were contoured and excluded from the CTV and 120% dose constraints were applied. In Plan 2, the ureters were contoured and excluded, but no dose constraints were applied to the ureter. In Plan 3, the CTV was created as if the location of the ureters was unknown and then ureteral dose was determined. There were 11 ureteral strictures observed in 255 nonstented cases and 0 ureteral strictures in 34 stented cases. Plan 1 reduced the ureter dose (D(0.1cc)) by a median 22% (7.0-53.8%) compared with Plan 2 and by a median of 30.9% (12.3-65%). compared with Plan 3. Placement of stents and ureteral dose constraints facilitates dosimetry and reduces the dose to ureters. Temporary ureteral stents prevent obstruction during interstitial gynecologic brachytherapy and allows the ureters to be addressed as an organ at risk. Copyright © 2015. Published by Elsevier Inc.

  16. Introduction of novel 3D-printed superficial applicators for high-dose-rate skin brachytherapy.

    Science.gov (United States)

    Jones, Emma-Louise; Tonino Baldion, Anna; Thomas, Christopher; Burrows, Tom; Byrne, Nick; Newton, Victoria; Aldridge, Sarah

    Custom-made surface mold applicators often allow more flexibility when carrying out skin brachytherapy, particularly for small treatment areas with high surface obliquity. They can, however, be difficult to manufacture, particularly if there is a lack of experience in superficial high-dose-rate brachytherapy techniques or with limited resources. We present a novel method of manufacturing superficial brachytherapy applicators utilizing three-dimensional (3D)-printing techniques. We describe the treatment planning process and the process of applicator manufacture. The treatment planning process, with the introduction of a pre-plan, allows for an "ideal" catheter arrangement within an applicator to be determined, exploiting varying catheter orientations, heights, and curvatures if required. The pre-plan arrangement is then 3D printed to the exact specifications of the pre-plan applicator design. This results in improved target volume coverage and improved sparing of organs at risk. Using a pre-plan technique for ideal catheter placement followed by automated 3D-printed applicator manufacture has greatly improved the entire process of superficial high-dose-rate brachytherapy treatment. We are able to design and manufacture flexible, well-fitting, superior quality applicators resulting in a more efficient and improved patient pathway and patient experience. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  17. Perioperative high-dose-rate interstitial brachytherapy boost for patients with early breast cancer.

    Science.gov (United States)

    Sharma, Daya Nand; Deo, S V S; Rath, Goura Kisor; Shukla, Nootan Kumar; Thulkar, Sanjay; Madan, Renu; Julka, Pramod Kumar

    2013-01-01

    To evaluate the clinical results of perioperative high-dose-rate interstitial brachytherapy boost treatment preceding whole breast external beam radiation therapy in patients with early breast cancer. From 2005-2010, 100 patients with early breast cancer who met the eligibility criteria were enrolled in the study. Brachytherapy implant was performed during the breast-conserving surgery procedure. The boost treatment was started on the 3rd postoperative day to deliver a dose of 15 Gy in 6 fractions over 3 days. Three weeks later, external beam radiation therapy to the whole breast was started for a prescription dose of 50 Gy. The study end points were local recurrence, acute toxicity and cosmetic outcome. Median age of the patients was 46 years, and median follow-up was 52 months. No patient developed a local recurrence but 5 patients developed distant metastases. The 5-year overall survival and disease-free survival were 86% and 77%, respectively. Eleven patients had acute toxicity; 4 wound complications and 7 grade III skin toxicity. Nine of the 11 patients had breast size of more than 1500 cc. Except for the breast volume (>1500 cc), there was no statistically significant correlation between any of the patient or dosimetry-related factors and acute toxicity. Good-excellent cosmesis was observed in 87% of patients. Perioperative high-dose-rate interstitial brachytherapy boost followed by whole breast external beam radiation therapy provides excellent local control, acceptable acute toxicity and good-excellent breast cosmesis in patients with early breast cancer.

  18. Radiobiological equivalent of low/high dose rate brachytherapy and evaluation of tumor and normal responses to the dose.

    Science.gov (United States)

    Manimaran, S

    2007-06-01

    The aim of this study was to compare the biological equivalent of low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy in terms of the more recent linear quadratic (LQ) model, which leads to theoretical estimation of biological equivalence. One of the key features of the LQ model is that it allows a more systematic radiobiological comparison between different types of treatment because the main parameters alpha/beta and micro are tissue-specific. Such comparisons also allow assessment of the likely change in the therapeutic ratio when switching between LDR and HDR treatments. The main application of LQ methodology, which focuses on by increasing the availability of remote afterloading units, has been to design fractionated HDR treatments that can replace existing LDR techniques. In this study, with LDR treatments (39 Gy in 48 h) equivalent to 11 fractions of HDR irradiation at the experimental level, there are increasing reports of reproducible animal models that may be used to investigate the biological basis of brachytherapy and to help confirm theoretical predictions. This is a timely development owing to the nonavailability of sufficient retrospective patient data analysis. It appears that HDR brachytherapy is likely to be a viable alternative to LDR only if it is delivered without a prohibitively large number of fractions (e.g., fewer than 11). With increased scientific understanding and technological capability, the prospect of a dose equivalent to HDR brachytherapy will allow greater utilization of the concepts discussed in this article.

  19. Experiences of high dose rate interstitial brachytherapy for carcinoma of the mobile tongue

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Hiroshi; Inoue, Toshihiko; Yamazaki, Hideya (Osaka Univ. (Japan). Faculty of Medicine) (and others)

    1994-03-01

    Interstitial brachytherapy was conducted for mobile tongue carcinoma using a high dose rate remote afterloading machine with small [sup 192]I source. Detailed method, named as 'linked double-botton technique', is to approach from submandibular skin by an open-ended stainless steel needles to the tongue lesion, and to replace each needle into flexible nylon tube from the oral cavity. Delivered dose was 60 Gy/10 Fr./5-6 days at the distance 5 mm from the source plane. Ten patients with mobile tongue carcinoma Tl-2N0 were treated with this method from October 1991 through August 1992. Local was uncontrolled in one patient, in whom the lesion was combined with leukoplakia at both lateral borders of the tongue. This was in accordance with the result in low dose rate treatment. This can be a substitute to low dose rate system for treatment of mobile tongue carcinoma. (author).

  20. A phantom for verification of dwell position and time of a high dose rate brachytherapy source.

    Science.gov (United States)

    Madebo, M; Pillainayagam, J; Kron, T; Franich, R

    2012-09-01

    Accuracy of dwell position and reproducibility of dwell time are critical in high dose rate (HDR) brachytherapy. A phantom was designed to verify dwell position and dwell time reproducibility for an Ir-192 HDR stepping source using Computed Radiography (CR). The central part of the phantom, incorporating thin alternating strips of lead and acrylic, was used to measure dwell positions. The outer part of the phantom features recesses containing different absorber materials (lead, aluminium, acrylic and polystyrene foam), and was used for determining reproducibility of dwell times. Dwell position errors of dwell time as low as 0.1 s, the minimum dwell time of the treatment unit, could be detected by choosing dwell times over the four materials that produce identical exposure at the CR detector.

  1. Adjuvant high dose rate brachytherapy for soft tissue sarcomas: initial experience report

    Directory of Open Access Journals (Sweden)

    Robert Whitfield

    2011-03-01

    Full Text Available Purpose: Adjuvant high-dose-rate brachytherapy (HDRBT offers advantages over low dose rate brachytherapy (LDRBT, although there are little data on local tumor control and treatment related toxicity. We report outcome in patients with primary, recurrent, and metastatic extremity and superficial trunk soft tissue sarcoma. Material and methods: Eleven patients (12 sites with intermediate or high grade sarcoma were treated with adjuvant HDRBT following surgical resection. Patients were treated at 3.4 Gy fractions delivered twice daily to a total dose of 34 Gy (1 patient received 9 fractions. Results: With median follow-up of 20.8 months, 1 patient developed a local recurrence. 2-year local control and overall survival are 89% and 71%, respectively. Wound complications occurred in 3 sites. Two of the wound complications developed in the area of previous external beam radiotherapy (EBRT. Conclusion: Surgical resection followed by HDRBT is associated with excellent early local tumor control and acceptable wound complication.

  2. Use of ultrasound in image-guided high-dose-rate brachytherapy: enumerations and arguments

    Science.gov (United States)

    Kataria, Tejinder; Gupta, Deepak; Goyal, Shikha; Bisht, Shyam Singh; Basu, Trinanjan; Abhishek, Ashu

    2017-01-01

    Inherently, brachytherapy is the most conformal radiotherapeutic technique. As an aid to brachytherapy, ultrasonography (USG) serves as a portable, inexpensive, and simple to use method allowing for accurate, reproducible, and adaptive treatments. Some newer brachytherapy planning systems have incorporated USG as the sole imaging modality. Ultrasonography has been successfully used to place applicator and dose planning for prostate, cervix, and anal canal cancers. It can guide placement of brachytherapy catheters for all other sites like breast, skin, and head and neck cancers. Traditional USG has a few limitations, but recent advances such as 3-dimensional (3D) USG and contrast USG have enhanced its potential as a dependable guide in high-dose-rate image-guided brachytherapy (HDR-IGBT). The authors in this review have attempted to enumerate various aspects of USG in brachytherapy, highlighting its use across various sites. PMID:28533803

  3. Use of ultrasound in image-guided high-dose-rate brachytherapy: enumerations and arguments

    Directory of Open Access Journals (Sweden)

    Susovan Banerjee

    2017-04-01

    Full Text Available Inherently, brachytherapy is the most conformal radiotherapeutic technique. As an aid to brachytherapy, ultrasonography (USG serves as a portable, inexpensive, and simple to use method allowing for accurate, reproducible, and adaptive treatments. Some newer brachytherapy planning systems have incorporated USG as the sole imaging modality. Ultrasonography has been successfully used to place applicator and dose planning for prostate, cervix, and anal canal cancers. It can guide placement of brachytherapy catheters for all other sites like breast, skin, and head and neck cancers. Traditional USG has a few limitations, but recent advances such as 3-dimensional (3D USG and contrast USG have enhanced its potential as a dependable guide in high-dose-rate image-guided brachytherapy (HDR-IGBT. The authors in this review have attempted to enumerate various aspects of USG in brachytherapy, highlighting its use across various sites.

  4. Feasibility and toxicity of a single fraction high-dose-rate brachytherapy followed by a course of EBRT for localized prostate cancer, a retrospective study: the Polyclinique Courlancy experience; Faisabilite et toxicite d'une seance unique de curietherapie de haut debit de dose suivie d'une irradiation externe dans le cancer localise de la prostate: etude retrospective de la polyclinique de Courlancy

    Energy Technology Data Exchange (ETDEWEB)

    Mallet, F.; Wdowczyk, D.; Bruna, A.; Joffroy, P.; Pangrazzi, T. [Centre de radiotherapie et d' oncologie, polyclinique Courlancy, Service de radiotherapie, 51 - Reims (France); Villena, P.; Herard, A.; Amory, J.P. [Cabinet d' urologie, polyclinique Courlancy, 51 - Reims (France)

    2010-01-15

    Purpose Evaluate the feasibility and toxicity of radiation dose escalation delivered with a single fraction high-dose-rate (H.D.R.) brachytherapy boost followed by external beam radiotherapy for intermediate and high risk localized prostate cancer - a retrospective study. Patients and methods: Between December 2004 and December 2008, 61 patients with intermediate risk or high-risk localized prostate cancer received a single 10 Gy fraction of interstitial H.D.R. brachytherapy followed by a 64 Gy course of external beam radiation therapy. Dose volume histograms, conformity index and side effects were systematically analyzed. Result; H.D.R. brachytherapy dosimetric criteria were respected. Early side effects (= 3 months after full treatment): 30 % reported grade 2 or grade 3 urinary toxicity and 26 % reported grade 2 or grade 3 bowel toxicity were reported. Late side effects (> 3 months): 12 % reported grade 2 or grade 3 urinary toxicity and 5 % reported grade 2 or grade 3 bowel toxicity were reported. No patients reported any grade 4 late toxicity events. Three months after treatment, 7 % grade 1, 25 % grade 2 and 39 % grade 3 erectile dysfunction were reported. Conclusion. Our mono fractionation protocol is an easy technique to implement logistically. Acute and late toxicities are acceptable and comparable to those published by various teams mostly using multi fractionation protocols. A longer follow-up is required to assess the effect of this dose escalation protocol on long-term biological control. (authors)

  5. High dose rate brachytherapy with customized applicators for malignant facial skin lesions.

    Science.gov (United States)

    Jumeau, R; Renard-Oldrini, S; Courrech, F; Buchheit, I; Oldrini, G; Vogin, G; Peiffert, D

    2016-07-01

    Brachytherapy is a well-known treatment in the management of skin tumors. For facial or scalp lesions, applicators have been developed to deliver non-invasive treatment. We present cases treated with customized applicators with high dose rate system. Patients with poor performance status treated for malignant skin lesions of the scalp or the facial skin between 2011 and 2014 were studied. Afterloading devices were chosen between Freiburg(®) Flap, silicone-mold or wax applicators. The clinical target volume (CTV) was created by adding margins to lesions (10mm to 20mm). The dose schedules were 25Gy in five fractions for postoperative lesions, 30Gy in six fractions for exclusive treatments and a single session of 8Gy could be considered for palliative treatments. In 30 months, 11 patients received a treatment for a total of 12 lesions. The median age was 80 years. The median follow-up was 17 months and the 2-year local control rate was 91%. The mean CTV surface was 41.1cm(2) with a mean thickness of 6.1mm. We conceived three wax applicators, used our silicone-mold eight times and the Freiburg(®) Flap one time. We observed only low-grade radiodermitis (grade I: 50%, grade II: 33%), and no high-grade skin toxicity. High dose rate brachytherapy with customized applicators for facial skin and scalp lesions is efficient and safe. It is a good modality to treat complex lesions in patients unfit for invasive treatment. Copyright © 2016 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  6. High-dose-rate (HDR) brachytherapy for the treatment of benign obstructive endobronchial granulation tissue.

    Science.gov (United States)

    Madu, Chika N; Machuzak, Michael S; Sterman, Daniel H; Musani, Ali; Ahya, Vivek; McDonough, James; Metz, James M

    2006-12-01

    Severe airway obstruction can occur in the setting of benign granulation tissue forming at bronchial anastomotic sites after lung transplantation in up to 20% of patients. Many of these benign lesions respond to stent placement, laser ablation, or balloon bronchoplasty. However, in certain cases, proliferation of granulation tissue may persist despite all therapeutic attempts. This study describes a series of refractory patients treated with high-dose-rate (HDR) brachytherapy for benign proliferation of granulation tissue, causing airway compromise. Between April 2002 and June 2005, 5 patients with significant airway compromise from recurrent granulation tissue were treated with HDR brachytherapy. All patients had previously failed to maintain a patent airway despite multiple bronchoscopic interventions. Treatment was delivered using an HDR brachytherapy afterloader with (192)Ir. Dose prescription was to a depth of 1 cm. All patients were treated weekly, with total doses ranging from 10 Gy to 21 Gy in two to three fractions. The median follow-up was 12 months. All patients experienced a reduction in therapeutic bronchoscopic procedures after HDR brachytherapy compared with the pretreatment period. With the exception of possible radiation-induced bronchitis in 1 patient, there were no other treatment related complications. At the time of this report, 2 patients have died and the other 3 are alive with marked symptomatic improvement and reduced bronchoscopic procedures. High-dose-rate brachytherapy is an effective treatment for benign proliferation of granulation tissue causing airway obstruction. The early response to therapy is encouraging and further follow-up is necessary to determine long-term durability and late effects.

  7. Non-melanoma skin cancer treated with high-dose-rate brachytherapy: a review of literature.

    Science.gov (United States)

    Delishaj, Durim; Rembielak, Agata; Manfredi, Bruno; Ursino, Stefano; Pasqualetti, Francesco; Laliscia, Concetta; Orlandi, Francesca; Morganti, Riccardo; Fabrini, Maria Grazia; Paiar, Fabiola

    2016-12-01

    The incidence of non-melanoma skin cancer (NMSC) has been increasing over the past 30 years. There are different treatment options and surgical excision is the most frequent treatment due to its low rates of recurrence. Radiotherapy is an effective alternative of surgery, and brachytherapy (BT) might be a better therapeutic option due to high radiation dose concentration to the tumor with rapid dose fall-off resulting in normal tissues sparing. The aim of this review was to evaluate the local control, toxicity, and cosmetic outcomes in NMSC treated with high-dose-rate BT (HDR-BT). In May 2016, a systematic search of bibliographic database of PubMed, Web of Science, Scopus, and Cochrane Library with a combination of key words of "skin cancer", "high dose rate brachytherapy", "squamous cell carcinoma", "basal cell carcinoma", and "non melanoma skin cancer" was performed. In this systematic review, we included randomized trials, non-randomized trials, prospective and retrospective studies in patients affected by NMSC treated with HDR-BT. Our searches generated a total of 85 results, and through a process of screening, 10 publications were selected for the review. Brachytherapy was well tolerated with acceptable toxicity and high local control rates (median: 97%). Cosmetic outcome was reported in seven study and consisted in an excellent and good cosmetic results in 94.8% of cases. Based on the review data, we can conclude that the treatment of NMSC with HDR-BT is effective with excellent and good cosmetics results, even in elderly patients. The hypofractionated course appears effective with very good local disease control. More data with large-scale randomized controlled trials are needed to assess the efficacy and safety of brachytherapy.

  8. Bladder wall recurrence of prostate cancer after high-dose-rate brachytherapy.

    Science.gov (United States)

    Raleigh, David R; Hsu, I-Chow; Braunstein, Steve; Chang, Albert J; Simko, Jeffry P; Roach, Mack

    2015-01-01

    Prostate cancer seeding after needle biopsy has been reported in the perineum, rectal wall, and periprostatic soft tissue. In this article, we report the results of a localized prostate cancer recurrence in the bladder following protrusion of a single high-dose-rate brachytherapy catheter through the bladder wall at the ultimate site of failure. A 62-year-old man with high-risk prostate adenocarcinoma was treated with long-term androgen deprivation therapy, intensity-modulated radiation, and high-dose-rate brachytherapy boost. He developed biochemical recurrence 4 years after treatment, and a CT scan of the pelvis revealed a nodule in the posterior, inferior bladder wall. Surgical pathology following transurethral resection of tumor within the bladder was consistent with high-grade prostate adenocarcinoma. The patient's prostate-specific antigen level fell to the range of normal postoperatively, and whole body imaging, including a multi-parametric MRI of the prostate with diffusion and spectroscopy, failed to reveal any other sites of disease. Review of the CT scan obtained for dosimetry at the time of brachytherapy demonstrated a lone catheter protruding through the bladder wall at the site of eventual recurrence. The tumor recurred in the bladder 12 months later, once more without evidence of disease within the prostate itself or distantly, and the patient was started on salvage androgen deprivation therapy. This case is the first report of prostate cancer recurrence in the bladder wall after brachytherapy and raises questions about prostate cancer biology, brachytherapy technique, and the timing of brachytherapy boost relative to whole pelvic radiotherapy for prostate cancer. Published by Elsevier Inc.

  9. Non-melanoma skin cancer treated with high-dose-rate brachytherapy: a review of literature

    Directory of Open Access Journals (Sweden)

    Durim Delishaj

    2016-12-01

    Full Text Available Purpose: The incidence of non-melanoma skin cancer (NMSC has been increasing over the past 30 years. There are different treatment options and surgical excision is the most frequent treatment due to its low rates of recurrence. Radiotherapy is an effective alternative of surgery, and brachytherapy (BT might be a better therapeutic option due to high radiation dose concentration to the tumor with rapid dose fall-off resulting in normal tissues sparing. The aim of this review was to evaluate the local control, toxicity, and cosmetic outcomes in NMSC treated with high-dose-rate BT (HDR-BT. Material and methods: In May 2016, a systematic search of bibliographic database of PubMed, Web of Science, Scopus, and Cochrane Library with a combination of key words of “skin cancer”, “high dose rate brachytherapy”, “squamous cell carcinoma”, “basal cell carcinoma”, and “non melanoma skin cancer“ was performed. In this systematic review, we included randomized trials, non-randomized trials, prospective and retrospective studies in patients affected by NMSC treated with HDR-BT. Results: Our searches generated a total of 85 results, and through a process of screening, 10 publications were selected for the review. Brachytherapy was well tolerated with acceptable toxicity and high local control rates (median: 97%. Cosmetic outcome was reported in seven study and consisted in an excellent and good cosmetic results in 94.8% of cases. Conclusions : Based on the review data, we can conclude that the treatment of NMSC with HDR-BT is effective with excellent and good cosmetics results, even in elderly patients. The hypofractionated course appears effective with very good local disease control. More data with large-scale randomized controlled trials are needed to assess the efficacy and safety of brachytherapy.

  10. 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

  11. Investigations of DNA damage induction and repair resulting from cellular exposure to high dose-rate pulsed proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Renis, M.; Malfa, G.; Tomasello, B. [Drug Sciences Department, University of Catania, Catania (Italy); Borghesi, M.; Schettino, G. [Queen' s University Belfast, Northern Ireland (United Kingdom); Favetta, M.; Romano, F.; Cirrone, G. A. P. [National Institute for Nuclear Physics (INFN-LNS), Catania (Italy); Manti, L. [Physics Science Department, University of Naples Federico II, Naples, and National Institute for Nuclear Physics (INFN), Naples (Italy)

    2013-07-26

    Studies regarding the radiobiological effects of low dose radiation, microbeam irradiation services have been developed in the world and today laser acceleration of protons and heavy ions may be used in radiation therapy. The application of different facilities is essential for studying bystander effects and relating signalling phenomena in different cells or tissues. In particular the use of ion beams results advantageous in cancer radiotherapy compared to more commonly used X-rays, since the ability of ions in delivering lethal amount of doses into the target tumour avoiding or limiting damage to the contiguous healthy tissues. At the INFN-LNS in Catania, a multidisciplinary radiobiology group is strategically structured aimed to develop radiobiological research, finalised to therapeutic applications, compatible with the use of high dose laser-driven ion beams. The characteristic non-continuous dose rates with several orders of magnitude of laser-driven ion beams makes this facility very interesting in the cellular systems' response to ultra-high dose rates with non-conventional pulse time intervals cellular studies. Our group have projected to examine the effect of high dose laser-driven ion beams on two cellular types: foetal fibroblasts (normal control cells) and DU145 (prostate cancer cells), studying the modulation of some different bio-molecular parameters, in particular cell proliferation and viability, DNA damage, redox cellular status, morphological alterations of both the cytoskeleton components and some cell organelles and the possible presence of apoptotic or necrotic cell death. Our group performed preliminary experiments with high energy (60 MeV), dose rate of 10 Gy/min, doses of 1, 2, 3 Gy and LET 1 keV/μm on human foetal fibroblasts (control cells). We observed that cell viability was not influenced by the characteristics of the beam, the irradiation conditions or the analysis time. Conversely, DNA damage was present at time 0, immediately

  12. Investigations of DNA damage induction and repair resulting from cellular exposure to high dose-rate pulsed proton beams

    Science.gov (United States)

    Renis, M.; Borghesi, M.; Favetta, M.; Malfa, G.; Manti, L.; Romano, F.; Schettino, G.; Tomasello, B.; Cirrone, G. A. P.

    2013-07-01

    Studies regarding the radiobiological effects of low dose radiation, microbeam irradiation services have been developed in the world and today laser acceleration of protons and heavy ions may be used in radiation therapy. The application of different facilities is essential for studying bystander effects and relating signalling phenomena in different cells or tissues. In particular the use of ion beams results advantageous in cancer radiotherapy compared to more commonly used X-rays, since the ability of ions in delivering lethal amount of doses into the target tumour avoiding or limiting damage to the contiguous healthy tissues. At the INFN-LNS in Catania, a multidisciplinary radiobiology group is strategically structured aimed to develop radiobiological research, finalised to therapeutic applications, compatible with the use of high dose laser-driven ion beams. The characteristic non-continuous dose rates with several orders of magnitude of laser-driven ion beams makes this facility very interesting in the cellular systems' response to ultra-high dose rates with non-conventional pulse time intervals cellular studies. Our group have projected to examine the effect of high dose laser-driven ion beams on two cellular types: foetal fibroblasts (normal control cells) and DU145 (prostate cancer cells), studying the modulation of some different bio-molecular parameters, in particular cell proliferation and viability, DNA damage, redox cellular status, morphological alterations of both the cytoskeleton components and some cell organelles and the possible presence of apoptotic or necrotic cell death. Our group performed preliminary experiments with high energy (60 MeV), dose rate of 10 Gy/min, doses of 1, 2, 3 Gy and LET 1 keV/μm on human foetal fibroblasts (control cells). We observed that cell viability was not influenced by the characteristics of the beam, the irradiation conditions or the analysis time. Conversely, DNA damage was present at time 0, immediately

  13. Comparative dosimetry of GammaMed Plus high-dose rate Ir brachytherapy source.

    Science.gov (United States)

    Patel, N P; Majumdar, B; Vijayan, V

    2010-07-01

    The comparative dosimetry of GammaMed (GM) Plus high-dose rate brachytherapy source was performed by an experiment using 0.1-cc thimble ionization chamber and simulation-based study using EGSnrc code. In-water dose measurements were performed with 0.1-cc chamber to derive the radial dose function (r = 0.8 to 20.0 cm) and anisotropy function (r = 5.0 cm with polar angle from 10° to 170°). The nonuniformity correction factor for 0.1-cc chamber was applied for in-water measurements at shorter distances from the source. The EGSnrc code was used to derive the dose rate constant (Λ), radial dose function g(L)(r) and anisotropy function F(r, θ) of GM Plus source. The dosimetric data derived using EGSnrc code in our study were in very good agreement relative to published data for GM Plus source. The radial dose function up to 12 cm derived from measured dose using 0.1-cc chamber was in agreement within ±3% of data derived by the simulation study.

  14. Postoperative single-dose interstitial high-dose-rate brachytherapy in therapy-resistant keloids.

    Science.gov (United States)

    Hafkamp, C J H; Lapid, O; Dávila Fajardo, R; van de Kar, A L; Koedooder, C; Stalpers, L J; Pieters, B R

    Patients with keloids complain of the cosmetic aspect, pain, and pruritus. Many different therapies are being used for keloids. The aim of this study was to evaluate the recurrence rate and outcome after resection followed by a single-dose brachytherapy. Patients treated by resection of the keloid plus a single dose of 13 Gy high-dose-rate brachytherapy were evaluated at least 1 year after treatment. Clinical response and cosmesis were assessed by a plastic surgeon and by the patients using the Patient and Observer Scar Assessment Scale. Only 24 of the 61 invited patients responded to participate with the study; 29 keloids were evaluated. The recurrence rate was 24.1% after a median followup of 53 months (19-95 months). Patients scored on average 24.3 for their total Patient and Observer Scar Assessment Scale score (range 6-52), whereas the observer scored on average 14.6 (range 6-42). This treatment has a higher recurrence rate than that reported in most other studies. This may be explained by differences in recurrence definition, differences in followup time among studies, and selection bias because of not contributing to the study. The cosmetic outcome for evaluated patients is relatively good. This treatment policy has the advantage that patients are treated in a single day. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  15. Assessment of dose uniformity around high dose rate 192Ir and 60Co stepping sources.

    Science.gov (United States)

    Farhood, Bagher; Ghorbani, Mahdi

    2017-12-01

    This study aimed to evaluate dose uniformity for 192Ir and 60Co stepping sources. High dose rate 192Ir and 60Co stepping sources were simulated by the MCNPX Monte Carlo code. To investigate dose uniformity, treatment lengths of 30, 50, 100, and 150 mm with stepping distances of 3, 5, 7, and 10 mm were considered. Finally, dose uniformity for the 192Ir and 60Co stepping sources with increasing distances from the source were assessed at these treatment lengths and steps. The findings showed that the dose distribution was non-uniform for regions in close vicinity of the source, especially in the high source steps, but for most points at distances >10 mm from the center of the source, the dose distribution was uniform. For most points, the dose uniformity increased with reduction of the source steps and increments of the transverse distance from the source. The dose non-uniformity was similar for most of the corresponding points of 60Co and 192Ir sources with the same treatment lengths and source steps, except at the distance of 150 mm. When using stepping technique for the treatment of tumors, more attention should be focused on treatment planning, especially with higher stepping distances and lower transverse distances from the source.

  16. High-dose-rate interstitial brachytherapy for the treatment of penile carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Petera, J.; Odrazka, K.; Zouhar, M.; Bedrosova, J.; Dolezel, M. [Dept. of Oncology and Radiotherapy, Charles Univ. Medical School and Teaching Hospital, Hradec Kralove (Czech Republic)

    2004-02-01

    Background: interstitial low-dose-rate (LDR) brachytherapy allows conservative treatment of T1-T2 penile carcinoma. High-dose-rate (HDR) is often considered to be dangerous for interstitial implants because of a higher risk of complications, but numerous reports suggest that results may be comparable to LDR. Nevertheless, there are no data in the literature available regarding HDR interstitial brachytherapy for carcinoma of the penis. Case report: a 64-year-old man with T1 NO MO epidermoid carcinoma of the glans is reported. Interstitial HDR brachytherapy was performed using the stainless hollow needle technique and a breast template for fixation and good geometry. The dose delivered was 18 x 3 Gy twice daily. Results: after 232 days from brachytherapy, the patient was without any evidence of the tumor, experienced no serious radiation-induced complications, and had a fully functional organ. Conclusion: HDR interstitial brachytherapy is feasible in selected case of penis carcinoma, when careful planning and small single fractions are used. (orig.)

  17. 3D-printed applicators for high dose rate brachytherapy: Dosimetric assessment at different infill percentage.

    Science.gov (United States)

    Ricotti, Rosalinda; Vavassori, Andrea; Bazani, Alessia; Ciardo, Delia; Pansini, Floriana; Spoto, Ruggero; Sammarco, Vittorio; Cattani, Federica; Baroni, Guido; Orecchia, Roberto; Jereczek-Fossa, Barbara Alicja

    2016-12-01

    Dosimetric assessment of high dose rate (HDR) brachytherapy applicators, printed in 3D with acrylonitrile butadiene styrene (ABS) at different infill percentage. A low-cost, desktop, 3D printer (Hamlet 3DX100, Hamlet, Dublin, IE) was used for manufacturing simple HDR applicators, reproducing typical geometries in brachytherapy: cylindrical (common in vaginal treatment) and flat configurations (generally used to treat superficial lesions). Printer accuracy was investigated through physical measurements. The dosimetric consequences of varying the applicator's density by tuning the printing infill percentage were analysed experimentally by measuring depth dose profiles and superficial dose distribution with Gafchromic EBT3 films (International Specialty Products, Wayne, NJ). Dose distributions were compared to those obtained with a commercial superficial applicator. Measured printing accuracy was within 0.5mm. Dose attenuation was not sensitive to the density of the material. Surface dose distribution comparison of the 3D printed flat applicators with respect to the commercial superficial applicator showed an overall passing rate greater than 94% for gamma analysis with 3% dose difference criteria, 3mm distance-to-agreement criteria and 10% dose threshold. Low-cost 3D printers are a promising solution for the customization of the HDR brachytherapy applicators. However, further assessment of 3D printing techniques and regulatory materials approval are required for clinical application. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  18. Fractionated high-dose-rate brachytherapy in the management of uterine cervical cancer.

    Science.gov (United States)

    Park, Hee-Chul; Suh, Chang Ok; Kim, Gwi Eon

    2002-12-01

    It is well known that intracavitary radiotherapy (ICR), either alone or in combination with external-beam radiotherapy (EBRT) is an essential component of the radiation treatment of uterine cervical cancer. Although low-dose-rate (LDR) brachytherapy has been successfully applied to the management of such patients, several radiation oncologists have experience of using high-dose-rate (HDR) brachytherapy with promising clinical results over the past 4 decades. However, there has been a considerable reluctance by radiation oncologists and gynecologists in North America to employ the HDR remote afterloading technique instead of the more firmly established LDR treatment modality. In contrast, the HDR-ICR system is rapidly gaining acceptance in Korea since the introduction of the Ralstron, remotely controlled afterloading system using HDR Co-60 sources, at the Yonsei Cancer Center in 1979. According to brachytherapy statistics reported by the Korean Society of Therapeutic Radiology and Oncology, in 1997, brachytherapy was performed upon 1,758 Korean patients with uterine cervical cancer, of whom approximately 83% received HDR brachytherapy. In this review, we present our experiences of HDR-ICR for the treatment of uterine cervical cancer. In addition, we discuss the controversial points, which are raised by those considering the use of HDR-ICR for uterine cervical cancer; these issues include physical and radiobiological considerations, and the prospect of future technical improvements.

  19. Hypofractionated high-dose-rate plesiotherapy in nonmelanoma skin cancer treatment.

    Science.gov (United States)

    Arenas, Meritxell; Arguís, Monica; Díez-Presa, Lorena; Henríquez, Ivan; Murcia-Mejía, Mauricio; Gascón, Marina; Gómez, David; Lafuerza, Anna; Mur, Encarna; Azón, Antoni; Rovirosa, Àngels; Sabater, Sebastià

    2015-01-01

    Nonmelanoma skin cancer (NMSC) is the commonest cancer in humans. NMSC treatment currently includes surgery, radiation therapy, and topical approaches. The objective was to analyze and compare the outcomes, toxicity, and cosmesis of NMSC treated by two hypofractionated high-dose-rate (HDR) plesiotherapy techniques. A retrospective institutional clinical study of 134 basal cell or squamous cell skin carcinomas treated at Radiation Oncology Department. Lesions were treated from November 2006 to December 2011 with a moderate hypofractionated HDR plesiotherapy using a fixed applicator or a customized mold. After a median follow-up of 33 months, overall disease-free survival at 3 and 5 years was 95.12% and 93.36%, respectively. For Leipzig applicator, disease-free survival at 3 years was 94.9% and 94.9% at 5 years, for customized mold was 93.1% at 3 years and 88% at 5 years. Complete regression was achieved in 98% of lesions. Two lesions persisted after treatment; both had been treated by a Leipzig applicator. Six lesions suffered local recurrence (five Leipzig applicators and three molds, p = 0.404). Grade skin toxicity. The cosmesis outcomes were excellent or good in 82% of patients, fair in 13%, and not available in 5%. Hypofractionated HDR plesiotherapy is an effective and well-tolerated treatment for NMSC with different toxicity levels depending on the plesiotherapy technique used. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  20. Prognostic factors in squamous cell lip carcinoma treated with high-dose-rate brachytherapy.

    Science.gov (United States)

    Guinot, Jose-Luis; Arribas, Leoncio; Vendrell, Juan B; Santos, Miguel; Tortajada, Maria I; Mut, Alejandro; Cruz, Julia; Mengual, Jose L; Chust, Maria L

    2014-12-01

    The purpose of this study was for us to present our analysis of the results and prognostic factors in squamous lip carcinoma treated with high-dose-rate (HDR) brachytherapy. From 1999 to 2010, 102 patients were treated with HDR-brachytherapy, 54 with T1, 33 with T2, and 15 with T4. Eight cases were N+. Twenty-one patients were treated with surgery plus brachytherapy because of close/positive margins. Nine fractions of 5 Gy were given over 5 days in 67% of the patients. Elective neck treatment was performed in 23 cases. The 10-year actuarial local control was 94.6%, nodal regional control was 88.6%, disease-free survival was 84.6%, and cause-specific survival was 93.2%. In the univariate analysis, T4 tumors had higher risk of local failure and T2 of regional relapse. In the multivariate analysis, skin involvement was the only significant factor for tumor progression. HDR-brachytherapy yields excellent local control rates. Skin involvement increases the risk of local and cervical recurrence. Elective neck treatment should be done in T2 to T4 tumors or with skin or commissure involvement. © 2014 Wiley Periodicals, Inc.

  1. A dose verification method for high-dose-rate brachytherapy treatment plans.

    Science.gov (United States)

    Kumar, Rajesh; Sharma, S D; Vijaykumar, C; Deshpande, Sudesh; Sharma, P K; Vandana, S; Philomena, A; Chilkulwar, Ravi H

    2008-01-01

    To evolve a fast dose verification method for high-dose-rate (HDR) brachytherapy treatment plans and to demonstrate its applicability in different clinical cases. We developed a software tool in VC++ for the Varisource HDR unit for HDR dosimetry plan verification using TG-43 parameters. HDR treatment dosimetry of a number clinical cases using Varisource was verified by comparison with the treatment planning system (TPS). A number of different types of clinical cases treated by Varisource were evaluated. TPS calculated dose values and verification code calculated dose values were found to agree to within 3% for most of the dose calculation points. We have validated with clinical cases a fast and independent dose verification method of the dosimetry at selected points for HDR brachytherapy treatments plan using TG-43 parameters. This can be used for the verification of the TPS calculated dose at various points. The code is written to work with Varisource, but it can conceivably be modified for other sources also by using the fitted constant of the respective source.

  2. Current situation of high-dose-rate brachytherapy for cervical cancer in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rogerio Matias Vidal da; Souza, Divanizia do Nascimento, E-mail: rmv.fisica@gmail.com [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil); Pinezi, Juliana Castro Dourado [Pontificia Universidade Catolica de Goias (PUC-Goias), Goiania, GO (Brazil); Macedo, Luiz Eduardo Andrade [Hospital Chama, Arapiraca, AL (Brazil)

    2014-05-15

    To assess the current situation of high-dose-rate (HDR) brachytherapy for cancer of the cervix in Brazil, regarding apparatuses, planning methods, prescription, fractionation schedule and evaluation of dose in organs at risk. Materials and methods: in the period between March/2012 and May/2013, a multiple choice questionnaire was developed and sent to 89 Brazilian hospitals which perform HDR brachytherapy. Results: sixty-one services answered the questionnaire. All regions of the country experienced a sharp increase in the number of HDR brachytherapy services in the period from 2001 to 2013. As regards planning, although a three-dimensional planning software was available in 91% of the centers, conventional radiography was mentioned by 92% of the respondents as their routine imaging method for such a purpose. Approximately 35% of respondents said that brachytherapy sessions are performed after teletherapy. The scheme of four 7 Gy intracavitary insertions was mentioned as the most frequently practiced. Conclusion: the authors observed that professionals have difficulty accessing adjuvant three-dimensional planning tools such as computed tomography and magnetic resonance imaging. (author)

  3. Verification of SuperMC for simulation of a high-dose-rate brachytherapy source

    Science.gov (United States)

    Naeem, Hamza; Wasaye, Muhammad Abdul; Chen, Chaobin; Zheng, Huaqing; Hao, Lijuan

    2017-06-01

    In this study, SuperMC (Super Monte Carlo simulation program for nuclear and radiation simulation) was tested and verified for simulation of a high-dose-rate brachytherapy source. The Monte Carlo simulation includes calculations of the air kerma strength, dose rate constant, radial dose function and anisotropy function as recommended by the American Association of Physicists in Medicine (AAPM) in Task Group reports 43 and 43U1 (TG-43, TG-43U1). The air kerma strength, dose rate constant, radial dose function and anisotropy function were compared with previously published Monte Carlo simulation results and experimental data. The calculated parameters were found to be in good agreement with published Monte Carlo and measured data. The value obtained from the SuperMC simulation for the air kerma strength was 9.779 × 10-8 U·Bq-1 and the dose rate constant was 1.1092 ± 0.02% cGy·h-1·U-1. The time to transport 5 × 107 photons showed SuperMC to be relatively faster than MCNP. The results show that SuperMC can be used for fast and accurate simulations and dosimetric calculations of HDR brachytherapy sources.

  4. High dose rate 192Ir source calibration: A single institution experience

    Science.gov (United States)

    Abdullah, R.; Abdullah, N. H.; Mohamed, M.; Idris, N. R. N.; Yusoff, A. L.; Chen, S. C.; Zakaria, A.

    2017-05-01

    Measurement of source strength of new high dose rate (HDR) 192Ir supplied by the manufacturer is part of quality assurance recommended by Radiation Safety Section, Ministry of Health of Malaysia. The source strength is determined in reference air kerma rate (RAKR). The purpose of this study was to evaluate RAKR measurement of 192Ir using well-type ionisation chamber with RAKR stated in the certificate provided by the manufacturer. A retrospective study on 19 MicroSelectron HDR 192Ir Classic from 2001 to 2009 and 12 MicroSelectron HDR 192Ir V2 sources from 2009 to 2016 supplied by manufacturer were compared. From the study, the agreement between measured RAKR and RAKR stated in the certificate by manufacturer for all 32 sources supplied were within ±2.5%. As a conclusion, a threshold level of ±2.5% can be used as suitable indicator to spot problems of the brachytherapy system in Department of Nuclear Medicine Radiotherapy and Oncology, Hospital USM.

  5. Preoperative high dose rate brachytherapy for clinical stage II endometrial carcinoma

    Directory of Open Access Journals (Sweden)

    Alexander Olawaiye

    2011-07-01

    Full Text Available Purpose: We sought to evaluate pathological response, tolerance, and outcome after preoperative (neoadjuvant high dose rate brachytherapy in a small series of patients with clinical stage II endometrial carcinoma, and to evaluate a dose and fractionation protocol for this treatment. Material and methods: Twelve women diagnosed with clinical stage II endometrial carcinoma from 1999-2010 were treated with preoperative radiation therapy. Their medical charts were retrospectively analyzed for HDR treatment regimen, pathological response, and longitudinal outcomes. Radiation doses were normalized to a biologically equi­valent dose of 2 Gy per fraction (EQD2. Results: Two patients had complete pathological response to neoadjuvant therapy; five more had only microscopic residual disease at the time of surgery. At a median follow up of 37 months (1-91 months, one patient has developed recurrence at the vaginal apex six months after completing initial therapy, while another developed a lung recurrence at 28 months. Two-year disease-free and cause-specific survivals were 88% and 100%, respectively. Conclusions: Our small study shows that the HDR fractionation schedule, as done in our series for preoperative radiation therapy for clinical stage II endometrial cancer, is well tolerated and would be an option for patients treated with neoadjuvant radiation therapy.

  6. Monte Carlo dose calculations for high-dose-rate brachytherapy using GPU-accelerated processing.

    Science.gov (United States)

    Tian, Z; Zhang, M; Hrycushko, B; Albuquerque, K; Jiang, S B; Jia, X

    2016-01-01

    Current clinical brachytherapy dose calculations are typically based on the Association of American Physicists in Medicine Task Group report 43 (TG-43) guidelines, which approximate patient geometry as an infinitely large water phantom. This ignores patient and applicator geometries and heterogeneities, causing dosimetric errors. Although Monte Carlo (MC) dose calculation is commonly recognized as the most accurate method, its associated long computational time is a major bottleneck for routine clinical applications. This article presents our recent developments of a fast MC dose calculation package for high-dose-rate (HDR) brachytherapy, gBMC, built on a graphics processing unit (GPU) platform. gBMC-simulated photon transport in voxelized geometry with physics in (192)Ir HDR brachytherapy energy range considered. A phase-space file was used as a source model. GPU-based parallel computation was used to simultaneously transport multiple photons, one on a GPU thread. We validated gBMC by comparing the dose calculation results in water with that computed TG-43. We also studied heterogeneous phantom cases and a patient case and compared gBMC results with Acuros BV results. Radial dose function in water calculated by gBMC showed GPU-based MC dose calculation package, gBMC, for HDR brachytherapy make it attractive for clinical applications. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  7. Clinical outcome of high-dose-rate interstitial brachytherapy in patients with oral cavity cancer

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    Lee, Sung Uk; Cho, Kwan Ho; Moon, Sung Ho; Choi, Sung Weon; Park, Joo Yong; Yun, Tak; Lee, Sang Hyun; Lim, Young Kyung; Jeong, Chi Young [National Cancer Center, Goyang (Korea, Republic of)

    2014-12-15

    To evaluate the clinical outcome of high-dose-rate (HDR) interstitial brachytherapy (IBT) in patients with oral cavity cancer. Sixteen patients with oral cavity cancer treated with HDR remote-control afterloading brachytherapy using 192Ir between 2001 and 2013 were analyzed retrospectively. Brachytherapy was administered in 11 patients as the primary treatment and in five patients as salvage treatment for recurrence after the initial surgery. In 12 patients, external beam radiotherapy (50-55 Gy/25 fractions) was combined with IBT of 21 Gy/7 fractions. In addition, IBT was administered as the sole treatment in three patients with a total dose of 50 Gy/10 fractions and as postoperative adjuvant treatment in one patient with a total of 35 Gy/7 fractions. The 5-year overall survival of the entire group was 70%. The actuarial local control rate after 3 years was 84%. All five recurrent cases after initial surgery were successfully salvaged using IBT +/- external beam radiotherapy. Two patients developed local recurrence at 3 and 5 months, respectively, after IBT. The acute complications were acceptable (< or =grade 2). Three patients developed major late complications, such as radio-osteonecrosis, in which one patient was treated by conservative therapy and two required surgical intervention. HDR IBT for oral cavity cancer was effective and acceptable in diverse clinical settings, such as in the cases of primary or salvage treatment.

  8. The use of adjuvant high-dose-rate breast brachytherapy in patients with collagen vascular disease: a collaborative experience.

    Science.gov (United States)

    Dragun, Anthony E; Harper, Jennifer L; Olyejar, S Eric; Zunzunegui, Raul G; Wazer, David E

    2011-01-01

    To analyze toxicity and cosmesis in patients with collagen vascular disease (CVD) treated with accelerated partial breast irradiation (APBI) via high-dose-rate (HDR) brachytherapy. This is a pooled analysis of patients with early stage and in situ breast cancer with CVD treated with adjuvant multicatheter or balloon brachytherapy. Physicians at multiple institutions were asked to review their experience and report data regarding toxicity and cosmesis in patients with CVD. All patients fit American Society of Breast Surgeons recommendations for APBI and were treated with HDR brachytherapy with ≥ 3 months followup. Nine cases from five institutions are the subject of this analysis. The median patient age was 54 years and median followup was 31 months. All patients had documented history and active signs/symptoms of rheumatoid arthritis, systemic lupus erythematosis, psoriatic arthritis, or scleroderma. All patients had received medical therapy for CVD in the past, and 78% were under active treatment at the time of brachytherapy. All the patients were treated with multicatheter or balloon (MammoSite [Hologic, Inc., Marlboro, MA], MammoSite ML [Hologic, Inc., Marlboro, MA], or Contura [Senorx, Irvine, CA]) brachytherapy with a median volume of 45.5 cc and a median skin distance of 7.5mm. Acute toxicity included Grade 1 skin erythema (5) and catheter-site wound dehiscence (1). Late toxicity included seroma (5), induration (5), pain (2), telangectasia (2), and superficial infection (1). Cosmesis was excellent or good for all the patients. Women with CVD have a toxicity and cosmesis profile consistent with other APBI series. Although confirmatory data is needed, it may not be necessary to exclude these patients from clinical trials of APBI. Copyright © 2011 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  9. Image-guided high-dose-rate brachytherapy of head and neck – a case series study

    Science.gov (United States)

    Kieszko, Dariusz; Brzozowska, Anna; Kordzin’ska-Cisek, Izabela; Mazurkiewicz, Maria

    2016-01-01

    Purpose The aim of the study was the evaluation of image guided transdermal application of interstitial brachytherapy in patients undergoing repeated irradiation for relapsed local tumor of the head and neck area. Material and methods The article describes transdermal application of interstitial high-dose-rate (HDR) brachytherapy in 4 patients treated due to relapsed local tumor in soft palate, submandibular area, laryngopharynx, as well as pterygoid muscles and maxillary sinus. The application was conducted under continuous computed tomography (CT)-image guidance (CT fluoroscopy). Patients qualified for this type of treatment had neoplastic lesions located deep under the skin surface. Because of their location, access to the lesions was limited, and the risk of damaging the adjacent tissues such as vessels and nerves was high. The following parameters have been evaluated: clinical response using RECIST 1.1, incidence of perisurgical complications using CTCAE 4.0 and the frequency of occurrence of radiotherapy related early morbidity using RTOG. Results Various radiation schemes were used, from 3 to 5 fractions of 3.5-5 Gy. The median total dose (D90) was 20.6 Gy. Biologic effective dose (BED) and equivalent 2 Gy (DEQ2) median doses were 30.4 Gy and 25.3 Gy, respectively. In the follow-up period of 3-7 months (the median value of 3.5 months), 2 patients had partial regression of the disease and in 2 others the neoplastic process was stabilized. None of the patients had serious complications of treatment (of 3rd degree or higher). Conclusions Computed tomography-image guided brachytherapy proved to be a safe method of treatment in patients with local relapse in sites, in which traditional visually controlled application was impossible due to risk of complications. Despite short observation period and small study group, it seems justified to conduct prospective studies for the evaluation of efficacy and safety of CT-image guided brachytherapy. PMID:28115962

  10. Image-guided high-dose-rate brachytherapy of head and neck – a case series study

    Directory of Open Access Journals (Sweden)

    Paweł Cisek

    2016-11-01

    Full Text Available Purpose: The aim of the study was the evaluation of image guided transdermal application of interstitial brachytherapy in patients undergoing repeated irradiation for relapsed local tumor of the head and neck area. Material and methods : The article describes transdermal application of interstitial high-dose-rate (HDR bra­chytherapy in 4 patients treated due to relapsed local tumor in soft palate, submandibular area, laryngopharynx, as well as pterygoid muscles and maxillary sinus. The application was conducted under continuous computed tomography (CT-image guidance (CT fluoroscopy. Patients qualified for this type of treatment had neoplastic lesions located deep under the skin surface. Because of their location, access to the lesions was limited, and the risk of damaging the adjacent tissues such as vessels and nerves was high. The following parameters have been evaluated: clinical response using RECIST 1.1, incidence of perisurgical complications using CTCAE 4.0 and the frequency of occurrence of radiotherapy related early morbidity using RTOG. Results: Various radiation schemes were used, from 3 to 5 fractions of 3.5-5 Gy. The median total dose (D90 was 20.6 Gy. Biologic effective dose (BED and equivalent 2 Gy (DEQ2 median doses were 30.4 Gy and 25.3 Gy, respectively. In the follow-up period of 3-7 months (the median value of 3.5 months, 2 patients had partial regression of the disease and in 2 others the neoplastic process was stabilized. None of the patients had serious complications of treatment (of 3rd degree or higher. Conclusions : Computed tomography-image guided brachytherapy proved to be a safe method of treatment in patients with local relapse in sites, in which traditional visually controlled application was impossible due to risk of complications. Despite short observation period and small study group, it seems justified to conduct prospective studies for the evaluation of efficacy and safety of CT-image guided brachytherapy.

  11. High-dose-rate intraoperative brachytherapy (IOHDR) using flab technique in the treatment of soft tissue sarcomas

    Energy Technology Data Exchange (ETDEWEB)

    Rachbauer, F.; Sununu, T.; Bach, C.; Nogler, M.; Krismer, M. [Dept. of Orthopedics, Univ. of Innsbruck (Austria); Sztankay, A.; Eichberger, P.; Schiestl, B.; Lukas, P. [Dept. of Radiotherapy-Radiooncology, Univ. of Innsbruck (Austria); Kreczy, A. [Inst. of Pathologic Anatomy, Univ. of Innsbruck (Austria)

    2003-07-01

    Background: Adjuvant radiotherapy has been shown to improve local control in patients with soft tissue sarcoma. Additional brachytherapy represents a means of enhancing the therapeutic ratio, as biological and dosimetric advantage over single external-beam irradiation (EBRT) can be expected. High-dose-rate intraoperative brachytherapy (IOHDR) as a boost therapy should therefore be able to further diminish the rate of local recurrence even when performing marginal resection. There are sparse data on IOHDR using flab applicators as adjuvant boost to EBRT in combination with marginal resection of soft tissue sarcomas. Patients and Methods: Within a period of 8 years, we prospectively studied 39 adult patients treated by marginal resection, IOHDR using the flab technique and EBRT for soft tissue sarcomas. There were 32 high-grade and seven low-grade tumors, 35 were > 5 cm. Mean follow-up was 26 months (range 3-59 months). Results: We could not detect any local recurrences. No treatment-related loss of limb or life occurred. There were no neurologic or vascular complications, all patients maintained functioning extremities as evidenced by a mean musculoskeletal tumor society (MSTS) functional score of 88.5 (70-100). Treatment-related wound morbidity occurred in eleven patients necessitating revision surgery in eight. Metastatic disease developed in seven patients, six of them had died. The 2-year actuarial disease-free survival was 84%. Conclusions: IOHDR using the flab technique in combination with EBRT and marginal resection is an efficient treatment technique leading to optimal local control rates and limited functional impairment. (orig.)

  12. Radioablation of adrenal gland malignomas with interstitial high-dose-rate brachytherapy. Efficacy and outcome

    Energy Technology Data Exchange (ETDEWEB)

    Mohnike, K. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Radiologie und Nuklearmedizin, Magdeburg (Germany); DTZ am Frankfurter Tor, Berlin (Germany); Neumann, K.; Seidensticker, M.; Seidensticker, R.; Pech, M.; Streitparth, T.; Ricke, J. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Radiologie und Nuklearmedizin, Magdeburg (Germany); Hass, P.; Gademann, G. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Strahlentherapie, Magdeburg (Germany); Klose, S. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Nieren- und Hochdruckkrankheiten, Diabetologie und Endokrinologie, Magdeburg (Germany); Garlipp, B.; Benckert, C. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Allgemein-, Viszeral- und Gefaesschirurgie, Magdeburg (Germany); Wendler, J.J.; Liehr, U.B.; Schostak, M. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Urologie und Kinderurologie, Magdeburg (Germany); Goeppner, D. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Dermatologie, Magdeburg (Germany)

    2017-08-15

    To assess the efficacy, safety, and outcome of image-guided high-dose-rate (HDR) brachytherapy in patients with adrenal gland metastases (AGM). From January 2007 to April 2014, 37 patients (7 female, 30 male; mean age 66.8 years, range 41.5-82.5 years) with AGM from different primary tumors were treated with CT-guided HDR interstitial brachytherapy (iBT). Primary endpoint was local tumor control (LTC). Secondary endpoints were time to untreatable progression (TTUP), time to progression (TTP), overall survival (OS), and safety. In a secondary analysis, risk factors with an influence on survival were identified. The median biological equivalent dose (BED) was 37.4 Gy. Mean LTC after 12 months was 88%; after 24 months this was 74%. According to CTCAE criteria, one grade 3 adverse event occurred. Median OS after first diagnosis of AGM was 18.3 months. Median OS, TTUP, and TTP after iBT treatment were 11.4, 6.6, and 3.5 months, respectively. Uni- and multivariate Cox regression analyses revealed significant influences of synchronous disease, tumor diameter, and the total number of lesions on OS or TTUP or both. Image-guided HDR-iBT is safe and effective. Treatment- and primary tumor-independent features influenced survival of patients with AGM after HDR-iBR treatment. (orig.) [German] Beurteilung der Effektivitaet, Sicherheit und Ergebnisse nach bildgefuehrter High-dose-rate-(HDR-)Brachytherapie bei Patienten mit Nebennierenmetastasen. Von Januar 2007 bis April 2014 wurden 37 Patienten (7 weiblich, 30 maennlich; mittleres Alter 66,8 Jahre, Spanne 41,5-82,5 Jahre) mit Nebennierenmetastasen verschiedener Primarien mit CT-gesteuerter interstitieller HDR-Brachytherapie (iBT) behandelt. Der primaere Endpunkt war die lokale Tumorkontrolle (LTC). Sekundaere Endpunkte umfassten die Zeit bis zum nicht mehr behandelbaren Progress (TTUP), die Zeit bis zum Progress (TTP), das Gesamtueberleben (OS) und die Sicherheit der Methode. In einer sekundaeren Analyse wurden Risikofaktoren

  13. Monte Carlo Dosimetry of the 60Co BEBIG High Dose Rate for Brachytherapy.

    Directory of Open Access Journals (Sweden)

    Luciana Tourinho Campos

    Full Text Available The use of high-dose-rate brachytherapy is currently a widespread practice worldwide. The most common isotope source is 192Ir, but 60Co is also becoming available for HDR. One of main advantages of 60Co compared to 192Ir is the economic and practical benefit because of its longer half-live, which is 5.27 years. Recently, Eckert & Ziegler BEBIG, Germany, introduced a new afterloading brachytherapy machine (MultiSource®; it has the option to use either the 60Co or 192Ir HDR source. The source for the Monte Carlo calculations is the new 60Co source (model Co0.A86, which is referred to as the new BEBIG 60Co HDR source and is a modified version of the 60Co source (model GK60M21, which is also from BEBIG.The purpose of this work is to obtain the dosimetry parameters in accordance with the AAPM TG-43U1 formalism with Monte Carlo calculations regarding the BEBIG 60Co high-dose-rate brachytherapy to investigate the required treatment-planning parameters. The geometric design and material details of the source was provided by the manufacturer and was used to define the Monte Carlo geometry. To validate the source geometry, a few dosimetry parameters had to be calculated according to the AAPM TG-43U1 formalism. The dosimetry studies included the calculation of the air kerma strength Sk, collision kerma in water along the transverse axis with an unbounded phantom, dose rate constant and radial dose function. The Monte Carlo code system that was used was EGSnrc with a new cavity code, which is a part of EGS++ that allows calculating the radial dose function around the source. The spectrum to simulate 60Co was composed of two photon energies, 1.17 and 1.33 MeV. Only the gamma part of the spectrum was used; the contribution of the electrons to the dose is negligible because of the full absorption by the stainless-steel wall around the metallic 60Co. The XCOM photon cross-section library was used in subsequent simulations, and the photoelectric effect, pair

  14. Verification of High Dose Rate 192Ir Source Position During Brachytherapy Treatment Using Silicon Pixel Detectors

    Science.gov (United States)

    Batic, Matej; Burger, Janez; Cindro, Vladimir; Kramberger, Gregor; Mandic, Igor; Mikuz, Marko; Studen, Andrej; Zavrtanik, Marko

    2011-10-01

    A system for in-vivo tracking of 192Ir source during high dose rate or pulsed dose rate brachytherapy treatment was built using 1 mm thick silicon pad detectors as image sensors and knife-edge lead pinholes as collimators. With source self-images obtained from a dual-pinhole system, location of the source could be reconstructed in three dimensions in real time. The system was tested with 192Ir clinical source (kerma rate in air at 1 m 2.38 Gy/h) in air and plexi-glass phantom. The locations of the source were tracked from a distance of 40 cm in a field of view of 20 × 20 × 20 cm3. Reconstruction precision, defined as the average distance between true and reconstructed source positions, with data collected in less than 1 s with 22 GBq 192Ir source was about 5 mm. The reconstruction precision was in our case mainly limited by imperfect alignment of detectors and pinholes. With perfect alignment the statistical error would allow precision of about 1 mm which could further be improved with larger detector placed at larger distance from the pinhole. However already the modest precision of few millimeters is sufficient for in-vivo detection of larger deviations from planned treatment caused by various misadministrations or malfunctioning of the brachytherapy treatment apparatus. Usage of silicon detectors offers a possibility for building a compact device which could be used as an independent online quality assurance system. In this paper details about sensors, readout system and reconstruction algorithm are described. Results from measurements with clinical source are presented.

  15. A method for verification of treatment times for high-dose-rate intraluminal brachytherapy treatment

    Directory of Open Access Journals (Sweden)

    Muhammad Asghar Gadhi

    2016-06-01

    Full Text Available Purpose: This study was aimed to increase the quality of high dose rate (HDR intraluminal brachytherapy treatment. For this purpose, an easy, fast and accurate patient-specific quality assurance (QA tool has been developed. This tool has been implemented at Bahawalpur Institute of Nuclear Medicine and Oncology (BINO, Bahawalpur, Pakistan.Methods: ABACUS 3.1 Treatment planning system (TPS has been used for treatment planning and calculation of total dwell time and then results were compared with the time calculated using the proposed method. This method has been used to verify the total dwell time for different rectum applicators for relevant treatment lengths (2-7 cm and depths (1.5-2.5 cm, different oesophagus applicators of relevant treatment lengths (6-10 cm and depths (0.9 & 1.0 cm, and a bronchus applicator for relevant treatment lengths (4-7.5 cm and depth (0.5 cm.Results: The average percentage differences between treatment time TM with manual calculation and as calculated by the TPS is 0.32% (standard deviation 1.32% for rectum, 0.24% (standard deviation 2.36% for oesophagus and 1.96% (standard deviation 0.55% for bronchus, respectively. These results advocate that the proposed method is valuable for independent verification of patient-specific treatment planning QA.Conclusion: The technique illustrated in the current study is an easy, simple, quick and useful for independent verification of the total dwell time for HDR intraluminal brachytherapy. Our method is able to identify human error-related planning mistakes and to evaluate the quality of treatment planning. It enhances the quality of brachytherapy treatment and reliability of the system.

  16. High-Dose-Rate Monotherapy: Safe and Effective Brachytherapy for Patients With Localized Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Demanes, D. Jeffrey, E-mail: jdemanes@mednet.ucla.edu [California Endocurietherapy at UCLA, Department of Radiation Oncology, David Geffen School of Medicine of University of California at Los Angeles, Los Angeles, CA (United States); Martinez, Alvaro A.; Ghilezan, Michel [William Beaumont Hospital, Royal Oak, MI (United States); Hill, Dennis R.; Schour, Lionel; Brandt, David [California Endocurietherapy, Oakland, CA (United States); Gustafson, Gary [William Beaumont Hospital, Royal Oak, MI (United States)

    2011-12-01

    Purpose: High-dose-rate (HDR) brachytherapy used as the only treatment (monotherapy) for early prostate cancer is consistent with current concepts in prostate radiobiology, and the dose is reliably delivered in a prospectively defined anatomic distribution that meets all the requirements for safe and effective therapy. We report the disease control and toxicity of HDR monotherapy from California Endocurietherapy (CET) and William Beaumont Hospital (WBH) in low- and intermediate-risk prostate cancer patients. Methods and Materials: There were 298 patients with localized prostate cancer treated with HDR monotherapy between 1996 and 2005. Two biologically equivalent hypofractionation protocols were used. At CET the dose was 42 Gy in six fractions (two implantations 1 week apart) delivered to a computed tomography-defined planning treatment volume. At WBH the dose was 38 Gy in four fractions (one implantation) based on intraoperative transrectal ultrasound real-time treatment planning. The bladder, urethral, and rectal dose constraints were similar. Toxicity was scored with the National Cancer Institute Common Toxicity Criteria for Adverse Events version 3. Results: The median follow-up time was 5.2 years. The median age of the patients was 63 years, and the median value of the pretreatment prostate-specific antigen was 6.0 ng/mL. The 8-year results were 99% local control, 97% biochemical control (nadir +2), 99% distant metastasis-free survival, 99% cause-specific survival, and 95% overall survival. Toxicity was scored per event, meaning that an individual patient with more than one symptom was represented repeatedly in the morbidity data table. Genitourinary toxicity consisted of 10% transient Grade 2 urinary frequency or urgency and 3% Grade 3 episode of urinary retention. Gastrointestinal toxicity was <1%. Conclusions: High disease control rates and low morbidity demonstrate that HDR monotherapy is safe and effective for patients with localized prostate cancer.

  17. Comparison of dose and catheter optimization algorithms in prostate high-dose-rate brachytherapy.

    Science.gov (United States)

    Poulin, Eric; Varfalvy, Nicolas; Aubin, Sylviane; Beaulieu, Luc

    2016-01-01

    The purpose of this work was to compare the hybrid inverse treatment planning optimization (HIPO), inverse dose-volume histogram-based optimization (DVHO), and fast simulated annealing stochastic algorithm (IPSA). The catheter optimization algorithm HIPO was also compared with the Centroidal Voronoi Tessellation (CVT) algorithm. In this study, eight high-dose-rate prostate cases were randomly selected from an anonymized bank of patients. Oncentra Prostate v4.1 was used to run DVHO and the HIPO catheter optimization (HIPO_cat), whereas Oncentra Brachy v4.3 was used for the remaining. For fixed catheter configurations, DVHO plans were compared with IPSA and HIPO. For catheter positions optimization, CVT and HIPO_cat algorithms were compared with standard clinical template plans. CVT catheters were further restrained to the template grid (CVT_grid) and compared with HIPO_cat. For dose optimization, IPSA and HIPO were not different from each other. The urethra D10 and the computation time were found significantly better with IPSA and HIPO compared with DVHO (p 0.05). For catheter placement, CVT plans were better, whereas HIPO_cat plans were significantly worse (p HIPO_cat plans do not for all catheter numbers. The CVT algorithm run time was significantly faster than HIPO_cat (p HIPO give similar dosimetric results. The CVT approach was found to be better than HIPO_cat and was able to reduce the number of catheters significantly. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  18. Automated high-dose rate brachytherapy treatment planning for a single-channel vaginal cylinder applicator

    Science.gov (United States)

    Zhou, Yuhong; Klages, Peter; Tan, Jun; Chi, Yujie; Stojadinovic, Strahinja; Yang, Ming; Hrycushko, Brian; Medin, Paul; Pompos, Arnold; Jiang, Steve; Albuquerque, Kevin; Jia, Xun

    2017-06-01

    High dose rate (HDR) brachytherapy treatment planning is conventionally performed manually and/or with aids of preplanned templates. In general, the standard of care would be elevated by conducting an automated process to improve treatment planning efficiency, eliminate human error, and reduce plan quality variations. Thus, our group is developing AutoBrachy, an automated HDR brachytherapy planning suite of modules used to augment a clinical treatment planning system. This paper describes our proof-of-concept module for vaginal cylinder HDR planning that has been fully developed. After a patient CT scan is acquired, the cylinder applicator is automatically segmented using image-processing techniques. The target CTV is generated based on physician-specified treatment depth and length. Locations of the dose calculation point, apex point and vaginal surface point, as well as the central applicator channel coordinates, and the corresponding dwell positions are determined according to their geometric relationship with the applicator and written to a structure file. Dwell times are computed through iterative quadratic optimization techniques. The planning information is then transferred to the treatment planning system through a DICOM-RT interface. The entire process was tested for nine patients. The AutoBrachy cylindrical applicator module was able to generate treatment plans for these cases with clinical grade quality. Computation times varied between 1 and 3 min on an Intel Xeon CPU E3-1226 v3 processor. All geometric components in the automated treatment plans were generated accurately. The applicator channel tip positions agreed with the manually identified positions with submillimeter deviations and the channel orientations between the plans agreed within less than 1 degree. The automatically generated plans obtained clinically acceptable quality.

  19. Quality control of high-dose-rate brachytherapy: treatment delivery analysis using statistical process control.

    Science.gov (United States)

    Able, Charles M; Bright, Megan; Frizzell, Bart

    2013-03-01

    Statistical process control (SPC) is a quality control method used to ensure that a process is well controlled and operates with little variation. This study determined whether SPC was a viable technique for evaluating the proper operation of a high-dose-rate (HDR) brachytherapy treatment delivery system. A surrogate prostate patient was developed using Vyse ordnance gelatin. A total of 10 metal oxide semiconductor field-effect transistors (MOSFETs) were placed from prostate base to apex. Computed tomography guidance was used to accurately position the first detector in each train at the base. The plan consisted of 12 needles with 129 dwell positions delivering a prescribed peripheral dose of 200 cGy. Sixteen accurate treatment trials were delivered as planned. Subsequently, a number of treatments were delivered with errors introduced, including wrong patient, wrong source calibration, wrong connection sequence, single needle displaced inferiorly 5 mm, and entire implant displaced 2 mm and 4 mm inferiorly. Two process behavior charts (PBC), an individual and a moving range chart, were developed for each dosimeter location. There were 4 false positives resulting from 160 measurements from 16 accurately delivered treatments. For the inaccurately delivered treatments, the PBC indicated that measurements made at the periphery and apex (regions of high-dose gradient) were much more sensitive to treatment delivery errors. All errors introduced were correctly identified by either the individual or the moving range PBC in the apex region. Measurements at the urethra and base were less sensitive to errors. SPC is a viable method for assessing the quality of HDR treatment delivery. Further development is necessary to determine the most effective dose sampling, to ensure reproducible evaluation of treatment delivery accuracy. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Salvage high-dose-rate brachytherapy for isolated vaginal recurrence of endometrial cancer.

    Science.gov (United States)

    Baek, Sungjae; Isohashi, Fumiaki; Yamaguchi, Hiroko; Mabuchi, Seiji; Yoshida, Ken; Kotsuma, Tadayuki; Yamazaki, Hideya; Tanaka, Eiichi; Sumida, Iori; Tamari, Keisuke; Otani, Keisuke; Seo, Yuji; Suzuki, Osamu; Yoshioka, Yasuo; Kimura, Tadashi; Ogawa, Kazuhiko

    We have retrospectively analyzed the outcomes of high-dose-rate (HDR) brachytherapy as a salvage therapy for vaginal recurrence of endometrial cancer. From 1997 to 2012, salvage HDR brachytherapy was performed in 43 patients. The median age was 64 years (range, 41-88 years). HDR brachytherapy was performed by interstitial brachytherapy in 34 patients (79%) and by intracavity brachytherapy in nine patients (21%). Seventeen (40%) of the 43 patients were treated with external beam radiotherapy. The median followup period was 58 months (range, 6-179 months). The 5-year overall survival (OS), progression-free survival (PFS), and local control rates (LC) were 84%, 52%, and 78%, respectively. Patients who received brachytherapy with external beam radiotherapy experienced no nodal recurrence (0 of 17 patients), whereas 23% of the patients (6 of 26 patients) who received brachytherapy alone experienced nodal recurrence (p = 0.047). The pathologic grade at the time of initial surgery (G1-2 vs. G3) was found to be a significant prognostic factor for both OS and PFS. The respective 5-year OS was 96% vs. 40% (p brachytherapy vs. intracavity brachytherapy) were significant prognostic factors for LC. The respective 5-year LC was 74% vs. 100% (p = 0.020) and 85% vs. 56% (p = 0.035). HDR brachytherapy is effective and feasible in patients with isolated vaginal recurrence of endometrial cancer. Pathologic grade, age, and modality were significant prognostic factors. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  1. High-dose-rate brachytherapy of rhabdomyosarcoma limited to the external auditory canal.

    Science.gov (United States)

    King, Martin T; Voros, Laszlo; Cohen, Gil'ad N; Lanning, Ryan M; Ganly, Ian; O'Suoji, Chibuzo C; Wolden, Suzanne L

    To report on the single-catheter high-dose-rate brachytherapy treatment of a 21-month-old girl child with an embryonal, botryoid-type, rhabdomyosarcoma limited to the external auditory canal (EAC). A 2.4-mm diameter catheter was inserted into the right EAC and placed against the tympanic membrane. A computed tomography simulation scan was acquired. A brachytherapy treatment plan, in which 21 Gy in seven fractions was prescribed to a 1-mm depth along the distal 2 cm of the catheter, was generated. Treatments were delivered under anesthesia without complication. A dosimetric comparison between this plan and an intensity-modulated radiation therapy (IMRT) plan was then conducted. A clinical target volume (CTV), which encompassed a 1-mm margin along the distal 2 cm of the catheter, was delineated for both plans. Given positioning uncertainty under image guidance, a planning target volume (PTV = CTV + 3-mm margin) was defined for the IMRT plan. The IMRT plan was optimized for maximal CTV coverage but subsequently normalized to the same CTV volume receiving 100% of the prescription dose (V100) of the brachytherapy plan. The IMRT plan was normalized to the brachytherapy CTV V100 of 82.0%. The PTV V100 of this plan was 34.1%. The PTV exhibited dosimetric undercoverage within the middle ear and toward the external ear. Mean cochlea doses for the IMRT and brachytherapy plans were 26.7% and 10.5% of prescription, respectively. For rhabdomyosarcomas limited to the EAC, a standard brachytherapy catheter can deliver a highly conformal radiation plan that can spare the nearby cochlea from excess radiation. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  2. Impact of source position on high-dose-rate skin surface applicator dosimetry.

    Science.gov (United States)

    Jeong, Jeho; Barker, Christopher A; Zaider, Marco; Cohen, Gil'ad N

    2016-01-01

    Skin surface dosimetric discrepancies between measured and treatment planning system predicted values were traced to source position sag inside the applicator and to source transit time. We quantified their dosimetric impact and propose corrections for clinical use. We measured the dose profiles from the Varian Leipzig-style high-dose-rate (HDR) skin applicator, using EBT3 film, photon diode, and optically stimulated luminescence dosimeter for three different GammaMedplus HDR afterloaders. The measured dose profiles at several depths were compared with BrachyVision Acuros calculated profiles. To assess the impact of the source sag, two different applicator orientations were considered. The dose contribution during source transit was assessed by comparing diode measurements using an HDR timer and an electrometer timer. Depth doses measured using the three dosimeters were in good agreement, but were consistently higher than the Acuros dose calculations. Measurements with the applicator face up were significantly (exceeding 10%) lower than those in the face down position, due to source sag inside the applicator. Based on the inverse square law, the effective source sag was evaluated to be about 0.5 mm from the planned position. The additional dose during source transit was evaluated to be about 2.8% for 30 seconds of treatment with a 40700 U (10 Ci) source. With a very short source-to-surface distance, the small source sag inside the applicator has a significant dosimetric impact. This effect is unaccounted for in the vendor's treatment planning template and should be considered before the clinical use of the applicator. Further investigation of other applicators with large source lumen diameter may be warranted. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  3. Prostate-Specific Antigen Bounce After High-Dose-Rate Monotherapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, Niraj H., E-mail: nmehta@mednet.ucla.edu [University of California, Los Angeles, Los Angeles, California (United States); Kamrava, Mitchell; Wang, Pin-Chieh; Steinberg, Michael; Demanes, Jeffrey [University of California, Los Angeles, Los Angeles, California (United States)

    2013-07-15

    Purpose: To characterize the magnitude and kinetics of prostate-specific antigen (PSA) bounces after high-dose-rate (HDR) monotherapy and determine relationships between certain clinical factors and PSA bounce. Methods and Materials: Longitudinal PSA data and various clinical parameters were examined in 157 consecutive patients treated with HDR monotherapy between 1996 and 2005. We used the following definition for PSA bounce: rise in PSA ≥threshold, after which it returns to the prior level or lower. Prostate-specific antigen failure was defined per the Phoenix definition (nadir +2 ng/mL). Results: A PSA bounce was noted in 67 patients (43%). The number of bounces per patient was 1 in 45 cases (67%), 2 in 19 (28%), 3 in 2 (3%), 4 in 0, and 5 in 1 (1%). The median time to maximum PSA bounce was 1.3 years, its median magnitude was 0.7, and its median duration was 0.75 years. Three patients (2%) were noted to have PSA failure. None of the 3 patients who experienced biochemical failure exhibited PSA bounce. In the fully adjusted model for predicting each bounce, patients aged <55 years had a statistically significant higher likelihood of experiencing a bounce (odds ratio 2.22, 95% confidence interval 1.38-3.57, P=.001). There was also a statistically significant higher probability of experiencing a bounce for every unit decrease in Gleason score (odds ratio 1.52, 95% confidence interval 1.01-2.04, P=.045). Conclusions: A PSA bounce occurs in a significant percentage of patients treated with HDR monotherapy, with magnitudes varying from <1 in 28% of cases to ≥1 in 15%. The median duration of bounce is <1 year. More bounces were identified in patients with lower Gleason score and age <55 years. Further investigation using a model to correlate magnitude and frequency of bounces with clinical variables are under way.

  4. An automated optimization tool for high-dose-rate (HDR) prostate brachytherapy with divergent needle pattern

    Science.gov (United States)

    Borot de Battisti, M.; Maenhout, M.; de Senneville, B. Denis; Hautvast, G.; Binnekamp, D.; Lagendijk, J. J. W.; van Vulpen, M.; Moerland, M. A.

    2015-10-01

    Focal high-dose-rate (HDR) for prostate cancer has gained increasing interest as an alternative to whole gland therapy as it may contribute to the reduction of treatment related toxicity. For focal treatment, optimal needle guidance and placement is warranted. This can be achieved under MR guidance. However, MR-guided needle placement is currently not possible due to space restrictions in the closed MR bore. To overcome this problem, a MR-compatible, single-divergent needle-implant robotic device is under development at the University Medical Centre, Utrecht: placed between the legs of the patient inside the MR bore, this robot will tap the needle in a divergent pattern from a single rotation point into the tissue. This rotation point is just beneath the perineal skin to have access to the focal prostate tumor lesion. Currently, there is no treatment planning system commercially available which allows optimization of the dose distribution with such needle arrangement. The aim of this work is to develop an automatic inverse dose planning optimization tool for focal HDR prostate brachytherapy with needle insertions in a divergent configuration. A complete optimizer workflow is proposed which includes the determination of (1) the position of the center of rotation, (2) the needle angulations and (3) the dwell times. Unlike most currently used optimizers, no prior selection or adjustment of input parameters such as minimum or maximum dose or weight coefficients for treatment region and organs at risk is required. To test this optimizer, a planning study was performed on ten patients (treatment volumes ranged from 8.5 cm3to 23.3 cm3) by using 2-14 needle insertions. The total computation time of the optimizer workflow was below 20 min and a clinically acceptable plan was reached on average using only four needle insertions.

  5. Dosimetric impact of interfraction catheter movement in high-dose rate prostate brachytherapy.

    Science.gov (United States)

    Foster, William; Cunha, J Adam M; Hsu, I-Chow; Weinberg, Vivan; Krishnamurthy, Devan; Pouliot, Jean

    2011-05-01

    To evaluate the impact of interfraction catheter movement on dosimetry in prostate high-dose-rate (HDR) brachytherapy. Fifteen patients were treated with fractionated HDR brachytherapy. Implants were performed on day 1 under transrectal ultrasound guidance. A computed tomography (CT) scan was performed. Inverse planning simulated annealing was used for treatment planning. The first fraction was delivered on day 1. A cone beam CT (CBCT) was performed on day 2 before the second fraction was given. A fusion of the CBCT and CT was performed using intraprostatic gold markers as landmarks. Initial prostate and urethra contours were transferred to the CBCT images. Bladder and rectum contours were drawn, and catheters were digitized on the CBCT. The planned treatment was applied to the CBCT dataset, and dosimetry was analyzed and compared to the initial dose distribution. This process was repeated after a reoptimization was performed, using the same constraints used on day 1. Mean interfraction catheter displacement was 5.1 mm. When we used the initial plan on day 2, the mean prostate V100 (volume receiving 100 Gy or more) decreased from 93.8% to 76.2% (p < 0.01). Rectal V75 went from 0.75 cm(3) to 1.49 cm(3) (p < 0.01). A reoptimization resulted in a mean prostate V100 of 88.1%, closer to the initial plan (p = 0.05). Mean rectal V75 was also improved with a value of 0.59 cm(3). There was no significant change in bladder and urethra dose on day 2. A mean interfraction catheter displacement of 5.1 mm results in a significant decrease in prostate V100 and an increase in rectum dose. A reoptimization before the second treatment improves dose distribution. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Custom-made micro applicators for high-dose-rate brachytherapy treatment of chronic psoriasis

    Directory of Open Access Journals (Sweden)

    Ivan M. Buzurovic

    2017-06-01

    Full Text Available Purpose: In this study, we present the treatment of the psoriatic nail beds of patients refractory to standard therapies using high-dose-rate (HDR brachytherapy. The custom-made micro applicators (CMMA were designed and constructed for radiation dose delivery to small curvy targets with complicated topology. The role of the HDR brachytherapy treatment was to stimulate the T cells for an increased immune response. Material and methods: The patient diagnosed with psoriatic nail beds refractory to standard therapies received monthly subunguinal injections that caused significant pain and discomfort in both hands. The clinical target was defined as the length from the fingertip to the distal interphalangeal joint. For the accurate and reproducible setup in the multi-fractional treatment delivery, the CMMAs were designed. Five needles were embedded into the dense plastic mesh and covered with 5 mm bolus material for each micro applicator. Five CMMAs were designed, resulting in the usage of 25 catheters in total. Results: The prescription dose was planned to the depth of the anterior surface of the distal phalanx, allowing for the sparing of the surrounding tissue. The total number of the active dwell positions was 145 with step size of 5 mm. The total treatment time was 115 seconds with a 7.36 Ci activity of the 192Ir source. The treatment resulted in good pain control. The patient did not require further injections to the nail bed. After this initial treatment, additional two patients with similar symptoms received HDR brachytherapy. The treatment outcome was favorable in all cases. Conclusions : The first HDR brachytherapy treatment of psoriasis of the nail bed is presented. The initial experience revealed that brachytherapy treatment was well-tolerated and resulted in adequate control of the disease. A larger cohort of patients will be required for additional conclusions related to the long-term clinical benefits.

  7. Second salvage high-dose-rate brachytherapy for radiorecurrent prostate cancer

    Directory of Open Access Journals (Sweden)

    Metha Maenhout

    2017-04-01

    Full Text Available Purpose : Salvage treatments for localized radiorecurrent prostate cancer can be performed safely when a focal and image guided approach is used. Due to the low toxicity, the opportunity exists to investigate a second salvage treatment when a second locally recurrent prostate cancer occurs. Here, we describe a second salvage treatment procedure of 4 patients. Material and methods : Four patients with a pathologically proven second local recurrence were treated in an outpatient magnetic resonance imaging (MRI-guided setting with a single fraction of 19 Gy focal high-dose-rate brachytherapy (HDR-BT. Delineation was performed using choline-PET-CT or a 68Ga-PSMA PET in combination with multiparametric 3 Tesla MRI in all four patients. Toxicity was measured using common toxicity criteria for adverse events (CTCAE version 4.0. Results : With a median follow-up of 12 months (range, 6-15, there were 2 patients with biochemical recurrence as defined by the Phoenix-definition. There were no patients with grade 3 or more toxicity. In all second salvage HDR-BT treatments, the constraints for rectum, bladder, and urethra were met. Median treatment volume (GTV was 4.8 cc (range, 1.9-6.6 cc. A median of 8 catheters (range, 6-9 were used, and the median dose to the treatment volume (GTV was a D95: 19.3 Gy (SD 15.5-19.4 Gy. Conclusions : Second focal salvage MRI-guided HDR-BT for a select group of patients with a second locally recurrent prostate cancer is feasible. There was no grade 3 or more acute toxicity for these four patients.

  8. High-dose-rate interstitial brachytherapy for female peri-urethral cancer

    Directory of Open Access Journals (Sweden)

    Daya Nand Sharma

    2016-01-01

    Full Text Available Purpose: Peri-urethral cancer (PUC in females is a rare malignancy. Surgery is not usually contemplated due to associated morbidity. Radiation therapy (RT can be employed in the form of interstitial brachytherapy (IBT alone for early lesions, and external beam radiation therapy (EBRT with or without IBT for advanced lesions. We report our first experience in the literature to evaluate the role of high-dose-rate (HDR IBT in female PUC. Material and methods : Between 2008 and 2013, 10 female patients with PUC (5 primary and 5 recurrent were treated with HDR-IBT with or without EBRT at our center. Size of the lesion ranged from 1.5 cm to 5.0 cm. A 2-3 plane free-hand implant was performed using plastic catheters. The prescribed dose of HDR-IBT was 42 Gy in 14 fractions for brachytherapy alone (5 patients, and 18-21 Gy for the boost along with EBRT (5 patients. Patients were followed up regularly for assessment of disease control and toxicity. Results: At a median follow up of 25 months, six patients were disease free at their last follow up. Four patients developed recurrence: 2 at inguinal nodes, 1 at local site, and 1 at both local as well as inguinal nodes. Moist desquamation was the commonest acute toxicity observed in all 5 patients treated with IBT alone, which healed within 4 weeks’ time. Overall, grade II delayed complication rate was 30%. Conclusions : Though small sample size, the results of our study have shown that HDR-IBT provides good loco-regional control with acceptable toxicity for female PUC.

  9. Clinical implementation of a novel applicator in high-dose-rate brachytherapy treatment of esophageal cancer

    Directory of Open Access Journals (Sweden)

    Ivan M. Buzurovic

    2016-08-01

    Full Text Available Purpose : In this study, we present the clinical implementation of a novel transoral balloon centering esophageal applicator (BCEA and the initial clinical experience in high-dose-rate (HDR brachytherapy treatment of esophageal cancer, using this applicator. Material and methods: Acceptance testing and commissioning of the BCEA were performed prior to clinical use. Full performance testing was conducted including measurements of the dimensions and the catheter diameter, evaluation of the inflatable balloon consistency, visibility of the radio-opaque markers, congruence of the markers, absolute and relative accuracy of the HDR source in the applicator using the radiochromic film and source position simulator, visibility and digitization of the applicator on the computed tomography (CT images under the clinical conditions, and reproducibility of the offset. Clinical placement of the applicator, treatment planning, treatment delivery, and patient’s response to the treatment were elaborated as well. Results : The experiments showed sub-millimeter accuracy in the source positioning with distal position at 1270 mm. The digitization (catheter reconstruction was uncomplicated due to the good visibility of markers. The treatment planning resulted in a favorable dose distribution. This finding was pronounced for the treatment of the curvy anatomy of the lesion due to the improved repeatability and consistency of the delivered fractional dose to the patient, since the radioactive source was placed centrally within the lumen with respect to the clinical target due to the five inflatable balloons. Conclusions : The consistency of the BCEA positioning resulted in the possibility to deliver optimized non-uniform dose along the catheter, which resulted in an increase of the dose to the cancerous tissue and lower doses to healthy tissue. A larger number of patients and long-term follow-up will be required to investigate if the delivered optimized treatment can

  10. High dose rate brachytherapy using custom made superficial mould applicators and Leipzig applicators for non melanoma localized skin cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pellizzon, A. Cassio A.; Miziara, Daniela; Lima, Flavia Pedroso de; Miziara, Miguel

    2014-07-01

    Purpose: advances in technology and the commercial production of Leipzig applicators allowed High Dose Rate after-load brachytherapy (HDR-BT) to address a number of the challenges associated with the delivery of superficial radiation to treat localized non melanoma skin cancer (NMSK). We reviewed our uni-institutional experience on the treatment of NMSK with HDR-BT. Methods: data were collected retrospectively from patients attending the Radiation Oncology Department at AV Carvalho Insitute, Sao Paulo, Brazil. HDR-BT was done using the stepping source HDR 192Ir Microselectron (Nucletron BV). The planning target volume consisted of the macroscopic lesion plus a 5mm to 10mm margin.The depth of treatment was 0.5 cm in smaller (< 2.0 cm) tumors and 10 to 15 mm for lesions bigger than that. Results: Thirteen patients were treated with HDR-BT from June, 2007 to June 2013. The median age and follow up time were 72 (38-90) years old and 36 (range, 7-73) months, respectively. There a predominance of males (61.5%) and of patients referred for adjuvant treatment due positive surgical margins or because they have had only a excision biopsy without safety margins (61.5%). Six (46.2%) patients presented with squamous cell carcinoma and 7 (53.8%) patients presented with basal cell carcinoma. The median tumor size was 20 (range, 5-42) mm. Patients were treated with a median total dose of 40 Gy (range, 20 -60), given in 10 (range, 2-15) fractions, given daily or twice a week. All patients responded very well to treatment and only one patient has failed locally so far, after 38 months of the end of the irradiation. The crude and actuarial 3-year local control rates were 100% and 80%, respectively. Moist desquamation, grade 2 RTOG, was observed in 4 (30.8%) patients. Severe late complication, radiation-induced dyspigmentation, occurred in 2 patients and 1 of the patients also showed telangiectasia in the irradiated area. The cosmetic result was considered good in 84% (11/13) patients

  11. High-Dose-Rate Brachytherapy Boost Effect on Local Tumor Control in Young Women With Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Guinot, Jose-Luis, E-mail: jguinot@fivo.org [Department of Radiation Oncology, Fundacion Instituto Valenciano de Oncologia, Valencia (Spain); Baixauli-Perez, Cristobal [Health Services Research Unit, Center for Public Health Research, Valencia (Spain); Soler, Pablo; Tortajada, Maria Isabel; Moreno, Araceli; Santos, Miguel Angel; Mut, Alejandro [Department of Radiation Oncology, Fundacion Instituto Valenciano de Oncologia, Valencia (Spain); Gozalbo, Francisco [Department of Pathology, Fundacion Instituto Valenciano de Oncologia, Valencia (Spain); Arribas, Leoncio [Department of Radiation Oncology, Fundacion Instituto Valenciano de Oncologia, Valencia (Spain)

    2015-01-01

    Purpose: To evaluate the local control rate and complications of a single fraction of high-dose-rate brachytherapy (HDR BT) boost in women aged 45 yeas and younger after breast-conserving therapy. Methods and Materials: Between 1999 and 2007, 167 patients between the ages of 26 and 45 years old (72 were 40 years old or younger), with stages T1 to T2 invasive breast cancer with disease-free margin status of at least 5 mm after breast-conserving surgery received 46 to 50 Gy whole-breast irradiation plus a 7-Gy HDR-BT boost (“fast boost”). An axillary dissection was performed in 72.5% of the patients and sentinel lymph node biopsy in 27.5%. A supraclavicular area was irradiated in 19% of the patients. Chemotherapy was used in 86% of the patients and hormone treatment in 77%. Clinical nodes were present in 18% and pathological nodes in 29%. The pathological stage was pT0: 5%, pTis: 3%, pT1: 69% and pT2: 23%. Intraductal component was present in 40% and 28% were G3. Results: At a median follow-up of 92 months, 9 patients relapsed on the margin of the implant, and 1 patient in another quadrant, resulting in a 10-year local relapse rate of 4.3% and a breast relapse rate of 4.9%, with breast preservation in 93.4%; no case of mastectomy due to poor cosmesis arose. Actuarial 5- and 10-year disease-free, cause-specific, and overall survival rates were 87.9% and 85.8%, and 92.1% and 88.4%, and 92.1% and 87.3%, respectively. In a univariate analysis, triple-negative cases and negative hormone receptors did worse, but in a multivariate analysis, only the last factor was significant for local and breast control. Asymptomatic fibrosis G2 was recorded in 3 cases, and there were no other late complications. Cosmetic results were good to excellent in 97% of cases. Conclusions: A single dose of 7 Gy using the fast-boost technique is well tolerated, with a low rate of late complications and improved local tumor control in women aged 45 and younger, compared to published data

  12. Direction-Modulated Brachytherapy for High-Dose-Rate Treatment of Cervical Cancer. I: Theoretical Design

    Energy Technology Data Exchange (ETDEWEB)

    Han, Dae Yup [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California (United States); Webster, Matthew J. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Department of Physics, University of California San Diego, La Jolla, California (United States); Scanderbeg, Daniel J.; Yashar, Catheryn; Choi, Dongju; Song, Bongyong [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Devic, Slobodan [Medical Physics Unit, McGill University, Montréal, Québec (Canada); Department of Radiation Oncology, Jewish General Hospital, Montréal, Québec (Canada); Ravi, Ananth [Department of Medical Physics, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Song, William Y., E-mail: wyjsong@gmail.com [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Department of Medical Physics, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada)

    2014-07-01

    Purpose: To demonstrate that utilization of the direction-modulated brachytherapy (DMBT) concept can significantly improve treatment plan quality in the setting of high-dose-rate (HDR) brachytherapy for cervical cancer. Methods and Materials: The new, MRI-compatible, tandem design has 6 peripheral holes of 1.3-mm diameter, grooved along a nonmagnetic tungsten-alloy rod (ρ = 18.0 g/cm{sup 3}), enclosed in Delrin tubing (polyoxymethylene, ρ = 1.41 g/cm{sup 3}), with a total thickness of 6.4 mm. The Monte Carlo N-Particle code was used to calculate the anisotropic {sup 192}Ir dose distributions. An in-house-developed inverse planning platform, geared with simulated annealing and constrained-gradient optimization algorithms, was used to replan 15 patient cases (total 75 plans) treated with a conventional tandem and ovoids (T and O) applicator. Prescription dose was 6 Gy. For replanning, we replaced the conventional tandem with that of the new DMBT tandem for optimization but left the ovoids in place and kept the dwell positions as originally planned. All DMBT plans were normalized to match the high-risk clinical target volume V100 coverage of the T and O plans. Results: In general there were marked improvements in plan quality for the DMBT plans. On average, D2cc for the bladder, rectum, and sigmoid were reduced by 0.59 ± 0.87 Gy (8.5% ± 28.7%), 0.48 ± 0.55 Gy (21.1% ± 27.2%), and 0.10 ± 0.38 Gy (40.6% ± 214.9%) among the 75 plans, with best single-plan reductions of 3.20 Gy (40.8%), 2.38 Gy (40.07%), and 1.26 Gy (27.5%), respectively. The high-risk clinical target volume D90 was similar, with 6.55 ± 0.96 Gy and 6.59 ± 1.06 Gy for T and O and DMBT, respectively. Conclusions: Application of the DMBT concept to cervical cancer allowed for improved organ at risk sparing while achieving similar target coverage on a sizeable patient population, as intended, by maximally utilizing the anatomic information contained in 3-dimensional

  13. Predictors of Toxicity After Image-guided High-dose-rate Interstitial Brachytherapy for Gynecologic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Larissa J. [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (United States); Viswanathan, Akila N., E-mail: aviswanathan@lroc.harvard.edu [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (United States)

    2012-12-01

    Purpose: To identify predictors of grade 3-4 complications and grade 2-4 rectal toxicity after three-dimensional image-guided high-dose-rate (HDR) interstitial brachytherapy for gynecologic cancer. Methods and Materials: Records were reviewed for 51 women (22 with primary disease and 29 with recurrence) treated with HDR interstitial brachytherapy. A single interstitial insertion was performed with image guidance by computed tomography (n = 43) or magnetic resonance imaging (n = 8). The median delivered dose in equivalent 2-Gy fractions was 72.0 Gy (45 Gy for external-beam radiation therapy and 24 Gy for brachytherapy). Toxicity was reported according to the Common Toxicity Criteria for Adverse Events. Actuarial toxicity estimates were calculated by the Kaplan-Meier method. Results: At diagnosis, the median patient age was 62 years and the median tumor size was 3.8 cm. The median D90 and V100 were 71.4 Gy and 89.5%; the median D2cc for the bladder, rectum, and sigmoid were 64.6 Gy, 61.0 Gy, and 52.7 Gy, respectively. The actuarial rates of all grade 3-4 complications at 2 years were 20% gastrointestinal, 9% vaginal, 6% skin, 3% musculoskeletal, and 2% lymphatic. There were no grade 3-4 genitourinary complications and no grade 5 toxicities. Grade 2-4 rectal toxicity was observed in 10 patients, and grade 3-4 complications in 4; all cases were proctitis with the exception of 1 rectal fistula. D2cc for rectum was higher for patients with grade 2-4 (68 Gy vs 57 Gy for grade 0-1, P=.03) and grade 3-4 (73 Gy vs 58 Gy for grade 0-2, P=.02) rectal toxicity. The estimated dose that resulted in a 10% risk of grade 2-4 rectal toxicity was 61.8 Gy (95% confidence interval, 51.5-72.2 Gy). Discussion: Image-guided HDR interstitial brachytherapy results in acceptable toxicity for women with primary or recurrent gynecologic cancer. D2cc for the rectum is a reliable predictor of late rectal complications. Three-dimensional-based treatment planning should be performed to ensure

  14. Inverse Planned High-Dose-Rate Brachytherapy for Locoregionally Advanced Cervical Cancer: 4-Year Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Tinkle, Christopher L.; Weinberg, Vivian [Department of Radiation Oncology, University of California, San Francisco, California (United States); Chen, Lee-May [Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, California (United States); Littell, Ramey [Gynecologic Oncology, The Permanente Medical Group, San Francisco, California (United States); Cunha, J. Adam M.; Sethi, Rajni A. [Department of Radiation Oncology, University of California, San Francisco, California (United States); Chan, John K. [Gynecologic Oncology, California Pacific Medical Center, San Francisco, California (United States); Hsu, I-Chow, E-mail: ichow.hsu@ucsf.edu [Department of Radiation Oncology, University of California, San Francisco, California (United States)

    2015-08-01

    Purpose: Evaluate the efficacy and toxicity of image guided brachytherapy using inverse planning simulated annealing (IPSA) high-dose-rate brachytherapy (HDRB) boost for locoregionally advanced cervical cancer. Methods and Materials: From December 2003 through September 2009, 111 patients with primary cervical cancer were treated definitively with IPSA-planned HDRB boost (28 Gy in 4 fractions) after external radiation at our institution. We performed a retrospective review of our experience using image guided brachytherapy. Of the patients, 70% had a tumor size >4 cm, 38% had regional nodal disease, and 15% had clinically evident distant metastasis, including nonregional nodal disease, at the time of diagnosis. Surgical staging involving pelvic lymph node dissection was performed in 15% of patients, and 93% received concurrent cisplatin-based chemotherapy. Toxicities are reported according to the Common Terminology Criteria for Adverse Events version 4.0 guidelines. Results: With a median follow-up time of 42 months (range, 3-84 months), no acute or late toxicities of grade 4 or higher were observed, and grade 3 toxicities (both acute and late) developed in 8 patients (1 constitutional, 1 hematologic, 2 genitourinary, 4 gastrointestinal). The 4-year Kaplan-Meier estimate of late grade 3 toxicity was 8%. Local recurrence developed in 5 patients (4 to 9 months after HDRB), regional recurrence in 3 (6, 16, and 72 months after HDRB), and locoregional recurrence in 1 (4 months after HDR boost). The 4-year estimates of local, locoregional, and distant control of disease were 94.0%, 91.9%, and 69.1%, respectively. The overall and disease-free survival rates at 4 years were 64.3% (95% confidence interval [CI] of 54%-73%) and 61.0% (95% CI, 51%-70%), respectively. Conclusions: Definitive radiation by use of inverse planned HDRB boost for locoregionally advanced cervical cancer is well tolerated and achieves excellent local control of disease. However, overall

  15. Learning curve of MRI-based planning for high-dose-rate brachytherapy for prostate cancer.

    Science.gov (United States)

    Buus, Simon; Rylander, Susanne; Hokland, Steffen; Søndergaard, Christian Skou; Pedersen, Erik Morre; Tanderup, Kari; Bentzen, Lise

    2016-01-01

    To evaluate introduction of MRI-based high-dose-rate brachytherapy (HDRBT), including procedure times, dose-volume parameters, and perioperative morbidity. Study included 42 high-risk prostate cancer patients enrolled in a clinical protocol, offering external beam radiotherapy + two HDRBT 8.5 Gy boosts. Time was recorded for initiation of anesthesia (A), fixation of needle implant (B), end of MR imaging (C), plan approval (D), and end of HDRBT delivery (E). We defined time A-E as total procedure time, A-B as operating room time, B-C as MRI procedure time, C-D as treatment planning time, and D to E as treatment delivery time. Dose-volume parameters were retrieved from the dose planning system. Results from the first 21 patients were compared with the last 21 patients. Total procedure time, operating room time, MRI procedure time, and treatment planning time decreased significantly from average 7.6 to 5.3 hours (p < 0.01), 3.6 to 2.4 hours (p < 0.01), 1.6 to 0.8 hours (p < 0.01), and 2.0 to 1.3 hours (p < 0.01), respectively. HDRBT delivery time remained unchanged at 0.5 hours. Clinical target volume prostate+3mmD90 fulfilled planning aim in 92% of procedures and increased significantly from average 8.3 to 9.0 Gy (p < 0.01). Urethral D0.1 cm(3) and rectal D2 cm(3) fulfilled planning aim in 78% and 95% of procedures, respectively, and did not change significantly. Hematuria occurred in (95%), hematoma (80%), moderate to strong pain (35%), and urinary retention (5%) of procedures. After introduction of MRI-based HDRBT, procedure times were significantly reduced. D90 Clinical target volumeprostate+3mm fulfilled constraints in most patients and improved over time, but not at expense of an increased urethral or rectal dose. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  16. Limitations of the TG-43 formalism for skin high-dose-rate brachytherapy dose calculations

    Energy Technology Data Exchange (ETDEWEB)

    Granero, Domingo, E-mail: dgranero@eresa.com [Department of Radiation Physics, ERESA, Hospital General Universitario, 46014 Valencia (Spain); Perez-Calatayud, Jose [Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia 46026 (Spain); Vijande, Javier [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and IFIC (UV-CSIC), Paterna 46980 (Spain); Ballester, Facundo [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)

    2014-02-15

    Purpose: In skin high-dose-rate (HDR) brachytherapy, sources are located outside, in contact with, or implanted at some depth below the skin surface. Most treatment planning systems use the TG-43 formalism, which is based on single-source dose superposition within an infinite water medium without accounting for the true geometry in which conditions for scattered radiation are altered by the presence of air. The purpose of this study is to evaluate the dosimetric limitations of the TG-43 formalism in HDR skin brachytherapy and the potential clinical impact. Methods: Dose rate distributions of typical configurations used in skin brachytherapy were obtained: a 5 cm × 5 cm superficial mould; a source inside a catheter located at the skin surface with and without backscatter bolus; and a typical interstitial implant consisting of an HDR source in a catheter located at a depth of 0.5 cm. Commercially available HDR{sup 60}Co and {sup 192}Ir sources and a hypothetical {sup 169}Yb source were considered. The Geant4 Monte Carlo radiation transport code was used to estimate dose rate distributions for the configurations considered. These results were then compared to those obtained with the TG-43 dose calculation formalism. In particular, the influence of adding bolus material over the implant was studied. Results: For a 5 cm × 5 cm{sup 192}Ir superficial mould and 0.5 cm prescription depth, dose differences in comparison to the TG-43 method were about −3%. When the source was positioned at the skin surface, dose differences were smaller than −1% for {sup 60}Co and {sup 192}Ir, yet −3% for {sup 169}Yb. For the interstitial implant, dose differences at the skin surface were −7% for {sup 60}Co, −0.6% for {sup 192}Ir, and −2.5% for {sup 169}Yb. Conclusions: This study indicates the following: (i) for the superficial mould, no bolus is needed; (ii) when the source is in contact with the skin surface, no bolus is needed for either {sup 60}Co and {sup 192}Ir. For

  17. Monte Carlo study of radiation dose enhancement by gadolinium in megavoltage and high dose rate radiotherapy.

    Directory of Open Access Journals (Sweden)

    Daniel G Zhang

    Full Text Available MRI is often used in tumor localization for radiotherapy treatment planning, with gadolinium (Gd-containing materials often introduced as a contrast agent. Motexafin gadolinium is a novel radiosensitizer currently being studied in clinical trials. The nanoparticle technologies can target tumors with high concentration of high-Z materials. This Monte Carlo study is the first detailed quantitative investigation of high-Z material Gd-induced dose enhancement in megavoltage external beam photon therapy. BEAMnrc, a radiotherapy Monte Carlo simulation package, was used to calculate dose enhancement as a function of Gd concentration. Published phase space files for the TrueBeam flattening filter free (FFF and conventional flattened 6MV photon beams were used. High dose rate (HDR brachytherapy with Ir-192 source was also investigated as a reference. The energy spectra difference caused a dose enhancement difference between the two beams. Since the Ir-192 photons have lower energy yet, the photoelectric effect in the presence of Gd leads to even higher dose enhancement in HDR. At depth of 1.8 cm, the percent mean dose enhancement for the FFF beam was 0.38±0.12, 1.39±0.21, 2.51±0.34, 3.59±0.26, and 4.59±0.34 for Gd concentrations of 1, 5, 10, 15, and 20 mg/mL, respectively. The corresponding values for the flattened beam were 0.09±0.14, 0.50±0.28, 1.19±0.29, 1.68±0.39, and 2.34±0.24. For Ir-192 with direct contact, the enhanced were 0.50±0.14, 2.79±0.17, 5.49±0.12, 8.19±0.14, and 10.80±0.13. Gd-containing materials used in MRI as contrast agents can also potentially serve as radiosensitizers in radiotherapy. This study demonstrates that Gd can be used to enhance radiation dose in target volumes not only in HDR brachytherapy, but also in 6 MV FFF external beam radiotherapy, but higher than the currently used clinical concentration (>5 mg/mL would be needed.

  18. Monte Carlo study of radiation dose enhancement by gadolinium in megavoltage and high dose rate radiotherapy.

    Science.gov (United States)

    Zhang, Daniel G; Feygelman, Vladimir; Moros, Eduardo G; Latifi, Kujtim; Zhang, Geoffrey G

    2014-01-01

    MRI is often used in tumor localization for radiotherapy treatment planning, with gadolinium (Gd)-containing materials often introduced as a contrast agent. Motexafin gadolinium is a novel radiosensitizer currently being studied in clinical trials. The nanoparticle technologies can target tumors with high concentration of high-Z materials. This Monte Carlo study is the first detailed quantitative investigation of high-Z material Gd-induced dose enhancement in megavoltage external beam photon therapy. BEAMnrc, a radiotherapy Monte Carlo simulation package, was used to calculate dose enhancement as a function of Gd concentration. Published phase space files for the TrueBeam flattening filter free (FFF) and conventional flattened 6MV photon beams were used. High dose rate (HDR) brachytherapy with Ir-192 source was also investigated as a reference. The energy spectra difference caused a dose enhancement difference between the two beams. Since the Ir-192 photons have lower energy yet, the photoelectric effect in the presence of Gd leads to even higher dose enhancement in HDR. At depth of 1.8 cm, the percent mean dose enhancement for the FFF beam was 0.38±0.12, 1.39±0.21, 2.51±0.34, 3.59±0.26, and 4.59±0.34 for Gd concentrations of 1, 5, 10, 15, and 20 mg/mL, respectively. The corresponding values for the flattened beam were 0.09±0.14, 0.50±0.28, 1.19±0.29, 1.68±0.39, and 2.34±0.24. For Ir-192 with direct contact, the enhanced were 0.50±0.14, 2.79±0.17, 5.49±0.12, 8.19±0.14, and 10.80±0.13. Gd-containing materials used in MRI as contrast agents can also potentially serve as radiosensitizers in radiotherapy. This study demonstrates that Gd can be used to enhance radiation dose in target volumes not only in HDR brachytherapy, but also in 6 MV FFF external beam radiotherapy, but higher than the currently used clinical concentration (>5 mg/mL) would be needed.

  19. Performance assessment of the BEBIG MultiSource® high dose rate brachytherapy treatment unit

    Science.gov (United States)

    Palmer, Antony; Mzenda, Bongile

    2009-12-01

    A comprehensive system characterisation was performed of the Eckert & Ziegler BEBIG GmbH MultiSource® High Dose Rate (HDR) brachytherapy treatment unit with an 192Ir source. The unit is relatively new to the UK market, with the first installation in the country having been made in the summer of 2009. A detailed commissioning programme was devised and is reported including checks of the fundamental parameters of source positioning, dwell timing, transit doses and absolute dosimetry of the source. Well chamber measurements, autoradiography and video camera analysis techniques were all employed. The absolute dosimetry was verified by the National Physical Laboratory, UK, and compared to a measurement based on a calibration from PTB, Germany, and the supplied source certificate, as well as an independent assessment by a visiting UK centre. The use of the 'Krieger' dosimetry phantom has also been evaluated. Users of the BEBIG HDR system should take care to avoid any significant bend in the transfer tube, as this will lead to positioning errors of the source, of up to 1.0 mm for slight bends, 2.0 mm for moderate bends and 5.0 mm for extreme curvature (depending on applicators and transfer tube used) for the situations reported in this study. The reason for these errors and the potential clinical impact are discussed. Users should also note the methodology employed by the system for correction of transit doses, and that no correction is made for the initial and final transit doses. The results of this investigation found that the uncorrected transit doses lead to small errors in the delivered dose at the first dwell position, of up to 2.5 cGy at 2 cm (5.6 cGy at 1 cm) from a 10 Ci source, but the transit dose correction for other dwells was accurate within 0.2 cGy. The unit has been mechanically reliable, and source positioning accuracy and dwell timing have been reproducible, with overall performance similar to other existing HDR equipment. The unit is capable of high

  20. Computed Tomography–Planned High-Dose-Rate Brachytherapy for Treating Uterine Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zolciak-Siwinska, Agnieszka, E-mail: agnieszka.zolciak@wp.pl [Department of Brachytherapy, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Gruszczynska, Ewelina; Bijok, Michal [Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Jonska-Gmyrek, Joanna [Department of Teleradiotherapy, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Dabkowski, Mateusz [Department of Brachytherapy, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Staniaszek, Jagna [Department of Teleradiotherapy, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Michalski, Wojciech [Department of Clinical Trials and Biostatistics, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Kowalczyk, Adam; Milanowska, Katarzyna [Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland)

    2016-09-01

    Purpose: To evaluate the long-term results of computed tomography (CT)–planned high-dose-rate (HDR) brachytherapy (BT) for treating cervical cancer patients. Methods and Materials: CT-planned HDR BT was performed according to the adapted Group European de Curietherapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) recommendations in 216 consecutive patients with locally advanced cervical cancer, International Federation of Gynecology and Obstetrics (FIGO) stage IB to IVA, who were treated with conformal external beam radiation therapy and concomitant chemotherapy. We analyzed outcomes and late side effects evaluated according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer and Subjective, Objective, Management, Analysis evaluation scoring system and compared them with the results from a historical group. Results: The median age was 56 years (range, 32-83 years). The median follow-up time for living patients was 52 months (range 37-63 months). The 5-year cumulative incidence function for the local recurrence rate for patients with FIGO II and III was 5.5% and 20%, respectively (P=.001). The 5-year rates of overall survival (OS) and disease-free survival (DFS) were 66.4% and 58.5%, respectively. The relative risk of failure for OS and DFS for FIGO III in relation to FIGO II was 2.24 (P=.003) and 2.6 (P=.000) and for lymph node enlargement was 2.3 (P=.002) and 2 (P=.006), respectively. In 2 patients, rectovaginal fistula occurred, and in 1 patient, vesicovaginal fistula occurred without local progression. Comparison of late adverse effects in patients treated according to the GEC-ESTRO recommendations and in the historical group revealed a reduction in fistula formation of 59% and also a reduction in rectal grade 3 to 4 late toxicity of >59%. Conclusions: This is the largest report with mature data of CT-planned BT HDR for the treatment of cervical cancer with good local control and

  1. Biological effective doses in the intracavitary high dose rate brachytherapy of cervical cancer

    Directory of Open Access Journals (Sweden)

    Y. Sobita Devi

    2011-12-01

    Full Text Available Purpose: The aim of this study is to evaluate the decrease of biological equivalent dose and its correlation withlocal/loco-regional control of tumour in the treatment of cervical cancer when the strength of the Ir-192 high dose rate(HDR brachytherapy (BT source is reduced to single, double and triple half life in relation to original strength of10 Ci (~ 4.081 cGy x m2 x h–1. Material and methods: A retrospective study was carried out on 52 cervical cancer patients with stage II and IIItreated with fractionated HDR-BT following external beam radiation therapy (EBRT. International Commission onRadiation Units and Measurement (ICRU points were defined according to ICRU Report 38, using two orthogonal radiographimages taken by Simulator (Simulix HQ. Biologically effective dose (BED was calculated at point A for diffe -rent Ir-192 source strength and its possible correlation with local/loco-regional tumour control was discussed. Result: The increase of treatment time per fraction of dose due to the fall of dose rate especially in HDR-BT of cervicalcancer results in reduction in BED of 2.59%, 7.02% and 13.68% with single, double and triple half life reduction ofsource strength, respectively. The probabilities of disease recurrence (local/loco-regional within 26 months are expectedas 0.12, 0.12, 0.16, 0.39 and 0.80 for source strength of 4.081, 2.041, 1.020, 0.510 and 0.347 cGy x m2 x h–1, respectively.The percentages of dose increase required to maintain the same BED with respect to initial BED were estimated as1.71, 5.00, 11.00 and 15.86 for the dose rate of 24.7, 12.4, 6.2 and 4.2 Gy/hr at point A, respectively. Conclusions: This retrospective study of cervical cancer patients treated with HDR-BT at different Ir-192 sourcestrength shows reduction in disease free survival according to the increase in treatment time duration per fraction.The probable result could be associated with the decrease of biological equivalent dose to point A. Clinical

  2. High-dose-rate brachytherapy monotherapy without androgen deprivation therapy for intermediate-risk prostate cancer.

    Science.gov (United States)

    Patel, Shyamal; Demanes, D Jeffrey; Ragab, Omar; Zhang, Mingle; Veruttipong, Darlene; Nguyen, Kristine; Park, Sang-June; Marks, Leonard; Pantuck, Allan; Steinberg, Michael; Kamrava, Mitchell

    Outcomes using high-dose-rate (HDR) brachytherapy monotherapy (without androgen deprivation therapy or external beam radiation therapy) for National Comprehensive Cancer Network-defined intermediate-risk (IR) patients are limited. We report our long-term data using HDR monotherapy for this patient population. One-hundred ninety IR prostate cancer patients were treated 1996-2013 with HDR monotherapy. Biochemical prostate-specific antigen (PSA) failure was per the Phoenix definition. Acute and late genitourinary and gastrointestinal toxicities were graded according to Common Toxicity Criteria of Adverse Events, version 4. Kaplan-Meier (KM) biochemical progression-free survival (BPFS), cause-specific survival, and overall survival rates were calculated. Univariate analyses were performed to determine relationships with BPFS. The median patient age was 66 years (43-90), and the median initial PSA was 7.4 ng/mL. The Gleason score was ≤6 in 26%, 3 + 4 in 62%, and 4 + 3 in 12%. The median treatment BED1.5 was 254 Gy; 83% of patients were treated with a dose of 7.25 Gy × six fractions delivered in two separate implants. With a median follow-up of 6.2 years, KM BPFS at 5/8 years was 97%/90%, cause-specific survival at 8 years was 100%, and overall survival at 5/8 years was 93%/88%. Late genitourinary toxicities were 36.3% Grade 1, 18.9% Grade 2, and 3.7% Grade 3. Late gastrointestinal toxicities were 6.3% Grade 1, 1.1% Grade 2, and no Grade ≥3. Of the patients with no sexual dysfunction before treatment, 68% maintained potency. Age, initial PSA, T stage, Gleason score, prostate volume, and percent positive cores did not correlate with BPFS. Stratifying by favorable vs. unfavorable IR groups did not affect BPFS. HDR brachytherapy monotherapy represents a safe and highly effective treatment for IR prostate cancer patients with long-term follow-up. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  3. Limitations of the TG-43 formalism for skin high-dose-rate brachytherapy dose calculations.

    Science.gov (United States)

    Granero, Domingo; Perez-Calatayud, Jose; Vijande, Javier; Ballester, Facundo; Rivard, Mark J

    2014-02-01

    In skin high-dose-rate (HDR) brachytherapy, sources are located outside, in contact with, or implanted at some depth below the skin surface. Most treatment planning systems use the TG-43 formalism, which is based on single-source dose superposition within an infinite water medium without accounting for the true geometry in which conditions for scattered radiation are altered by the presence of air. The purpose of this study is to evaluate the dosimetric limitations of the TG-43 formalism in HDR skin brachytherapy and the potential clinical impact. Dose rate distributions of typical configurations used in skin brachytherapy were obtained: a 5 cm × 5 cm superficial mould; a source inside a catheter located at the skin surface with and without backscatter bolus; and a typical interstitial implant consisting of an HDR source in a catheter located at a depth of 0.5 cm. Commercially available HDR(60)Co and (192)Ir sources and a hypothetical (169)Yb source were considered. The Geant4 Monte Carlo radiation transport code was used to estimate dose rate distributions for the configurations considered. These results were then compared to those obtained with the TG-43 dose calculation formalism. In particular, the influence of adding bolus material over the implant was studied. For a 5 cm × 5 cm(192)Ir superficial mould and 0.5 cm prescription depth, dose differences in comparison to the TG-43 method were about -3%. When the source was positioned at the skin surface, dose differences were smaller than -1% for (60)Co and (192)Ir, yet -3% for (169)Yb. For the interstitial implant, dose differences at the skin surface were -7% for (60)Co, -0.6% for (192)Ir, and -2.5% for (169)Yb. This study indicates the following: (i) for the superficial mould, no bolus is needed; (ii) when the source is in contact with the skin surface, no bolus is needed for either (60)Co and (192)Ir. For lower energy radionuclides like (169)Yb, bolus may be needed; and (iii) for the interstitial case, at

  4. Predictors of toxicity after image-guided high-dose-rate interstitial brachytherapy for gynecologic cancer.

    Science.gov (United States)

    Lee, Larissa J; Viswanathan, Akila N

    2012-12-01

    To identify predictors of grade 3-4 complications and grade 2-4 rectal toxicity after three-dimensional image-guided high-dose-rate (HDR) interstitial brachytherapy for gynecologic cancer. Records were reviewed for 51 women (22 with primary disease and 29 with recurrence) treated with HDR interstitial brachytherapy. A single interstitial insertion was performed with image guidance by computed tomography (n = 43) or magnetic resonance imaging (n = 8). The median delivered dose in equivalent 2-Gy fractions was 72.0 Gy (45 Gy for external-beam radiation therapy and 24 Gy for brachytherapy). Toxicity was reported according to the Common Toxicity Criteria for Adverse Events. Actuarial toxicity estimates were calculated by the Kaplan-Meier method. At diagnosis, the median patient age was 62 years and the median tumor size was 3.8 cm. The median D90 and V100 were 71.4 Gy and 89.5%; the median D2cc for the bladder, rectum, and sigmoid were 64.6 Gy, 61.0 Gy, and 52.7 Gy, respectively. The actuarial rates of all grade 3-4 complications at 2 years were 20% gastrointestinal, 9% vaginal, 6% skin, 3% musculoskeletal, and 2% lymphatic. There were no grade 3-4 genitourinary complications and no grade 5 toxicities. Grade 2-4 rectal toxicity was observed in 10 patients, and grade 3-4 complications in 4; all cases were proctitis with the exception of 1 rectal fistula. D2cc for rectum was higher for patients with grade 2-4 (68 Gy vs 57 Gy for grade 0-1, P=.03) and grade 3-4 (73 Gy vs 58 Gy for grade 0-2, P=.02) rectal toxicity. The estimated dose that resulted in a 10% risk of grade 2-4 rectal toxicity was 61.8 Gy (95% confidence interval, 51.5-72.2 Gy). Image-guided HDR interstitial brachytherapy results in acceptable toxicity for women with primary or recurrent gynecologic cancer. D2cc for the rectum is a reliable predictor of late rectal complications. Three-dimensional-based treatment planning should be performed to ensure adequate tumor coverage while minimizing the D2cc to the

  5. Patient-specific dose calculation methods for high-dose-rate iridium-192 brachytherapy

    Science.gov (United States)

    Poon, Emily S.

    In high-dose-rate 192Ir brachytherapy, the radiation dose received by the patient is calculated according to the AAPM Task Group 43 (TG-43) formalism. This table-based dose superposition method uses dosimetry parameters derived with the radioactive 192Ir source centered in a water phantom. It neglects the dose perturbations caused by inhomogeneities, such as the patient anatomy, applicators, shielding, and radiographic contrast solution. In this work, we evaluated the dosimetric characteristics of a shielded rectal applicator with an endocavitary balloon injected with contrast solution. The dose distributions around this applicator were calculated by the GEANT4 Monte Carlo (MC) code and measured by ionization chamber and GAFCHROMIC EBT film. A patient-specific dose calculation study was then carried out for 40 rectal treatment plans. The PTRAN_CT MC code was used to calculate the dose based on computed tomography (CT) images. This study involved the development of BrachyGUI, an integrated treatment planning tool that can process DICOM-RT data and create PTRAN_CT input initialization files. BrachyGUI also comes with dose calculation and evaluation capabilities. We proposed a novel scatter correction method to account for the reduction in backscatter radiation near tissue-air interfaces. The first step requires calculating the doses contributed by primary and scattered photons separately, assuming a full scatter environment. The scatter dose in the patient is subsequently adjusted using a factor derived by MC calculations, which depends on the distances between the point of interest, the 192Ir source, and the body contour. The method was validated for multicatheter breast brachytherapy, in which the target and skin doses for 18 patient plans agreed with PTRAN_CT calculations better than 1%. Finally, we developed a CT-based analytical dose calculation method. It corrects for the photon attenuation and scatter based upon the radiological paths determined by ray tracing

  6. High-Dose-Rate Monotherapy for Localized Prostate Cancer: 10-Year Results

    Energy Technology Data Exchange (ETDEWEB)

    Hauswald, Henrik; Kamrava, Mitchell R.; Fallon, Julia M.; Wang, Pin-Chieh; Park, Sang-June; Van, Thanh; Borja, Lalaine; Steinberg, Michael L.; Demanes, D. Jeffrey, E-mail: JDemanes@mednet.ucla.edu

    2016-03-15

    Purpose: High-dose-rate (HDR) brachytherapy was originally used with external beam radiation therapy (EBRT) to increase the dose to the prostate without injuring the bladder or rectum. Numerous studies have reported HDR brachytherapy is safe and effective. We adapted it for use without EBRT for cases not requiring lymph node treatment. Patients and Methods: We entered the patient demographics, disease characteristics, and treatment parameters into a prospective registry and serially added follow-up data for 448 men with low-risk (n=288) and intermediate-risk (n=160) prostate cancer treated from 1996 to 2009. Their median age was 64 years (range 42-90). The median prostate-specific antigen (PSA) level was 6.0 ng/mL (range 0.2-18.2). The Gleason score was ≤6 in 76% and 7 in 24%. The median dose was 43.5 Gy in 6 fractions. The clinical and biochemical disease control and survival rates were calculated. Adverse events were graded according to the Common Toxicity Criteria of Adverse Events. Results: The median follow-up period was 6.5 years (range 0.3-15.3). The actuarial 6- and 10-year PSA progression-free survival was 98.6% (95% confidence interval [CI] 96.9%-99.4%) and 97.8% (95% CI 95.5%-98.9%). Overall survival at 10 years was 76.7% (95% CI 69.9%-82.2%). The local control, distant metastasis-free survival, and cause-specific survival were 99.7% (95% CI 97.9%-99.9%), 98.9% (95% CI 96.3%-99.7%), and 99.1% (95% CI 95.8%-99.8%). T stage, initial PSA level, Gleason score, National Comprehensive Cancer Network risk group, patient age, and androgen deprivation therapy did not significantly correlate with disease control or survival. No late grade 3 to 4 rectal toxicities developed. Late grade 3 to 4 genitourinary toxicity occurred in 4.9% (grade 3 in 4.7%). Conclusions: HDR monotherapy is a safe and highly effective treatment of low- and intermediate-risk prostate cancer.

  7. In vivo dose verification method in catheter based high dose rate brachytherapy.

    Science.gov (United States)

    Jaselskė, Evelina; Adlienė, Diana; Rudžianskas, Viktoras; Urbonavičius, Benas Gabrielis; Inčiūra, Arturas

    2017-12-01

    In vivo dosimetry is a powerful tool for dose verification in radiotherapy. Its application in high dose rate (HDR) brachytherapy is usually limited to the estimation of gross errors, due to inability of the dosimetry system/ method to record non-uniform dose distribution in steep dose gradient fields close to the radioactive source. In vivo dose verification in interstitial catheter based HDR brachytherapy is crucial since the treatment is performed inserting radioactive source at the certain positions within the catheters that are pre-implanted into the tumour. We propose in vivo dose verification method for this type of brachytherapy treatment which is based on the comparison between experimentally measured and theoretical dose values calculated at well-defined locations corresponding dosemeter positions in the catheter. Dose measurements were performed using TLD 100-H rods (6 mm long, 1 mm diameter) inserted in a certain sequences into additionally pre-implanted dosimetry catheter. The adjustment of dosemeter positioning in the catheter was performed using reconstructed CT scans of patient with pre-implanted catheters. Doses to three Head&Neck and one Breast cancer patient have been measured during several randomly selected treatment fractions. It was found that the average experimental dose error varied from 4.02% to 12.93% during independent in vivo dosimetry control measurements for selected Head&Neck cancer patients and from 7.17% to 8.63% - for Breast cancer patient. Average experimental dose error was below the AAPM recommended margin of 20% and did not exceed the measurement uncertainty of 17.87% estimated for this type of dosemeters. Tendency of slightly increasing average dose error was observed in every following treatment fraction of the same patient. It was linked to the changes of theoretically estimated dosemeter positions due to the possible patient's organ movement between different treatment fractions, since catheter reconstruction was

  8. Nationwide, Multicenter, Retrospective Study on High-Dose-Rate Brachytherapy as Monotherapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Yasuo, E-mail: yoshioka@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Kotsuma, Tadayuki [Department of Radiation Oncology, Osaka National Hospital, Osaka (Japan); Komiya, Akira [Department of Urology, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Toyama (Japan); Department of Urology, Chiba University Hospital, Chiba (Japan); Kariya, Shinji [Department of Radiology, Kochi Medical School, Kochi (Japan); Konishi, Koji [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Nonomura, Norio [Department of Urology, Osaka University Graduate School of Medicine, Osaka (Japan); Ogawa, Kazuhiko [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Tanaka, Eiichi [Department of Radiation Oncology, Osaka National Hospital, Osaka (Japan); Nishimura, Kensaku [Department of Urology, Osaka National Hospital, Osaka (Japan); Fujiuchi, Yasuyoshi; Kitamura, Hiroshi [Department of Urology, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Toyama (Japan); Yamagami, Takuji [Department of Radiology, Kochi Medical School, Kochi (Japan); Yamasaki, Ichiro [Department of Urology, Kochi Medical School, Kochi (Japan); Nishimura, Kazuo [Department of Urology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Teshima, Teruki [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Nakamura, Katsumasa [Department of Radiation Oncology, Hamamatsu University School of Medicine, Shizuoka (Japan); Itami, Jun [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)

    2017-04-01

    Purpose: To present, analyze, and discuss results of a nationwide, multicenter, retrospective study on high-dose-rate brachytherapy (HDR-BT) as monotherapy for low-, intermediate-, and high-risk prostate cancer. Methods and Materials: From 1995 through 2013, 524 patients, 73 (14%) with low-risk, 207 (40%) with intermediate-risk, and 244 (47%) with high-risk prostate cancer, were treated with HDR-BT as monotherapy at 5 institutions in Japan. Dose fractionations were 27 Gy/2 fractions for 69 patients (13%), 45.5 Gy/7 fractions for 168 (32%), 49 Gy/7 fractions for 149 (28%), 54 Gy/9 fractions for 130 (25%), and others for 8 (2%). Of these patients, 156 (30%) did not receive androgen deprivation therapy, and 202 patients (39%) did receive androgen deprivation therapy <1 year, 112 (21%) for 1-3 years, and 54 (10%) for >3 years. Median follow-up time was 5.9 years (range, 0.4-18.1 years), with a minimum of 2 years for surviving patients. Results: After 5 years, respective actuarial rates of no biochemical evidence of disease, overall survival, cause-specific survival, and metastasis-free survival for all patients were 92%, 97%, 99%, and 94%. For low/intermediate/high-risk patients, the 5-year no biochemical evidence of disease rates were 95%/94%/89%, the 5-year overall survival rates were 98%/98%/94%, the 5-year cause-specific survival rates were 98%/100%/98%, and the 5-year metastasis-free survival rates were 98%/95%/90%, respectively. The cumulative incidence of late grade 2 to 3 genitourinary toxicity at 5 years was 19%, and that of late grade 3 was 1%. The corresponding incidences of gastrointestinal toxicity were 3% and 0% (0.2%). No grade 4 or 5 of either type of toxicity was detected. Conclusions: The findings of this nationwide, multicenter, retrospective study demonstrate that HDR-BT as monotherapy was safe and effective for all patients with low-, intermediate-, and high-risk prostate cancer.

  9. Concomitant cervical and transperineal parametrial high-dose-rate brachytherapy boost for locally advanced cervical cancer

    Directory of Open Access Journals (Sweden)

    Caroline Bailleux

    2016-01-01

    Full Text Available Purpose: There is no consensus for parametrial boost technic while both transvaginal and transperineal approaches are discussed. A prototype was developed consisting of a perineal template, allowing transperineal needle insertion. This study analyzed acute toxicity of concomitant cervical and transperineal parametrial high-dose-rate brachytherapy (HDRB boost for locally advanced cervical cancer. Material and methods: From 01.2011 to 12.2014, 33 patients (pts presenting a locally advanced cervical cancer with parametrial invasion were treated. After the first course of external beam radiation therapy with cisplatinum, HDRB was performed combining endocavitary and interstitial technique for cervical and parametrial disease. Post-operative delineation (CTV, bladder, rectum, sigmoid and planification were based on CT-scan/MRI. HDRB was delivered in 3-5 fractions over 2-3 consecutive days. Acute toxicities occurring within 6 months after HDRB were retrospectively reviewed. Results: Median age was 56.4 years (27-79. Clinical stages were: T2b = 23 pts (69.7%, T3a = 1 pt (3%, T3b = 6 pts (18.2%, and T4a = 3 pts (9.1%. Median HDRB prescribed dose was 21 Gy (21-27. Median CTVCT (16 pts and HR-CTV MRI (17 pts were 52.6 cc (28.5-74.3, 31.9 cc (17.1-58, respectively. Median EQD2αβ10 for D90CTV and D90HR-CTV were 82.9 Gy (78.2-96.5, 84.8 Gy (80.6-91.4, respectively. Median EQD2αβ3 (CT/MRI for D2cc bladder, rectum and sigmoid were 75.5 Gy (66.6-90.9, 64.4 Gy (51.9-77.4, and 60.4 Gy (50.9-81.1, respectively. Median follow-up was 14 months (ranged 6-51. Among the 24 pts with MFU = 24 months, 2-year LRFS rate, RRFS, and OS were 86.8%, 88.8%, and 94.1%, respectively. The rates of acute genitourinary and gastrointestinal toxicities were 36% (G1 dysuria = 8 pts, G2 infection = 2 pt, G3 infection = 2 pts, and 27% (G1 diarrhea = 9 pts, respectively. One patient presented vaginal bleeding at the time of applicator withdrawal (G3-blood transfusion; no bleeding was

  10. Image guided radiation therapy boost in combination with high-dose-rate intracavitary brachytherapy for the treatment of cervical cancer

    Directory of Open Access Journals (Sweden)

    Xianliang Wang

    2016-04-01

    Full Text Available Purpose : The purpose of this study was to demonstrate the dosimetric and clinical feasibility of image guided radiation therapy (IGRT combined with high-dose-rate (HDR intracavitary brachytherapy (ICBT to improve dose distribution in cervical cancer treatment. Material and methods: For 42 cervical cancer patients, magnetic resonance imaging (MRI scans were acquired after completion of whole pelvic irradiation 45-46 Gy and 5 fractions of B + I (ICBT + IGRT treatment were subsequently received. The high risk clinical target volume (HRCTV, intermediate risk clinical target volume (IRCTV, bladder, rectum, and sigmoid were contoured on the computed tomography (CT scans. The total planning aim doses for HRCTV was D 90% > 85 Gy, whilst constraints for rectum and sigmoid were D 2cc < 75 Gy and D 2cc < 90 Gy for bladder in terms of an equivalent dose in 2 Gy (EQD2 for external beam radiotherapy (EBRT and brachytherapy boost. The IGRT plan was optimized on top of the ICBT dose distribution. A dosimetric comparison was made between B + I and optimized ICBT (O-ICBT only. Results: The mean D 90% of HRCTV was comparable for B + I and O-ICBT (p = 0.82. For B + I plan, HRCTV D100%, IRCTV D 100% , and IRCTV D 90% were significantly increased by a mean of 10.52 Gy, 5.61 Gy, and 2.70 Gy, respectively (p < 0.01. The D 2cc for bladder, rectum, and sigmoid were lower by a mean of 21.36, 6.78, and 10.65 Gy, respectively (p < 0.01. The mean rectum V60 Gy value over 42 patients was almost the same for both techniques but for bladder and sigmoid B + I had higher V60 Gy mean values as compared with the O-ICBT. Conclusions : B + I can improve dose distribution in cervical cancer treatment; it could be useful for tumors extended beyond the reach of intracavitary/interstitial brachytherapy (IC/ISBT or for centers that are inexperienced or ill-equipped with IC/ISBT techniques. Additional confirmatory prospective studies with larger numbers of patients and longer follow

  11. Adaptation of the CVT algorithm for catheter optimization in high dose rate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, Eric; Fekete, Charles-Antoine Collins; Beaulieu, Luc [Département de Physique, de Génie Physique et d’Optique et Centre de recherche sur le cancer de l’Université Laval, Université Laval, Québec, Québec G1V 0A6, Canada and Département de Radio-Oncologie et Axe oncologie du Centre de Recherche du CHU de Québec, CHU de Québec, 11 Côte du Palais, Québec, Québec G1R 2J6 (Canada); Létourneau, Mélanie [Département de Radio-Oncologie, CHU de Québec, 11 Côte du Palais, Québec, Québec G1R 2J6 (Canada); Fenster, Aaron [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8 (United Kingdom); Pouliot, Jean [Department of Radiation Oncology, University of California San Francisco, Helen Diller Family Comprehensive Cancer Center, 1600 Divisadero Street, San Francisco, California 94143-1708 (United States)

    2013-11-15

    Purpose: An innovative, simple, and fast method to optimize the number and position of catheters is presented for prostate and breast high dose rate (HDR) brachytherapy, both for arbitrary templates or template-free implants (such as robotic templates).Methods: Eight clinical cases were chosen randomly from a bank of patients, previously treated in our clinic to test our method. The 2D Centroidal Voronoi Tessellations (CVT) algorithm was adapted to distribute catheters uniformly in space, within the maximum external contour of the planning target volume. The catheters optimization procedure includes the inverse planning simulated annealing algorithm (IPSA). Complete treatment plans can then be generated from the algorithm for different number of catheters. The best plan is chosen from different dosimetry criteria and will automatically provide the number of catheters and their positions. After the CVT algorithm parameters were optimized for speed and dosimetric results, it was validated against prostate clinical cases, using clinically relevant dose parameters. The robustness to implantation error was also evaluated. Finally, the efficiency of the method was tested in breast interstitial HDR brachytherapy cases.Results: The effect of the number and locations of the catheters on prostate cancer patients was studied. Treatment plans with a better or equivalent dose distributions could be obtained with fewer catheters. A better or equal prostate V100 was obtained down to 12 catheters. Plans with nine or less catheters would not be clinically acceptable in terms of prostate V100 and D90. Implantation errors up to 3 mm were acceptable since no statistical difference was found when compared to 0 mm error (p > 0.05). No significant difference in dosimetric indices was observed for the different combination of parameters within the CVT algorithm. A linear relation was found between the number of random points and the optimization time of the CVT algorithm. Because the

  12. CT-guided high-dose-rate brachytherapy of unresectable hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Collettini, Federico; Schreiber, Nadja; Schnapauff, Dirk; Denecke, Timm; Hamm, Bernd; Gebauer, Bernhard [ChariteUniversitaetsmedizin Berlin, Department of Diagnostic and Interventional Radiology, Berlin (Germany); Wust, Peter [ChariteUniversitaetsmedizin Berlin, Department of Radiation Oncology, Berlin (Germany); Schott, Eckart [Universitaetsmedizin Berlin, Department of Gastroenterology, Berlin (Germany)

    2015-05-01

    The purpose of the present study was to evaluate the clinical outcome of CT-guided high-dose-rate brachytherapy (CT-HDRBT) in patients with unresectable hepatocellular carcinoma (HCC). Over a 6-year period, 98 patients with 212 unresectable HCC underwent CT-HDRBT applying a {sup 192}Ir source at our institution. Magnetic resonance imaging (MRI) follow-up was performed 6 weeks after the intervention and then every 3 months. The primary endpoint was local tumor control (LTC); secondary endpoints included progression-free survival (PFS) and overall survival (OS). Patients were available for MRI evaluation for a mean follow-up of 23.1 months (range 4-64 months; median 20 months). Mean tumor diameter was 5 cm (range 1.8-12 cm). Eighteen of 212 (8.5 %) tumors showed local progression after a mean LTC of 21.1 months. In all, 67 patients (68.4 %) experienced distant tumor progression. The mean PFS was 15.2 months. Forty-six patients died during the follow-up period. Median OS was 29.2 months. Actuarial 1-, 2-, and 3-year OS rates were 80, 62, and 46 %, respectively. CT-HDRBT is an effective therapy to attain local tumor control in patients with unresectable HCC. Prospective randomized studies comparing CT-HDRBT with the standard treatments like Radiofrequency ablation (RFA) and chemoembolization (TACE) are mandatory. (orig.) [German] Zweck der vorliegenden Arbeit war die Analyse der klinischen Effektivitaet der CT-gesteuerten Hochdosis-Brachytherapie (CT-HDRBT) bei Patienten mit inoperablem hepatozellulaeren Karzinom (HCC). Ueber einen Zeitraum von 6 Jahren, wurden an unserer Klinik 98 Patienten mit 212 inoperablen HCC mittels CT-HDRBT mit {sup 192}Ir behandelt. MRT-Verlaufskontrollen erfolgten 6 Wochen nach der Intervention und dann alle 3 Monate. Primaerer Endpunkt der Studie war die lokale Tumorkontrolle (LTC); sekundaere Endpunkte waren das progressionsfreie Ueberleben (PFS) und Gesamtueberleben (OS). Die mittlere Nachbeobachtungszeit betrug 23,1 Monate (Spanne 4

  13. Radioablation of liver malignancies with interstitial high-dose-rate brachytherapy. Complications and risk factors

    Energy Technology Data Exchange (ETDEWEB)

    Mohnike, Konrad; Wolf, Steffen; Damm, Robert; Seidensticker, Max; Seidensticker, Ricarda; Fischbach, Frank; Pech, Maciej; Ricke, Jens [Otto-von-Guericke-Universitaet, Klinik fuer Radiologie und Nuklearmedizin, Universitaetsklinikum Magdeburg A.oe.R., Magdeburg (Germany); Peters, Nils; Hass, Peter; Gademann, Guenther [Otto-von-Guericke-Universitaet, Klinik fuer Strahlentherapie, Universitaetsklinikum Magdeburg A.oe.R., Magdeburg (Germany)

    2016-05-15

    To evaluate complications and identify risk factors for adverse events in patients undergoing high-dose-rate interstitial brachytherapy (iBT). Data from 192 patients treated in 343 CT- or MRI-guided interventions from 2006-2009 at our institution were analyzed. In 41 %, the largest tumor treated was ≥ 5 cm, 6 % of the patients had tumors ≥ 10 cm. Prior to iBT, 60 % of the patients had chemotherapy, 22 % liver resection, 19 % thermoablation or transarterial chemoembolization (TACE). Safety was the primary endpoint; survival data were obtained as the secondary endpoints. During follow-up, MRI or CT imaging was performed and clinical and laboratory parameters were obtained. The rate of major complications was below 5 %. Five major bleedings (1.5 %) occurred. The frequency of severe bleeding was significantly higher in patients with advanced liver cirrhosis. One patient developed signs of a nonclassic radiation-induced liver disease. In 3 patients, symptomatic gastrointestinal (GI) ulcers were detected. A dose exposure to the GI wall above 14 Gy/ml was a reliable threshold to predict ulcer formation. A combination of C-reactive protein ≥ 165 mg/l and/or leukocyte count ≥ 12.7 Gpt/l on the second day after the intervention predicted infection (sensitivity 90.0 %; specificity 92.8 %.) Two patients (0.6 %) died within 30 days. Median overall survival after the first liver treatment was 20.1 months for all patients and the local recurrence-free surviving proportion was 89 % after 12 months. Image-guided iBT yields a low rate of major complications and is effective. (orig.) [German] Evaluierung der Komplikationsrate und Identifizierung von Risikofaktoren fuer Komplikationen und Nebenwirkungen bei Patienten mit Lebermalignomen, die mit der hochdosierten interstitiellen Brachytherapie (iBT) behandelt wurden. Von 2006 bis 2009 wurden 192 Patienten in 343 CT- oder MRT-gefuehrten Interventionen behandelt und deren Daten ausgewertet. Der groesste behandelte Tumor war in

  14. Optimal bladder filling during high-dose-rate intracavitary brachytherapy for cervical cancer: a dosimetric study

    Directory of Open Access Journals (Sweden)

    Umesh Mahantshetty

    2017-04-01

    Full Text Available Purpose: The aim of this study is to compare 3D dose volume histogram (DVH parameters of bladder and other organs at risk with different bladder filling protocol during high-dose-rate intracavitary brachytherapy (HDR-ICBT in cervical cancer, and to find optimized bladder volume. Material and methods : This dosimetric study was completed with 21 patients who underwent HDR-ICBT with computed tomography/magnetic resonance compatible applicator as a routine treatment. Computed tomography planning was done for each patient with bladder emptied (series 1, after 50 ml (series 2, and 100 ml (series 3 bladder filling with a saline infusion through the bladder catheter. Contouring was done on the Eclipse Planning System. 7 Gy to point A was prescribed with the standard loading patterns. Various 3D DVH parameters including 0.1 cc, 1 cc, 2 cc doses and mean doses to the OAR’s were noted. Paired t-test was performed. Results : The mean (± SD bladder volume was 64.5 (± 25 cc, 116.2 (± 28 cc, and 172.9 (± 29 cc, for series 1, 2, and 3, respectively. The 0.1 cm 3 ,1 cm 3 , 2 cm 3 mean bladder doses for series 1, series 2, and series 3 were 9.28 ± 2.27 Gy, 7.38 ± 1.72 Gy, 6.58 ± 1.58 Gy; 9.39 ± 2.28 Gy, 7.85 ± 1.85 Gy, 7.05 ± 1.59 Gy, and 10.09 ± 2.46 Gy, 8.33 ± 1.75 Gy, 7.6 ± 1.55 Gy, respectively. However, there was a trend towards higher bladder doses in series 3. Similarly, for small bowel dose 0.1 cm 3 , 1 cm 3 , and 2 cm 3 in series 1, 2, and 3 were 5.44 ± 2.2 Gy, 4.41 ± 1.84 Gy, 4 ± 1.69 Gy; 4.57 ± 2.89 Gy, 3.78 ± 2.21 Gy, 3.35 ± 2.02 Gy, and 4.09 ± 2.38 Gy, 3.26 ± 1.8 Gy, 3.05 ± 1.58 Gy. Significant increase in small bowel dose in empty bladder (series 1 compared to full bladder (series 3 (p = 0.03 was noted. However, the rectal and sigmoid doses were not significantly affected with either series. Conclusions : Bladder filling protocol with 50 ml and 100 ml was well tolerated and achieved a reasonably reproducible bladder volume

  15. SU-E-T-165: Characterization of Dose Distributions in High-Dose-Rate Surface Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Buzurovic, I; Hansen, J; Bhagwat, M; O’Farrell, D; Damato, A; Friesen, S; Devlin, P; Cormack, R [Dana-Farber/Brigham and Women’s Cancer Center, Harvard Medical School, Boston, MA (United States)

    2015-06-15

    Purpose: To characterize dose distributions in high-dose-rate(HDR) surface brachytherapy using an Ir-125 source for different geometries, field sizes and topology of the clinical targets(CT). To investigate the depth doses at the central axis(CAX), edges of the treatment fields(E), and lateral dose distributions(L) present when using flap applicators in skin cancer treatments. Methods: When malignancies diagnosed on the skin are treated, various geometries of the CT require proper adaptation of the flap or custom-made applicators to the treatment site. Consequently, the dose at the depth on CAX and field edges changes with variation of the curvatures and size of the applicators. To assess the dose distributions, we created a total of 10 treatment plans(TP) for 10×10 and 20×20 field sizes(FS) with a step size of 1cm. The geometry of the applicators was: planar(PA), curved to 30(CA30) and 60(CA60) degrees with respect to the CAX, half-cylinder(HC), and cylindrical shape(CS). One additional TP was created in which the applicators were positioned to form a dome shape(DS) with a diameter of 16cm. This TP was used to emulate treatment of the average sized scalp. All TPs were optimized to deliver a prescription dose at 8mm equidistantly from the planes containing the dwell positions. This optimization is equivalent to the clinical arrangement since the SSD for the flap applicators is 5mm and the prescription depth is 3mm in the majority of clinical cases. Results: The depths (in mm) of the isodose lines were: FS(10×10):PA[90%(9.1CAX,8.0E,7.6L),50%(28.3CAX,20E,17.3L), 25%(51.1CAX,40E,27L)],CA30[90%(10.3CAX,8.2E,7.9L),50%(32.1CAX, 16.2E,15.8L),25%(61.3CAX,36.7E,31.8L)],CA60[90%(12.2CAX,6.1E,6.3L ),50%(47CAX,14E,16.6L),25%(70.8CAX,31.9E,35.4L)],HC[90%(11.1CA X,6.3E,7.3L),50%(38.3CAX,14.6E,16.1L),25%(66.2CAX,33.8E,34.2L)];FS (20×20):PA[90%(11.1CAX,9.0E,7.0L),50%(34.4CAX,21.9E,15.3L),25%(7 0.4CAX,50.9E,34.8L)],CA30[90%(10.9CAX,7.5E,7.1L),50%(38.8CAX,16. 7E,15.4L),25

  16. Image-Guided High-Dose-Rate (HDR) Boost Localization Using MRI/MR Spectroscopy: A Correlation Study with Biopsy

    OpenAIRE

    Vigneault, Eric; Mbodji, Khaly; Racine, Louis G; Chevrette, Eric; Lavallee, Marie C; Martin, Andr?-Guy; Despres, Philippe; Beaulieu, Luc

    2016-01-01

    Purpose: The purpose of this study is to compare the blind interpretations of magnetic resonance imaging (MRI) sequences, diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC), mapping, and magnetic resonance spectroscopy (MRS) of the prostate, in comparison to prostate biopsy to identify a valid dominant intraprostatic lesion (DIL) for dose escalation using high-dose rate brachytherapy. Methods: MRI/MRS were performed on 20 patients with intermediate risk adenocarcinoma of t...

  17. Numerical reconstruction of high dose rate zones due to the Fukushima Dai-ichi Nuclear Power Plant accident.

    Science.gov (United States)

    Katata, Genki; Terada, Hiroaki; Nagai, Haruyasu; Chino, Masamichi

    2012-09-01

    To understand how the high dose rate zones were created during the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident on March 2011, the atmospheric dispersion of radionuclides during the period from 15 to 17 March was reproduced by using a computer-based nuclear emergency response system, WSPEEDI-II. With use of limited environmental monitoring data, prediction accuracy of meteorological and radiological fields by the system was improved to obtain best estimates of release rates, radiation dose maps, and plume movements. A large part of current high dose rate zones in Fukushima was explained by simulated surface deposition of radionuclides due to major releases of radionuclides on 15 March. In the simulation, the highest dose rate zones to the northwest of FNPP1 were created by a significant deposition of radionuclides discharged from FNPP1 during the afternoon. The results indicate that two environmental factors, i.e., rainfall and topography, strongly affected the spatial patterns of surface deposition of radionuclides. The wet deposition due to rainfall particularly played an important role in the formation of wide and heterogeneous distributions of high dose rate zones. The simulation also demonstrated that the radioactive plume flowed along the valleys to its leeward, which can expand the areas of a large amount of surface deposition in complex topography. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Development of Real-Time Measurement of Effective Dose for High Dose Rate Neutron Fields

    CERN Document Server

    Braby, L A; Reece, W D

    2003-01-01

    Studies of the effects of low doses of ionizing radiation require sources of radiation which are well characterized in terms of the dose and the quality of the radiation. One of the best measures of the quality of neutron irradiation is the dose mean lineal energy. At very low dose rates this can be determined by measuring individual energy deposition events, and calculating the dose mean of the event size. However, at the dose rates that are normally required for biology experiments, the individual events can not be separated by radiation detectors. However, the total energy deposited in a specified time interval can be measured. This total energy has a random variation which depends on the size of the individual events, so the dose mean lineal energy can be calculated from the variance of repeated measurements of the energy deposited in a fixed time. We have developed a specialized charge integration circuit for the measurement of the charge produced in a small ion chamber in typical neutron irradiation exp...

  19. Dosimetric evaluation of internal shielding in a high dose rate skin applicator

    Directory of Open Access Journals (Sweden)

    Françoise Lliso

    2011-03-01

    Full Text Available Purpose: The Valencia HDR applicators are accessories of the microSelectron HDR afterloading system (Nucletron shaped as truncated cones. The base of the cone is either 2 or 3 cm diameter. They are intended to treat skin lesions, being the typical prescription depth 3 mm. In patients with eyelid lesions, an internal shielding is very useful to reduce the dose to the ocular globe. The purpose of this work was to evaluate the dose enhancement from potential backscatter and electron contamination due to the shielding. Material and methods: Two methods were used: a Monte Carlo simulation, performed with the GEANT4 code, 2 cm Valencia applicator was placed on the surface of a water phantom in which 2 mm lead slab was located at 3 mm depth; b radiochromic EBT films, used to verify the Monte Carlo results, positioning the films at 1.5, 3, 5 and 7 mm depth, inside the phantom. Two irradiations, with and without the lead shielding slab, were carried out. Results: The Monte Carlo results showed that due to the backscatter component from the lead, the dose level raised to about 200% with a depth range of 0.5 mm. Under the lead the dose level was enhanced to about 130% with a depth range of 1 mm. Two millimeters of lead reduce the dose under the slab with about 60%. These results agree with film measurements within uncertainties. Conclusions: In conclusion, the use of 2 mm internal lead shielding in eyelid skin treatments with the Valencia applicators were evaluated using MC methods and EBT film dosimetry. The minimum bolus thickness that was needed above and below the shielding was 0.5 mm and 1 mm respectively, and the shielding reduced the absorbed dose delivered to the ocular globe by about 60%.

  20. High-dose-rate brachytherapy as salvage modality for locally recurrent prostate cancer after definitive radiotherapy. A systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Chatzikonstantinou, Georgios; Zamboglou, Nikolaos; Roedel, Claus; Tselis, Nikolaos [J.W. Goethe University of Frankfurt, Department of Radiotherapy and Oncology, Frankfurt am Main (Germany); Zoga, Eleni [Sana Klinikum Offenbach, Department of Radiotherapy and Oncology, Offenbach am Main (Germany); Strouthos, Iosif [Medical Center - University of Freiburg, Department of Radiotherapy and Oncology, University of Freiburg, Freiburg (Germany); Butt, Saeed Ahmed [Sana Klinikum Offenbach, Department of Medical Physics and Engineering, Offenbach am Main (Germany)

    2017-09-15

    To review the current status of interstitial high-dose-rate brachytherapy as a salvage modality (sHDR BRT) for locally recurrent prostate cancer after definitive radiotherapy (RT). A literature search was performed in PubMed using ''high-dose-rate, brachytherapy, prostate cancer, salvage'' as search terms. In all, 51 search results published between 2000 and 2016 were identified. Data tables were generated and summary descriptions created. The main outcome parameters used were biochemical control (BC) and toxicity scores. Eleven publications reported clinical outcome and toxicity with follow-up ranging from 4-191 months. A variety of dose and fractionation schedules were described, including 19.0 Gy in 2 fractions up to 42.0 Gy in 6 fractions. The 5-year BC ranged from 18-77%. Late grade 3 genitourinary and gastrointestinal toxicity was 0-32% and 0-5.1%, respectively. sHDR BRT appears as safe and effective salvage modality for the reirradiation of locally recurrent prostate cancer after definitive RT. (orig.) [German] Zusammenfassende Darstellung relevanter Literatur zur interstitiellen High-Dose-Rate-Brachytherapie als Salvage-Modalitaet (sHDR-BRT) bei der Behandlung des lokal rezidivierten Prostatakarzinoms nach vorausgegangener definitiver Radiotherapie (RT). In der PubMed-Datenbank wurde eine Literaturrecherche mit den Suchbegriffen ''high-dose-rate, brachytherapy, prostate cancer, salvage'' durchgefuehrt. Zwischen den Jahren 2000 und 2016 wurden 51 Publikationen identifiziert. Die biochemische Kontrolle (BC) sowie das assoziierte Toxizitaetsprofil waren onkologische Hauptpunkte in der Analyse der beruecksichtigten Literatur. Von onkologischen Ergebnissen und Toxizitaeten berichteten 11 Publikationen bei einer medianen Nachbeobachtungszeit von 4-191 Monaten. Eine Variabilitaet von Dosis- und Fraktionierungsregimen wurde beschrieben mit totalen physikalischen Dosen von 19,0 Gy in 2 Fraktionen bis zu 42,0 Gy in 6 Fraktionen

  1. High dose rate prostate brachytherapy: an overview of the rationale, experience and emerging applications in the treatment of prostate cancer

    Science.gov (United States)

    Challapalli, A; Jones, E; Harvey, C; Hellawell, G O; Mangar, S A

    2012-01-01

    The technological advances in real-time ultrasound image guidance for high dose rate (HDR) prostate brachytherapy places this treatment modality at the forefront of innovation in radiotherapy. This review article will explore the rationale for HDR brachytherapy as a highly conformal method of dose delivery and safe dose escalation to the prostate, in addition to the particular radiobiological advantages it has over low dose rate and external beam radiotherapy. The encouraging outcome data and favourable toxicity profile will be discussed before looking at emerging applications for the future and how this procedure will feature alongside stereotactic radiosurgery. PMID:23118099

  2. High dose rate endobronchial brachytherapy: a curative treatment; La curietherapie endobronchique de haut debit de dose: un traitement curatif

    Energy Technology Data Exchange (ETDEWEB)

    Peiffert, D.; Spaeth, D.; Winnefeld, J. [Centre Alexis-Vautrin, 54 - Vandoeuvre-les-Nancy (France); Menard, O. [Centre Hospitalier Universitaire Nancy-Brabois, 54 - Vandoeuvre-les-Nancy (France)

    2000-06-01

    New endobronchial techniques of treatment allow a good unblocking. Nevertheless, only high dose rate brachytherapy delivers a curative treatment for invasive carcinomas. This study analyses the results of the first 33 consecutive patients treated with curative intent by this technique from 1994 to 1997, and followed-up more than one year. Thirty-seven lesions were treated, with usual schedule delivering 30 Gy at 1 cm depth in six fractions and three to five weeks. All the patients were meticulously selected on the local involvement of the tumour and absolute contraindications to a surgical treatment. All of them have a pulmonary disease history or a general contraindication. With a 14-month follow-up, the local control at two months after the treatment was 95 % (endoscopic and histologic), and 90 % of the patients presented a prolonged local control. Four patients died of the treated cancer, another of a controlateral cancer. Ten patients died of another disease, five of them from a respiratory insufficiency. The overall survival rate at two years was 53 % and the specific survival rate 80 %. The acute tolerance was good, without incident. Asymptomatic bronchial stenoses, described by endoscopic follow-up, were described for seven patients. We conclude that, on the basis of a good selection of the patients, and a respect of the indications, high dose rate endobronchial brachytherapy is an effective curative treatment. It offers a new curative option and must be proposed for the small invasive carcinomas in non-operable patients. (author)

  3. Development and evaluation of an automatic interstitial catheter digitization tool for adaptive high-dose-rate brachytherapy.

    Science.gov (United States)

    Dise, Joseph; Liang, Xing; Scheuermann, Joshua; Anamalayil, Shibu; Mesina, Carmen; Lin, Lilie L; Teo, Boon-Keng Kevin

    2015-01-01

    To develop and evaluate an automatic interstitial catheter digitization algorithm for use in adaptive high-dose-rate brachytherapy for gynecologic cancers using the Syed-Neblett template. We developed an automatic catheter digitization tool, which uses a region growing algorithm in conjunction with a spline model of the catheters. Seed locations were selected in each catheter for the region growing algorithm. The region growing was constrained by a spline model of the catheters, which prevents intercatheter crossover or incorrect digitization due to air pockets. Plan reoptimization was performed on successive day computed tomography scans using dwell positions for the Day 1 computed tomography. This method was applied to 10 patients who had received high-dose-rate interstitial brachytherapy using the Syed-Neblett template. The prescribed dose was 18.75 or 20 Gy delivered in five fractions, twice daily, and more than 3 consecutive days. Dosimetric comparisons were made between automatically and manually digitized plans. The region growing algorithm was able to successfully digitize all catheters. The mean difference between automatic and manually digitized positions was 0.4 ± 0.2 mm. No significant difference was found in dosimetric parameters between the automatic and manually digitized plans. The mean D90% of the clinical target volume over all 3 days of treatment of the manual vs. reoptimized automatic plans was 94.3 ± 6.58% and 92.32 ± 8.34%, respectively (p = 0.50). The algorithm discussed in this article is the first developed for adaptive interstitial brachytherapy for a large number of catheters (14 on average). The algorithm has future potential in digitization quality assurance. A region growing algorithm was developed to automatically digitize interstitial catheters in high-dose-rate brachytherapy. This automatic digitization tool was shown to be accurate compared with manual digitization. Copyright © 2015 American Brachytherapy Society

  4. Image-guided high-dose-rate interstitial brachytherapy – a valuable salvage treatment approach for loco-regional recurrence of papillary thyroid cancer

    Directory of Open Access Journals (Sweden)

    Ning Wu

    2016-04-01

    Full Text Available Purpose : To report the treatment effect of image-guided high-dose-rate (HDR interstitial brachytherapy for refractory recurrence of papillary thyroid cancer (PTC. Case report: This 66-year-old female presented with recurrence 5 years after thyroidectomy for PTC. Despite external irradiation and radioactive 131I, the lesion expanded as 3.7 × 3.0 × 2.3 cm3 and 2.0 × 1.5 × 1.5 cm3. The locoregional recurrent tumor was treated with image-guided HDR interstitial brachytherapy. The total dose of 30 Gy in 6 fractions were delivered on the whole recurrent tumor. Results: Removal of the recurrent tumor was securely achieved by HDR interstitial brachytherapy guided with ultrasound, computed tomography (CT, and magnetic resonance imaging (MRI scanning. The refractory tumor in the patients healed uneventfully after HDR interstitial brachytherapy without recurrence during the 14 months of follow-up. Conclusions : The image-guided HDR interstitial brachytherapy may be a valuable salvage treatment approach for refractory recurrence of PTC.

  5. Two-piece customized mold technique for high-dose-rate brachytherapy on cancers of the buccal mucosa and lip.

    Science.gov (United States)

    Matsuzaki, Hidenobu; Takemoto, Mitsuhiro; Hara, Marina; Unetsubo, Teruhisa; Yanagi, Yoshinobu; Katsui, Kuniaki; Katayama, Norihisa; Yoshio, Kotaro; Takenobu, Toshihiko; Kuroda, Masahiro; Kanazawa, Susumu; Asaumi, Jun-Ichi

    2012-01-01

    High-dose-rate (HDR) brachytherapy using a customized mold is a minimally invasive treatment for oral cancer; however, it is difficult to use this technique for buccal and lip cancers involving the commissura labiorum, owing to its anatomic form. The purpose of this study was to introduce an improved customized mold consisting of 2 pieces to allow the fixation of molds to these sites. Five patients with buccal carcinoma and 1 patient with lip carcinoma were treated with this technique after external beam radiotherapy. One patient with neck metastasis underwent both neck dissection and partial tumor resection before HDR brachytherapy. At the end of the follow-up period, 5 patients had no tumor recurrence, and 1 patient had suffered local recurrence. Our technique is a viable therapeutic option for patients with buccal and lip carcinomas for whom the therapeutic modalities are limited by age, performance status, and other factors. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Brachytherapy optimization using radiobiological-based planning for high dose rate and permanent implants for prostate cancer treatment

    Science.gov (United States)

    Seeley, Kaelyn; Cunha, J. Adam; Hong, Tae Min

    2017-01-01

    We discuss an improvement in brachytherapy--a prostate cancer treatment method that directly places radioactive seeds inside target cancerous regions--by optimizing the current standard for delivering dose. Currently, the seeds' spatiotemporal placement is determined by optimizing the dose based on a set of physical, user-defined constraints. One particular approach is the ``inverse planning'' algorithms that allow for tightly fit isodose lines around the target volumes in order to reduce dose to the patient's organs at risk. However, these dose distributions are typically computed assuming the same biological response to radiation for different types of tissues. In our work, we consider radiobiological parameters to account for the differences in the individual sensitivities and responses to radiation for tissues surrounding the target. Among the benefits are a more accurate toxicity rate and more coverage to target regions for planning high-dose-rate treatments as well as permanent implants.

  7. Pediatric peri-operative fractionated high-dose-rate brachytherapy for recurrent Wilms’ tumor using a reconstructed Freiburg flap

    Directory of Open Access Journals (Sweden)

    Emily Flower

    2016-10-01

    Full Text Available Purpose : To report peri-operative fractionated high-dose-rate (HDR brachytherapy with a 3D customized Freiburg flap applicator to treat locally recurrent Wilms’ tumor, followed by immediate hyperthermic intraperitoneal chemotherapy for a 16-year-old with a second recurrence of nephroblastoma (Wilms’ tumor. Material and methods: The tumor was excised and surgical bed was treated with fractionated HDR brachytherapy using a Freiburg flap applicator. Hyperthermic intraperitoneal chemotherapy was performed immediately after the removal of brachytherapy applicator. Results: The Freiburg flap was successfully reconstructed to enable delivery of conformable peri-operative HDR brachytherapy. The clinical target volume (CTV D90 was 26 Gy in 5 fractions. Conclusions : Peri-operative fractionated HDR brachytherapy with a customized Freiburg flap applicator was delivered successfully across a large multi-disciplinary team.

  8. Automated construction of an intraoperative high-dose-rate treatment plan library for the Varian brachytherapy treatment planning system.

    Science.gov (United States)

    Deufel, Christopher L; Furutani, Keith M; Dahl, Robert A; Haddock, Michael G

    2016-01-01

    The ability to create treatment plans for intraoperative high-dose-rate (IOHDR) brachytherapy is limited by lack of imaging and time constraints. An automated method for creation of a library of high-dose-rate brachytherapy plans that can be used with standard planar applicators in the intraoperative setting is highly desirable. Nonnegative least squares algebraic methods were used to identify dwell time values for flat, rectangular planar applicators. The planar applicators ranged in length and width from 2 cm to 25 cm. Plans were optimized to deliver an absorbed dose of 10 Gy to three different depths from the patient surface: 0 cm, 0.5 cm, and 1.0 cm. Software was written to calculate the optimized dwell times and insert dwell times and positions into a .XML plan template that can be imported into the Varian brachytherapy treatment planning system. The user may import the .XML template into the treatment planning system in the intraoperative setting to match the patient applicator size and prescribed treatment depth. A total of 1587 library plans were created for IOHDR brachytherapy. Median plan generation time was approximately 1 minute per plan. Plan dose was typically 100% ± 1% (mean, standard deviation) of the prescribed dose over the entire length and width of the applicator. Plan uniformity was best for prescription depths of 0 cm and 0.5 cm from the patient surface. An IOHDR plan library may be created using automated methods. Thousands of plan templates may be optimized and prepared in a few hours to accommodate different applicator sizes and treatment depths and reduce treatment planning time. The automated method also enforces dwell time symmetry for symmetrical applicator geometries, which simplifies quality assurance. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  9. Perioperative Interstitial High-Dose-Rate Brachytherapy for the Treatment of Recurrent Keloids: Feasibility and Early Results

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Ping, E-mail: ping.jiang@uksh.de [Department of Radiation Oncology, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany); Baumann, René [Department of Radiation Oncology, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany); Dunst, Juergen [Department of Radiation Oncology, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany); Department of Radiation Oncology, University of Copenhagen, Copenhagen (Denmark); Geenen, Matthias [Department of Reconstructive Surgery, Lubinus Clinic Kiel, Kiel (Germany); Siebert, Frank-André [Department of Radiation Oncology, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany); Niehoff, Peter [Department of Radiation Oncology, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany); Department of Radiation Oncology, Community Clinic Köln, Köln (Germany); Department of Radiation Oncology, University Witten/Herdecke, Witten (Germany); Bertolini, Julia; Druecke, Daniel [Department of Reconstructive Surgery, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany)

    2016-03-01

    Purpose: To prospectively evaluate high-dose-rate brachytherapy in the treatment of therapy-resistant keloids and report first results, with emphasis on feasibility and early treatment outcome. Methods and Materials: From 2009 to 2014, 24 patients with 32 recurrent keloids were treated with immediate perioperative high-dose-rate brachytherapy; 3 patients had been previously treated with adjuvant external beam radiation therapy and presented with recurrences in the pretreated areas. Two or more different treatment modalities had been tried in all patients and had failed to achieve remission. After (re-)excision of the keloids, a single brachytherapy tube was placed subcutaneously before closing the wound. The target volume covered the scar in total length. Brachytherapy was given in 3 fractions with a single dose of 6 Gy in 5 mm tissue depth. The first fraction was given within 6 hours after surgery, the other 2 fractions on the first postoperative day. Thus, a total dose of 18 Gy in 3 fractions was administered within 36 hours after the resection. Results: The treatment was feasible in all patients. No procedure-related complications (eg, secondary infections) occurred. Nineteen patients had keloid-related symptoms before treatment like pain and pruritus; disappearance of symptoms was noticed in all patients after treatment. After a median follow-up of 29.4 months (range, 7.9-72.4 months), 2 keloid recurrences and 2 mildly hypertrophied scars were observed. The local control rate was 94%. Pigmentary abnormalities were detected in 3 patients, and an additional 6 patients had a mild delay in the wound-healing process. Conclusions: The early results of this study prove the feasibility and the efficacy of brachytherapy for the prevention of keloids. The results also suggest that brachytherapy may be advantageous in the management of high-risk keloids or as salvage treatment for failure after external beam therapy.

  10. Electromagnetic tracking for catheter reconstruction in ultrasound-guided high-dose-rate brachytherapy of the prostate.

    Science.gov (United States)

    Bharat, Shyam; Kung, Cynthia; Dehghan, Ehsan; Ravi, Ananth; Venugopal, Niranjan; Bonillas, Antonio; Stanton, Doug; Kruecker, Jochen

    2014-01-01

    The accurate delivery of high-dose-rate brachytherapy is dependent on the correct identification of the position and shape of the treatment catheters. In many brachytherapy clinics, transrectal ultrasound (TRUS) imaging is used to identify the catheters. However, manual catheter identification on TRUS images can be time consuming, subjective, and operator dependent because of calcifications and distal shadowing artifacts. We report the use of electromagnetic (EM) tracking technology to map the position and shape of catheters inserted in a tissue-mimicking phantom. The accuracy of the EM system was comprehensively quantified using a three-axis robotic system. In addition, EM tracks acquired from catheters in a phantom were compared with catheter positions determined from TRUS and CT images to compare EM system performance to standard clinical imaging modalities. The tracking experiments were performed in a controlled laboratory environment and also in a typical brachytherapy operating room to test for potential EM distortions. The robotic validation of the EM system yielded a mean accuracy of brachytherapy operating room. The achievable accuracy depends to a large extent on the calibration of the TRUS probe, geometry of the tracked devices relative to the EM field generator, and locations of surrounding clinical equipment. To address the issue of variable accuracy, a robust calibration algorithm has been developed and integrated into the workflow. The proposed mapping technique was also found to improve the workflow efficiency of catheter identification. The high baseline accuracy of the EM system, the consistent agreement between EM-tracked, TRUS- and CT-identified catheters, and the improved workflow efficiency illustrate the potential value of using EM tracking for catheter mapping in high-dose-rate brachytherapy. Copyright © 2014 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  11. Perioperative high-dose-rate interstitial brachytherapy combined with external beam radiation therapy for soft tissue sarcoma.

    Science.gov (United States)

    Sharma, Daya Nand; Deo, S V Suryanarayana; Rath, Goura Kisor; Shukla, Nootan Kumar; Bakhshi, Sameer; Gandhi, Ajeet Kumar; Julka, Pramod Kumar

    2015-01-01

    The aim of our study was to evaluate the role of perioperative high-dose-rate interstitial brachytherapy (PHDRIBT) in combination with external beam radiation therapy (EBRT) in patients with localized soft tissue sarcoma (STS). From year 2004 to 2010, 52 patients with localized STS were treated with wide local excision plus PHDRIBT followed by EBRT. Median size of the tumor was 8 cm (range, 4-19 cm). A single-plane interstitial brachytherapy implant with an average of nine catheters was performed during the surgical resection. The PHDRIBT was started on third postoperative day to deliver a high-dose-rate dose of 16 Gy in four fractions over 2 days using twice-a-day fractionation schedule. After 4 weeks, EBRT was started for a prescription dose of 50 Gy by conventional fractionation. Subsequently, chemotherapy was administered, if indicated as per our institutional policy. Patients were followed up regularly to study local control, survival, and toxicity. At a median followup of 46 months, no patient developed local recurrence, but 12 patients developed distant metastases. The 5-year overall survival and disease-free survival were 67% and 63%, respectively. Main acute toxicity was delayed wound healing observed in 3 patients (5.7%). Commonest late toxicity was chronic skin/subcutaneous fibrosis noticed in 5 patients (9.6%). The PHDRIBT combined with EBRT provides excellent local control and survival rates with acceptable acute and late toxicity in patients with localized STS. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  12. Low and high dose rate heavy ion radiation-induced intestinal and colonic tumorigenesis in APC1638N/+ mice

    Science.gov (United States)

    Suman, Shubhankar; Kumar, Santosh; Moon, Bo-Hyun; Fornace, Albert J.; Datta, Kamal

    2017-05-01

    Ionizing radiation (IR) is a recognized risk factor for colorectal cancer (CRC) and astronauts undertaking long duration space missions are expected to receive IR doses in excess of permissible limits with implications for colorectal carcinogenesis. Exposure to IR in outer space occurs at low doses and dose rates, and energetic heavy ions due to their high linear energy transfer (high-LET) characteristics remain a major concern for CRC risk in astronauts. Previously, we have demonstrated that intestinal tumorigenesis in a mouse model (APC1638N/+) of human colorectal cancer was significantly higher after exposure to high dose rate energetic heavy ions relative to low-LET γ radiation. The purpose of the current study was to compare intestinal tumorigenesis in APC1638N/+ mice after exposure to energetic heavy ions at high (50 cGy/min) and relatively low (0.33 cGy/min) dose rate. Male and female mice (6-8 weeks old) were exposed to either 10 or 50 cGy of 28Si (energy: 300 MeV/n; LET: 70 keV/μm) or 56Fe (energy: 1000 MeV/n; LET: 148 keV/μm) ions at NASA Space Radiation Laboratory in Brookhaven National Laboratory. Mice (n = 20 mice/group) were euthanized and intestinal and colon tumor frequency and size were counted 150 days after radiation exposure. Intestinal tumorigenesis in male mice exposed to 56Fe was similar for high and low dose rate exposures. Although male mice showed a decreasing trend at low dose rate relative to high dose rate exposures, the differences in tumor frequency between the two types of exposures were not statistically significant after 28Si radiation. In female mice, intestinal tumor frequency was similar for both radiation type and dose rates tested. In both male and female mice intestinal tumor size was not different after high and low dose rate radiation exposures. Colon tumor frequency in male and female mice after high and low dose rate energetic heavy ions was also not significantly different. In conclusion, intestinal and colonic tumor

  13. Needle migration and dosimetric impact in high-dose-rate brachytherapy for prostate cancer evaluated by repeated MRI.

    Science.gov (United States)

    Buus, Simon; Lizondo, Maria; Hokland, Steffen; Rylander, Susanne; Pedersen, Erik M; Tanderup, Kari; Bentzen, Lise

    To quantify needle migration and dosimetric impact in high-dose-rate brachytherapy for prostate cancer and propose a threshold for needle migration. Twenty-four high-risk prostate cancer patients treated with an HDR boost of 2 × 8.5 Gy were included. Patients received an MRI for planning (MRI1), before (MRI2), and after treatment (MRI3). Time from needle insertion to MRI3 was ∼3 hours. Needle migration was evaluated from coregistered images: MRI1-MRI2 and MRI1-MRI3. Dose volume histogram parameters from the treatment plan based on MRI1 were related to parameters based on needle positions in MRI2 or MRI3. Regression was used to model the average needle migration per implant and change in D90 clinical target volume, CTV prostate+3mm . The model fit was used for estimating the dosimetric impact in equivalent dose in 2 Gy fractions for dose levels of 6, 8.5, 10, 15, and 19 Gy. Needle migration was on average 2.2 ± 1.8 mm SD from MRI1-MRI2 and 5.0 ± 3.0 mm SD from MRI1-MRI3. D90 CTV prostate+3mm was robust toward average needle migration ≤3 mm, whereas for migration >3 mm D90 decreased by 4.5% per mm. A 3 mm of needle migration resulted in a decrease of 0.9, 1.7, 2.3, 4.8, and 7.6 equivalent dose in 2 Gy fractions for dose levels of 6, 8.5, 10, 15, and 19 Gy, respectively. Substantial needle migration in high-dose-rate brachytherapy occurs frequently in 1-3 hours following needle insertion. A 3-mm threshold of needle migration is proposed, but 2 mm may be considered for dose levels ≥15 Gy. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  14. Global convergence analysis of fast multiobjective gradient-based dose optimization algorithms for high-dose-rate brachytherapy.

    Science.gov (United States)

    Lahanas, M; Baltas, D; Giannouli, S

    2003-03-07

    We consider the problem of the global convergence of gradient-based optimization algorithms for interstitial high-dose-rate (HDR) brachytherapy dose optimization using variance-based objectives. Possible local minima could lead to only sub-optimal solutions. We perform a configuration space analysis using a representative set of the entire non-dominated solution space. A set of three prostate implants is used in this study. We compare the results obtained by conjugate gradient algorithms, two variable metric algorithms and fast-simulated annealing. For the variable metric algorithm BFGS from numerical recipes, large fluctuations are observed. The limited memory L-BFGS algorithm and the conjugate gradient algorithm FRPR are globally convergent. Local minima or degenerate states are not observed. We study the possibility of obtaining a representative set of non-dominated solutions using optimal solution rearrangement and a warm start mechanism. For the surface and volume dose variance and their derivatives, a method is proposed which significantly reduces the number of required operations. The optimization time, ignoring a preprocessing step, is independent of the number of sampling points in the planning target volume. Multiobjective dose optimization in HDR brachytherapy using L-BFGS and a new modified computation method for the objectives and derivatives has been accelerated, depending on the number of sampling points, by a factor in the range 10-100.

  15. The American Brachytherapy Society Treatment Recommendations for Locally Advanced Carcinoma of the Cervix Part II: High Dose-Rate Brachytherapy

    Science.gov (United States)

    Viswanathan, Akila N.; Beriwal, Sushil; De Los Santos, Jennifer; Demanes, D. Jeffrey; Gaffney, David; Hansen, Jorgen; Jones, Ellen; Kirisits, Christian; Thomadsen, Bruce; Erickson, Beth

    2012-01-01

    Purpose This report presents the 2011 update to the American Brachytherapy Society (ABS) high-dose-rate (HDR) brachytherapy guidelines for locally advanced cervical cancer. Methods Members of the American Brachytherapy Society (ABS) with expertise in cervical cancer brachytherapy formulated updated guidelines for HDR brachytherapy using tandem and ring, ovoids, cylinder or interstitial applicators for locally advanced cervical cancer were revised based on medical evidence in the literature and input of clinical experts in gynecologic brachytherapy. Results The Cervical Cancer Committee for Guideline Development affirms the essential curative role of tandem-based brachytherapy in the management of locally advanced cervical cancer. Proper applicator selection, insertion, and imaging are fundamental aspects of the procedure. Three-dimensional imaging with magnetic resonance or computed tomography or radiographic imaging may be used for treatment planning. Dosimetry must be performed after each insertion prior to treatment delivery. Applicator placement, dose specification and dose fractionation must be documented, quality assurance measures must be performed, and follow-up information must be obtained. A variety of dose/fractionation schedules and methods for integrating brachytherapy with external-beam radiation exist. The recommended tumor dose in 2 Gray (Gy) per fraction radiobiologic equivalence (EQD2) is 80–90 Gy, depending on tumor size at the time of brachytherapy. Dose limits for normal tissues are discussed. Conclusion These guidelines update those of 2000 and provide a comprehensive description of HDR cervical cancer brachytherapy in 2011. PMID:22265437

  16. Needle migration and dosimetric impact in high-dose-rate brachytherapy for prostate cancer evaluated by repeated MRI

    DEFF Research Database (Denmark)

    Buus, Simon; Lizondo, Maria; Hokland, Steffen

    2017-01-01

    PURPOSE: To quantify needle migration and dosimetric impact in high-dose-rate brachytherapy for prostate cancer and propose a threshold for needle migration. METHODS AND MATERIALS: Twenty-four high-risk prostate cancer patients treated with an HDR boost of 2 × 8.5 Gy were included. Patients...... received an MRI for planning (MRI1), before (MRI2), and after treatment (MRI3). Time from needle insertion to MRI3 was ∼3 hours. Needle migration was evaluated from coregistered images: MRI1-MRI2 and MRI1-MRI3. Dose volume histogram parameters from the treatment plan based on MRI1 were related...... to parameters based on needle positions in MRI2 or MRI3. Regression was used to model the average needle migration per implant and change in D90 clinical target volume, CTVprostate+3mm. The model fit was used for estimating the dosimetric impact in equivalent dose in 2 Gy fractions for dose levels of 6, 8.5, 10...

  17. In-Containment Signal Conditioning and Transmission via Power Lines within High Dose Rate Areas of Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Steffen; Weigel, Robert; Koelpin, Alexander [Institute for Electronics Engineering, University of Erlangen-Nuremberg, Cauerstr. 9, 91058 Erlangen (Germany); Dennerlein, Juergen; Janke, Iryna; Weber, Johannes [AREVA GmbH, Paul-Gossen-Str. 100, 91052 Erlangen (Germany)

    2015-07-01

    Signal conditioning and transmission for sensor systems and networks within the containment of nuclear power plants (NPPs) still poses a challenge to engineers, particularly in the case of equipment upgrades for existing plants, temporary measurements, decommissioning of plants, but also for new builds. This paper presents an innovative method for efficient and cost-effective instrumentation within high dose rate areas inside the containment. A transmitter-receiver topology is proposed that allows simultaneous, unidirectional point-to-point transmission of multiple sensor signals by superimposing them on existing AC or DC power supply cables using power line communication (PLC) technology. Thereby the need for costly installation of additional cables and containment penetrations is eliminated. Based on commercial off-the-shelf (COTS) electronic parts, a radiation hard transmitter is designed to operate in harsh environment within the containment during full plant operation. Hardware modularity of the transmitter allows application specific tradeoffs between redundancy and channel bandwidth. At receiver side in non-radiated areas, signals are extracted from the power line, demodulated, and provided either in analog or digital output format. Laboratory qualification tests and field test results within a boiling water reactor (BWR) are validating the proof of concept of the proposed system. (authors)

  18. Comparison of treatment planning on dosimetric differences between 192Ir sources for high-dose rate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Oh Nam [Dept. of Radiology, Mokpo Science University, Mokpo (Korea, Republic of); Shin, Seong Soo; Ahn, Woo Sang; KIm, Dae Yong; Choi, Won Sik [Dept. of Radiation Oncology, Gangenung Asan Hospital, University of Ulsan College of Medicine, Gangenung (Korea, Republic of); Kwon, Kyung Tae [Dept. of Radiologic Technology, Dongam Health University, Suwon (Korea, Republic of); Lim, Cheong Hwan [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of); Lee, Sang Ho [Dept. of Radiological Science, Seonam University, Namwon (Korea, Republic of)

    2016-06-15

    To evaluate whether the difference in geometrical characteristics between high-dose-rate (HDR) 192Ir sources would influence the dose distributions of intracavitary brachytherapy. Two types of microSelectron HDR 192Ir sources (classic and new models) were selected in this study. Two-dimensional (2D) treatment plans for classic and new sources were generated by using PLATO treatment planning system. We compared the point A, point B, and bladder and rectum reference points based on ICRU 38 recommendation. The radial dose function of the new source agrees with that of the classic source except difference of up to 2.6% at the nearest radial distance. The differences of anisotropy functions agree within 2% for r=1, 3, and 5 cm and 20°<θ<165°. The largest discrepancies of anisotropy functions reached up to 27% for θ<20° at r=0.25 cm and were up to 13%, 10%, and 7% at r=1, 3, and 5 cm for θ>170°, respectively. There were no significant differences in doses of point A, point B, and bladder point for the treatment plans between the new and classic sources. For the ICRU rectum point, the percent dose difference was on average 0.65% and up to 1.0%. The dose discrepancies between two treatment plans are mainly affected due to the geometrical difference of the source and the sealed capsule.

  19. Cosmetic Analysis Following Breast-Conserving Surgery and Adjuvant High-Dose-Rate Interstitial Brachytherapy for Early-Stage Breast Cancer: A Prospective Clinical Study

    Energy Technology Data Exchange (ETDEWEB)

    Garsa, Adam A.; Ferraro, Daniel J.; DeWees, Todd [Department of Radiation Oncology, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Margenthaler, Julie A. [Department of Surgery, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Naughton, Michael [Department of Medicine, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Aft, Rebecca [Department of Surgery, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Department of Surgery, John Cochran Veterans Hospital, St. Louis, Missouri (United States); Gillanders, William E.; Eberlein, Timothy [Department of Surgery, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Matesa, Melissa A. [Department of Radiation Oncology, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Zoberi, Imran, E-mail: izoberi@radonc.wustl.edu [Department of Radiation Oncology, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States)

    2013-03-15

    Purpose: To prospectively evaluate cosmetic outcomes in women treated with accelerated partial breast irradiation using high-dose-rate interstitial brachytherapy for early-stage breast cancer. Methods and Materials: Between 2004 and 2008, 151 patients with early-stage breast cancer were enrolled in a phase 2 prospective clinical trial. Eligible patients had stage Tis-T2 tumors of ≤3 cm that were excised with negative margins and with no nodal involvement. Patients received 3.4 Gy twice daily to a total dose of 34 Gy. Both the patients and the treating radiation oncologist qualitatively rated cosmesis as excellent, good, fair, or poor over time and ascribed a cause for changes in cosmesis. Cosmetic outcome was evaluated quantitatively by percentage of breast retraction assessment (pBRA). Patients also reported their satisfaction with treatment over time. Results: Median follow-up was 55 months. The rates of excellent-to-good cosmesis reported by patients and the treating radiation oncologist were 92% and 97% pretreatment, 91% and 97% at 3 to 4 months' follow-up, 87% and 94% at 2 years, and 92% and 94% at 3 years, respectively. Breast infection and adjuvant chemotherapy were independent predictors of a fair-to-poor cosmetic outcome at 3 years. Compared to pretreatment pBRA (7.35), there was no significant change in pBRA over time. The volume receiving more than 150 Gy (V150) was the only significant predictor of pBRA. The majority of patients (86.6%) were completely satisfied with their treatment. Conclusions: Patients and the treating physician reported a high rate of excellent-to-good cosmetic outcomes at all follow-up time points. Acute breast infection and chemotherapy were associated with worse cosmetic outcomes. Multicatheter interstitial brachytherapy does not significantly change breast size as measured by pBRA.

  20. A Prospective Longitudinal Clinical Trial Evaluating Quality of Life After Breast-Conserving Surgery and High-Dose-Rate Interstitial Brachytherapy for Early-Stage Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Garsa, Adam A.; Ferraro, Daniel J.; DeWees, Todd A. [Department of Radiation Oncology, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Deshields, Teresa L. [Department of Medicine, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Margenthaler, Julie A.; Cyr, Amy E. [Department of Surgery, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Naughton, Michael [Department of Medicine, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Aft, Rebecca [Department of Surgery, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Department of Surgery, John Cochran Veterans Hospital, St. Louis, Missouri (United States); Gillanders, William E.; Eberlein, Timothy [Department of Surgery, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Matesa, Melissa A.; Ochoa, Laura L. [Department of Radiation Oncology, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Zoberi, Imran, E-mail: izoberi@radonc.wustl.edu [Department of Radiation Oncology, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States)

    2013-12-01

    Purpose: To prospectively examine quality of life (QOL) of patients with early stage breast cancer treated with accelerated partial breast irradiation (APBI) using high-dose-rate (HDR) interstitial brachytherapy. Methods and Materials: Between March 2004 and December 2008, 151 patients with early stage breast cancer were enrolled in a phase 2 prospective clinical trial. Eligible patients included those with Tis-T2 tumors measuring ≤3 cm excised with negative surgical margins and with no nodal involvement. Patients received 3.4 Gy twice daily to a total dose of 34 Gy. QOL was measured using European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, version 3.0, and QLQ-BR23 questionnaires. The QLQ-C30 and QLQ-BR23 questionnaires were evaluated during pretreatment and then at 6 to 8 weeks, 3 to 4 months, 6 to 8 months, and 1 and 2 years after treatment. Results: The median follow-up was 55 months. Breast symptom scores remained stable in the months after treatment, and they significantly improved 6 to 8 months after treatment. Scores for emotional functioning, social functioning, and future perspective showed significant improvement 2 years after treatment. Symptomatic fat necrosis was associated with several changes in QOL, including increased pain, breast symptoms, systemic treatment side effects, dyspnea, and fatigue, as well as decreased role functioning, emotional functioning, and social functioning. Conclusions: HDR multicatheter interstitial brachytherapy was well tolerated, with no significant detrimental effect on measured QOL scales/items through 2 years of follow-up. Compared to pretreatment scores, there was improvement in breast symptoms, emotional functioning, social functioning, and future perspective 2 years after treatment.

  1. The Curie-Da Vinci Connection: 5-Years' Experience With Laparoscopic (Robot-Assisted) Implantation for High-Dose-Rate Brachytherapy of Solitary T2 Bladder Tumors.

    Science.gov (United States)

    van der Steen-Banasik, Elzbieta M; Smits, Geert A H J; Oosterveld, Bernard J; Janssen, Theo; Visser, Andries G

    2016-08-01

    To report experience and early results of laparoscopic implantation for interstitial brachytherapy (BT) of solitary bladder tumors and the feasibility of a high-dose-rate (HDR) schedule. From December 2009 to April 2015, 57 patients with a T2 solitary bladder tumor were treated in Arnhem with transurethral bladder resection followed by external beam irradiation, applied to the bladder and regional iliac lymph nodes, 40 Gy in 20 fractions, 5 fractions per week, and within 1 week interstitial HDR BT, in selected cases combined with partial cystectomy and lymph node dissection. The BT catheters were placed via a transabdominal approach with robotic assistance from a Da Vinci robot after a successful initial experience with a nonrobotic laparoscopic approach. The fraction schedule for HDR was 10 fractions of 2.5 Gy, 3 fractions per day. This was calculated to be equivalent to a reference low-dose-rate schedule of 30 Gy in 60 hours. Data for oncologic outcomes and toxicity (Common Toxicity Criteria version 4) were prospectively collected. These modifications resulted in an average postoperative hospitalization of 6 days, minimal blood loss, and no wound healing problems. Two patients had severe acute toxicity: 1 pulmonary embolism grade 4 and 1 cardiac death. Late toxicity was mild (n=2 urogenital grade 3 toxicity). The median follow-up was 2 years. Using cumulative incidence competing risk analysis, the 2-year overall, disease-free, and disease-specific survival and local control rates were 59%, 71%, 87%, and 82%, respectively. The benefits of minimally invasive surgery for implantation of BT catheters and the feasibility of HDR BT in bladder cancer are documented. The patient outcome and adverse events are comparable to the best results published for a bladder-sparing approach. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Reirradiation of head and neck cancer with high-dose-rate brachytherapy: a customizable intraluminal solution for postoperative treatment of tracheal mucosa recurrence.

    Science.gov (United States)

    Doyle, Laura A; Harrison, Amy S; Cognetti, David; Xiao, Ying; Yu, Yan; Liu, Haisong; Ahn, Peter H; Anné, P Rani; Showalter, Timothy N

    2011-01-01

    Delivering adequate dose to tracheal mucosa recurrence after multiple prior courses of surgery and radiation presented a challenge for radiation delivery. Tumor bed location and size, combined with previous doses to surrounding areas, complicated the use of external beam therapy with either photons or electrons. High-dose-rate (HDR) brachytherapy was explored to provide sufficient dose coverage. A 45-year-old gentleman presented with recurrent head and neck cancer. After undergoing additional excision of gross tumor in the tracheal region, radiation was recommended to improve local control. The region of residual tumor was confined to a small superficial lesion at the posterior-superior aspect of the trachea, involving mucosa located along the bend of the trachea, immediately deep to the stoma. External beam treatment was discussed but was not recommended based on recurrence location in the prior radiation field and patient's flexed chin position. HDR technique with a custom applicator was preferred. A three-dimensional HDR plan based on computed tomography used a single catheter optimized to cover gross tumor volume as delineated by physician. Prescribed dose was 5 Gy/fraction for six fractions (two fractions/wk). The applicator position was verified daily with computed tomography and physician setup approval before treatment. The patient was positioned on a wing board to allow access to the stoma. HDR brachytherapy was well tolerated. Intraluminal HDR brachytherapy is a viable option for providing dose to region inside tracheal stoma. Advantages over photon and electron beam therapy include reduced dose to surrounding tissues previously irradiated, skin dose, and reproducibility of treatment delivery. Copyright © 2011 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  3. A prospective cohort study to compare treatment results between 2 fractionation schedules of high-dose-rate intracavitary brachytherapy (HDR-ICBT) in patients with cervical cancer.

    Science.gov (United States)

    Huang, Eng-Yen; Sun, Li-Min; Lin, Hao; Lan, Jen-Hong; Chanchien, Chan-Chao; Huang, Yu-Jie; Wang, Chang-Yu; Wang, Chong-Jong

    2013-01-01

    To compare the treatment results of 2 fractionation schedules for high-dose-rate intracavitary brachytherapy (HDR-ICBT) in patients with cervical cancer. From June 2001 through January 2008, 267 patients with stage IB-IVA cervical cancer were enrolled in the study. All patients underwent 4-field pelvic irradiation and HDR-ICBT. The median central and parametrial doses were 39.6 Gy and 45 Gy, respectively. Patient underwent either 6 Gy×4 (HDR-4) (n=144) or 4.5 Gy×6 (HDR-6) (n=123) to point A of ICBT using 192Ir isotope twice weekly. The rates of overall survival, locoregional failure, distant metastasis, proctitis, cystitis, and enterocolitis were compared between HDR-4 and HDR-6. There were no significant differences in the demographic data between HDR-4 and HDR-6 except for total treatment time. The 5-year proctitis rates were 23.0% and 21.5% in HDR-4 and HDR-6 (P=.399), respectively. The corresponding rates of grade 2-4 proctitis were 18.7% and 9.6% (P=.060). The corresponding rates of grades 3-4 proctitis were 5.2% and 1.3% (P=.231). Subgroup analysis revealed that HDR-4 significantly increased grade 2-4 proctitis in patients aged≥62 years old (P=.012) but not in patients agedschedules. The small fraction size of HDR-ICBT is associated with grade 2 proctitis without compromise of prognosis in elderly patients. This schedule is suggested for patients who tolerate an additional 2 applications of HDR-ICBT. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Template guided transperineal saturation biopsy of the prostate: lessons for focal and urethra-sparing high-dose-rate brachytherapy for localized prostate cancer

    Directory of Open Access Journals (Sweden)

    Sergey Nikolaevich Novikov

    2016-04-01

    Full Text Available Purpose : The aim of this work is to evaluate results of prostate transperineal saturation biopsy as a guide for focal high-dose-rate brachytherapy in patients with prostate cancer (PCa. Material and methods: Template guided saturation biopsy was performed in 67 primary patients with suspicion for prostate cancer. Biopsy was performed under ultrasonography (US control with the help of brachytherapy grid and 5 mm distance between samples. We put special attention for accurate sampling of prostate in periurethral region. The number of cores varied from 17 to 81 (average 36 cores. Finally, in 40 patients with confirmed prostate cancer results of biopsy were used for brachytherapy planning. Results : Saturation biopsy revealed prostate cancer in 40 of 67 evaluated patients. The extent of biopsy core involvement varied from 5% to 100% (average: 57%. Focal nature of PCa (single unilateral tumor nodule was diagnosed in 10 (25%, multifocal – in another 30 (75% patients. Hemigland invasion was mentioned in 12 (30% cases. Saturation biopsy detected PCa in periurethral cores in 27 (67.5% of 40 evaluated patients. In 10 patients, the extent of involvement in periurethral cores varied between 10% and 50%; in another, 17 observations exceeded 50%. According to results obtained on saturation biopsy, we performed HDR brachytherapy with “urethra low dose tunnel” (D10ur ≤ 80-90% in 13 patients with noninvolved periurethral cores. Theoretically, hemigland brachytherapy was possible in 12 of 40 evaluated patients with PCa. Conclusions : In low risk patients with PCa results of template guided saturation biopsy indicates high frequency (75% of multifocal disease and high probability (67.5% of periurethral invasion. Suitable candidates for focal HDR brachytherapy or irradiation with additional sparing of urethra can be effectively determined with the help of saturation biopsy.

  5. High-dose-rate interstitial brachytherapy in early stage oral tongue cancer – 15 year experience from a tertiary care institute

    Directory of Open Access Journals (Sweden)

    Anshuma Bansal

    2016-02-01

    Full Text Available Purpose: To determine outcomes of interstitial high-dose-rate brachytherapy (HDR-BT in patients with early stage oral tongue cancer. Material and methods : Ninety-two patients with stage I and II oral tongue cancer were treated with HDR-BT between 1999 and 2014: brachytherapy alone = 62 (67.4%, and combination of external beam radiotherapy (EBRT and brachytherapy = 30 (32.6%. Median follow-up was 53.5 months. Patterns of failure, overall survival (OS, disease-free survival (DFS, local control rates (LCR, and nodal control rates (NCR were determined. Results : 5-year OS, DFS, LCR, and NCR were 73.2%, 58.2%, 64.2%, and 83.8%, respectively. In total, 43 patients (46.7% failed treatment: isolated local failures = 28 (30.4%, isolated nodal failures = 8 (8.7%, both local and regional failures = 7 (7.6%. While in T1 stage, 5 year LCR were significantly higher in brachytherapy alone group compared to combined EBRT and brachytherapy group (81.7% vs. 62.5%, p = 0.04, the isolated nodal failure rates were not significantly different among the two groups. For T2 stage, NCR were higher in combined EBRT and brachytherapy group compared to brachytherapy alone (92.9% vs. 74.3%. Acute mucositis (grade ≥ 2 was seen more in brachytherapy alone group compared to the combined modality group (87% vs. 66%, and this correlated significantly with the higher biological equivalent dose (BED in the brachytherapy alone group. Conclusions : Our study recommends treating patients with brachytherapy alone in T1 stage, and demonstrates the need for addressing nodal region either by neck dissection or nodal irradiation in T2 stage patients. Also, the study highlights the need for dose escalation (from the doses used in the study in both T1 and T2 stage tumors when using interstitial brachytherapy either as sole modality or as a boost.

  6. Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry.

    Science.gov (United States)

    Casey, Kevin E; Alvarez, Paola; Kry, Stephen F; Howell, Rebecca M; Lawyer, Ann; Followill, David

    2013-11-01

    The aim of this work was to create a mailable phantom with measurement accuracy suitable for Radiological Physics Center (RPC) audits of high dose-rate (HDR) brachytherapy sources at institutions participating in National Cancer Institute-funded cooperative clinical trials. Optically stimulated luminescence dosimeters (OSLDs) were chosen as the dosimeter to be used with the phantom. The authors designed and built an 8 × 8 × 10 cm(3) prototype phantom that had two slots capable of holding Al2O3:C OSLDs (nanoDots; Landauer, Glenwood, IL) and a single channel capable of accepting all (192)Ir HDR brachytherapy sources in current clinical use in the United States. The authors irradiated the phantom with Nucletron and Varian (192)Ir HDR sources in order to determine correction factors for linearity with dose and the combined effects of irradiation energy and phantom characteristics. The phantom was then sent to eight institutions which volunteered to perform trial remote audits. The linearity correction factor was kL = (-9.43 × 10(-5) × dose) + 1.009, where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters using (60)Co irradiation. Separate block correction factors were determined for current versions of both Nucletron and Varian (192)Ir HDR sources and these vendor-specific correction factors differed by almost 2.6%. For the Nucletron source, the correction factor was 1.026 [95% confidence interval (CI) = 1.023-1.028], and for the Varian source, it was 1.000 (95% CI = 0.995-1.005). Variations in lateral source positioning up to 0.8 mm and distal∕proximal source positioning up to 10 mm had minimal effect on dose measurement accuracy. The overall dose measurement uncertainty of the system was estimated to be 2.4% and 2.5% for the Nucletron and Varian sources, respectively (95% CI). This uncertainty was sufficient to establish a ± 5% acceptance criterion for source strength audits under a formal RPC audit program. Trial

  7. Image-Guided High-Dose-Rate (HDR) Boost Localization Using MRI/MR Spectroscopy: A Correlation Study with Biopsy.

    Science.gov (United States)

    Vigneault, Eric; Mbodji, Khaly; Racine, Louis G; Chevrette, Eric; Lavallee, Marie C; Martin, André-Guy; Despres, Philippe; Beaulieu, Luc

    2016-09-21

    The purpose of this study is to compare the blind interpretations of magnetic resonance imaging (MRI) sequences, diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC), mapping, and magnetic resonance spectroscopy (MRS) of the prostate, in comparison to prostate biopsy to identify a valid dominant intraprostatic lesion (DIL) for dose escalation using high-dose rate brachytherapy. MRI/MRS were performed on 20 patients with intermediate risk adenocarcinoma of the prostate. T1W, T2W, DWI-ADC, and MRS sequences were performed at 1.5 T with pelvic and endorectal coils. An experienced radiologist rated the presence of cancer in each sextant by using a dichotomic approach, first on MR standard acquisitions (T1W and T2W), then on DWI-ADC mapping, and later on MRS images. Areas under the receiver's operating characteristic curve were calculated using a sextant as the unit of analysis. The transrectal ultrasonography-guided biopsy results were used as the reference standard. A table summarizing the MRI/MRS findings was made and compared to the corresponding area in the prostate biopsy report. A perfect match was defined to be the presence of cancer in the same sextant of the MRI/MRS exam and the prostate biopsy. The interpretation of the MRI/MRS exams per sextant was compared to the diagnostic biopsy report. MRI readings were compared with the biopsy as a surrogate for the complete pathology specimen of the prostate. A sensitivity (Sn) of 98.6% (95% confidence interval, 92.2% - 99.9%) and specificity (Sp) of 60.8% (46.1% - 74.2%) were found. The positive and negative predictive values (PPV, NPV) were 77.3% (67.1% - 85.5%) and 96.9% (83.8% - 99.9%), respectively. When MRS readings were compared with biopsy, we found a Sn of 96.4% (87.7% - 99.6%) and Sp of 54.8% (38.7% - 70.2%). The PPV and NPV were 74% (62.4% - 83.6%) and 92% (74% - 99%), respectively. DWI-ADC mapping results were also compared with biopsy. We found a Sn and Sp of 93.7% (84.5% - 98.2%) and 82

  8. Prostate gland edema after single-fraction high-dose rate brachytherapy before external beam radiation therapy.

    Science.gov (United States)

    Cury, Fabio L; Duclos, Marie; Aprikian, Armen; Patrocinio, Horacio; Souhami, Luis

    2010-01-01

    High-dose rate brachytherapy (HDRB) is frequently used as a boost to external beam radiation therapy (EBRT) in prostate cancer patients. With the increasing use of small planning target volume margins in EBRT, prostatic edema induced by HDRB can be a contributing factor to geometric miss when HDRB is performed before or during EBRT. We assessed prostate gland volumetric change after single-fraction HDRB and its impact on definition of treatment volume for EBRT. Thirty-one consecutive patients with intermediate-risk prostate cancer treated with single-fraction HDRB (10 Gy) combined with hypofractionated EBRT were analyzed. A second CT scan was performed 7 days after HDRB, and images were coregistered with the planning CT scan that contained the original clinical target volume (CTV). The post-HDRB prostate CTV volume was compared with the original CTV by a single observer. All patients presented volumetric variation. In most cases (68%), the prostate increased in volume, whereas it decreased in 32%. The mean prostatic volume was 42.2 cc before HDRB and 43.6 cc after HDRB, representing a mean volume difference of 3.4%, ranging from -14.2% to 23.8% (p=0.756). This difference is the result of mean changes of 0.6mm (-6.1 to 6.6) in the anterior-posterior, 0.5mm (-5.5 to 3.0) in the lateral, and 0.2mm (-5.0 to 5.0) in the superior-inferior axes. Although a nonsignificant volumetric change occurs after single-fraction HDRB, individual variations on specific axis could lead to important uncertainties during EBRT. (c) 2010. Published by Elsevier Inc.

  9. Absorbed dose simulations in near-surface regions using high dose rate Iridium-192 sources applied for brachytherapy

    Science.gov (United States)

    Moura, E. S.; Zeituni, C. A.; Sakuraba, R. K.; Gonçalves, V. D.; Cruz, J. C.; Júnior, D. K.; Souza, C. D.; Rostelato, M. E. C. M.

    2014-02-01

    Brachytherapy treatment with Iridium-192 high dose rate (HDR) sources is widely used for various tumours and it could be developed in many anatomic regions. Iridium-192 sources are inserted inside or close to the region that will be treated. Usually, the treatment is performed in prostate, gynaecological, lung, breast and oral cavity regions for a better clinical dose coverage compared with other techniques, such as, high energy photons and Cobalt-60 machines. This work will evaluate absorbed dose distributions in near-surface regions around Ir-192 HDR sources. Near-surface dose measurements are a complex task, due to the contribution of beta particles in the near-surface regions. These dose distributions should be useful for non-tumour treatments, such as keloids, and other non-intracavitary technique. For the absorbed dose distribution simulations the Monte Carlo code PENELOPE with the general code penEasy was used. Ir-192 source geometry and a Polymethylmethacrylate (PMMA) tube, for beta particles shield were modelled to yield the percentage depth dose (PDD) on a cubic water phantom. Absorbed dose simulations were realized at the central axis to yield the Ir-192 dose fall-off along central axis. The results showed that more than 99.2% of the absorbed doses (relative to the surface) are deposited in 5 cm depth but with slower rate at higher distances. Near-surface treatments with Ir-192 HDR sources yields achievable measurements and with proper clinical technique and accessories should apply as an alternative for treatment of lesions where only beta sources were used.

  10. SU-E-T-428: Class Solution for Prostate High Dose Rate Brachytherapy with Inverse Planning Simulated Annealing.

    Science.gov (United States)

    Sheth, N; Mistry, N; Chen, Y; Yang, C

    2012-06-01

    To develop and validate a class solution for inverse planning simulated annealing (IPSA) with CT based prostate high dose rate brachytherapy (HDR). Between November 2008 and November 2011, our institution treated 40 prostate cancer patients with HDR in 7 Gy fractions followed by external beam radiotherapy. The HDR treatments were planned with Nucletron Oncentra using manual graphical optimization (GO). Plans were optimized to the following clinical goals: = 95% of prostate volume received 7 Gy, plans were manually customized using IPSA (MC-IPSA) for each patient to match prostate coverage by the prescription dose to within ± 1% of the GO plans while meeting the rectal and urethral dose constraints. An IPSA class solution (CS-IPSA) was created from the mean MC-IPSA parameters. New plans were developed for each of these 40 patients using only CS-IPSA with no further optimization. Additionally, plans were created on an independent dataset of 30 different patients using only CS-IPSA with no further optimization. Plans were optimized in about 30 minutes using GO, MC-IPSA took an average of 14.1 ± 6.5 minutes, and CS-IPSA optimizationwas 0.05) among the optimization methods for all clinical goals over the 40 CS-IPSA source patients. There was no significant difference (p > 0.05) between the source and the independent datasets for all clinical goals when using CS-IPSA with no further optimization. A prostate HDR IPSA class solution was developed and validated on a source and an independent dataset. The IPSA class solution yields plans comparable to custom manual IPSA and graphical optimization while saving considerable time. © 2012 American Association of Physicists in Medicine.

  11. The influence of a rectal ultrasound probe on the separation between prostate and rectum in high-dose-rate brachytherapy.

    Science.gov (United States)

    Rylander, Susanne; Buus, Simon; Bentzen, Lise; Pedersen, Erik Morre; Tanderup, Kari

    2015-01-01

    The aim of this study was to compare the distance between prostate and rectum as well as rectal dose-volume histogram (DVH) parameters for high-dose-rate (HDR) prostate brachytherapy (BT) with and without a transrectal ultrasound (US) probe in place during delivery. The study included 20 patients with high-risk prostate cancer treated consecutively with combined external beam radiotherapy (EBRT) and MRI-based HDR-BT. The MRI-based HDR-BT dose plan and prostate gland contour were transferred to the US images after rigid MRI/US coregistration, followed by delineation of the rectum on US images acquired with a transrectal US probe. The prostate-rectum separation was estimated at the apex, reference, and base plane on the US (with rectal probe) and MR images (without rectal probe). Rectal DVH parameters for EBRT + HDR-BT given in equivalent 2 Gy fractionation doses were estimated and compared for US-based and MRI-based HDR-BT dose planning. The median (and range) prostate-rectum separation increased on MR images (without rectal probe) as compared with on US images (with rectal probe) by 10 mm (-5, 18) at the base, 1 mm (-2, 3) at the reference and decreased at the apex by 2 mm (-5, 11). The rectal D5.0cm3, D2.0cm3, and D0.1cm3 decreased by a median of 4 Gy (-1, 10), 4 Gy (-2, 13), and 7 Gy (-4, 26), respectively. MRI-based HDR-BT without a rectal US probe in place as compared with US-based BT with the probe in place demonstrated a significant increase in the prostate-rectum separation, with a potential of reducing rectal dose. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  12. Rotational IMRT delivery using a digital linear accelerator in very high dose rate 'burst mode'

    Energy Technology Data Exchange (ETDEWEB)

    Salter, Bill J; Sarkar, Vikren; Wang, Brian; Szegedi, Martin; Rassiah-Szegedi, Prema [Department of Radiation Oncology, University of Utah, Salt Lake City, UT (United States); Shukla, Himanshu, E-mail: bill.salter@hci.utah.edu [Oncology Care Systems Group, Siemens Medical Solutions (USA), 4040 Nelson Avenue, Concord, CA (United States)

    2011-04-07

    Recently, there has been a resurgence of interest in arc-based IMRT, through the use of 'conventional' multileaf collimator (MLC) systems that can treat large tumor volumes in a single, or very few pass(es) of the gantry. Here we present a novel 'burst mode' modulated arc delivery approach, wherein 2000 monitor units per minute (MU min{sup -1}) high dose rate bursts of dose are facilitated by a flattening-filter-free treatment beam on a Siemens Artiste (Oncology Care Systems, Siemens Medical Solutions, Concord, CA, USA) digital linear accelerator in a non-clinical configuration. Burst mode delivery differs from continuous mode delivery, used by Elekta's VMAT (Elekta Ltd, Crawley, UK) and Varian's RapidArc (Varian Medical Systems, Palo Alto, CA, USA) implementations, in that dose is not delivered while MLC leaves are moving. Instead, dose is delivered in bursts over very short arc angles and only after an MLC segment shape has been completely formed and verified by the controller. The new system was confirmed to be capable of delivering a wide array of clinically relevant treatment plans, without machine fault or other delivery anomalies. Dosimetric accuracy of the modulated arc platform, as well as the Prowess (Prowess Inc., Concord, CA, USA) prototype treatment planning version utilized here, was quantified and confirmed, and delivery times were measured as significantly brief, even with large hypofractionated doses. The burst mode modulated arc approach evaluated here appears to represent a capable, accurate and efficient delivery approach.

  13. Optimization for high-dose-rate brachytherapy of cervical cancer with adaptive simulated annealing and gradient descent.

    Science.gov (United States)

    Yao, Rui; Templeton, Alistair K; Liao, Yixiang; Turian, Julius V; Kiel, Krystyna D; Chu, James C H

    2014-01-01

    To validate an in-house optimization program that uses adaptive simulated annealing (ASA) and gradient descent (GD) algorithms and investigate features of physical dose and generalized equivalent uniform dose (gEUD)-based objective functions in high-dose-rate (HDR) brachytherapy for cervical cancer. Eight Syed/Neblett template-based cervical cancer HDR interstitial brachytherapy cases were used for this study. Brachytherapy treatment plans were first generated using inverse planning simulated annealing (IPSA). Using the same dwell positions designated in IPSA, plans were then optimized with both physical dose and gEUD-based objective functions, using both ASA and GD algorithms. Comparisons were made between plans both qualitatively and based on dose-volume parameters, evaluating each optimization method and objective function. A hybrid objective function was also designed and implemented in the in-house program. The ASA plans are higher on bladder V75% and D2cc (p=0.034) and lower on rectum V75% and D2cc (p=0.034) than the IPSA plans. The ASA and GD plans are not significantly different. The gEUD-based plans have higher homogeneity index (p=0.034), lower overdose index (p=0.005), and lower rectum gEUD and normal tissue complication probability (p=0.005) than the physical dose-based plans. The hybrid function can produce a plan with dosimetric parameters between the physical dose-based and gEUD-based plans. The optimized plans with the same objective value and dose-volume histogram could have different dose distributions. Our optimization program based on ASA and GD algorithms is flexible on objective functions, optimization parameters, and can generate optimized plans comparable with IPSA. Copyright © 2014 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  14. High-dose rate brachytherapy as monotherapy in prostate cancer: A systematic review of its safety and efficacy.

    Science.gov (United States)

    Sánchez-Gómez, L M; Polo-deSantos, M; Rodríguez-Melcón, J I; Angulo, J C; Luengo-Matos, S

    2017-03-01

    High-dose rate brachytherapy (HDR-BT) is an increasingly popular treatment for patients with localised prostate cancer (PC). To assess the safety and efficacy of HDR-BT as monotherapy in PC. A systematic literature review was conducted through searches on MEDLINE (PubMed), Cochrane Library, CDR, ClinicalTrials and EuroScan. We assessed safety and efficacy indicators. We selected 2 reviews and 12 uncontrolled studies, included in these 2 reviews. In terms of efficacy, local control in 6 studies was 97-100%. The biochemical progression-free survival varied as follows: 85-100% for low risk and 79-92% for high risk. Survival free of metastases was >95% at 8 years, except in one study where the survival rate was 87% at 5 years. The overall survival was ≥95% in 8 studies. In terms of safety, most of the studies recorded acute and long-term genitourinary and gastrointestinal complications, especially grade ≥2. Only 3 studies found grade 4 complications. All studies, except for one without complications, observed genitourinary complications that were more frequent and severe than the gastrointestinal complications. Two studies assessed the quality of life and showed an initial reduction in various domains and subsequent partial or total recovery, except in the sexual domain. HDR-BT is effective as monotherapy, especially in cases of low to intermediate risk. There is insufficient information on high-risk patients. The short to medium-term toxicity was acceptable. Further research needs to be funded to provide more information on the long-term safety and efficacy of this treatment. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Extrascleral extension of choroidal melanoma: post-enucleation high-dose-rate interstitial brachytherapy of the orbit.

    Science.gov (United States)

    Finger, Paul T; Tena, Lawrence B; Semenova, Ekaterina; Aridgides, Paul; Choi, Walter H

    2014-01-01

    To investigate if orbital extension of uveal melanoma can be treated with high-dose-rate (HDR) brachytherapy. This study is a retrospective analysis of the results of a clinical case series was performed on 10 patients. Each underwent primary enucleation for uveal melanoma, was discovered to have orbital extension, and consented for HDR brachytherapy. By American Joint Committee on Cancer (AJCC) initial tumor grading, there was one each (T1c, T2c, T2d, and T3d, three T4c, and two T4d-staged uveal melanomas. One was AJCC-staged R2 due to orbital recurrence presenting 16 months after enucleation. (192)Ir HDR brachytherapy involved transcutaneous circumferential orbital incisions allowing for evenly spaced brachytherapy catheters into the orbit. A target dose of 32.85 Gy (range, 32.85-34 Gy) was delivered in 9-10 twice-daily fractions (range, 3.4-3.65 Gy per fraction) over 5 consecutive days. Data analysis included but was not limited to radiation therapy methods, local tumor control, side effects, and metastatic rate. In the 9 patients who tolerated treatment, there has been no orbital recurrence at a median follow-up of 18 months (range, 1-62 months). Four patients died of metastatic disease (one presented with a treated solitary liver metastasis before brachytherapy). There was no significant eyelash or eyebrow loss. There was no radiation-induced eyelid erythema, orbital infection, or contracted sockets. All orbits accepted and maintained ocular prostheses. Brachytherapy was used as an alternative to external beam radiation treatment for postenucleation orbital melanoma. This series reports complete local control, few side effects, and excellent cosmetic results. Copyright © 2014 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  16. 360-degree 3D transvaginal ultrasound system for high-dose-rate interstitial gynaecological brachytherapy needle guidance

    Science.gov (United States)

    Rodgers, Jessica R.; Surry, Kathleen; D'Souza, David; Leung, Eric; Fenster, Aaron

    2017-03-01

    Treatment for gynaecological cancers often includes brachytherapy; in particular, in high-dose-rate (HDR) interstitial brachytherapy, hollow needles are inserted into the tumour and surrounding area through a template in order to deliver the radiation dose. Currently, there is no standard modality for visualizing needles intra-operatively, despite the need for precise needle placement in order to deliver the optimal dose and avoid nearby organs, including the bladder and rectum. While three-dimensional (3D) transrectal ultrasound (TRUS) imaging has been proposed for 3D intra-operative needle guidance, anterior needles tend to be obscured by shadowing created by the template's vaginal cylinder. We have developed a 360-degree 3D transvaginal ultrasound (TVUS) system that uses a conventional two-dimensional side-fire TRUS probe rotated inside a hollow vaginal cylinder made from a sonolucent plastic (TPX). The system was validated using grid and sphere phantoms in order to test the geometric accuracy of the distance and volumetric measurements in the reconstructed image. To test the potential for visualizing needles, an agar phantom mimicking the geometry of the female pelvis was used. Needles were inserted into the phantom and then imaged using the 3D TVUS system. The needle trajectories and tip positions in the 3D TVUS scan were compared to their expected values and the needle tracks visualized in magnetic resonance images. Based on this initial study, 360-degree 3D TVUS imaging through a sonolucent vaginal cylinder is a feasible technique for intra-operatively visualizing needles during HDR interstitial gynaecological brachytherapy.

  17. American Brachytherapy Task Group Report: A pooled analysis of clinical outcomes for high-dose-rate brachytherapy for cervical cancer.

    Science.gov (United States)

    Mayadev, Jyoti; Viswanathan, Akila; Liu, Yu; Li, Chin-Shang; Albuquerque, Kevin; Damato, Antonio L; Beriwal, Sushil; Erickson, Beth

    Advanced imaging used in combination with brachytherapy (BT) has revolutionized the treatment of patients with cervical cancer. We present a comprehensive review of the literature for definitive radiation with high-dose-rate (HDR) BT. In addition, we investigate potential outcome improvement with image-based brachytherapy (IBBT) compared to studies using traditional Point A dosing. This review extensively investigates acute and late toxicities. This study reviews the literature from 2000 to 2015 with an emphasis on modern approaches including concurrent chemotherapy (chemoRT), radiation, and HDR BT and IBBT. Descriptive statistics and pelvic control (PC), disease-free survival (DFS), and overall survival (OS) outcomes were calculated using weighted means to report pooled analysis of outcomes. Literature search yielded 16 prospective, 51 retrospective studies that reported survival outcomes, and 13 retrospective studies that focused on acute and late toxicity outcomes regardless of applicator type. There are 57 studies that report Point A dose specification with 33 having chemoRT, and 10 studies that use IBBT, 8 with chemoRT. Patients receiving radiation and chemoRT with HDR BT in the prospective studies, with >24 months followup, rates of PC were: for RT: 73%, SD: 11; CRT: 82%, SD: 8; DFS-RT: 55%, SD: 10; CRT: 65%, SD: 7; OS-RT: 66%, SD: 7; CRT: 70%, SD: 11. In the retrospective studies, the PC rates (weighted means) for the radiation and chemoradiation outcomes are 75% vs. 80%, and for DFS, the values were 55% vs. 63%, respectively. Comparing patients receiving chemoRT and IBBT to traditional Point A dose specification, there is a significant improvement in PC (p Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  18. High-dose-rate brachytherapy as a monotherapy for prostate cancer--Single-institution results of the extreme fractionation regimen.

    Science.gov (United States)

    Kukiełka, Andrzej Marek; Dąbrowski, Tomasz; Walasek, Tomasz; Olchawa, Agnieszka; Kudzia, Roksana; Dybek, Dorota

    2015-01-01

    We report a single-institution retrospective analysis of the outcomes, disease control, and toxicity of high-dose-rate (HDR) brachytherapy used as the only treatment modality (monotherapy) for localized prostate cancer. Between 2006 and 2012, 77 patients with diagnosed prostate cancer were treated with HDR brachytherapy as a monotherapy. The prescribed dose was 45 Gy in three separate implants 21 days apart, with single fraction per implant. Of the 77 patients, 67 (87%) received hormonal therapy. Prostate-specific antigen failure was defined according to Phoenix consensus, as nadir + 2 ng/mL. Toxicity was scored according to Common Terminology Criteria for Adverse Events, version 4.03. The median followup time was 57 months (4.75 years). The 5-year actuarial overall survival was 98.7%, biochemical control 96.7%, local control 96.9%, and metastasis-free survival 98.4%. Younger age at the beginning of brachytherapy predicted the onset of bounce phenomenon. There were no Grade 3 or higher acute toxicities detected, and Grade 2 genitourinary acute toxicity developed in 19 patients (24.6%). There were no Grade 2 gastrointestinal complications. No Grade 4 or 5 late toxicity was detected. There were also no Grade 3 gastrointestinal toxicities detected. One patient (1.3%) underwent transurethral resection of the prostate because of Grade 3 urethral stenosis and urinary retention. A total of 26 patients (33.8%) developed Grade 2 late toxicity. HDR brachytherapy as monotherapy for localized prostate cancer was feasible, effective, and had acceptable toxicity profile. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  19. High-dose-rate interstitial brachytherapy for T1-T2-stage penile carcinoma: short-term results.

    Science.gov (United States)

    Sharma, Daya Nand; Joshi, Nikhil P; Gandhi, Ajeet Kumar; Haresh, Kunhi P; Gupta, Subhash; Julka, Pramod Kumar; Rath, Goura Kisor

    2014-01-01

    Interstitial brachytherapy (IBT) is a preferred treatment option over partial penectomy in selected patients with T1-T2-stage penile carcinoma because of its organ preservation ability. Literature is mostly based on the use of low-dose-rate IBT, and experience with high-dose-rate (HDR) IBT is extremely limited. We studied the role of HDR-IBT alone in patients with T1-T2-stage penile carcinoma. Between April 2010 and July 2013, 14 patients with T1-T2-stage penile carcinoma were treated with HDR-IBT at our center. Size of the primary lesion ranged from 1.5 to 4.0cm. A two-to-four-plane free-hand implant was performed using plastic catheters. The prescribed dose of HDR-IBT was 42-51Gy in 14-17 fractions using twice-a-day fractionation schedule. Patients were followed up regularly for assessment of local control, survival, toxicity, and sexual function. At a median followup of 22 months, 2 patients developed recurrent disease at locoregional site. The 3-year overall survival was 83% with penis preservation rate of 93%. All patients developed acute Grade III skin toxicity that healed during 6-8-weeks time. Urethral stenosis and soft tissue necrosis was not seen in any of the patients. A total of 4 patients experienced mild asymptomatic fibrosis in the implanted area. Around 10 patients had satisfactory sexual function status at the last followup visit. Although it was a small sample size, our results have demonstrated excellent local control rate and acceptable toxicity with HDR-IBT in patients with T1-T2-stage penile carcinoma. Copyright © 2014 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  20. High-Dose-Rate Interstitial Brachytherapy as Monotherapy for Clinically Localized Prostate Cancer: Treatment Evolution and Mature Results

    Energy Technology Data Exchange (ETDEWEB)

    Zamboglou, Nikolaos [Department of Radiation Oncology, Klinikum Offenbach, Offenbach (Germany); Tselis, Nikolaos, E-mail: ntselis@hotmail.com [Department of Radiation Oncology, Klinikum Offenbach, Offenbach (Germany); Baltas, Dimos [Department of Medical Physics and Engineering, Klinikum Offenbach, Offenbach (Germany); Buhleier, Thomas [Department of Radiation Oncology, Klinikum Offenbach, Offenbach (Germany); Martin, Thomas [Department of Radiation Oncology, Klinikum Bremen-Mitte, Bremen (Germany); Milickovic, Natasa; Papaioannou, Sokratis [Department of Medical Physics and Engineering, Klinikum Offenbach, Offenbach (Germany); Ackermann, Hanns [Institute of Biostatistics, J.W. Goethe University of Frankfurt, Frankfurt (Germany); Tunn, Ulf W. [Department of Urology, Klinikum Offenbach, Offenbach (Germany)

    2013-03-01

    Purpose: To report the clinical outcome of high-dose-rate (HDR) interstitial (IRT) brachytherapy (BRT) as sole treatment (monotherapy) for clinically localized prostate cancer. Methods and Materials: Between January 2002 and December 2009, 718 consecutive patients with clinically localized prostate cancer were treated with transrectal ultrasound (TRUS)-guided HDR monotherapy. Three treatment protocols were applied; 141 patients received 38.0 Gy using one implant in 4 fractions of 9.5 Gy with computed tomography-based treatment planning; 351 patients received 38.0 Gy in 4 fractions of 9.5 Gy, using 2 implants (2 weeks apart) and intraoperative TRUS real-time treatment planning; and 226 patients received 34.5 Gy, using 3 single-fraction implants of 11.5 Gy (3 weeks apart) and intraoperative TRUS real-time treatment planning. Biochemical failure was defined according to the Phoenix consensus, and toxicity was evaluated using Common Toxicity Criteria for Adverse Events version 3. Results: The median follow-up time was 52.8 months. The 36-, 60-, and 96-month biochemical control and metastasis-free survival rates for the entire cohort were 97%, 94%, and 90% and 99%, 98%, and 97%, respectively. Toxicity was scored per event, with 5.4% acute grade 3 genitourinary and 0.2% acute grade 3 gastrointestinal toxicity. Late grade 3 genitourinary and gastrointestinal toxicities were 3.5% and 1.6%, respectively. Two patients developed grade 4 incontinence. No other instance of grade 4 or greater acute or late toxicity was reported. Conclusion: Our results confirm IRT-HDR-BRT is safe and effective as monotherapy for clinically localized prostate cancer.

  1. The usefulness of fleet rectal enemas on high-dose-rate intracavitary cervical cancer brachytherapy. A prospective trial

    Directory of Open Access Journals (Sweden)

    Ignacio Andres

    2017-05-01

    Full Text Available Purpose: To evaluate the effects of rectal enemas on rectal doses during radical high-dose-rate (HDR intracavitary cervical brachytherapy (BT. Material and methods : Twenty patients suffering from cervical cancer and treated with external beam radiotherapy and HDR-BT were included in a prospective trial. The first brachytherapy fraction was considered the basal status, and patients were instructed to self-administer two rectal cleansing enemas before the second fraction. Dose-volume histogram (DVH values were generated for the rectum and correlated with rectal volume variation. Brachytherapy was carried out with a Fletcher or Utrecht applicator. Results : No significant rectal volume differences were observed between fractions with or without rectal enemas (without, 52.64 ± 15.92 cc; with, 53.16 ± 19.28 cc. There was a significant correlation between both rectal volumes (r = 0.722, p = 0.001. No significant differences were observed in analyzed DVH parameters (median values: ΔD 0.1cc , 4.17 vs. 3.61 Gy; ΔD 1cc , 3.23 vs. 2.87 Gy; Δ D2cc , 2.9 vs. 2.54 Gy; ΔD 5cc , 2.35 vs. 2.05 Gy, for no enema and enema fraction, respectively. No significant rectal volume differences nor DVH parameter differences were observed according the applicator type. Conclusions : Our rectal enemas protocol prior to HDR-BT was ineffective in significantly modifying rectal DVH parameters. No differences were observed according to the type of applicator used.

  2. Electron and high-dose-rate brachytherapy boost in the conservative treatment of stage I-II breast cancer. First results of the randomized Budapest boost trial

    Energy Technology Data Exchange (ETDEWEB)

    Polgar, C.; Fodor, J. [National Institute of Oncology, Department of Radiotherapy, Budapest (Hungary); Orosz, Z. [National Institute of Oncology, Center of Experimental and Human Tumor Pathology Budapest (HU)] [and others

    2002-11-01

    Background and Aims: To evaluate the effect of electron and high-dose-rate brachytherapy (HDR BT) boost on local tumor control (LTC), side effects and cosmesis after breast-conserving surgery (BCS) in a prospective randomized study. Patients and Methods: 207 women with stage I-II breast cancer who underwent BCS were treated by 50 Gy irradiation to the whole breast and then randomly assigned to receive either a boost to the tumor bed (n=104) or no further radiotherapy (n=103). Boost treatments consisted of either 16 Gy electron irradiation (n=52) or 12-14.25 Gy HDR BT (n=52). Breast cancer-related events, side effects, and cosmetic results were assessed. Results: At a median follow-up of 5.3 years, the crude rate of local recurrence was 6.7% (7/104) with and 15.5% (16/103) without boost. The 5-year probability of LTC, relapse-free survival (RFS), and cancer-specific survival (CSS) was 92.7% vs 84.9% (p=0.049), 76.6% vs 66.2% (p=0.044), and 90.4% vs. 82.1% (p=0.053), respectively. There was no significant difference in LTC between patients treated with electron or HDR BT boost (94.2% vs 91.4%; p=0.74). On multivariate analysis, patient age <40 years (RR: 4.53), positive margin status (RR: 4.17), and high mitotic activity index (RR: 3.60) were found to be significant risk factors for local recurrence. The incidence of grade 2-3 side effects was higher in the boost arm (17.3% vs 7.8%; p=0.03). However, the rate of excellent/good cosmetic results was similar for the two arms (85.6% vs 91.3%; p=0.14). Cosmesis was rated as excellent/good in 88.5% of patients treated with HDR BT and 82.7% of patients with electron boost (p=0.29). Conclusions: Boost dose significantly improves LTC and RFS in patients treated with BCS and radiotherapy. In spite of the higher incidence of late side effects in the boost arm, boost dose is strongly recommended for patients at high risk for local recurrence. Positive or close margin status, high mitotic activity index, and young patient age

  3. Design and characterization of a new high-dose-rate brachytherapy Valencia applicator for larger skin lesions.

    Science.gov (United States)

    Candela-Juan, C; Niatsetski, Y; van der Laarse, R; Granero, D; Ballester, F; Perez-Calatayud, J; Vijande, J

    2016-04-01

    The aims of this study were (i) to design a new high-dose-rate (HDR) brachytherapy applicator for treating surface lesions with planning target volumes larger than 3 cm in diameter and up to 5 cm in size, using the microSelectron-HDR or Flexitron afterloader (Elekta Brachytherapy) with a (192)Ir source; (ii) to calculate by means of the Monte Carlo (MC) method the dose distribution for the new applicator when it is placed against a water phantom; and (iii) to validate experimentally the dose distributions in water. The penelope2008 MC code was used to optimize dwell positions and dwell times. Next, the dose distribution in a water phantom and the leakage dose distribution around the applicator were calculated. Finally, MC data were validated experimentally for a (192)Ir mHDR-v2 source by measuring (i) dose distributions with radiochromic EBT3 films (ISP); (ii) percentage depth-dose (PDD) curve with the parallel-plate ionization chamber Advanced Markus (PTW); and (iii) absolute dose rate with EBT3 films and the PinPoint T31016 (PTW) ionization chamber. The new applicator is made of tungsten alloy (Densimet) and consists of a set of interchangeable collimators. Three catheters are used to allocate the source at prefixed dwell positions with preset weights to produce a homogenous dose distribution at the typical prescription depth of 3 mm in water. The same plan is used for all available collimators. PDD, absolute dose rate per unit of air kerma strength, and off-axis profiles in a cylindrical water phantom are reported. These data can be used for treatment planning. Leakage around the applicator was also scored. The dose distributions, PDD, and absolute dose rate calculated agree within experimental uncertainties with the doses measured: differences of MC data with chamber measurements are up to 0.8% and with radiochromic films are up to 3.5%. The new applicator and the dosimetric data provided here will be a valuable tool in clinical practice, making treatment of

  4. 20-Year Experience With Intraoperative High-Dose-Rate Brachytherapy for Pediatric Sarcoma: Outcomes, Toxicity, and Practice Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Folkert, Michael R.; Tong, William Y. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); LaQuaglia, Michael P. [Department of Pediatric Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wexler, Leonard H.; Chou, Alexander J.; Magnan, Heather [Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zelefsky, Michael J. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wolden, Suzanne L., E-mail: woldens@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2014-10-01

    Purpose: To assess outcomes and toxicity of high-dose-rate intraoperative radiation therapy (HDR-IORT) in the management of pediatric sarcoma. Methods and Materials: Seventy-five pediatric patients underwent HDR-IORT for sarcoma from May 1993 to November 2013. The median age was 9 years old (36 patients were ≤6 years old). HDR-IORT was part of initial therapy in 37 patients (49%) and for recurrent disease in 38 patients (51%). Forty-one patients (55%) received HDR-IORT and postoperative external beam RT (PORT), and 22 patients (29%) were previously treated with external beam radiation therapy to the IORT site. Local control (LC), overall survival (OS) and event-free survival (EFS) were estimated using Kaplan-Meier methods. Results: At a median follow-up of 7.8 years for surviving patients, 5-year projected rates of LC, EFS, and OS were 63% (95% confidence interval [CI] 50%-76%), 33% (95% CI 21%-45%), and 43% (95% CI 30%-55%), with a median survival of 3.1 years. The 5-year LC, EFS, and OS rates for patients with recurrent disease were 46% (95% CI, 28%-64%), 30% (95% CI, 13%-46%), and 36% (95% CI, 18%-54%). Acute toxicity ≥grade 3 occurred in 2 (2.5%) treatments; late toxicity ≥grade 3 occurred in 4 (5.3%) patients 0.3-9.9 years after HDR-IORT. The incidence of toxicity ≥grade 3 was not associated with HDR-IORT applicator size, HDR-IORT dose, prior RT or PORT, or prior or postoperative chemotherapy, but all toxicity ≥grade 3 occurred in patients ≤6 years treated with HDR-IORT doses ≥12 Gy. Conclusions: HDR-IORT is a well-tolerated component of multimodality therapy for pediatric sarcoma, allowing additional local treatment while reducing external beam exposure. Taking clinical considerations into account, doses between 8-12 Gy are appropriate for HDR-IORT in patients ≤6 years of age.

  5. Development of a phantom to validate high-dose-rate brachytherapy treatment planning systems with heterogeneous algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Eduardo S., E-mail: emoura@wisc.edu [Department of Medical Physics, University of Wisconsin–Madison, Madison, Wisconsin 53705 and Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil); Micka, John A.; Hammer, Cliff G.; Culberson, Wesley S.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin–Madison, Madison, Wisconsin 53705 (United States); Rostelato, Maria Elisa C. M.; Zeituni, Carlos A. [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil)

    2015-04-15

    Purpose: This work presents the development of a phantom to verify the treatment planning system (TPS) algorithms used for high-dose-rate (HDR) brachytherapy. It is designed to measure the relative dose in a heterogeneous media. The experimental details used, simulation methods, and comparisons with a commercial TPS are also provided. Methods: To simulate heterogeneous conditions, four materials were used: Virtual Water™ (VM), BR50/50™, cork, and aluminum. The materials were arranged in 11 heterogeneity configurations. Three dosimeters were used to measure the relative response from a HDR {sup 192}Ir source: TLD-100™, Gafchromic{sup ®} EBT3 film, and an Exradin™ A1SL ionization chamber. To compare the results from the experimental measurements, the various configurations were modeled in the PENELOPE/penEasy Monte Carlo code. Images of each setup geometry were acquired from a CT scanner and imported into BrachyVision™ TPS software, which includes a grid-based Boltzmann solver Acuros™. The results of the measurements performed in the heterogeneous setups were normalized to the dose values measured in the homogeneous Virtual Water™ setup and the respective differences due to the heterogeneities were considered. Additionally, dose values calculated based on the American Association of Physicists in Medicine-Task Group 43 formalism were compared to dose values calculated with the Acuros™ algorithm in the phantom. Calculated doses were compared at the same points, where measurements have been performed. Results: Differences in the relative response as high as 11.5% were found from the homogeneous setup when the heterogeneous materials were inserted into the experimental phantom. The aluminum and cork materials produced larger differences than the plastic materials, with the BR50/50™ material producing results similar to the Virtual Water™ results. Our experimental methods agree with the PENELOPE/penEasy simulations for most setups and dosimeters. The

  6. Commissioning of a 3D image-based treatment planning system for high-dose-rate brachytherapy of cervical cancer.

    Science.gov (United States)

    Kim, Yongbok; Modrick, Joseph M; Pennington, Edward C; Kim, Yusung

    2016-03-08

    The objective of this work is to present commissioning procedures to clinically implement a three-dimensional (3D), image-based, treatment-planning system (TPS) for high-dose-rate (HDR) brachytherapy (BT) for gynecological (GYN) cancer. The physical dimensions of the GYN applicators and their values in the virtual applicator library were varied by 0.4 mm of their nominal values. Reconstruction uncertainties of the titanium tandem and ovoids (T&O) were less than 0.4 mm on CT phantom studies and on average between 0.8-1.0 mm on MRI when compared with X-rays. In-house software, HDRCalculator, was developed to check HDR plan parameters such as independently verifying active tandem or cylinder probe length and ovoid or cylinder size, source calibration and treatment date, and differences between average Point A dose and prescription dose. Dose-volume histograms were validated using another independent TPS. Comprehensive procedures to commission volume optimization algorithms and process in 3D image-based planning were presented. For the difference between line and volume optimizations, the average absolute differences as a percentage were 1.4% for total reference air KERMA (TRAK) and 1.1% for Point A dose. Volume optimization consistency tests between versions resulted in average absolute differences in 0.2% for TRAK and 0.9 s (0.2%) for total treatment time. The data revealed that the optimizer should run for at least 1 min in order to avoid more than 0.6% dwell time changes. For clinical GYN T&O cases, three different volume optimization techniques (graphical optimization, pure inverse planning, and hybrid inverse optimization) were investigated by comparing them against a conventional Point A technique. End-to-end testing was performed using a T&O phantom to ensure no errors or inconsistencies occurred from imaging through to planning and delivery. The proposed commissioning procedures provide a clinically safe implementation technique for 3D image-based TPS for HDR

  7. High-Dose-Rate Brachytherapy as a Monotherapy for Favorable-Risk Prostate Cancer: A Phase II Trial

    Energy Technology Data Exchange (ETDEWEB)

    Barkati, Maroie [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Williams, Scott G., E-mail: scott.williams@petermac.org [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Department of Pathology, University of Melbourne, Melbourne (Australia); Foroudi, Farshad; Tai, Keen Hun; Chander, Sarat [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Department of Pathology, University of Melbourne, Melbourne (Australia); Dyk, Sylvia van [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); See, Andrew [Ballarat Austin Radiation Oncology Centre, Ballarat (Australia); Duchesne, Gillian M. [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Department of Pathology, University of Melbourne, Melbourne (Australia)

    2012-04-01

    Purpose: There are multiple treatment options for favorable-risk prostate cancer. High-dose-rate (HDR) brachytherapy as a monotherapy is appealing, but its use is still investigational. A Phase II trial was undertaken to explore the value of such treatment in low-to-intermediate risk prostate cancer. Methods and Materials: This was a single-institution, prospective study. Eligible patients had low-risk prostate cancer features but also Gleason scores of 7 (51% of patients) and stage T2b to T2c cancer. Treatment with HDR brachytherapy with a single implant was administered over 2 days. One of four fractionation schedules was used in a dose escalation study design: 3 fractions of 10, 10.5, 11, or 11.5 Gy. Patients were assessed with the Common Terminology Criteria for Adverse Events version 2.0 for urinary toxicity, the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scoring schema for rectal toxicity, and the Expanded Prostate Cancer Index Composite (EPIC) questionnaire to measure patient-reported health-related quality of life. Biochemical failure was defined as a prostate-specific antigen (PSA) nadir plus 2 ng/ml. Results: Between 2003 and 2008, 79 patients were enrolled. With a median follow-up of 39.5 months, biochemical relapse occurred in 7 patients. Three- and 5-year actuarial biochemical control rates were 88.4% (95% confidence interval [CI], 78.0-96.2%) and 85.1% (95% CI, 72.5-94.5%), respectively. Acute grade 3 urinary toxicity was seen in only 1 patient. There was no instance of acute grade 3 rectal toxicity. Rates of late grade 3 rectal toxicity, dysuria, hematuria, urinary retention, and urinary incontinence were 0%, 10.3%, 1.3%, 9.0%, and 0%, respectively. No grade 4 or greater toxicity was recorded. Among the four (urinary, bowel, sexual, and hormonal) domains assessed with the EPIC questionnaire, only the sexual domain did not recover with time. Conclusions: HDR brachytherapy as a monotherapy for favorable

  8. A novel adaptive needle insertion sequencing for robotic, single needle MR-guided high-dose-rate prostate brachytherapy

    Science.gov (United States)

    Borot de Battisti, M.; de Senneville, B. Denis; Hautvast, G.; Binnekamp, D.; Lagendijk, J. J. W.; Maenhout, M.; Moerland, M. A.

    2017-05-01

    MR-guided high-dose-rate (HDR) brachytherapy has gained increasing interest as a treatment for patients with localized prostate cancer because of the superior value of MRI for tumor and surrounding tissues localization. To enable needle insertion into the prostate with the patient in the MR bore, a single needle MR-compatible robotic system involving needle-by-needle dose delivery has been developed at our institution. Throughout the intervention, dose delivery may be impaired by: (1) sub-optimal needle positioning caused by e.g. needle bending, (2) intra-operative internal organ motion such as prostate rotations or swelling, or intra-procedural rectum or bladder filling. This may result in failure to reach clinical constraints. To assess the first aforementioned challenge, a recent study from our research group demonstrated that the deposited dose may be greatly improved by real-time adaptive planning with feedback on the actual needle positioning. However, the needle insertion sequence is left to the doctor and therefore, this may result in sub-optimal dose delivery. In this manuscript, a new method is proposed to determine and update automatically the needle insertion sequence. This strategy is based on the determination of the most sensitive needle track. The sensitivity of a needle track is defined as its impact on the dose distribution in case of sub-optimal positioning. A stochastic criterion is thus presented to determine each needle track sensitivity based on needle insertion simulations. To assess the proposed sequencing strategy, HDR prostate brachytherapy was simulated on 11 patients with varying number of needle insertions. Sub-optimal needle positioning was simulated at each insertion (modeled by typical random angulation errors). In 91% of the scenarios, the dose distribution improved when the needle was inserted into the most compared to the least sensitive needle track. The computation time for sequencing was less than 6 s per needle track. The

  9. Design and characterization of a new high-dose-rate brachytherapy Valencia applicator for larger skin lesions

    Energy Technology Data Exchange (ETDEWEB)

    Candela-Juan, C., E-mail: ccanjuan@gmail.com [Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026, Spain and National Dosimetry Centre (CND), Valencia 46009 (Spain); Niatsetski, Y. [Elekta Brachytherapy, Veenendaal 3905 TH (Netherlands); Laarse, R. van der [Quality Radiation Therapy BV, Zeist 3707 HB (Netherlands); Granero, D. [Department of Radiation Physics, ERESA, Hospital General Universitario, Valencia 46014 (Spain); Ballester, F. [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Perez-Calatayud, J. [Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026, Spain and Department of Radiotherapy, Clínica Benidorm, Benidorm 03501 (Spain); Vijande, J. [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and Instituto de Física Corpuscular (UV-CSIC), Burjassot 46100 (Spain)

    2016-04-15

    Purpose: The aims of this study were (i) to design a new high-dose-rate (HDR) brachytherapy applicator for treating surface lesions with planning target volumes larger than 3 cm in diameter and up to 5 cm in size, using the microSelectron-HDR or Flexitron afterloader (Elekta Brachytherapy) with a {sup 192}Ir source; (ii) to calculate by means of the Monte Carlo (MC) method the dose distribution for the new applicator when it is placed against a water phantom; and (iii) to validate experimentally the dose distributions in water. Methods: The PENELOPE2008 MC code was used to optimize dwell positions and dwell times. Next, the dose distribution in a water phantom and the leakage dose distribution around the applicator were calculated. Finally, MC data were validated experimentally for a {sup 192}Ir mHDR-v2 source by measuring (i) dose distributions with radiochromic EBT3 films (ISP); (ii) percentage depth–dose (PDD) curve with the parallel-plate ionization chamber Advanced Markus (PTW); and (iii) absolute dose rate with EBT3 films and the PinPoint T31016 (PTW) ionization chamber. Results: The new applicator is made of tungsten alloy (Densimet) and consists of a set of interchangeable collimators. Three catheters are used to allocate the source at prefixed dwell positions with preset weights to produce a homogenous dose distribution at the typical prescription depth of 3 mm in water. The same plan is used for all available collimators. PDD, absolute dose rate per unit of air kerma strength, and off-axis profiles in a cylindrical water phantom are reported. These data can be used for treatment planning. Leakage around the applicator was also scored. The dose distributions, PDD, and absolute dose rate calculated agree within experimental uncertainties with the doses measured: differences of MC data with chamber measurements are up to 0.8% and with radiochromic films are up to 3.5%. Conclusions: The new applicator and the dosimetric data provided here will be a valuable

  10. Clinical and cosmetic outcomes in patients treated with high-dose-rate electronic brachytherapy for nonmelanoma skin cancer.

    Science.gov (United States)

    Paravati, Anthony J; Hawkins, Peter G; Martin, Amanda N; Mansy, Gina; Rahn, Doug A; Advani, Sunil J; Hoisak, Jeremy; Dragojevic, Irena; Martin, Peter J; Miller, Charles J; Sanghvi, Parag

    2015-01-01

    To retrospectively analyze clinical and cosmetic outcomes in patients treated for nonmelanoma skin cancer (NMSC) with high-dose-rate (HDR) electronic brachytherapy (EBT) using surface applicators. We identified 127 patients who had 154 NMSC lesions, 149 of which were basal cell carcinoma, treated with HDR EBT at our institution between July 2012 and March 2014. Lesions were treated to 40 Gy in 8 fractions. Local control, acute toxicity, late toxicity, and cosmetic outcomes were analyzed retrospectively. Acute and late toxicities were graded using the Common Terminology Criteria for Adverse Events, version 4.0. Cosmetic outcomes were graded using a standard scale based on the Radiation Therapy Oncology Group and European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Schema. Median (range) follow-up from completion of treatment was 16.1 (3.4-34.8 months). The overall crude recurrence rate was 1.3% (n = 2). Grade 0 to 1 acute radiation dermatitis was observed in 52.6% of treated lesions (n = 81), grade 2 in 34.4% (n = 53), and grade 3 in 13.0% (n = 20). No acute toxicity greater than grade 3 was observed and all acute toxic events resolved after treatment. Grade 0 to 1 late toxicity was observed in 94.2% of cases (n = 145), and grade 2 in 5.8% (n = 9). No late toxicity greater than grade 2 was observed. Across the 152 controlled lesions, cosmetic results were excellent in 94.2% of treated lesions (n = 145), good in 3.3% (n = 5), fair in 0.7% (n = 1), and poor in 0.7% (n = 1). HDR EBT confers promising local control, minimal toxicity, and excellent cosmesis in our institutional experience. It should be considered ideal for NMSC of the head and neck, particularly for basal cell carcinoma involving central facial locations where surgical cosmesis may be inferior. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  11. Dosimetric evaluation of multilumen intracavitary balloon applicator rotation in high-dose-rate brachytherapy for breast cancer.

    Science.gov (United States)

    Kim, Yongbok; Trombetta, Mark G

    2014-01-06

    The objective of this work is to evaluate dosimetric impact of multilumen balloon applicator rotation in high-dose-rate (HDR) brachytherapy for breast cancer. Highly asymmetrical dose distribution was generated for patients A and B, depending upon applicator proximity to skin and rib. Both skin and rib spacing was ≤ 0.7 cm for A; only rib spacing was ≤ 0.7 cm for B. Thirty-five rotation scenarios were simulated for each patient by rotating outer lumens every 10° over ± 180° range with respect to central lumen using mathematically calculated rotational matrix. Thirty-five rotated plans were compared with three plans: 1) original multidwell multilumen (MDML) plan, 2) multidwell single-lumen (MDSL) plan, and 3) single-dwell single-lumen (SDSL) plan. For plan comparison, planning target volume for evaluation (PTV_EVAL) coverage (dose to 95% and 90% volume of PTV_EVAL) (D95 and D90), skin and rib maximal dose (Dmax), and normal breast tissue volume receiving 150% (V150) and 200% (V200) of prescribed dose (PD) were evaluated. Dose variation due to device rotation ranged from -5.6% to 0.8% (A) and -6.5% to 0.2% (B) for PTV_EVAL D95; -5.2% to 0.4% (A) and -4.1% to 0.7% (B) for PTV_EVAL D90; -2.0 to 18.4% (A) and -7.8 to 17.5% (B) for skin Dmax; -11.1 to 22.8% (A) and -4.7 to 55.1% (B) of PD for rib Dmax, respectively. Normal breast tissue V150 and V200 variation was < 1.0 cc, except for -0.1 to 2.5cc (B) of V200. Furthermore, 30° device rotation increased rib Dmax over 145% of PD: 152.9% (A) by clockwise 30° rotation and 152.5% (B) by counterclockwise 30° rotation. For a highly asymmetric dose distribution, device rotation can outweigh the potential benefit of improved dose shaping capability afforded by multilumen and make dosimetric data worse than single-lumen plans unless it is properly corrected.

  12. Intraoperative High Dose Rate 32P Brachytherapy for Diffuse Recalcitrant Conjunctival Neoplasms: A Retrospective Case Series and Report of Toxicity

    Science.gov (United States)

    Marr, Brian P.; Abramson, David H.; Cohen, Gil’ad N.; Williamson, Matthew J.; McCormick, Beryl; Barker, Christopher A.

    2017-01-01

    improved in five of the seven eyes. Conclusions and Relevance Our results show the use of Intraoperative High Dose Rate 32P Brachytherapy in selected cases of recalcitrant diffuse conjunctival neoplasms. This technique offers a novel adjunct in the treatment of these cancers. Further follow-up and study is warranted. Trial Registration N/A PMID:25502420

  13. Salvage high-dose-rate brachytherapy for histologically confirmed macroscopic local relapsed prostate cancer after radical prostatectomy

    Directory of Open Access Journals (Sweden)

    David Buchser

    2016-12-01

    Full Text Available Purpose: To evaluate the feasibility of the use of real-time magnetic resonance imaging (MRI-transrectal ultrasound (TRUS fusion guided high-dose-rate brachytherapy (HDR-BT +/– external beam radiation therapy (EBRT in patients with histologically-proven local relapse after radical prostatectomy. Material and methods : We retrospectively reviewed 13 patients treated with real-time MRI-TRUS fusion HDR-BT for a local relapse of prostate cancer after radical surgery. All patients underwent multiparametric magnetic resonance imaging (mpMRI to confirm the presence of macroscopic lesions in prostate bed, and choline positron emission tomography/computed tomography (PET/CT to rule out nodal or distant metastases. Local failure was confirmed by transrectal biopsy. Patients without previous EBRT received 1 fraction of 15 Gy with HDR-BT plus hypofractionated EBRT (37.5 Gy in 15 fractions. Two patients received 2 fractions of 12 Gy with HDR-BT without EBRT. Follow-up visits were at 1, 3, 6 months, and every 6 months thereafter. Results : After a median follow-up of 7 months, all patients showed an appropriate biochemical response. Median prostate-specific antigen (PSA levels before treatment, 1 month, and 6 months after HDR-BT were 2.62 ng/ml (range: 1.55-9.61, 0.97 ng/ml (range: 0.12-3.14, 0.23 ng/ml (range: 0.1-0.74, respectively. Five patients (42% experienced acute grade 1 GU toxicity and 1 patient (8% suffered from grade 2 GU toxicity. Regarding gastrointestinal (GI toxicity, 5 patients referred grade 1 acute toxicity and 1 grade 2 (proctitis. No late toxicity has been observed so far. Conclusions : MRI-TRUS fusion guided salvage HDR-BT +/– EBRT is a feasible procedure for patients with local macroscopic relapse in tumor bed after radical prostatectomy. Exquisite selection of patients through mpMRI and choline PET/CT is crucial to avoid overtreatment. A larger number of patients and longer follow-up are required in order to draw more solid

  14. Effect of rectal enemas on rectal dosimetric parameters during high-dose-rate vaginal cuff brachytherapy. A prospective trial

    Energy Technology Data Exchange (ETDEWEB)

    Sabater, Sebastia; Andres, Ignacio; Sevillano, Marimar; Berenguer, Roberto; Aguayo, Manuel; Villas, Maria Victoria [Complejo Hospitalario Universitario de Albacete (CHUA), Department of Radiation Oncology, Albacete (Spain); Gascon, Marina; Arenas, Meritxell [Hospital Universitari Sant Joan, Department of Radiation Oncology, Reus (Spain); Rovirosa, Angeles; Camacho-Lopez, Cristina [University of Barcelona, IDIBAPS, Gynecological Cancer Unit, Radiation Oncology Department, ICMHO, Hospital Clinic, Barcelona (Spain)

    2016-04-15

    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{sub 0.1} {sub cc}: 6.6 vs. 7.21 Gy; D{sub 1} {sub cc}: 5.35 vs. 5.52 Gy; D{sub 2} {sub cc}: 4.67 vs. 4.72 Gy, before and after rectal cleaning, respectively (where D{sub x} {sub cc} is the dose to the most exposed x cm {sup 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{sub 5} {sub %}, D{sub 25} {sub %}, and D{sub 50} {sub %}. In contrast, in patients whose rectal volume decreased, significance was only seen for D{sub 25} {sub %} and D{sub 50} {sub %} (D{sub x} {sub %} dose covering x % of the volume). In the latter patients, nonsignificant reductions in D{sub 2} {sub cc}, D{sub 5} {sub cc} and V{sub 5} {sub 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.) [German] Beurteilung der Auswirkungen von rektalen Dosen waehrend postoperativer High-Dose-Rate-(HDR-)Brachytherapie an der Scheidenmanschette (''vaginal cuff brachytherapy'', VCB). An

  15. Comparison BIPM.RI(I)-K8 of high dose-rate Ir-192 brachytherapy standards for reference air kerma rate of the VSL and the BIPM

    DEFF Research Database (Denmark)

    Alvarez, J.T.; De Pooter, J.A.; Andersen, Claus E.

    2014-01-01

    An indirect comparison of the standards for reference air kerma rate for 192Ir high dose rate brachytherapy sources of the Dutch Metrology Institute (VSL), The Netherlands, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the VSL in November 2009. The comparison resu...

  16. High-dose-rate brachytherapy and external-beam radiotherapy for hormone-naïve low- and intermediate-risk prostate cancer: A 7-year experience

    NARCIS (Netherlands)

    S. Aluwini (Shafak); P.H. van Rooij (Peter); W.J. Kirkels (Wim); P.P. Jansen (Peter); J. Praag (John); C.H. Bangma (Chris); I.-K.K. Kolkman-Deurloo (Inger-Karina)

    2012-01-01

    textabstractPurpose: To report clinical outcomes and early and late complications in 264 hormone-naïve patients with low- and intermediate-risk prostate cancer treated with high-dose-rate brachytherapy (HDR-BT) in combination with external-beam radiotherapy (EBRT). Methods and Materials: Between

  17. Comparison of (192) Ir, (169) Yb, and (60) Co high-dose rate brachytherapy sources for skin cancer treatment.

    Science.gov (United States)

    Safigholi, Habib; Meigooni, Ali S; Song, William Y

    2017-09-01

    To evaluate the possibility of utilizing the high-dose rate (HDR) (169) Yb and (60) Co sources, in addition to (192) Ir, for the treatment of skin malignancies with conical applicators. Monte Carlo (MC) simulations were used to benchmark the dosimetric parameters of single (169) Yb (4140), (60) Co (Co0.A86), and (192) Ir (mHDR-V2) brachytherapy sources in a water phantom and compared their results against published data. A standard conical tungsten alloy Leipzig-style applicator (Stand.Appl) was used for determination of the dose distributions at various depths with a single dwell position of the HDR sources. The HDR sources were modeled with its long axis parallel to the treatment plane within the opening section of the applicator. The source-to-surface distance (SSD) was 1.6 cm, which included a 0.1 cm thick removable plastic end-cap used for clinical applications. The prescription depth was considered to be 0.3 cm in a water phantom following the definitions in the literature for this treatment technique. Dose distributions generated with the Stand.Appl and the (169) Yb and (60) Co sources have been compared with those of the (192) Ir source, for the same geometry. Then, applicator wall thickness for the (60) Co source was increased (doubled) in MC simulations in order to minimize the leakage dose and penumbra to levels that were comparable to that from the (192) Ir source. For each source-applicator combination, the optimized plastic end-cap dimensions were determined in order to avoid over-dosage to the skin surface. The normalized dose profiles at the prescription depth for the (169) Yb-Stand.Appl and the (60) Co-double-wall applicator were found to be similar to that of the (192) Ir-Stand.Appl, with differences percentage depth doses (PDD) for the (192) Ir-, (169) Yb- and (60) Co-Stand.Appl were found to be comparable to the values with the (60) Co-double-walled applicator, with differences depth were also comparable at 0.309, 0.316, and 0.298 (cGy/hU) for

  18. Outcomes Associated With 3 Treatment Schedules of High-Dose-Rate Brachytherapy Monotherapy for Favorable-Risk Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jawad, Maha Saada; Dilworth, Joshua T.; Gustafson, Gary S.; Ye, Hong; Wallace, Michelle [Department of Radiation Oncology, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States); Martinez, Alvaro [Michigan HealthCare Professionals/21" s" t Century Oncology, Farmington Hills, Michigan (United States); Chen, Peter Y. [Department of Radiation Oncology, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States); Krauss, Daniel J., E-mail: DKrauss@beaumont.edu [Department of Radiation Oncology, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States)

    2016-03-15

    Purpose: We report the outcomes associated with 3 high-dose-rate (HDR) brachytherapy regimens used as monotherapy for favorable-risk prostate cancer. Methods and Materials: Four hundred ninety-four patients with stage ≤T2b prostate cancer, Gleason score ≤7, and prostate-specific antigen levels ≤15 ng/mL underwent HDR brachytherapy as monotherapy. Of those, 319 received 38 Gy in 4 fractions, 79 received 24 Gy in 2 fractions, and 96 received 27 Gy in 2 fractions. Acute and chronic genitourinary (GU) and gastrointestinal (GI) toxicities were defined as side effects occurring ≤6 and >6 months, respectively, after radiation therapy (RT) and were graded according to the Common Terminology Criteria for Adverse Events version 3.0. The time to toxicity was calculated from the date of RT completion. Variables were analyzed with χ{sup 2} test. P values <.05 were considered significant. Results: The median overall follow-up time was 4 years (range, 5.5, 3.5, and 2.5 years for 38 Gy, 24 Gy, and 27 Gy, respectively, P<.001). Acute and chronic grade ≥2 GU and GI toxicity profiles were similar among groups. Acceptable rates of grade 2 GU toxicities were seen with overall acute/chronic frequency/urgency, dysuria, retention, incontinence, and hematuria rates of 14%/20%, 6%/7%, 7%/4%, 1.5%/2%, and 1.5%/7%, respectively. Minimal grade 3 and no grade 4 or 5 toxicities were seen. Grade 1, 2, and 3 chronic urethral stricture rates were 0.3%, 2%, and 1%, respectively. All GI toxicities were similar between groups, with overall rates of acute/chronic grade 2 diarrhea, rectal pain/tenesmus, rectal bleeding, and proctitis of 1%/1%, <1%/0.5%, 0%/2%, and <1%/1%, respectively. No grade 3, 4, or 5 toxicities were seen. All comparisons were similar for hormone-naïve patients. The median time to maximal GU/GI toxicity was similar between groups, ranging from 1 to 1.6 to 0.9 to 1.2 years, respectively. There were no differences in clinical outcomes between the 3 groups at 5

  19. Proposal of a postal system for Ir-192 sources calibration used in high dose rate brachytherapy with LiF:Mn:Ti thermoluminescent dosemeters; Proposta de um sistema postal para a calibracao de fontes de {sup 192} Ir, utilizadas em braquiterapia de alta taxa de dose, com dosimetros termoluminescentes de LiF: Mn: Ti

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, W.S.; Borges, J.C.; Almeida, C.E.V. [Instituto de Radioprotecao e Dosimetria. CNEN Caixa Postal 37750, 22780-160, Rio de Janeiro (Brazil)

    1998-12-31

    A proposal in order to improve the brachytherapy quality control and to allow postal intercomparison of Ir-192 sources used in high dose rate brachytherapy has been presented. The LiF: Mn: Ti (TLD 100) detector has been selected for such purpose. The experimental array and the TLDs irradiation and calibration techniques, at the treatment units, have been specified in the light of more recent methodology of Ir-192 calibration sources. (Author)

  20. Implementation of a High-Dose-Rate Brachytherapy Program for Carcinoma of the Cervix in Senegal: A Pragmatic Model for the Developing World

    Energy Technology Data Exchange (ETDEWEB)

    Einck, John P., E-mail: jeinck@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California San Diego, San Diego, California (United States); Hudson, Alana [Department of Oncology, Tom Baker Cancer Centre, University of Calgary, Calgary, Alberta (Canada); Shulman, Adam C. [Overlook Medical Center, Summit, New Jersey (United States); Yashar, Catheryn M. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, San Diego, California (United States); Dieng, Mamadou M.; Diagne, Magatte; Gueye, Latifatou; Gningue, Fama; Gaye, Pape M. [Départemént de Radiothérapie, Institut Joliot-Curie, Hôpital Aristide Le Dantec, Dakar (Senegal); Fisher, Brandon J. [GammaWest Cancer Services, Salt Lake City, Utah (United States); Mundt, Arno J. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, San Diego, California (United States); Brown, Derek W. [Department of Oncology, Tom Baker Cancer Centre, University of Calgary, Calgary, Alberta (Canada)

    2014-07-01

    West Africa has one of the highest incidence rates of carcinoma of the cervix in the world. The vast majority of women do not have access to screening or disease treatment, leading to presentation at advanced stages and to high mortality rates. Compounding this problem is the lack of radiation treatment facilities in Senegal and many other parts of the African continent. Senegal, a country of 13 million people, had a single {sup 60}Co teletherapy unit before our involvement and no brachytherapy capabilities. Radiating Hope, a nonprofit organization whose mission is to provide radiation therapy equipment to countries in the developing world, provided a high-dose-rate afterloading unit to the cancer center for curative cervical cancer treatment. Here we describe the implementation of high-dose-rate brachytherapy in Senegal requiring a nonstandard fractionation schedule and a novel treatment planning approach as a possible blueprint to providing this technology to other developing countries.

  1. The American College of Radiology and the American Brachytherapy Society practice parameter for the performance of radionuclide-based high-dose-rate brachytherapy.

    Science.gov (United States)

    Erickson, Beth A; Bittner, Nathan H J; Chadha, Manjeet; Mourtada, Firas; Demanes, D Jeffrey

    Brachytherapy is a radiation therapy method in which radionuclide sources are used to deliver a radiation dose at a distance of up to a few centimeters by surface, intracavitary, intraluminal, or interstitial application. This practice parameter refers only to the use of radionuclides for brachytherapy. Brachytherapy alone or combined with external beam therapy plays an important role in the management and treatment of patients with cancer. High-dose-rate (HDR) brachytherapy uses radionuclides such as iridium-192 at dose rates of 20 cGy per minute (12 Gy per hour) or more to a designated target point or volume. High-dose-rate (HDR) brachytherapy is indicated for treating malignant or benign tumors where the treatment volume or targeted points are defined and accessible. Copyright © 2016 American Brachytherapy Society and American College of Radiology. Published by Elsevier Inc. All rights reserved.

  2. External beam boost versus interstitial high-dose-rate brachytherapy boost in the adjuvant radiotherapy following breast-conserving therapy in early-stage breast cancer: a dosimetric comparison

    Science.gov (United States)

    Melchert, Corinna; Kovács, György

    2016-01-01

    Purpose This study aims to compare the dosimetric data of local tumor's bed dose escalation (boost) with photon beams (external beam radiation therapy – EBRT) versus high-dose-rate interstitial brachytherapy (HDR-BT) after breast-conserving treatment in women with early-stage breast cancer. Material and methods We analyzed the treatment planning data of 136 irradiated patients, treated between 2006 and 2013, who underwent breast-conserving surgery and adjuvant whole breast irradiation (WBI; 50.4 Gy) and boost (HDR-BT: 10 Gy in one fraction [n = 36]; EBRT: 10 Gy in five fractions [n = 100]). Organs at risk (OAR; heart, ipsilateral lung, skin, most exposed rib segment) were delineated. Dosimetric parameters were calculated with the aid of dose-volume histograms (DVH). A non-parametric test was performed to compare the two different boost forms. Results There was no difference for left-sided cancers regarding the maximum dose to the heart (HDR-BT 29.8% vs. EBRT 29.95%, p = 0.34). The maximum doses to the other OAR were significantly lower for HDR-BT (Dmax lung 47.12% vs. 87.7%, p skin 57.1% vs. 94.75%, p < 0.01; in the case of right-sided breast irradiation, dose of the heart 6.00% vs. 16.75%, p < 0.01). Conclusions Compared to EBRT, local dose escalation with HDR-BT presented a significant dose reduction to the investigated OAR. Only left-sided irradiation showed no difference regarding the maximum dose to the heart. Reducing irradiation exposure to OAR could result in a reduction of long-term side effects. Therefore, from a dosimetric point of view, an interstitial boost complementary to WBI via EBRT seems to be more advantageous in the adjuvant radiotherapy of breast cancer. PMID:27648082

  3. External beam boost versus interstitial high-dose-rate brachytherapy boost in the adjuvant radiotherapy following breast-conserving therapy in early-stage breast cancer: a dosimetric comparison

    Directory of Open Access Journals (Sweden)

    Martje Marie Terheyden

    2016-08-01

    Full Text Available Purpose : This study aims to compare the dosimetric data of local tumor’s bed dose escalation (boost with photon beams (external beam radiation therapy – EBRT versus high-dose-rate interstitial brachytherapy (HDR-BT after breast-conserving treatment in women with early-stage breast cancer. Material and methods : We analyzed the treatment planning data of 136 irradiated patients, treated between 2006 and 2013, who underwent breast-conserving surgery and adjuvant whole breast irradiation (WBI; 50.4 Gy and boost (HDR-BT: 10 Gy in one fraction [n = 36]; EBRT: 10 Gy in five fractions [n = 100]. Organs at risk (OAR; heart, ipsilateral lung, skin, most exposed rib segment were delineated. Dosimetric parameters were calculated with the aid of dose-volume histograms (DVH. A non-parametric test was performed to compare the two different boost forms. Results : There was no difference for left-sided cancers regarding the maximum dose to the heart (HDR-BT 29.8% vs. EBRT 29.95%, p = 0.34. The maximum doses to the other OAR were significantly lower for HDR-BT (Dmax lung 47.12% vs. 87.7%, p < 0.01; rib 61.17% vs. 98.5%, p < 0.01; skin 57.1% vs. 94.75%, p < 0.01; in the case of right-sided breast irradiation, dose of the heart 6.00% vs. 16.75%, p < 0.01. Conclusions : Compared to EBRT, local dose escalation with HDR-BT presented a significant dose reduction to the investigated OAR. Only left-sided irradiation showed no difference regarding the maximum dose to the heart. Reducing irradiation exposure to OAR could result in a reduction of long-term side effects. Therefore, from a dosimetric point of view, an interstitial boost complementary to WBI via EBRT seems to be more advantageous in the adjuvant radiotherapy of breast cancer.

  4. Dedicated high dose rate 192Ir brachytherapy radiation fields for in vitro cell exposures at variable source-target cell distances: killing of mammalian cells depends on temporal dose rate fluctuation

    Science.gov (United States)

    Veigel, Cornelia; Hartmann, Günther H.; Fritz, Peter; Debus, Jürgen; Weber, Klaus-Josef

    2017-02-01

    Afterloading brachytherapy is conducted by the stepwise movement of a radioactive source through surgically implanted applicator tubes where at predefined dwell positions calculated dwell times optimize spatial dose delivery with respect to a planned dose level. The temporal exposure pattern exhibits drastic fluctuations in dose rate at a given coordinate and within a single treatment session because of the discontinuous and repeated source movement into the target volume. This could potentially affect biological response. Therefore, mammalian cells were exposed as monolayers to a high dose rate 192Ir source by utilizing a dedicated irradiation device where the distance between a planar array of radioactive source positions and the plane of the cell monolayer could be varied from 2.5 mm to 40 mm, thus varying dose rate pattern for any chosen total dose. The Gammamed IIi afterloading system equipped with a nominal 370 GBq (10 Ci) 192-Ir source was used to irradiate V79 Chinese hamster lung fibroblasts from both confluent and from exponential growth phase with dose up to 12 Gy (at room temperature, total exposure not exceeding 1 h). For comparison, V79 cells were also exposed to 6 MV x-rays from a clinical linear accelerator (dose rate of 2.5 Gy min-1). As biological endpoint, cell survival was determined by standard colony forming assay. Dose measurements were conducted with a diamond detector (sensitive area 7.3 mm2), calibrated by means of 60Co radiation. Additionally, dose delivery was simulated by Monte Carlo calculations using the EGSnrc code system. The calculated secondary electron fluence spectra at the cell location did not indicate a significant change of radiation quality (i.e. higher linear energy transfer) at the lower distances. Clonogenic cell survival curves obtained after brachytherapy exhibited an altered biological response compared to x-rays which was characterized by a significant reduction of the survival curve shoulder when dose rate

  5. Cancer radiotherapy based on femtosecond IR laser-beam filamentation yielding ultra-high dose rates and zero entrance dose.

    Science.gov (United States)

    Meesat, Ridthee; Belmouaddine, Hakim; Allard, Jean-François; Tanguay-Renaud, Catherine; Lemay, Rosalie; Brastaviceanu, Tiberius; Tremblay, Luc; Paquette, Benoit; Wagner, J Richard; Jay-Gerin, Jean-Paul; Lepage, Martin; Huels, Michael A; Houde, Daniel

    2012-09-18

    Since the invention of cancer radiotherapy, its primary goal has been to maximize lethal radiation doses to the tumor volume while keeping the dose to surrounding healthy tissues at zero. Sadly, conventional radiation sources (γ or X rays, electrons) used for decades, including multiple or modulated beams, inevitably deposit the majority of their dose in front or behind the tumor, thus damaging healthy tissue and causing secondary cancers years after treatment. Even the most recent pioneering advances in costly proton or carbon ion therapies can not completely avoid dose buildup in front of the tumor volume. Here we show that this ultimate goal of radiotherapy is yet within our reach: Using intense ultra-short infrared laser pulses we can now deposit a very large energy dose at unprecedented microscopic dose rates (up to 10(11) Gy/s) deep inside an adjustable, well-controlled macroscopic volume, without any dose deposit in front or behind the target volume. Our infrared laser pulses produce high density avalanches of low energy electrons via laser filamentation, a phenomenon that results in a spatial energy density and temporal dose rate that both exceed by orders of magnitude any values previously reported even for the most intense clinical radiotherapy systems. Moreover, we show that (i) the type of final damage and its mechanisms in aqueous media, at the molecular and biomolecular level, is comparable to that of conventional ionizing radiation, and (ii) at the tumor tissue level in an animal cancer model, the laser irradiation method shows clear therapeutic benefits.

  6. High-dose-rate Three-dimensional Conformal Radiotherapy Combined with Active Breathing Control for Stereotactic Body Radiotherapy of Early-stage Non-small-cell Lung Cancer.

    Science.gov (United States)

    Wang, Ruozheng; Yin, Yong; Qin, Yonghui; Yu, Jinming

    2015-12-01

    The purpose of this study was to evaluate the feasibility and benefits of using high-dose-rate three-dimensional conformal radiotherapy (3D-CRT) combined with active breathing control (ABC) for stereotactic body radiotherapy (SBRT) of patients with early-stage non-small-cell lung cancer (NSCLC). Eight patients with early-stage NSCLC underwent CT scans under standard free-breathing (FB) and moderately deep inspiration breath-hold (mDIBH) with ABC. Two high-dose-rate 3D-CRT plans (1000 Mu/min) were designed based on the CT scans with FB and mDIBH. The maximal dose (D1%), minimal dose (D99%), conformity index (CI), and homogeneity index (HI) of the planning target volume (PTV), and dose-volume indices of the organs at risk between each plan were compared. The mean PTV volume decreased from 158.04 cm(3) with FB to 76.90 cm(3) with mDIBH (p < 0.05). When mDIBH was used, increases in the affected lung volume (by 47%), contralateral lung volume (by 55%), and total lung volume (by 50%) were observed compared to FB (p < 0.05). The V5-V40 of the affected lung (Vx represented the percentage volume of organs receiving at least the x Gy), V5-V40 and the mean dose for the total lung, V5-V40 and mean dose of the chest wall, and the maximum dose of the spinal cord were less for mDIBH than FB (p < 0.05). There were no significant differences in CI, HI, D1%, or D99% for the PTV between the plans. In conclusion, high-dose-rate 3D-CRT combined with ABC reduced the radiation dose to the lungs and chest wall without affecting the dose distribution in SBRT of early-stage NSCLC patients. © The Author(s) 2014.

  7. TU-AB-201-08: Rotating Shield High Dose Rate Brachytherapy with 153Gd and 75Se Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Renaud, M; Seuntjens, J; Enger, S [McGill University, Montreal, Quebec (Canada); Flynn, R [University of Iowa Hospitals and Clinics, Iowa City, IA (United States)

    2015-06-15

    Purpose: To introduce rotating shield brachytherapy (RSBT) for different cancer sites with {sup 153}Gd and {sup 75}Se isotopes. RSBT is a form of intensity modulated brachytherapy, using shielded rotating catheters to provide a better dose distribution in the tumour while protecting healthy tissue. Methods: BrachySource, a Geant4-based Monte Carlo dose planning system was developed for investigation of RSBT with {sup 153}Gd and {sup 75}Se for different cancer sites. Dose distributions from {sup 153}Gd, {sup 75}Se and {sup 192}Ir isotopes were calculated in a 40 cm radius water phantom by using the microSelectron-v2 source model. The source was placed inside a cylindrical platinum shield with 1.3 mm diameter. An emission window coinciding with the active core of the source was created by removing half (180°) of the wall of the shield. Relative dose rate distributions of the three isotopes were simulated. As a proof of concept, a breast cancer patient originally treated with Mammosite was re-simulated with unshielded {sup 192}Ir and shielded {sup 153}Gd. Results: The source with the lowest energy, {sup 153}Gd, decreased the dose on the shielded side by 91%, followed by {sup 75}Se and {sup 192}Ir with 36% and 16% reduction at 1 cm from the source. The breast cancer patient simulation showed the ability of shielded {sup 153}Gd to spare the chest wall by a 90% dose reduction when only one emission window angle is considered. In this case, fully covering the PTV would require more delivery angles and the chest wall dose reduction would be less, however, the simulation demonstrates the potential of shielded {sup 153}Gd to selectively isolate organs at risk. Conclusion: Introducing {sup 153}Gd and {sup 75}Se sources combined with RSBT will allow escalation of dose in the target volume while maintaining low doses in radiation sensitive healthy tissue. Tailoring treatments to each individual patient by treating all parts of the tumour without over-irradiation of normal

  8. Medically inoperable endometrial cancer in patients with a high body mass index (BMI): Patterns of failure after 3-D image-based high dose rate (HDR) brachytherapy

    DEFF Research Database (Denmark)

    Acharya, Sahaja; Esthappan, Jacqueline; Badiyan, Shahed

    2016-01-01

    BACKGROUND AND PURPOSE: High BMI is a reason for medical inoperability in patients with endometrial cancer in the United States. Definitive radiation is an alternative therapy for these patients; however, data on patterns of failure after definitive radiotherapy are lacking. We describe...... the patterns of failure after definitive treatment with 3-D image-based high dose rate (HDR) brachytherapy for medically inoperable endometrial cancer. MATERIALS AND METHODS: Forty-three consecutive patients with endometrial cancer FIGO stages I-III were treated definitively with HDR brachytherapy...

  9. High-dose rate iridium-192 brachytherapy with flexible applicator. A trial toward decrease of stress during treatment and improvement of quality of life

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Keiji; Kasahara, Kotaro; Karashima, Takashi; Inoue, Yuichiro; Kariya, Shinji; Inomata, Taisuke; Yoshida, Shoji; Shuin, Taro [Kochi Medical School, Nankoku (Japan)

    2001-07-01

    We tried to improve the materials and methods of high-dose rate Iridium-192 brachytherapy for localized prostate cancer and evaluated the stress during the treatment in 20 patients with whom the therapy was performed. Rigid applicators made of stainless steel of 1.6 mm in diameter were indwelt with a template as usual for 30 hours in 14 patients (group A). Flexible applicators made of polyoxymethylene rosin (POM) of 2.0 mm in diameter were indwelt without a template for 30 hours after the applicator insertion in 6 patients (group B). We made inquiries about lumbago, inconvenience and necessity of assistant help and sleep in the course of therapy, and urinary incontinence and erectile function after the course of therapy as the QOL. The stress during the course of therapy in the patients of group B was obviously less than that of group A. There were no significant differences in urinary incontinence and erectile function after the course of therapy between group A and B. In this study, our trial successfully reduced the stress during the course of therapy in the patients with localized prostate cancer in the course of high-dose rate Iridium-192 brachytherapy. (author)

  10. American Society for Radiation Oncology (ASTRO) and American College of Radiology (ACR) practice guideline for the performance of high-dose-rate brachytherapy.

    Science.gov (United States)

    Erickson, Beth A; Demanes, D Jeffrey; Ibbott, Geoffrey S; Hayes, John K; Hsu, I-Chow J; Morris, David E; Rabinovitch, Rachel A; Tward, Jonathan D; Rosenthal, Seth A

    2011-03-01

    High-Dose-Rate (HDR) brachytherapy is a safe and efficacious treatment option for patients with a variety of different malignancies. Careful adherence to established standards has been shown to improve the likelihood of procedural success and reduce the incidence of treatment-related morbidity. A collaborative effort of the American College of Radiology (ACR) and American Society for Therapeutic Radiation Oncology (ASTRO) has produced a practice guideline for HDR brachytherapy. The guideline defines the qualifications and responsibilities of all the involved personnel, including the radiation oncologist, physicist and dosimetrists. Review of the leading indications for HDR brachytherapy in the management of gynecologic, thoracic, gastrointestinal, breast, urologic, head and neck, and soft tissue tumors is presented. Logistics with respect to the brachytherapy implant procedures and attention to radiation safety procedures and documentation are presented. Adherence to these practice guidelines can be part of ensuring quality and safety in a successful HDR brachytherapy program. Copyright © 2011. Published by Elsevier Inc.

  11. Preventing Complications from High-Dose Rate Brachytherapy when Treating Mobile Tongue Cancer via the Application of a Modular Lead-Lined Spacer.

    Directory of Open Access Journals (Sweden)

    Shumei Murakami

    Full Text Available To point out the advantages and drawbacks of high-dose rate brachytherapy in the treatment of mobile tongue cancer and indicate the clinical importance of modular lead-lined spacers when applying this technique to patients.First, all basic steps to construct the modular spacer are shown. Second, we simulate and evaluate the dose rate reduction for a wide range of spacer configurations.With increasing distance to the source absorbed doses dropped considerably. Significantly more shielding was obtained when lead was added to the spacer and this effect was most pronounced on shorter (i.e. more clinically relevant distances to the source.The modular spacer represents an important addition to the planning and treatment stages of mobile tongue cancer using HDR-ISBT.

  12. Role of vaginal pallor reaction in predicting late vaginal stenosis after high-dose-rate brachytherapy in treatment-naive patients with cervical cancer.

    Science.gov (United States)

    Yoshida, Ken; Yamazaki, Hideya; Nakamura, Satoaki; Masui, Koji; Kotsuma, Tadayuki; Akiyama, Hironori; Tanaka, Eiichi; Yoshikawa, Nobuhiko; Uesugi, Yasuo; Shimbo, Taiju; Narumi, Yoshifumi; Yoshioka, Yasuo

    2015-07-01

    To assess actual rates of late vaginal stenosis and identify predisposing factors for complications among patients with previously untreated cervical cancer following high-dose-rate brachytherapy. We performed longitudinal analyses of 57 patients using the modified Dische score at 6, 12, 18, 24, 36, and 60 months after treatment, which consisted of 15 interstitial brachytherapys and 42 conventional intracavitary brachytherapys, with a median follow-up time of 36 months (range, 6 to 144 months). More than half of the patients developed grade 1 (mild) vaginal stenosis within the first year of follow-up, and grade 2 (97.5%, moderate) to grade 3 (severe) stenosis gradually increased with time. Actual stenosis rates for grade 1, 2, and 3 were 97.5% (95% confidence interval [CI], 92.7 to 97.5), 60.7% (95% CI, 42.2 to 79.3), and 7.4% (95% CI, 0 to 18.4) at 3 years after treatment. Pallor reaction grade 2-3 at 6 months was only a statistically significant predisposing factor for grade 2-3 late vaginal stenosis 3 years or later with a hazard ratio of 3.48 (95% CI, 1.32 to 9.19; p=0.018) by a multivariate Cox proportional hazard model. Patients with grade 0-1 pallor reaction at 6 months showed a grade ≥2 vaginal stenosis rate of 53%, whereas the grade 2-3 pallor reaction group achieved a grade ≥2 vaginal stenosis rate at 3 years at 100% (p=0.001). High-dose-rate brachytherapy was associated with high incidence of late vaginal stenosis. Pallor reaction grade 2-3 at 6 months was predictive of late grade 2-3 vaginal stenosis at 3 years after treatment. These findings should prove helpful for patient counseling and preventive intervention.

  13. TLD skin dose measurements and acute and late effects after lumpectomy and high-dose-rate brachytherapy only for early breast cancer.

    Science.gov (United States)

    Perera, Francisco; Chisela, Frank; Stitt, Larry; Engel, Jay; Venkatesan, Varagur

    2005-08-01

    This report examines the relationships between measured skin doses and the acute and late skin and soft tissue changes in a pilot study of lumpectomy and high-dose-rate brachytherapy only for breast cancer. Thirty-seven of 39 women enrolled in this pilot study of high-dose-rate brachytherapy (37.2 Gy in 10 fractions b.i.d.) each had thermoluminescent dosimetry (TLD) at 5 points on the skin of the breast overlying the implant volume. Skin changes at TLD dose points and fibrosis at the lumpectomy site were documented every 6 to 12 months posttreatment using a standardized physician-rated cosmesis questionnaire. The relationships between TLD dose and acute skin reaction, pigmentation, or telangiectasia at 5 years were analyzed using the GEE algorithm and the GENMOD procedure in the SAS statistical package. Fisher's exact test was used to determine whether there were any significant associations between acute skin reaction and late pigmentation or telangiectasia or between the volumes encompassed by various isodoses and fibrosis or fat necrosis. The median TLD dose per fraction (185 dose points) multiplied by 10 was 9.2 Gy. In all 37 patients, acute skin reaction Grade 1 or higher was observed at 5.9% (6 of 102) of dose points receiving 10 Gy or less vs. 44.6% (37 of 83) of dose points receiving more than 10 Gy (p skin reaction was also significantly associated with development of Grade 1 or more pigmentation or telangiectasia at 60 months. This association was most significant for acute reaction and telangiectasia directly over the lumpectomy site (p brachytherapy to the lumpectomy site, TLD skin dose was significantly related to acute skin reaction and to pigmentation and telangiectasia at 60 months. An acute skin reaction was also significantly associated with the development of telangiectasia at 60 months. TLD skin dose measurement may allow modification of the brachytherapy implant geometry (dwell times and position) to minimize late skin toxicity.

  14. Chemoradiation in cervical cancer with cisplatin and high-dose rate brachytherapy combined with external beam radiotherapy. Results of a phase-II study

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, H.G.; Laban, C.; Puschmann, D.; Koelbl, H. [Dept. of Gynecology, Martin-Luther Univ. Halle-Wittenberg (Germany); Kuhnt, T.; Pigorsch, S.; Dunst, J.; Haensgen, G. [Dept. of Radiotherapy, Martin-Luther Univ. Halle-Wittenberg (Germany)

    2002-07-01

    Background: In 1999, five randomized studies demonstrated that chemoradiation with cisplatin and low-dose rate (LDR) brachytherapy has a benefit in locally advanced cervical cancer and for surgically treated patients in high-risk situations. We evaluated the safety and efficacy of concomitant chemoradiation with cisplatin and high-dose rate (HDR) brachytherapy in patients with cervical cancer. Patients and Method: 27 patients were included in our phase-II trial: 13 locally advanced cases (group A) and 14 adjuvant-therapy patients in high-risk situations (group B). A definitive radiotherapy was performed with 25 fractions of external beam therapy (1.8 Gy per fraction/middle shielded after eleven fractions). Brachytherapy was delivered at HDR schedules with 7 Gy in point A per fraction (total dose 35 Gy) in FIGO Stages IIB-IIIB. The total dose of external and brachytherapy was 70 Gy in point A and 52-54 Gy in point B. All patients in stage IVA were treated without brachytherapy. Adjuvant radiotherapy was performed with external beam radiotherapy of the pelvis with 1.8 Gy single-dose up to 50.4 Gy. Brachytherapy was delivered at HDR schedules with two fractions of 5 Gy only in patients with tumor-positive margins or tumor involvement of the upper vagina. The chemotherapeutic treatment schedule provided six courses of cisplatin 40 mg/m{sup 2} weekly recommended in the randomized studies GOG-120 and -123. Results: A total of 18/27 patients (66.7%) completed all six courses of chemotherapy. Discontinuation of radiotherapy due to therapy-related morbidity was not necessary in the whole study group. G3 leukopenia (29.6%) was the only relevant acute toxicity. There were no differences in toxicity between group A and B. Serious late morbidity occurred in 2/27 patients (7.4%). 12/13 patients (92.3%) with IIB-IVA cervical cancer showed a complete response (CR). 13/14 adjuvant cases (92.8%) are free of recurrence (median follow up: 19.1 months). Conclusion: Concomitant

  15. Real-Time Verification of a High-Dose-Rate Iridium 192 Source Position Using a Modified C-Arm Fluoroscope

    Energy Technology Data Exchange (ETDEWEB)

    Nose, Takayuki, E-mail: nose-takayuki@nms.ac.jp [Department of Radiation Oncology, Nippon Medical School Tamanagayama Hospital, Tama (Japan); Chatani, Masashi [Department of Radiation Oncology, Osaka Rosai Hospital, Sakai (Japan); Otani, Yuki [Department of Radiology, Kaizuka City Hospital, Kaizuka (Japan); Teshima, Teruki [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Kumita, Shinichirou [Department of Radiology, Nippon Medical School Hospital, Tokyo (Japan)

    2017-03-15

    Purpose: High-dose-rate (HDR) brachytherapy misdeliveries can occur at any institution, and they can cause disastrous results. Even a patient's death has been reported. Misdeliveries could be avoided with real-time verification methods. In 1996, we developed a modified C-arm fluoroscopic verification of an HDR Iridium 192 source position prevent these misdeliveries. This method provided excellent image quality sufficient to detect errors, and it has been in clinical use at our institutions for 20 years. The purpose of the current study is to introduce the mechanisms and validity of our straightforward C-arm fluoroscopic verification method. Methods and Materials: Conventional X-ray fluoroscopic images are degraded by spurious signals and quantum noise from Iridium 192 photons, which make source verification impractical. To improve image quality, we quadrupled the C-arm fluoroscopic X-ray dose per pulse. The pulse rate was reduced by a factor of 4 to keep the average exposure compliant with Japanese medical regulations. The images were then displayed with quarter-frame rates. Results: Sufficient quality was obtained to enable observation of the source position relative to both the applicators and the anatomy. With this method, 2 errors were detected among 2031 treatment sessions for 370 patients within a 6-year period. Conclusions: With the use of a modified C-arm fluoroscopic verification method, treatment errors that were otherwise overlooked were detected in real time. This method should be given consideration for widespread use.

  16. 3-D conformal treatment of prostate cancer to 74 Gy vs. high-dose-rate brachytherapy boost: A cross-sectional quality-of-life survey

    Energy Technology Data Exchange (ETDEWEB)

    Vordermark, Dirk [Univ. of Wuerzburg (DE). Dept. of Radiation Oncology] (and others)

    2006-09-15

    The effects of two modalities of dose-escalated radiotherapy on health-related quality of life (HRQOL) were compared. Forty-one consecutive patients were treated with a 3-D conformal (3-DC) boost to 74 Gy, and 43 with high-dose rate (HDR) brachytherapy boost (2x9 Gy), following 3-D conformal treatment to 46 Gy. Median age was 70 years in both groups, median initial PSA was 7.9 {mu}g/l in 3-DC boost patients and 8.1 {mu}g/l in HDR boost patients. Stage was 7 in 52% and 47%, respectively. HRQOL was assessed cross-sectionally using EORTC QLQ-C30 and organ-specific PR25 modules 3-32 (median 19) and 4-25 (median 14) months after treatment, respectively. Questionnaires were completed by 93% and 97% of patients, respectively. Diarrhea and insomnia scores were significantly increased in both groups. In the PR25 module, scores of 3-DC boost and HDR boost patients for urinary, bowel and treatment-related symptoms were similar. Among responders, 34% of 3-DC boost patients and 86% of HDR boost patients had severe erectile problems. Dose escalation in prostate cancer by either 3-DC boost to 74 Gy or HDR brachytherapy boost appears to result in similar HRQOL profiles.

  17. Medically inoperable endometrial cancer in patients with a high body mass index (BMI): Patterns of failure after 3-D image-based high dose rate (HDR) brachytherapy.

    Science.gov (United States)

    Acharya, Sahaja; Esthappan, Jacqueline; Badiyan, Shahed; DeWees, Todd A; Tanderup, Kari; Schwarz, Julie K; Grigsby, Perry W

    2016-01-01

    High BMI is a reason for medical inoperability in patients with endometrial cancer in the United States. Definitive radiation is an alternative therapy for these patients; however, data on patterns of failure after definitive radiotherapy are lacking. We describe the patterns of failure after definitive treatment with 3-D image-based high dose rate (HDR) brachytherapy for medically inoperable endometrial cancer. Forty-three consecutive patients with endometrial cancer FIGO stages I-III were treated definitively with HDR brachytherapy with or without external beam radiation therapy. Cumulative incidence of failures was estimated and prognostic variables were identified Mean follow up was 29.7 months. Median BMI was 50.2 kg/m(2) (range: 25.1-104 kg/m(2)). The two-year overall survival was 65.2%. The two-year cumulative incidence of pelvic and distant failures was 8.3% and 13.5%, respectively. Grade 3 disease was associated with a higher risk of all-failures (Hazard Ratio [HR]: 4.67, 95% CI: 1.04-20.9, p=0.044). The incidence of acute Grade 3 GI/GU toxicities was 4.6%. Pelvic failure at two years was less than 10%. Patients with grade 3 disease were more likely to experience disease failure and may warrant closer follow up. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. Development of a new flexible electrode for interstitial hyperthermia compatible with a high dose rate {sup 192}Ir remote after-loading system

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Nobue; Moriyama, Masahiro; Kitagaki, Hajime [Shimane Medical Univ., Izumo (Japan); Kato, Hirokazu; Kasai, Toshifumi; Sugimura, Kazuro

    1999-09-01

    We developed a new electrode for induction of RF interstitial hyperthermia combined with a high dose rate (HDR) {sup 192}Ir remote after-loading system (RALS), and studied the heating characteristics of using an agar phantom. This hyperthermia induction system consists of two types of electrodes: a flexible internal electrode made of coil-spring (1.14 mm in diameter, 5 or 10-cm in length) which can be inserted into a 5-Fr. nylon RALS catheter; and a rectangular external electrode made of copper plate. The results from computer simulation showed that overheating does not occur in proximity to the external electrode. Experiments using the phantom showed that with application of a 5 W at 13.56 MHz RF signal for 2 min, the temperature rose uniformly along the electrode, while no overheating around the outer electrode was observed. The specific absorption rate (SAR) values at 1-cm and 1.5-cm distance were about 25% and 7%, respectively, with 100% defined as the value at the electrode. The electrodes we developed efficiently provide a uniform distribution of increasing temperature, suggesting that their use may make it possible to avoid the trauma of catheter re-insertion. (author)

  19. Clinicopathologic Comparison of High-Dose-Rate Endorectal Brachytherapy versus Conventional Chemoradiotherapy in the Neoadjuvant Setting for Resectable Stages II and III Low Rectal Cancer

    Directory of Open Access Journals (Sweden)

    Jessica A. Smith

    2012-01-01

    Full Text Available Purpose. To assess for differences in clinical, radiologic, and pathologic outcomes between patients with stage II-III rectal adenocarcinoma treated neoadjuvantly with conventional external beam radiotherapy (3D conformal radiotherapy (3DRT or intensity-modulated radiotherapy (IMRT versus high-dose-rate endorectal brachytherapy (EBT. Methods. Patients undergoing neoadjuvant EBT received 4 consecutive daily 6.5 Gy fractions without chemotherapy, while those undergoing 3DRT or IMRT received 28 daily 1.8 Gy fractions with concurrent 5-fluorouracil. Data was collected prospectively for 7 EBT patients and retrospectively for 25 historical 3DRT/IMRT controls. Results. Time to surgery was less for EBT compared to 3DRT and IMRT (P<0.001. There was a trend towards higher rate of pathologic CR for EBT (P=0.06. Rates of margin and lymph node positivity at resection were similar for all groups. Acute toxicity was less for EBT compared to 3DRT and IMRT (P=0.025. Overall and progression-free survival were noninferior for EBT. On MRI, EBT achieved similar complete response rate and reduction in tumor volume as 3DRT and IMRT. Histopathologic comparison showed that EBT resulted in more localized treatment effects and fewer serosal adhesions. Conclusions. EBT offers several practical benefits over conventional radiotherapy techniques and appears to be at least as effective against low rectal cancer as measured by short-term outcomes.

  20. Parallelized patient-specific quality assurance for high-dose-rate image-guided brachytherapy in an integrated computed tomography-on-rails brachytherapy suite.

    Science.gov (United States)

    Kim, Taeho; Showalter, Timothy N; Watkins, W Tyler; Trifiletti, Daniel M; Libby, Bruce

    2015-01-01

    To describe a parallelized patient-specific quality assurance (QA) program designed to ensure safety and quality in image-guided high-dose-rate brachytherapy in an integrated computed tomography (CT)-on-rails brachytherapy suite. A patient-specific QA program has been modified for the image-guided brachytherapy (IGBT) program in an integrated CT-on-rails brachytherapy suite. In the modification of the QA procedures of Task Group-59, the additional patient-specific QA procedures are included to improve rapid IGBT workflow with applicator placement, imaging, planning, treatment, and applicator removal taking place in one room. The IGBT workflow is partitioned into two groups of tasks that can be performed in parallel by two or more staff members. One of the unique components of our implemented workflow is that groups work together to perform QA steps in parallel and in series during treatment planning and contouring. Coordinating efforts in this systematic way enable rapid and safe brachytherapy treatment while incorporating 3-dimensional anatomic variations between treatment days. Implementation of these patient-specific QA procedures in an integrated CT-on-rails brachytherapy suite ensures confidence that a rapid workflow IGBT program can be implemented without sacrificing patient safety or quality and deliver highly-conformal dose to target volumes. These patient-specific QA components may be adapted to other IGBT environments that seek to provide rapid workflow while ensuring quality. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  1. Clinical outcomes with high-dose-rate surface mould brachytherapy for intra-oral and skin malignancies involving head and neck region.

    Science.gov (United States)

    Budrukkar, Ashwini; Dasgupta, Archya; Pandit, Prakash; Laskar, Sarbani Ghosh; Murthy, Vedang; Upreti, Ritu Raj; Gupta, Tejpal; Dholam, Kanchan; Agarwal, Jai Prakash

    2017-06-01

    The literature and experience of high-dose-rate (HDR) surface mould brachytherapy (SMB) in head and neck cancer is sparse. We report our institutional experience of SMB for such tumours. Thirty-five patients with malignant localized early T1/T2, N0 (21 intra-oral and 14 skin) tumours treated with SMB during 2008-2014 were analyzed. Treatment was delivered using HDR (192)Ir source to a median dose of 49 Gy (range, 38.5-52.5 Gy) as radical brachytherapy and 18 Gy (range, 15.5-30 Gy) as boost with 3-4 Gy/fraction twice daily using customized surface mould. Median follow-up was 52 months (range, 6 to 98 months). Local control (LC) for skin tumours and intra-oral malignancies at 5 years were 92% and 76%, respectively. Five-year cause specific survival was 92%. For T1 and T2 tumours, 5 year LC was 94.2% and 68.2%, respectively. T stage (p brachytherapy results in excellent LC rates for skin tumours and T1 intraoral tumours when considered as radical treatment, and preferable to consider it as a boost for T2 intraoral tumours. Surface mould brachytherapy results in excellent organ and function preservation.

  2. Clinical outcomes with high-dose-rate surface mould brachytherapy for intra-oral and skin malignancies involving head and neck region

    Directory of Open Access Journals (Sweden)

    Ashwini Budrukkar

    2017-03-01

    Full Text Available Purpose : The literature and experience of high-dose-rate (HDR surface mould brachytherapy (SMB in head and neck cancer is sparse. We report our institutional experience of SMB for such tumours. Material and methods: Thirty-five patients with malignant localized early T1/T2, N0 (21 intra-oral and 14 skin tumours treated with SMB during 2008-2014 were analyzed. Treatment was delivered using HDR 192Ir source to a median dose of 49 Gy (range, 38.5-52.5 Gy as radical brachytherapy and 18 Gy (range, 15.5-30 Gy as boost with 3-4 Gy/fraction twice daily using customized surface mould. Results : Median follow-up was 52 months (range, 6 to 98 months. Local control (LC for skin tumours and intra-oral malignancies at 5 years were 92% and 76%, respectively. Five-year cause specific survival was 92%. For T1 and T2 tumours, 5 year LC was 94.2% and 68.2%, respectively. T stage (p < 0.04 and dose/fractions (p < 0.003 were the only significant prognostic factors for LC on univariate analysis. Conclusions : Surface mould brachytherapy results in excellent LC rates for skin tumours and T1 intraoral tumours when considered as radical treatment, and preferable to consider it as a boost for T2 intraoral tumours. Surface mould brachytherapy results in excellent organ and function preservation.

  3. Complete response of endemic Kaposi sarcoma lesions with high-dose-rate brachytherapy: treatment method, results, and toxicity using skin surface applicators.

    Science.gov (United States)

    Kasper, Michael E; Richter, Sam; Warren, Nicholas; Benda, Rashmi; Shang, Charles; Ouhib, Zoubir

    2013-01-01

    To analyze the clinical outcome of Kaposi sarcoma skin lesions treated with high-dose-rate (HDR) brachytherapy in patients with a minimum of 2 years of followup. Between February 2006 and July 2008, all patients with Kaposi sarcoma who received (192)Ir HDR brachytherapy using a skin surface applicator were evaluated for clinical response. Responses to treatment and toxicity were scored using standard criteria. Sixteen cases were collected. Treatment was delivered in four to six fractions, over a period of approximately 12 days. The specified dose ranged from 24 to 35Gy. Median followup the lesion was 41.4 months. No lesion was greater than 2cm. All patients had a complete response to treatment, with no evidence of local recurrence or tumor progression. Thirteen lesions developed Grade 1 and two lesions had Grade 2 acute skin reactions. One patient developed late skin changes with telangiectasias and hypopigmentation. HDR brachytherapy treatment seems to be an effective noninvasive option for patients with small cutaneous Kaposi sarcoma lesions, delivering excellent cosmesis and local control in our small series. Fewer fractions over a shorter period used in our group offer patients more convenience compared with other common regimens. Although HDR is being used more frequently for many surface applications, additional clinical studies with larger numbers of patients and longer followup are needed to confirm the general impression that it is an excellent option for many patients. Copyright © 2013 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  4. Design and development of an inflatable latex balloon to reduce rectal and bladder doses for patients undergoing high dose rate brachytherapy

    Directory of Open Access Journals (Sweden)

    Raghukumar P

    2009-01-01

    Full Text Available Multiple fractions of High Dose Rate (HDR brachytherapy along with external beam therapy is the common method of treatment for cancer of the uterine cervix. Urinary bladder and rectum are the organs at risk (OARs that receive a significant dose during treatment. To reduce the dose to these organs, a majority of hospitals use vaginal gauze packing, as it is a simple, nontraumatic, and easy method. This article describes the design and development of an inflatable balloon that can be used along with the applicator as a substitute for gauze packing. The balloon has two parts-the bladder part (B-part and the rectum part (R-part, both of them are independently inflatable. The selection of the material, its width, length, and thickness are described. A mould/former for making the balloon was designed. Polished steel was used as the mould. This was dipped in specially prepared natural rubber latex (NRL solution several times; the layers were dried and stripped to get the balloon. The composition of NRL and the compounding recipe of the latex are also described. Physical tests like tensile strength, elongation at break, bursting volume, and radiation attenuation caused by the balloon, were checked. Biological tests for assessing type I and type IV allergies, like dermal irritation and skin irritation tests, were also done.

  5. Real-Time Verification of a High-Dose-Rate Iridium 192 Source Position Using a Modified C-Arm Fluoroscope.

    Science.gov (United States)

    Nose, Takayuki; Chatani, Masashi; Otani, Yuki; Teshima, Teruki; Kumita, Shinichirou

    2017-03-15

    High-dose-rate (HDR) brachytherapy misdeliveries can occur at any institution, and they can cause disastrous results. Even a patient's death has been reported. Misdeliveries could be avoided with real-time verification methods. In 1996, we developed a modified C-arm fluoroscopic verification of an HDR Iridium 192 source position prevent these misdeliveries. This method provided excellent image quality sufficient to detect errors, and it has been in clinical use at our institutions for 20 years. The purpose of the current study is to introduce the mechanisms and validity of our straightforward C-arm fluoroscopic verification method. Conventional X-ray fluoroscopic images are degraded by spurious signals and quantum noise from Iridium 192 photons, which make source verification impractical. To improve image quality, we quadrupled the C-arm fluoroscopic X-ray dose per pulse. The pulse rate was reduced by a factor of 4 to keep the average exposure compliant with Japanese medical regulations. The images were then displayed with quarter-frame rates. Sufficient quality was obtained to enable observation of the source position relative to both the applicators and the anatomy. With this method, 2 errors were detected among 2031 treatment sessions for 370 patients within a 6-year period. With the use of a modified C-arm fluoroscopic verification method, treatment errors that were otherwise overlooked were detected in real time. This method should be given consideration for widespread use. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. A dosimetric study of polyethylene glycol hydrogel in 200 prostate cancer patients treated with high-dose rate brachytherapy±intensity modulated radiation therapy.

    Science.gov (United States)

    Strom, Tobin J; Wilder, Richard B; Fernandez, Daniel C; Mellon, Eric A; Saini, Amarjit S; Hunt, Dylan C; Pow-Sang, Julio M; Spiess, Phillipe E; Sexton, Wade J; Poch, Michael A; Biagioli, Matthew C

    2014-04-01

    We sought to analyze the effect of polyethylene glycol (PEG) hydrogel on rectal doses in prostate cancer patients undergoing radiotherapy. Between July 2009 and April 2013, we treated 200 clinically localized prostate cancer patients with high-dose rate (HDR) brachytherapy±intensity modulated radiation therapy. Half of the patients received a transrectal ultrasound (TRUS)-guided transperineal injection of 10mL PEG hydrogel (DuraSeal™ Spinal Sealant System; Covidien, Mansfield, MA) in their anterior perirectal fat immediately prior to the first HDR brachytherapy treatment and 5mL PEG hydrogel prior to the second HDR brachytherapy treatment. Prostate, rectal, and bladder doses and prostate-rectal distances were calculated based upon treatment planning CT scans. There was a success rate of 100% (100/100) with PEG hydrogel implantation. PEG hydrogel significantly increased the prostate-rectal separation (mean±SD, 12±4mm with gel vs. 4±2mm without gel, phydrogel temporarily displaced the rectum away from the prostate by an average of 12mm and led to a significant reduction in rectal radiation doses, regardless of BMI. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. High dose-rate brachytherapy as a treatment option in primary tracheal tumors Braquiterapia de alta taxa de dose como opção terapêutica nos tumores primários da traquéia

    Directory of Open Access Journals (Sweden)

    Heloisa de Andrade Carvalho

    2005-08-01

    Full Text Available PURPOSE: To present experience with high dose-rate endobronchial brachytherapy in the treatment of primary tracheal tumors. PATIENTS AND METHODS: Four patients with nonresected primary tracheal tumors are presented: 2 cases of squamous cell carcinoma of the trachea, 1 of recurrent adenoid cystic carcinoma, and 1 with recurrent plasmacytoma. All received brachytherapy, alone or as a boost for primary irradiation, in 3 or 4 fractions of 7.5 Gy, calculated at a depth of 1 cm. Follow-up was considered to start from the end of brachytherapy. RESULTS: Local control was achieved in all cases at the time of first bronchoscopic evaluation. Two patients with squamous cell carcinoma died at 6th and 33rd months after brachytherapy, respectively. The first had no evidence of disease, and the latter had local recurrence. The other 2 patients were alive after 64 and 110 months of follow-up, respectively, both with no evidence of disease. Tracheal stenosis developed in these 2 cases, 22 and 69 months after brachytherapy. Tracheal stent placement was needed only for the patient with an adenoid cystic carcinoma. CONCLUSIONS: Endobronchial high dose-rate brachytherapy may be used for tracheal tumors, even as a boost for external beam irradiation, or in recurrences. Local control in 3 out of 4 patients indicates that individual cases may benefit from the treatment. Long-term survival may also be expected, mainly for tumors with adenoid cystic histology.OBJETIVO: Apresentar a experiência do tratamento de 4 pacientes com tumores primários de traquéia, não operados, submetidos à braquiterapia endobrônquica de alta taxa de dose. PACIENTES E MÉTODOS: Dois casos de carcinoma espinocelular, uma recidiva de carcinoma adenóide cístico e uma recidiva de plasmocitoma primário da traquéia. Todos receberam braquiterapia endobrônquica, exclusiva ou como reforço de dose da radioterapia externa. Foram administradas 3 ou 4 frações de 7,5 Gy cada, calculados a 1 cm de

  8. The Curie–Da Vinci Connection: 5-Years' Experience With Laparoscopic (Robot-Assisted) Implantation for High-Dose-Rate Brachytherapy of Solitary T2 Bladder Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Steen-Banasik, Elzbieta M. van der, E-mail: E.vanderSteen-Banasik@radiotherapiegroep.nl [Radiotherapiegroep, Arnhem (Netherlands); Smits, Geert A.H.J. [Department of Urology, Rijnstate Hospital, Arnhem (Netherlands); Oosterveld, Bernard J.; Janssen, Theo; Visser, Andries G. [Radiotherapiegroep, Arnhem (Netherlands)

    2016-08-01

    Purpose: To report experience and early results of laparoscopic implantation for interstitial brachytherapy (BT) of solitary bladder tumors and the feasibility of a high-dose-rate (HDR) schedule. Methods and Materials: From December 2009 to April 2015, 57 patients with a T2 solitary bladder tumor were treated in Arnhem with transurethral bladder resection followed by external beam irradiation, applied to the bladder and regional iliac lymph nodes, 40 Gy in 20 fractions, 5 fractions per week, and within 1 week interstitial HDR BT, in selected cases combined with partial cystectomy and lymph node dissection. The BT catheters were placed via a transabdominal approach with robotic assistance from a Da Vinci robot after a successful initial experience with a nonrobotic laparoscopic approach. The fraction schedule for HDR was 10 fractions of 2.5 Gy, 3 fractions per day. This was calculated to be equivalent to a reference low-dose-rate schedule of 30 Gy in 60 hours. Data for oncologic outcomes and toxicity (Common Toxicity Criteria version 4) were prospectively collected. Results: These modifications resulted in an average postoperative hospitalization of 6 days, minimal blood loss, and no wound healing problems. Two patients had severe acute toxicity: 1 pulmonary embolism grade 4 and 1 cardiac death. Late toxicity was mild (n=2 urogenital grade 3 toxicity). The median follow-up was 2 years. Using cumulative incidence competing risk analysis, the 2-year overall, disease-free, and disease-specific survival and local control rates were 59%, 71%, 87%, and 82%, respectively. Conclusions: The benefits of minimally invasive surgery for implantation of BT catheters and the feasibility of HDR BT in bladder cancer are documented. The patient outcome and adverse events are comparable to the best results published for a bladder-sparing approach.

  9. Single-fraction high-dose-rate brachytherapy and hypofractionated external beam radiation therapy in the treatment of intermediate-risk prostate cancer - long term results.

    Science.gov (United States)

    Cury, Fabio L; Duclos, Marie; Aprikian, Armen; Patrocinio, Horacio; Kassouf, Wassim; Shenouda, George; Faria, Sergio; David, Marc; Souhami, Luis

    2012-03-15

    We present the long-term results of a cohort of patients with intermediate-risk prostate cancer (PC) treated with single-fraction high-dose-rate brachytherapy (HDRB) combined with hypofractionated external beam radiation therapy (HypoRT). Patients were treated exclusively with HDRB and HypoRT. HDRB delivered a dose of 10 Gy to the prostate surface and HypoRT consisted of 50 Gy delivered in 20 daily fractions. The first 121 consecutive patients with a minimum of 2 years posttreatment follow-up were assessed for toxicity and disease control. The median follow-up was 65.2 months. No acute Grade III or higher toxicity was seen. Late Grade II gastrointestinal toxicity was seen in 9 patients (7.4%) and Grade III in 2 (1.6%). Late Grade III genitourinary toxicity was seen in 2 patients (1.6%). After a 24-month follow-up, a rebiopsy was offered to the first 58 consecutively treated patients, and 44 patients agreed with the procedure. Negative biopsies were found in 40 patients (91%). The 5-year biochemical relapse-free survival rate was 90.7% (95% CI, 84.5-96.9%), with 13 patients presenting biochemical failure. Among them, 9 were diagnosed with distant metastasis. Prostate cancer-specific and overall survival rates at 5 years were 100% and 98.8% (95% CI, 96.4-100%), respectively. The combination of HDRB and HypoRT is well tolerated, with acceptable toxicity rates. Furthermore, results from rebiopsies revealed an encouraging rate of local control. These results confirm that the use of conformal RT techniques, adapted to specific biological tumor characteristics, have the potential to improve the therapeutic ratio in intermediate-risk PC patients. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. The impact of body mass index on rectal dose in locally advanced cervical cancer treated with high-dose-rate brachytherapy.

    Science.gov (United States)

    Lim, Jihoon; Durbin-Johnson, Blythe; Valicenti, Richard; Mathai, Matthew; Stern, Robin L; Mayadev, Jyoti

    2013-01-01

    The impact of body mass index (BMI) on rectal dose in brachytherapy for cervical cancer is unknown. We assessed the association of BMI on rectal dose and lower gastrointestinal (GI) toxicity. Between 2007 and 2010, 51 patients with 97 brachytherapy planning images were reviewed. Volumetric measurements of the maximum percentage, mean percentage, dose to 2cc (D2cc), and dose to 1cc (D1cc) of the rectum, and the Internal Commission on Radiation Units and Measurement (ICRU) rectal point were recorded. Linear mixed effect models, analysis of variance, and regression analyses were used to determine the correlation between multiple observations or to detect a difference in the mean. The GI acute and late toxicity were prospectively recorded and retrospectively analyzed. The average BMI (kg/m(2)) was 27.7 with a range of 17.4-46.6. Among the patients, 8% were morbidly obese, 25% obese, 25% overweight, 40% normal weight, and 2% underweight. The mean D1cc, D2cc, mean rectal dose (%), maximum rectal dose (%), and ICRU rectum was 3.03 Gy, 2.78 Gy, 20%, 60%, and 2.99 Gy, respectively. On multivariate analysis, there was a significant decrease in the D1cc and D2cc rectal dose (p=0.016), ICRU rectal point dose (p=0.022), and mean rectal dose percentage (p=0.021) with an increase in BMI. There was, however, no statistically significant relationship between BMI and GI toxicity. Obesity decreases the rectal dose given in high-dose-rate brachytherapy for locally advanced cervical cancer because of an increase in fatty tissue in the recto-uterine space. There is no significant correlation between BMI and acute or late GI toxicity. Published by Elsevier Inc.

  11. Evaluation of a real-time BeO ceramic fiber-coupled luminescence dosimetry system for dose verification of high dose rate brachytherapy.

    Science.gov (United States)

    Santos, Alexandre M Caraça; Mohammadi, Mohammad; Afshar V, Shahraam

    2015-11-01

    The authors evaluate the capability of a beryllium oxide (BeO) ceramic fiber-coupled luminescence dosimeter, named radioluminescence/optically stimulated luminescence (RL/OSL) BeO FOD, for dosimetric verification of high dose rate (HDR) treatments. The RL/OSL BeO FOD is capable of RL and OSL measurements. The RL/OSL BeO FOD is able to be inserted in 6F proguide needles, used in interstitial HDR treatments. Using a custom built Perspex phantom, 6F proguide needles could be submerged in a water tank at 1 cm separations from each other. A second background fiber was required to correct for the stem effect. The stem effect, dose linearity, reproducibility, depth-dose curves, and angular and temperature dependency of the RL/OSL BeO FOD were characterised using an Ir-192 source. The RL/OSL BeO FOD was also applied to the commissioning of a 10 mm horizontal Leipzig applicator. Both the RL and OSL were found to be reproducible and their percentage depth-dose curves to be in good agreement with those predicted via TG-43. A combined uncertainty of 7.9% and 10.1% (k=1) was estimated for the RL and OSL, respectively. For the 10 mm horizontal Leipzig applicator, measured percentage depth doses were within 5% agreement of the published reference calculations. The output at the 3 mm prescription depth for a 1 Gy delivery was verified to be 0.99±0.08 Gy and 1.01±0.10 Gy by the RL and OSL, respectively. The use of the second background fiber under the current setup means that the two fibers cannot fit into a single 6F needle. Hence, use of the RL is currently not adequate for the purpose of in vivo brachytherapy dosimetry. While not real-time, the OSL is shown to be adequate for in vivo brachytherapy dosimetry.

  12. Time-driven activity-based costing of low-dose-rate and high-dose-rate brachytherapy for low-risk prostate cancer.

    Science.gov (United States)

    Ilg, Annette M; Laviana, Aaron A; Kamrava, Mitchell; Veruttipong, Darlene; Steinberg, Michael; Park, Sang-June; Burke, Michael A; Niedzwiecki, Douglas; Kupelian, Patrick A; Saigal, Christopher

    Cost estimates through traditional hospital accounting systems are often arbitrary and ambiguous. We used time-driven activity-based costing (TDABC) to determine the true cost of low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy for prostate cancer and demonstrate opportunities for cost containment at an academic referral center. We implemented TDABC for patients treated with I-125, preplanned LDR and computed tomography based HDR brachytherapy with two implants from initial consultation through 12-month followup. We constructed detailed process maps for provision of both HDR and LDR. Personnel, space, equipment, and material costs of each step were identified and used to derive capacity cost rates, defined as price per minute. Each capacity cost rate was then multiplied by the relevant process time and products were summed to determine total cost of care. The calculated cost to deliver HDR was greater than LDR by $2,668.86 ($9,538 vs. $6,869). The first and second HDR treatment day cost $3,999.67 and $3,955.67, whereas LDR was delivered on one treatment day and cost $3,887.55. The greatest overall cost driver for both LDR and HDR was personnel at 65.6% ($4,506.82) and 67.0% ($6,387.27) of the total cost. After personnel costs, disposable materials contributed the second most for LDR ($1,920.66, 28.0%) and for HDR ($2,295.94, 24.0%). With TDABC, the true costs to deliver LDR and HDR from the health system perspective were derived. Analysis by physicians and hospital administrators regarding the cost of care afforded redesign opportunities including delivering HDR as one implant. Our work underscores the need to assess clinical outcomes to understand the true difference in value between these modalities. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  13. Early observed transient prostate-specific antigen elevations on a pilot study of external beam radiation therapy and fractionated MRI guided High Dose Rate brachytherapy boost

    Directory of Open Access Journals (Sweden)

    Stall Bronwyn R

    2006-08-01

    Full Text Available Abstract Purpose To report early observation of transient PSA elevations on this pilot study of external beam radiation therapy and magnetic resonance imaging (MRI guided high dose rate (HDR brachytherapy boost. Materials and methods Eleven patients with intermediate-risk and high-risk localized prostate cancer received MRI guided HDR brachytherapy (10.5 Gy each fraction before and after a course of external beam radiotherapy (46 Gy. Two patients continued on hormones during follow-up and were censored for this analysis. Four patients discontinued hormone therapy after RT. Five patients did not receive hormones. PSA bounce is defined as a rise in PSA values with a subsequent fall below the nadir value or to below 20% of the maximum PSA level. Six previously published definitions of biochemical failure to distinguish true failure from were tested: definition 1, rise >0.2 ng/mL; definition 2, rise >0.4 ng/mL; definition 3, rise >35% of previous value; definition 4, ASTRO defined guidelines, definition 5 nadir + 2 ng/ml, and definition 6, nadir + 3 ng/ml. Results Median follow-up was 24 months (range 18–36 mo. During follow-up, the incidence of transient PSA elevation was: 55% for definition 1, 44% for definition 2, 55% for definition 3, 33% for definition 4, 11% for definition 5, and 11% for definition 6. Conclusion We observed a substantial incidence of transient elevations in PSA following combined external beam radiation and HDR brachytherapy for prostate cancer. Such elevations seem to be self-limited and should not trigger initiation of salvage therapies. No definition of failure was completely predictive.

  14. Posttraumatic Stress Disorder After High-Dose-Rate Brachytherapy for Cervical Cancer With 2 Fractions in 1 Application Under Spinal/Epidural Anesthesia: Incidence and Risk Factors

    Energy Technology Data Exchange (ETDEWEB)

    Kirchheiner, Kathrin, E-mail: kathrin.kirchheiner@meduniwien.ac.at [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna (Austria); Czajka-Pepl, Agnieszka [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Ponocny-Seliger, Elisabeth [Department of Psychology, Sigmund Freud Private University Vienna, Vienna (Austria); Scharbert, Gisela; Wetzel, Léonore [Department of Anaesthesia, General Intensive Care and Pain Management, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Nout, Remi A. [Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands); Sturdza, Alina [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Dimopoulos, Johannes C. [Metropolitan Hospital, Athens (Greece); Dörr, Wolfgang; Pötter, Richard [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna (Austria)

    2014-06-01

    Purpose: To investigate the psychological consequences of high-dose-rate brachytherapy with 2 fractions in 1 application under spinal/epidural anesthesia in the treatment of locally advanced cervical cancer. Methods and Materials: In 50 patients with locally advanced cervical cancer, validated questionnaires were used for prospective assessment of acute and posttraumatic stress disorder (ASD/PTSD) (Impact of Event Scale–Revision), anxiety/depression (Hospital Anxiety and Depression Scale), quality of life (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30/Cervical Cancer 24), physical functioning (World Health Organization performance status), and pain (visual analogue scale), before and during treatment and 1 week and 3 months after treatment. Qualitative interviews were recorded in open format for content analysis. Results: Symptoms of ASD occurred in 30% of patients 1 week after treatment; and of PTSD in 41% 3 months after treatment in association with this specific brachytherapy procedure. Pretreatment predictive variables explain 82% of the variance of PTSD symptoms. Helpful experiences were the support of the treatment team, psychological support, and a positive attitude. Stressful factors were pain, organizational problems during treatment, and immobility between brachytherapy fractions. Conclusions: The specific brachytherapy procedure, as performed in the investigated mono-institutional setting with 2 fractions in 1 application under spinal/epidural anesthesia, bears a considerable risk of traumatization. The source of stress seems to be not the brachytherapy application itself but the maintenance of the applicator under epidural anesthesia in the time between fractions. Patients at risk may be identified before treatment, to offer targeted psycho-social support. The patients' open reports regarding helpful experiences are an encouraging feedback for the treatment team; the reported stressful

  15. Determination of Prognostic Factors for Vaginal Mucosal Toxicity Associated With Intravaginal High-Dose Rate Brachytherapy in Patients With Endometrial Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bahng, Agnes Y.; Dagan, Avner [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Bruner, Deborah W. [University of Pennsylvania School of Nursing, Philadelphia, PA (United States); Lin, Lilie L., E-mail: lin@xrt.upenn.edu [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States)

    2012-02-01

    Purpose: The objective of this study was to determine the patient- and treatment-related prognostic factors associated with vaginal toxicity in patients who received intravaginal high dose rate (HDR) brachytherapy alone as adjuvant treatment for endometrial cancer. Secondary goals of this study included a quantitative assessment of optimal dilator use frequency and a crude assessment of clinical predictors for compliant dilator use. Methods and Materials: We retrospectively reviewed the charts of 100 patients with histologically confirmed endometrial cancer who underwent total hysterectomy and bilateral salpingo-oophorectomy with or without lymph node dissection and adjuvant intravaginal brachytherapy between 1995 and 2009 at the Hospital of University of Pennsylvania. The most common treatment regimen used was 21 Gy in three fractions (71 patients). Symptoms of vaginal mucosal toxicity were taken from the history and physical exams noted in the patients' charts and were graded according to the Common Toxicity Criteria for Adverse Events v. 4.02. Results: The incidence of Grade 1 or asymptomatic vaginal toxicity was 33% and Grade 2-3 or symptomatic vaginal toxicity was 14%. Multivariate analysis of age, active length, and dilator use two to three times a week revealed odds ratios of 0.93 (p = 0.013), 3.96 (p = 0.008), and 0.17 (p = 0.032) respectively. Conclusion: Increasing age, vaginal dilator use of at least two to three times a week, and shorter active length were found to be significantly associated with a decreased risk of vaginal stenosis. Future prospective studies are necessary to validate our findings.

  16. Favorable Preliminary Outcomes for Men With Low- and Intermediate-risk Prostate Cancer Treated With 19-Gy Single-fraction High-dose-rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, Daniel J., E-mail: dkrauss@beaumont.edu [Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States); Ye, Hong [Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States); Martinez, Alvaro A. [21st Century Oncology, Farmington Hills, Michigan (United States); Mitchell, Beth; Sebastian, Evelyn; Limbacher, Amy; Gustafson, Gary S. [Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States)

    2017-01-01

    Purpose: To report the toxicity and preliminary clinical outcomes of a prospective trial evaluating 19-Gy, single-fraction high-dose-rate (HDR) brachytherapy for men with low- and intermediate-risk prostate cancer. Methods and Materials: A total of 63 patients were treated according to an institutional review board-approved prospective study of single-fraction HDR brachytherapy. Eligible patients had tumor stage ≤T2a, prostate-specific antigen level ≤15 ng/mL, and Gleason score ≤7. Patients with a prostate gland volume >50 cm{sup 3} and baseline American Urologic Association symptom score >12 were ineligible. Patients underwent transrectal ultrasound-guided transperineal implantation of the prostate, followed by single-fraction HDR brachytherapy. Treatment was delivered using {sup 192}Ir to a dose of 19 Gy prescribed to the prostate, with no additional margin applied. Results: Of the 63 patients, 58 had data available for analysis. Five patients had withdrawn consent during the follow-up period. The median follow-up period was 2.9 years (range 0.3-5.2). The median age was 61.4 years. The median gland volume at treatment was 34.8 cm{sup 3}. Of the 58 patients, 91% had T1 disease, 71% had Gleason score ≤6 (29% with Gleason score 7), and the median pretreatment prostate-specific antigen level was 5.1 ng/mL. The acute and chronic grade 2 genitourinary toxicity incidence was 12.1% and 10.3%, respectively. No grade 3 urinary toxicity occurred. No patients experienced acute rectal toxicity grade ≥2, and 2 experienced grade ≥2 chronic gastrointestinal toxicity. Three patients experienced biochemical failure, yielding a 3-year cumulative incidence estimate of 6.8%. Conclusions: Single-fraction HDR brachytherapy is well-tolerated, with favorable preliminary biochemical and clinical disease control rates.

  17. Tandem-ring dwell time ratio in Nigeria: dose comparisons of two loading patterns in standard high-dose-rate brachytherapy planning for cervical cancer.

    Science.gov (United States)

    Ibhade, Obed Rachel; Oyeyemi, Oyekunle Emmanuel; Idayat, Akinlade Bidemi; Atara I, Ntekim

    2015-04-01

    In high-dose-rate (HDR) brachytherapy (BT), the source dwell times and dwell positions are essential treatment planning parameters. An optimal choice of these factors is fundamental to obtain the desired target coverage with the lowest achievable dose to the organs at risk (OARs). This study evaluates relevant dose parameters in cervix brachytherapy in order to assess existing tandem-ring dwell time ratio used at the first HDR BT center in Nigeria, and compare it with an alternative source loading pattern. At the Radiotherapy Department, University College Hospital (UCH), Ibadan, Nigeria, a total of 370 standard treatment plans in two alternative sets were generated with HDR basic 2.6 software for one hundred and eighty five cervical cancer patients. The initial 185 individual plans were created for clinical treatment using the tandem-ring dwell time ratio of 1 : 1. Modifying the initial applicator loading ratio, the second set of plans with related dose data were also obtained for study purposes only. Total reference air kerma (TRAK), total time index (TTI), ICRU volume, treatment time, point B dose, ICRU bladder dose, and rectal points dose were evaluated for both sets of plans. The means of all evaluated dose parameters decreased when the existing tandem-ring dwell time ratio (1 : 1) was modified to other dwell weightings (1 : 1 - 3 : 1). These reductions were 13.43% (ICRU volume), 9.83% (rectal dose), 6.68% (point B dose), 6.08% (treatment time), 5.90% (TRAK), 5.88% (TTI), and 1.08% (bladder dose). Correspondingly, coefficients of variation changed by -7.98%, -5.02%, -5.23%, -4.20%, -3.93%, 8.65%, and 3.96% from the existing pattern to the alternative one. Tandem-ring dwell time ratio has significant influence on dosimetric parameters. This study has indicated the need to modify the existing planning approach at UCH.

  18. High-dose-rate brachytherapy with or without intensity modulated radiation therapy as salvage treatment for an isolated, gross local recurrence of prostate cancer post-prostatectomy.

    Science.gov (United States)

    Strom, Tobin J; Wilder, Richard B; Fernandez, Daniel C; Mellon, Eric A; Saini, Amarjit S; Hunt, Dylan C; Biagioli, Matthew C

    2014-01-01

    To evaluate the use of high-dose-rate (HDR) brachytherapy ± intensity modulated radiation therapy (IMRT) as salvage therapy for patients with an isolated, gross local recurrence of prostate cancer after radical prostatectomy. Between October 2009 and May 2013, the authors treated six patients with salvage iridium-192 HDR brachytherapy ± IMRT for biopsy-proven, recurrent prostate cancer post-prostatectomy. In each patient, a pelvic MRI scan or CT scan demonstrated a nodule (range 1.6, 4.7 cm) in the prostate bed. Although prostate-specific antigen values were 0.2-9.5 ng/mL at the time of salvage brachytherapy, there was no pelvic adenopathy on CT or MRI scan, and a bone scan was negative in all cases. Five patients were treated with IMRT to 4500-5040 cGy in 25-28 fractions to the prostate bed followed by two 950 cGy HDR brachytherapy fractions separated by 1-2 weeks. A sixth patient underwent HDR brachytherapy monotherapy consisting of 3800 cGy in four fractions over 3 days. Toxicities were graded according to the Common Terminology Criteria for Adverse Events, version 4.0. Median followup was 9 months (range 3, 40 months). All six patients have been free of androgen deprivation therapy and have an undetectable prostate-specific antigen. One patient developed late Grade 2 urinary incontinence. There was no late grade ≥2 gastrointestinal toxicity. HDR brachytherapy ± IMRT is a safe and effective salvage therapy option for an isolated, gross local recurrence of prostate cancer after radical prostatectomy and merits further study. Copyright © 2014. Published by Elsevier Inc.

  19. Image-guided high-dose-rate brachytherapy boost to the dominant intraprostatic lesion using multiparametric magnetic resonance imaging including spectroscopy: Results of a prospective study.

    Science.gov (United States)

    Vigneault, Eric; Mbodji, Khaly; Racine, Louis-Gabriel; Chevrette, Eric; Lavallée, Marie-Claude; Martin, André-Guy; Després, Philippe; Beaulieu, Luc

    To evaluate the long-term outcomes of image-guided high-dose-rate (HDR) brachytherapy boost to the dominant intraprostatic lesion (DIL) using multiparametric magnetic resonance imaging (MRI), including spectroscopy (MRI/magnetic resonance spectroscopy [MRS]). Between December 2009 and March 2011, 20 patients with intermediate-risk prostate cancer underwent multiparametric MRI/MRS protocol before treatment. All patients were treated with an external beam radiotherapy dose of 40 Gy, combined with an HDR brachytherapy boost of 15 Gy. Concurrently, the DIL received a boost of 18 Gy. Missing data during followup were handled with multiple imputations. The median followup was 62 months (range, 23-71 months). Six patients (31%) were classified as favorable intermediate risk and 13 patients (69%) as unfavorable intermediate risk. One patient experienced a prostate-specific antigen biochemical failure, and the 5-year biochemical failure-free survival rate was of 94.7%. The mean International Prostate Symptom Score rose from 7, with respect to baseline, to 10.42 1 month after treatment, and rapidly decreased to 6.97 after 3 months. Grade 1, 2, and 3 acute genitourinary toxicities were reported in 13 (68%), 3 (16%), and 1 (5%) patients, respectively. Grade 1 and 2 late genitourinary toxicities were reported in 9 (53%) and 3 (18%) patients, respectively. Only grade 1 acute and late gastrointestinal toxicities were reported in 4 (21%) and 3 (18%) patients, respectively. Delivering an HDR brachytherapy boost to the DIL using image-guided multiparametric MRI/MRS is feasible with good outcomes for biochemical control, acute and late toxicities, and dosimetric constraints for critical organs. Copyright © 2016 American Brachytherapy Society. All rights reserved.

  20. A quantitative analysis of two-dimensional manually segmented transrectal ultrasound axial images in planning high dose rate brachytherapy for prostate cancer

    Directory of Open Access Journals (Sweden)

    Dabić-Stanković Kata

    2017-01-01

    Full Text Available Background/Aim. Prostate delineation, pre-planning and catheter implantation procedures, in high-dose rate brachytherapy (HDR-BT, are commonly based on the prostate manually segmented transrectal ultrasound (TRUS images. The aim of this study was to quantitatively analyze the consistency of prostate capsule delineation, done by a single therapist, prior to each HDR-BT fraction and the changes in the shape of the prostate capsule during HDR-BT, using two dimensional (2D TRUS axial image. Methods. A group of 16 patients were treated at the Medical System Belgrade Brachytherapy Department with definitive HDRBT. The total applied median dose of 52 Gy was divided into four individual fractions, each fraction being delivered 2– 3 weeks apart. Real time prostate axial visualization and the manual segmentation prior to each fraction were performed using B-K Medical ultrasound. Quantitative analyses, analysis of an area and shape were applied on 2D-TRUS axial images of the prostate. Area analyses were used to calculate the average value of the cross-sectional area of the prostate image. The parameters of the prostate shape, the fractal dimension and the circularity ratio of the prostate capsule contour were estimated at the maximum axial cross section of the prostate image. Results. The sample group consisted of four phases, each phase being performed prior to the first, second, third and fourth HDR-BT fraction, respectively. Statistical analysis showed that during HDR-BT fractions there were no significant differences in the average value of area, as well as in the maximum shape of prostate capsule. Conclusions. Quantitative analysis of TRUS axial prostate segmented images shows a successful capsule delineation in the series of manually segmented TRUS images, and the prostate maximum shape remaining unchanged during HDR-BT fractions.

  1. Dose comparison between TG-43-based calculations and radiochromic film measurements of the Freiburg flap applicator used for high-dose-rate brachytherapy treatments of skin lesions.

    Science.gov (United States)

    Aldelaijan, Saad; Bekerat, Hamed; Buzurovic, Ivan; Devlin, Phillip; DeBlois, Francois; Seuntjens, Jan; Devic, Slobodan

    Current high-dose-rate brachytherapy skin treatments with the Freiburg flap (FF) applicator are planned with treatment planning systems based on the American Association of Physicists in Medicine TG-43 data sets, which assume full backscatter conditions in dose calculations. The aim of this work is to describe an experimental method based on radiochromic film dosimetry to evaluate dose calculation accuracy during surface treatments with the FF applicator at different depths and bolus thicknesses. Absolute doses were measured using a reference EBT3 radiochromic film dosimetry system within a Solid Water phantom at different depths (0, 0.5, 1, 2, and 3 cm) with respect to the phantom surface. The impact of bolus (up to 3-cm thickness) placed on top of the applicator was investigated for two clinical loadings created using Oncentra MasterPlan: 5 cm × 5 cm and 11 cm × 11 cm. For smaller loading and depths beyond 2 cm and for larger loading and depths beyond 1 cm, the dose difference was less than 3% (±4%). At shallower depths, differences of up to 6% (±4%) at the surface were observed if no bolus was added. The addition of 2-cm bolus for the smaller loading and 1 cm for larger loading minimized the difference to less than 3% (±4%). For typical FF applicator loading sizes, the actual measured dose was 6% (±4%) lower at the skin level when compared with TG-43. Additional bolus above the FF was shown to decrease the dose difference. The consideration of change in clinical practice should be carefully investigated in light of clinical reference data. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  2. SU-F-T-65: AutomaticTreatment Planning for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: High dose rate (HDR) brachytherapy treatment planning is conventionally performed in a manual fashion. Yet it is highly desirable to perform computerized automated planning to improve treatment planning efficiency, eliminate human errors, and reduce plan quality variation. The goal of this research is to develop an automatic treatment planning tool for HDR brachytherapy with a cylinder applicator for vaginal cancer. Methods: After inserting the cylinder applicator into the patient, a CT scan was acquired and was loaded to an in-house developed treatment planning software. The cylinder applicator was automatically segmented using image-processing techniques. CTV was generated based on user-specified treatment depth and length. Locations of relevant points (apex point, prescription point, and vaginal surface point), central applicator channel coordinates, and dwell positions were determined according to their geometric relations with the applicator. Dwell time was computed through an inverse optimization process. The planning information was written into DICOM-RT plan and structure files to transfer the automatically generated plan to a commercial treatment planning system for plan verification and delivery. Results: We have tested the system retrospectively in nine patients treated with vaginal cylinder applicator. These cases were selected with different treatment prescriptions, lengths, depths, and cylinder diameters to represent a large patient population. Our system was able to generate treatment plans for these cases with clinically acceptable quality. Computation time varied from 3–6 min. Conclusion: We have developed a system to perform automated treatment planning for HDR brachytherapy with a cylinder applicator. Such a novel system has greatly improved treatment planning efficiency and reduced plan quality variation. It also served as a testbed to demonstrate the feasibility of automatic HDR treatment planning for more complicated cases.

  3. Phase II Trial of Combined High Dose Rate Brachytherapy and External Beam Radiotherapy for Adenocarcinoma of the Prostate: Preliminary Results of RTOG 0321

    Science.gov (United States)

    Hsu, I-Chow; Bae, Kyounghwa; Shinohara, Katsuto; Pouliot, Jean; Purdy, James; Ibbott, Geoffrey; Speight, Joycelyn; Vigneault, Eric; Ivker, Robert; Sandler, Howard

    2010-01-01

    Purpose To estimate the rate of late grade 3 or greater genitourinary (GU) and gastrointestinal (GI) adverse events (AEs) following treatment with external beam radiation therapy and prostate high dose rate (HDR) brachytherapy. Methods and Materials Each participating institution submitted CT based HDR brachytherapy dosimetry data electronically for credentialing and for each study patient. Patients with locally confined T1c-T3b prostate cancer were eligible for this study. All patients were treated with 45 Gy in 25 fractions from external beam radiotherapy and one HDR implant delivering 19 Gy in 2 fractions. All AEs were graded according to CTCAEv3.0. Late GU/ GI AEs were defined as those occurring more than nine months from the start of the protocol treatment, in patients with at least 18 months of potential follow-up. Results A total of 129 patients from 14 institutions were enrolled in this study. 125 patients were eligible and AE data was available for 112 patients. The pretreatment characteristics of the patients were as follows: T1c-T2c 91%, T3a-T3b 9%, PSA ≤ 10 70%, PSA >10-≤20 30%, GS 2-6 10%, GS 7 72%, and GS 8-10 18%. At a median follow-up time of 29.6 months, 3 acute and 4 late grade 3 GU/GI AEs were reported. The estimated rate of late grade 3-5 GU and GI AE at 18 months was 2.56%. Conclusion This is the first prospective, multi-institutional trial of CT based HDR brachytherapy and external beam radiotherapy. The technique and doses used in this study resulted in acceptable levels of adverse events. PMID:20207506

  4. Dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with high-dose-rate brachytherapy for large prostate volumes

    Energy Technology Data Exchange (ETDEWEB)

    Yang, George; Strom, Tobin J.; Shrinath, Kushagra; Mellon, Eric A.; Fernandez, Daniel C.; Biagioli, Matthew C. [Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL (United States); Wilder, Richard B., E-mail: mcbiagioli@yahoo.com [Cancer Treatment Centers of America, Newnan, GA (United States)

    2015-05-15

    Purpose: to evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with HDR brachytherapy for large prostate volumes. Materials and methods: one hundred and two prostate cancer patients with prostate volumes >50 mL (range: 5-29 mL) were treated with high-dose-rate (HDR) brachytherapy ± intensity modulated radiation therapy (IMRT) to 4,500 cGy in 25 daily fractions between 2009 and 2013. HDR brachytherapy monotherapy doses consisted of two 1,350-1,400 cGy fractions separated by 2-3 weeks, and HDR brachytherapy boost doses consisted of two 950-1,150 cGy fractions separated by 4 weeks. Twelve of 32 (38%) unfavorable intermediate risk, high risk, and very high risk patients received androgen deprivation therapy. Acute toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4. Results: median follow-up was 14 months. Dosimetric goals were achieved in over 90% of cases. Three of 102 (3%) patients developed Grade 2 acute proctitis. No variables were significantly associated with Grade 2 acute proctitis. Seventeen of 102 (17%) patients developed Grade 2 acute urinary retention. American Urological Association (AUA) symptom score was the only variable significantly associated with Grade 2 acute urinary retention (p-0.04). There was no ≥ Grade 3 acute toxicity. Conclusions: dosimetric coverage of the prostate and normal tissue sparing were adequate in patients with prostate volumes >50 mL. Higher pre-treatment AUA symptom scores increased the relative risk of Grade 2 acute urinary retention. However, the overall incidence of acute toxicity was acceptable in patients with large prostate volumes. (author)

  5. Updated results of high-dose rate brachytherapy and external beam radiotherapy for locally and locally advanced prostate cancer using the RTOG-ASTRO phoenix definition

    Directory of Open Access Journals (Sweden)

    Antonio C. Pellizzon

    2008-06-01

    Full Text Available PURPOSE: To evaluate the prognostic factors for patients with local or locally advanced prostate cancer treated with external beam radiotherapy (RT and high dose rate brachytherapy (HDR according to the RTOG-ASTRO Phoenix Consensus Conference. MATERIALS AND METHODS: The charts of 209 patients treated between 1997 and 2005 with localized RT and HDR as a boost at the Department of Radiation Oncology, AC Camargo Hospital, Sao Paulo, Brazil were reviewed. Clinical and treatment parameters i.e.: patient's age, Gleason score, clinical stage, initial PSA (iPSA, risk group (RG for biochemical failure, doses of RT and HDR were evaluated. Median age and median follow-up time were 68 and 5.3 years, respectively. Median RT and HDR doses were 45 Gy and 20 Gy. RESULTS: Disease specific survival (DSS at 3.3 year was 94.2%. Regarding RG, for the LR (low risk, IR (intermediate risk and HR (high risk, the DSS rates at 3.3 years were 91.5%, 90.2% and 88.5%, respectively. On univariate analysis prognostic factors related to DSS were RG (p = 0.040, Gleason score ≤ 6 ng/mL (p = 0.002, total dose of HDR ≥ 20 Gy (p < 0.001 On multivariate analysis the only statistical significant predictive factor for biochemical control (bNED was the RG, p < 0.001 (CI - 1.147-3.561. CONCLUSIONS: Although the radiation dose administered to the prostate is an important factor related to bNED, this could not be established with statistical significance in this group of patients. To date , in our own experience, HDR associated to RT could be considered a successful approach in the treatment of prostate cancer.

  6. SU-G-TeP2-10: Feasibility of Newly Designed Applicator for High Dose Rate Brachytherapy Treatment of Patients with Vaginal Vault Recurrence

    Energy Technology Data Exchange (ETDEWEB)

    Lee, V; Wong, M; Chan, M; Cheung, S; Leung, R; Lee, K; Law, G; Tung, S [Tuen Mun Hospital (Hong Kong); Huang, X; Chui, E; Leung, K [The Chinese University of Hong Kong (Hong Kong); Kwong, D [The University of Hong Kong (Hong Kong)

    2016-06-15

    Purpose: To compare the dose of an in-house 3D-printed gynecology applicator (TMHGA) for vaginal vault recurrence of corpus cancer patients after operation for high dose rate brachytherapy treatment with commercially available applicators. Methods: A newly designed applicator is made from 3D-printing methods using ABSM30i. The isodose of the applicator is compared with Elekta multi-channel (MC) applicator and titanium Rotterdam applicator with coupling central tube and vaginal cylinder (RC). Three plans are created using three applicators in a CT set of water phantom. The applicators are anchored using the applicator library and implant library in the Elekta Oncentra treatment planning system (ver.4.5). The rectum is mimicked by creating a 2cm diameter cylinder, with a distance 1mm posteriorly away from the high risk CTV (HR-CTV). Similarly, the bladder is replicated by a 6cm diameter cylinder with distance 1mm anteriorly from the HR-CTV. Three plans are all normalized 1.5cm superior, 0.5cm anterior and 0.5cm posterior of the applicator surface. By fixing D90 of HR-CTV to 6Gy, the D2cc of rectum and bladder of three plans are compared. Results: The D2cc of the bladder for using TMHGA is lower than MC and RC by 14.0% and 11.9% respectively. While the D2cc of the rectum for using TMHGA is lower than MC and RC by 18.9% and 12.4% respectively. The total treatment time of TMHGA plan is shorter than MC and RC by 11.2% and 12.9%. Conclusion: The applicator created via 3D printing delivers a lower dose to the bladder and the rectum while keeping the same coverage to HR-CTV as other commercially available applicators. Additionally, the new applicator resulted in a reduction of treatment time, which is always welcome.

  7. High-Dose-Rate Brachytherapy and External-Beam Radiotherapy for Hormone-Naieve Low- and Intermediate-Risk Prostate Cancer: A 7-Year Experience

    Energy Technology Data Exchange (ETDEWEB)

    Aluwini, Shafak, E-mail: s.aluwini@erasmusmc.nl [Department of Radiation Oncology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Rooij, Peter H. van [Department of Radiation Oncology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Kirkels, Wim J. [Department of Urology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Jansen, Peter P.; Praag, John O. [Department of Radiation Oncology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Bangma, Chris H. [Department of Urology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Kolkman-Deurloo, Inger-Karine K. [Department of Radiation Oncology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

    2012-08-01

    Purpose: To report clinical outcomes and early and late complications in 264 hormone-naieve patients with low- and intermediate-risk prostate cancer treated with high-dose-rate brachytherapy (HDR-BT) in combination with external-beam radiotherapy (EBRT). Methods and Materials: Between February 2000 and July 2007, 264 patients underwent HDR-BT in combination with EBRT as a treatment for their low- to intermediate-risk prostate cancer. The HDR-BT was performed using ultrasound-based implantation. The total HDR-BT dose was 18 Gy in 3 fractions within 24 h, with a 6-h minimum interval. The EBRT started 2 weeks after HDR-BT and was delivered in 25 fractions of 1.8 Gy to 45 Gy within 5 weeks. Results: After a mean follow-up of 74.5 months, 4 patients (1.5%) showed prostate-specific antigen progression according to the American Society for Radiation Oncology definition and 8 patients (3%) according to the Phoenix definition. A biopsy-proven local recurrence was registered in 1 patient (0.4%), and clinical progression (bone metastases) was documented in 2 patients (0.7%). Seven-year actuarial freedom from biochemical failure was 97%, and 7-year disease-specific survival and overall survival were 100% and 91%, respectively. Toxicities were comparable to other series. Conclusions: Treatment with interstitial HDR-BT plus EBRT shows a low incidence of late complications and a favorable oncologic outcome after 7 years follow-up.

  8. High-dose-rate brachytherapy and external-beam radiotherapy for hormone-naïve low- and intermediate-risk prostate cancer: a 7-year experience.

    Science.gov (United States)

    Aluwini, Shafak; van Rooij, Peter H; Kirkels, Wim J; Jansen, Peter P; Praag, John O; Bangma, Chris H; Kolkman-Deurloo, Inger-Karine K

    2012-08-01

    To report clinical outcomes and early and late complications in 264 hormone-naïve patients with low- and intermediate-risk prostate cancer treated with high-dose-rate brachytherapy (HDR-BT) in combination with external-beam radiotherapy (EBRT). Between February 2000 and July 2007, 264 patients underwent HDR-BT in combination with EBRT as a treatment for their low- to intermediate-risk prostate cancer. The HDR-BT was performed using ultrasound-based implantation. The total HDR-BT dose was 18 Gy in 3 fractions within 24 h, with a 6-h minimum interval. The EBRT started 2 weeks after HDR-BT and was delivered in 25 fractions of 1.8 Gy to 45 Gy within 5 weeks. After a mean follow-up of 74.5 months, 4 patients (1.5%) showed prostate-specific antigen progression according to the American Society for Radiation Oncology definition and 8 patients (3%) according to the Phoenix definition. A biopsy-proven local recurrence was registered in 1 patient (0.4%), and clinical progression (bone metastases) was documented in 2 patients (0.7%). Seven-year actuarial freedom from biochemical failure was 97%, and 7-year disease-specific survival and overall survival were 100% and 91%, respectively. Toxicities were comparable to other series. Treatment with interstitial HDR-BT plus EBRT shows a low incidence of late complications and a favorable oncologic outcome after 7 years follow-up. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Outcomes of salvage high-dose-rate brachytherapy with or without external beam radiotherapy for isolated vaginal recurrence of endometrial cancer

    Directory of Open Access Journals (Sweden)

    Shuhei Sekii

    2017-05-01

    Full Text Available Purpose: This study was designed to retrospectively analyze outcomes of high-dose-rate (HDR brachytherapy, with or without external beam radiotherapy (EBRT, in patients with vaginal recurrence of endometrial carcinoma, and to identify factors prognostic of patient outcomes. Material and methods : The medical records of all patients who underwent HDR brachytherapy for initial recurrence in the vagina of endometrial cancer after definitive surgery between 1992 and 2014 were retrospectively reviewed. All patients underwent either intracavitary brachytherapy (ICBT or interstitial brachytherapy (ISBT with or without EBRT. Late toxicity was graded using the EORTC (LENT/SOMA scale, revised in 1995. Results : Thirty-seven patients were identified. The median follow-up time was 48 months (range: 6-225 months. Of these 37 patients, 23 underwent ICBT, 14 underwent ISBT, and 26 underwent EBRT. Tumor size at first examination of initial relapse was significantly larger in the ISBT than in the ICBT group. The 4-year respective overall survival (OS, local control (LC, and progression-free survival (PFS rates in the entire cohort were 81.0%, 77.9%, and 56.8%, respectively. The interval between diagnosis of first recurrence and radiotherapy (< 3 months, ≥ 3 months was a significant predictor of LC and PFS. OS and LC rates did not differ significantly in the ICBT and ISBT groups. Two patients experienced grade 2 rectal bleeding, and four experienced grade 2 hematuria. No grade 3 or higher late complications were observed. Conclusions : Salvage HDR brachytherapy is an optimal for treating vaginal recurrence of endometrial carcinoma with acceptable morbidity. Early radiotherapy, including brachytherapy, should be considered for women who experience vaginal recurrence of endometrial cancer.

  10. SU-E-J-93: Parametrisation of Dose to the Mucosa of the Anterior Rectal Wall in Transrectal Ultrasound Guided High-Dose-Rate Brachytherapy of the Prostate

    Energy Technology Data Exchange (ETDEWEB)

    Aitkenhead, A; Hamlett, L; Wood, D; Choudhury, A [The Christie Hospital NHS Foundation Trust, Manchester, Greater Manchester (United Kingdom)

    2014-06-01

    Purpose: In high-dose-rate (HDR) brachytherapy of the prostate, radiation is delivered from a number of radioactive sources which are inserted via catheter into the target volume. The rectal mucosa also receives dose during the treatment, which may lead to late toxicity effects. To allow possible links between rectal dose and toxicity to be investigated, suitable methods of parametrising the rectal dose are needed. Methods: During treatment of a series of 95 patients, anatomy and catheter locations were monitored by transrectal ultrasound, and target volume positions were contoured on the ultrasound scan by the therapist. The anterior rectal mucosal wall was identified by contouring the transrectal ultrasound balloon within the ultrasound scan. Source positions and dwell times, along with the dose delivered to the patient were computed using the Oncentra Prostate treatment planning system (TPS). Data for the series of patients were exported from the TPS in Dicom format, and a series of parametrisation methods were developed in a Matlab environment to assess the rectal dose. Results: Contours of the anterior rectal mucosa were voxelised within Matlab to allow the dose to the rectal mucosa to be analysed directly from the 3D dose grid. Dose parametrisations based on dose-surface (DSH) and dose-line (DLH) histograms were obtained. Both lateral and longitudinal extents of the mucosal dose were parametrised using dose-line histograms in the relevant directions. Conclusion: We have developed a series of dose parametrisations for quantifying the dose to the rectal mucosa during HDR prostate brachytherapy which are suitable for future studies investigating potential associations between mucosal dose and late toxicity effects. The geometry of the transrectal probe standardises the rectal anatomy, making this treatment technique particularly suited to studies of this nature.

  11. Physiological Interaction of Heart and Lung in Thoracic Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ghobadi, Ghazaleh; Veen, Sonja van der [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Bartelds, Beatrijs [Center for Congenital Heart Disease, Beatrix Children Hospital, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Boer, Rudolf A. de [Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Dickinson, Michael G. [Center for Congenital Heart Disease, Beatrix Children Hospital, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Jong, Johan R. de [Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Faber, Hette; Niemantsverdriet, Maarten [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Brandenburg, Sytze [Kernfysisch Versneller Instituut, University of Groningen, Groningen (Netherlands); Berger, Rolf M.F. [Center for Congenital Heart Disease, Beatrix Children Hospital, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Coppes, Robert P. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Luijk, Peter van, E-mail: p.van.luijk@umcg.nl [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)

    2012-12-01

    Introduction: The risk of early radiation-induced lung toxicity (RILT) limits the dose and efficacy of radiation therapy of thoracic tumors. In addition to lung dose, coirradiation of the heart is a known risk factor in the development RILT. The aim of this study was to identify the underlying physiology of the interaction between lung and heart in thoracic irradiation. Methods and Materials: Rat hearts, lungs, or both were irradiated to 20 Gy using high-precision proton beams. Cardiopulmonary performance was assessed using breathing rate measurements and F{sup 18}-fluorodeoxyglucose positron emission tomography ({sup 18}F-FDG-PET) scans biweekly and left- and right-sided cardiac hemodynamic measurements and histopathology analysis at 8 weeks postirradiation. Results: Two to 12 weeks after heart irradiation, a pronounced defect in the uptake of {sup 18}F-FDG in the left ventricle (LV) was observed. At 8 weeks postirradiation, this coincided with LV perivascular fibrosis, an increase in LV end-diastolic pressure, and pulmonary edema in the shielded lungs. Lung irradiation alone not only increased pulmonary artery pressure and perivascular edema but also induced an increased LV relaxation time. Combined irradiation of lung and heart induced pronounced increases in LV end-diastolic pressure and relaxation time, in addition to an increase in right ventricle end-diastolic pressure, indicative of biventricular diastolic dysfunction. Moreover, enhanced pulmonary edema, inflammation and fibrosis were also observed. Conclusions: Both lung and heart irradiation cause cardiac and pulmonary toxicity via different mechanisms. Thus, when combined, the loss of cardiopulmonary performance is intensified further, explaining the deleterious effects of heart and lung coirradiation. Our findings show for the first time the physiological mechanism underlying the development of a multiorgan complication, RILT. Reduction of dose to either of these organs offers new opportunities to

  12. Metal stent and endoluminal high-dose rate [sup 192]iridium brachytherapy in palliative treatment of malignant biliary tract obstruction. First experiences. Metallgeflecht-Endoprothese und intraluminare High-dose-rate-[sup 192]Iridium-Brachytherapie zur palliativen Behandlung maligner Gallengangsobstruktionen. Erste Erfahrungen

    Energy Technology Data Exchange (ETDEWEB)

    Pakisch, B.; Stuecklschweiger, G.; Poier, E.; Leitner, H.; Poschauko, J.; Hackl, A. (Universitaets-Klinik fuer Radiologie, Abt. fuer Strahlentherapie, Graz (Austria)); Klein, G.E.; Lammer, J.; Hausegger, K.A. (Universitaets-Klinik fuer Radiologie, Abt. fuer Spezielle Roentgendiagnostik und Digitale Bilddiagnostische Verfahren, Graz (Austria))

    1992-06-01

    Since December 1989, 9 patients with inoperable malignant biliary tract obstruction were treated palliatively by a combined modality treatment consisting of placement of a permanent biliary endoprosthesis followed by intraluminal high dose-rate [sup 192]Ir brachytherapy. A dose of 10 Gy was delivered in a hyperfractionated schedule at the point of reference in a distance of 7.5 mm of centre of the source. External small field radiotherapy (50.4 Gy, 1.8 Gy per day, 5 fractions per week) was also given in six cases (M/O, Karnofsky >60%). In 9/9 cases an unrestrained bile flow and an interruption of pruritus was achieved, in 78% (7/9) of cases the duration of palliation was as long as the survival time (median survival time 7.5 months). (orig.).

  13. A Novel Form of Breast Intraoperative Radiation Therapy With CT-Guided High-Dose-Rate Brachytherapy: Results of a Prospective Phase 1 Clinical Trial

    Energy Technology Data Exchange (ETDEWEB)

    Showalter, Shayna L., E-mail: snl2t@virginia.edu [Division of Surgical Oncology, Department of Surgery, University of Virginia School of Medicine, Charlottesville, Virginia (United States); Petroni, Gina [Division of Translation Research and Applied Statistics, Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, Virginia (United States); Trifiletti, Daniel M.; Libby, Bruce [Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Virginia (United States); Schroen, Anneke T.; Brenin, David R. [Division of Surgical Oncology, Department of Surgery, University of Virginia School of Medicine, Charlottesville, Virginia (United States); Dalal, Parchayi [Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Virginia (United States); Smolkin, Mark [Division of Translation Research and Applied Statistics, Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, Virginia (United States); Reardon, Kelli A.; Showalter, Timothy N. [Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Virginia (United States)

    2016-09-01

    Purpose: Existing intraoperative radiation therapy (IORT) techniques are criticized for the lack of image guided treatment planning and energy deposition with, at times, poor resultant dosimetry and low radiation dose. We pioneered a novel method of IORT that incorporates customized, computed tomography (CT)-based treatment planning and high-dose-rate (HDR) brachytherapy to overcome these drawbacks: CT-HDR-IORT. Methods and Materials: A phase 1 study was conducted to demonstrate the feasibility and safety of CT-HDR-IORT. Eligibility criteria included age ≥50 years, invasive or in situ breast cancer, tumor size <3 cm, and N0 disease. Patients were eligible before or within 30 days of breast-conserving surgery (BCS). BCS was performed, and a multilumen balloon catheter was placed. CT images were obtained, a customized HDR brachytherapy plan was created, and a dose of 12.5 Gy was delivered to 1-cm depth from the balloon surface. The catheter was removed, and the skin was closed. The primary endpoints were feasibility and acute toxicity. Feasibility was defined as IORT treatment interval (time from CT acquisition until IORT completion) ≤90 minutes. The secondary endpoints included dosimetry, cosmetic outcome, quality of life, and late toxicity. Results: Twenty-eight patients were enrolled. The 6-month follow-up assessments were completed by 93% of enrollees. The median IORT treatment interval was 67.2 minutes (range, 50-108 minutes). The treatment met feasibility criteria in 26 women (93%). The dosimetric goals were met in 22 patients (79%). There were no Radiation Therapy Oncology Group grade 3+ toxicities; 6 patients (21%) experienced grade 2 events. Most patients (93%) had good/excellent cosmetic outcomes at the last follow-up visit. Conclusions: CT-HDR-IORT is feasible and safe. This promising approach for a conformal, image-based, higher-dose breast IORT is being evaluated in a phase 2 trial.

  14. A fast inverse treatment planning strategy facilitating optimized catheter selection in image-guided high-dose-rate interstitial gynecologic brachytherapy.

    Science.gov (United States)

    Guthier, Christian V; Damato, Antonio L; Hesser, Juergen W; Viswanathan, Akila N; Cormack, Robert A

    2017-12-01

    Interstitial high-dose rate (HDR) brachytherapy is an important therapeutic strategy for the treatment of locally advanced gynecologic (GYN) cancers. The outcome of this therapy is determined by the quality of dose distribution achieved. This paper focuses on a novel yet simple heuristic for catheter selection for GYN HDR brachytherapy and their comparison against state of the art optimization strategies. The proposed technique is intended to act as a decision-supporting tool to select a favorable needle configuration. The presented heuristic for catheter optimization is based on a shrinkage-type algorithm (SACO). It is compared against state of the art planning in a retrospective study of 20 patients who previously received image-guided interstitial HDR brachytherapy using a Syed Neblett template. From those plans, template orientation and position are estimated via a rigid registration of the template with the actual catheter trajectories. All potential straight trajectories intersecting the contoured clinical target volume (CTV) are considered for catheter optimization. Retrospectively generated plans and clinical plans are compared with respect to dosimetric performance and optimization time. All plans were generated with one single run of the optimizer lasting 0.6-97.4 s. Compared to manual optimization, SACO yields a statistically significant (P ≤ 0.05) improved target coverage while at the same time fulfilling all dosimetric constraints for organs at risk (OARs). Comparing inverse planning strategies, dosimetric evaluation for SACO and "hybrid inverse planning and optimization" (HIPO), as gold standard, shows no statistically significant difference (P > 0.05). However, SACO provides the potential to reduce the number of used catheters without compromising plan quality. The proposed heuristic for needle selection provides fast catheter selection with optimization times suited for intraoperative treatment planning. Compared to manual optimization, the

  15. Magnetic Resonance Imaging (MRI) Markers for MRI-Guided High-Dose-Rate Brachytherapy: Novel Marker-Flange for Cervical Cancer and Marker Catheters for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Schindel, Joshua; Muruganandham, Manickam [Department of Radiation Oncology, University of Iowa, Iowa City, Iowa (United States); Pigge, F. Christopher [Department of Chemistry, University of Iowa, Iowa City, Iowa (United States); Anderson, James [Department of Radiation Oncology, University of Iowa, Iowa City, Iowa (United States); Kim, Yusung, E-mail: yusung-kim@uiowa.edu [Department of Radiation Oncology, University of Iowa, Iowa City, Iowa (United States)

    2013-06-01

    Purpose: To present a novel marker-flange, addressing source-reconstruction uncertainties due to the artifacts of a titanium intracavitary applicator used for magnetic resonance imaging (MRI)-guided high-dose-rate (HDR) brachytherapy (BT); and to evaluate 7 different MRI marker agents used for interstitial prostate BT and intracavitary gynecologic HDR BT when treatment plans are guided by MRI. Methods and Materials: Seven MRI marker agents were analyzed: saline solution, Conray-60, copper sulfate (CuSO{sub 4}) (1.5 g/L), liquid vitamin E, fish oil, 1% agarose gel (1 g agarose powder per 100 mL distilled water), and a cobalt–chloride complex contrast (C4) (CoCl{sub 2}/glycine = 4:1). A plastic, ring-shaped marker-flange was designed and tested on both titanium and plastic applicators. Three separate phantoms were designed to test the marker-flange, interstitial catheters for prostate BT, and intracavitary catheters for gynecologic HDR BT. T1- and T2-weighted MRI were analyzed for all markers in each phantom and quantified as percentages compared with a 3% agarose gel background. The geometric accuracy of the MR signal for the marker-flange was measured using an MRI-CT fusion. Results: The CuSO{sub 4} and C4 markers on T1-weighted MRI and saline on T2-weighted MRI showed the highest signals. The marker-flange showed hyper-signals of >500% with CuSO{sub 4} and C4 on T1-weighted MRI and of >400% with saline on T2-weighted MRI on titanium applicators. On T1-weighted MRI, the MRI signal inaccuracies of marker-flanges were measured <2 mm, regardless of marker agents, and that of CuSO{sub 4} was 0.42 ± 0.14 mm. Conclusion: The use of interstitial/intracavitary markers for MRI-guided prostate/gynecologic BT was observed to be feasible, providing accurate source pathway reconstruction. The novel marker-flange can produce extremely intense, accurate signals, demonstrating its feasibility for gynecologic HDR BT.

  16. High-Dose-Rate Brachytherapy as Monotherapy Delivered in Two Fractions Within One Day for Favorable/Intermediate-Risk Prostate Cancer: Preliminary Toxicity Data

    Energy Technology Data Exchange (ETDEWEB)

    Ghilezan, Michel, E-mail: mghilezan@beaumont.edu [Department of Radiation Oncology, William Beaumont Hospital and Rose Cancer Institute, Royal Oak, Michigan (United States); Martinez, Alvaro; Gustason, Gary; Krauss, Daniel; Antonucci, J. Vito; Chen, Peter; Fontanesi, James; Wallace, Michelle; Ye Hong; Casey, Alyse; Sebastian, Evelyn; Kim, Leonard; Limbacher, Amy [Department of Radiation Oncology, William Beaumont Hospital and Rose Cancer Institute, Royal Oak, Michigan (United States)

    2012-07-01

    Purpose: To report the toxicity profile of high-dose-rate (HDR)-brachytherapy (BT) as monotherapy in a Human Investigation Committee-approved study consisting of a single implant and two fractions (12 Gy Multiplication-Sign 2) for a total dose of 24 Gy, delivered within 1 day. The dose was subsequently increased to 27 Gy (13.5 Gy Multiplication-Sign 2) delivered in 1 day. We report the acute and early chronic genitourinary and gastrointestinal toxicity. Methods and Materials: A total of 173 patients were treated between December 2005 and July 2010. However, only the first 100 were part of the IRB-approved study and out of these, only 94 had a minimal follow-up of 6 months, representing the study population for this preliminary report. All patients had clinical Stage T2b or less (American Joint Committee on Cancer, 5th edition), Gleason score 6-7 (3+4), and prostate-specific antigen level of {<=}12 ng/mL. Ultrasound-guided HDR-BT with real-time dosimetry was used. The prescription dose was 24 Gy for the first 50 patients and 27 Gy thereafter. The dosimetric goals and constraints were the same for the two dose groups. Toxicity was scored using the National Cancer Institute Common Terminology Criteria for Adverse Events, version 3. The highest toxicity scores encountered at any point during follow-up are reported. Results: The median follow-up was 17 months (range, 6-40.5). Most patients had Grade 0-1 acute toxicity. The Grade 2 acute genitourinary toxicity was mainly frequency/urgency (13%), dysuria (5%), hematuria, and dribbling/hesitancy (2%). None of the patients required a Foley catheter at any time; however, 8% of the patients experienced transient Grade 1 diarrhea. No other acute gastrointestinal toxicities were found. The most common chronic toxicity was Grade 2 urinary frequency/urgency in 16% of patients followed by dysuria in 4% of patients; 2 patients had Grade 2 rectal bleeding and 1 had Grade 4, requiring laser treatment. Conclusions: Favorable

  17. Evaluation of a real-time BeO ceramic fiber-coupled luminescence dosimetry system for dose verification of high dose rate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Alexandre M. Caraça, E-mail: alexandre.santos@adelaide.edu.au [Department of Medical Physics, Royal Adelaide Hospital, Adelaide 5000, Australia and Institute for Photonics and Advanced Sensing, School of Physical Sciences, University of Adelaide, Adelaide 5005 (Australia); Mohammadi, Mohammad [Department of Medical Physics, Royal Adelaide Hospital, Adelaide 5000, Australia and Department of Medical Physics, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan 65167-3-8736 (Iran, Islamic Republic of); Shahraam, Afshar V. [Laser Physics and Photonic Devices Laboratories, School of Engineering, The University of South Australia, Adelaide 5095 (Australia); Institute for Photonics and Advanced Sensing, School of Physical Sciences, University of Adelaide, Adelaide 5005 (Australia)

    2015-11-15

    Purpose: The authors evaluate the capability of a beryllium oxide (BeO) ceramic fiber-coupled luminescence dosimeter, named radioluminescence/optically stimulated luminescence (RL/OSL) BeO FOD, for dosimetric verification of high dose rate (HDR) treatments. The RL/OSL BeO FOD is capable of RL and OSL measurements. Methods: The RL/OSL BeO FOD is able to be inserted in 6F proguide needles, used in interstitial HDR treatments. Using a custom built Perspex phantom, 6F proguide needles could be submerged in a water tank at 1 cm separations from each other. A second background fiber was required to correct for the stem effect. The stem effect, dose linearity, reproducibility, depth-dose curves, and angular and temperature dependency of the RL/OSL BeO FOD were characterised using an Ir-192 source. The RL/OSL BeO FOD was also applied to the commissioning of a 10 mm horizontal Leipzig applicator. Results: Both the RL and OSL were found to be reproducible and their percentage depth-dose curves to be in good agreement with those predicted via TG-43. A combined uncertainty of 7.9% and 10.1% (k = 1) was estimated for the RL and OSL, respectively. For the 10 mm horizontal Leipzig applicator, measured percentage depth doses were within 5% agreement of the published reference calculations. The output at the 3 mm prescription depth for a 1 Gy delivery was verified to be 0.99 ± 0.08 Gy and 1.01 ± 0.10 Gy by the RL and OSL, respectively. Conclusions: The use of the second background fiber under the current setup means that the two fibers cannot fit into a single 6F needle. Hence, use of the RL is currently not adequate for the purpose of in vivo brachytherapy dosimetry. While not real-time, the OSL is shown to be adequate for in vivo brachytherapy dosimetry.

  18. Objective method to report planner-independent skin/rib maximal dose in balloon-based high dose rate (HDR) brachytherapy for breast cancer.

    Science.gov (United States)

    Kim, Yongbok; Trombetta, Mark G

    2011-04-01

    An objective method was proposed and compared with a manual selection method to determine planner-independent skin and rib maximal dose in balloon-based high dose rate (HDR) brachytherapy planning. The maximal dose to skin and rib was objectively extracted from a dose volume histogram (DVH) of skin and rib volumes. A virtual skin volume was produced by expanding the skin surface in three dimensions (3D) external to the breast with a certain thickness in the planning computed tomography (CT) images. Therefore, the maximal dose to this volume occurs on the skin surface the same with a conventional manual selection method. The rib was also delineated in the planning CT images and its maximal dose was extracted from its DVH. The absolute (Abdiff = [D(max) Man - D (max)DVH]) and relative (Rediff[%] = 100 x ([D(max)Man-D(max)DVH])/D(max)DVH) maximal skin and rib dose differences between the manual selection method (D(max)Man) and the objective method (D(max)DVH) were measured for 50 balloon-based HDR (25 MammoSite and 25 Contura) patients. The average +/- standard deviation of maximal dose difference was 1.67% +/- 1.69% of the prescribed dose (PD). No statistical difference was observed between MammoSite and Contura patients for both Abdiff and Rediff[%] values. However, a statistically significant difference (p value skin dose difference for both Abdiff (2.30% +/- 1.71% vs 1.05% +/- 1.43%) and Rediff[%] (2.32% +/- 1.79% vs 1.21% +/- 1.41%). In general, rib has a more irregular contour and it is more proximally located to the balloon for 50 HDR patients. Due to the inverse square law factor, more dose difference was observed in higher dose range (D(max) > 90%) compared with lower dose range (D(max) skin and rib can determine the planner-independent maximal dose compared with the manual selection method. However, the difference was < 2% of PD, on average, if appropriate attention is paid to selecting a manual dose point in 3D planning CT images.

  19. Objective method to report planner-independent skin/rib maximal dose in balloon-based high dose rate (HDR) brachytherapy for breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yongbok; Trombetta, Mark G. [Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212 (United States) and Drexel University College of Medicine, Allegheny Campus, Pittsburgh, Pennsylvania 15212 (United States)

    2011-04-15

    Purpose: An objective method was proposed and compared with a manual selection method to determine planner-independent skin and rib maximal dose in balloon-based high dose rate (HDR) brachytherapy planning. Methods: The maximal dose to skin and rib was objectively extracted from a dose volume histogram (DVH) of skin and rib volumes. A virtual skin volume was produced by expanding the skin surface in three dimensions (3D) external to the breast with a certain thickness in the planning computed tomography (CT) images. Therefore, the maximal dose to this volume occurs on the skin surface the same with a conventional manual selection method. The rib was also delineated in the planning CT images and its maximal dose was extracted from its DVH. The absolute (Abdiff=|D{sub max}{sup Man}-D{sub max}{sup DVH}|) and relative (Rediff[%]=100x(|D{sub max}{sup Man}-D{sub max}{sup DVH}|)/D{sub max}{sup DVH}) maximal skin and rib dose differences between the manual selection method (D{sub max}{sup Man}) and the objective method (D{sub max}{sup DVH}) were measured for 50 balloon-based HDR (25 MammoSite and 25 Contura) patients. Results: The average{+-}standard deviation of maximal dose difference was 1.67%{+-}1.69% of the prescribed dose (PD). No statistical difference was observed between MammoSite and Contura patients for both Abdiff and Rediff[%] values. However, a statistically significant difference (p value <0.0001) was observed in maximal rib dose difference compared with maximal skin dose difference for both Abdiff (2.30%{+-}1.71% vs 1.05%{+-}1.43%) and Rediff[%] (2.32%{+-}1.79% vs 1.21%{+-}1.41%). In general, rib has a more irregular contour and it is more proximally located to the balloon for 50 HDR patients. Due to the inverse square law factor, more dose difference was observed in higher dose range (D{sub max}>90%) compared with lower dose range (D{sub max}<90%): 2.16%{+-}1.93% vs 1.19%{+-}1.25% with p value of 0.0049. However, the Rediff[%] analysis eliminated the

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

    Science.gov (United States)

    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 5mm. Rectum, bladder, urethra, and femoral heads were considered as organs at risk. A 78Gy in 39 fractions were prescribed for PTV. For HDR and LDR plans, the dose prescription was D90 of 34Gy in 8.5Gy per fraction, and 145Gy 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 2Gy per fraction, EQD2) for comparison of 3 techniques. HDR and LDR significantly reduced the dose to rectum and bladder compared with VMAT. The Dmean (EQD2) of rectum decreased 22.36Gy in HDR and 17.01Gy in LDR from 30.24Gy in VMAT, respectively. The Dmean (EQD2) of bladder decreased 6.91Gy in HDR and 2.53Gy in LDR from 13.46Gy 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 (EQD2) was 80.26, 70.23, and 104.91Gy 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. Copyright © 2016 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  1. Prostate-specific antigen nadir after high-dose-rate brachytherapy predicts long-term survival outcomes in high-risk prostate cancer

    Directory of Open Access Journals (Sweden)

    Hideyasu Tsumura

    2016-04-01

    Full Text Available Purpose : To evaluate the prognostic value of prostate-specific antigen nadir (nPSA after high-dose-rate (HDR brachytherapy in clinically non-metastatic high-risk prostate cancer patients. Material and methods : Data from 216 patients with high-risk or locally advanced prostate cancer who underwent HDR brachytherapy and external beam radiation therapy with long-term androgen deprivation therapy (ADT between 2003 and 2008 were analyzed. The median prostate-specific antigen (PSA level at diagnosis was 24 ng/ml (range: 3-338 ng/ml. The clinical stage was T1c-2a in 55 cases (26%, T2b-2c in 48 (22%, T3a in 75 (35%, and T3b-4 in 38 (17%. The mean dose to 90% of the planning target volume was 6.3 Gy/fraction of HDR brachytherapy. After 5 fractions, external beam radiation therapy with 10 fractions of 3 Gy was administered. All patients initially underwent neoadjuvant ADT for at least 6 months, and adjuvant ADT was continued for 36 months. The median follow-up was 7 years from the start of radiotherapy. Results : The 7-year PSA relapse-free rate among patients with a post-radiotherapy nPSA level of ≤ 0.02 ng/ml was 94%, compared with 23% for patients with higher nPSA values (HR = 28.57; 95% CI: 12.04-66.66; p < 0.001. Multivariate analysis revealed that the nPSA value after radiotherapy was a significant independent predictor of biochemical failure, whereas pretreatment predictive values for worse biochemical control including higher level of initial PSA, Gleason score ≥ 8, positive biopsy core rate ≥ 67%, and T3b-T4, failed to reach independent predictor status. The 7-year cancer-specific survival rate among patients with a post-radiotherapy nPSA level of ≤ 0.02 ng/ml was 99%, compared with 82% for patients with higher nPSA values (HR = 32.25; 95% CI: 3.401-333.3; p = 0.002. Conclusions : A post-radiotherapy nPSA value of ≤ 0.02 ng/ml was associated with better long-term biochemical tumor control even if patients had pretreatment predictive

  2. Comparison of 2D and 3D Imaging and Treatment Planning for Postoperative Vaginal Apex High-Dose Rate Brachytherapy for Endometrial Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Russo, James K. [Department of Radiation Oncology, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina (United States); Armeson, Kent E. [Division of Biostatistics and Epidemiology, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina (United States); Richardson, Susan, E-mail: srichardson@radonc.wustl.edu [Department of Radiation Oncology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri (United States)

    2012-05-01

    Purpose: To evaluate bladder and rectal doses using two-dimensional (2D) and 3D treatment planning for vaginal cuff high-dose rate (HDR) in endometrial cancer. Methods and Materials: Ninety-one consecutive patients treated between 2000 and 2007 were evaluated. Seventy-one and 20 patients underwent 2D and 3D planning, respectively. Each patient received six fractions prescribed at 0.5 cm to the superior 3 cm of the vagina. International Commission on Radiation Units and Measurements (ICRU) doses were calculated for 2D patients. Maximum and 2-cc doses were calculated for 3D patients. Organ doses were normalized to prescription dose. Results: Bladder maximum doses were 178% of ICRU doses (p < 0.0001). Two-cubic centimeter doses were no different than ICRU doses (p = 0.22). Two-cubic centimeter doses were 59% of maximum doses (p < 0.0001). Rectal maximum doses were 137% of ICRU doses (p < 0.0001). Two-cubic centimeter doses were 87% of ICRU doses (p < 0.0001). Two-cubic centimeter doses were 64% of maximum doses (p < 0.0001). Using the first 1, 2, 3, 4 or 5 fractions, we predicted the final bladder dose to within 10% for 44%, 59%, 83%, 82%, and 89% of patients by using the ICRU dose, and for 45%, 55%, 80%, 85%, and 85% of patients by using the maximum dose, and for 37%, 68%, 79%, 79%, and 84% of patients by using the 2-cc dose. Using the first 1, 2, 3, 4 or 5 fractions, we predicted the final rectal dose to within 10% for 100%, 100%, 100%, 100%, and 100% of patients by using the ICRU dose, and for 60%, 65%, 70%, 75%, and 75% of patients by using the maximum dose, and for 68%, 95%, 84%, 84%, and 84% of patients by using the 2-cc dose. Conclusions: Doses to organs at risk vary depending on the calculation method. In some cases, final dose accuracy appears to plateau after the third fraction, indicating that simulation and planning may not be necessary in all fractions. A clinically relevant level of accuracy should be determined and further research conducted to address

  3. SU-E-T-579: Impact of Cylinder Size in High-Dose Rate Brachytherapy (HDRBT) for Primary Cancer in the Vagina

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    Zhang, H; Gopalakrishnan, M; Lee, P; Sathiaseelan, V [Department of Radiation Oncology, Northwestern Memorial Hospital, Chicago, IL (United States)

    2014-06-01

    Purpose: To evaluate the dosimetric impact of cylinder size in high dose rate Brachytherapy for primary vaginal cancers. Methods: Patients treated with HDR vaginal vault radiation in a list of cylinders ranging from 2.5 to 4 cm in diameter at 0.5 cm increment were analyzed. All patients’ doses were prescribed at the 0.5 cm from the vaginal surface with different treatment lengths. A series of reference points were created to optimize the dose distribution. The fraction dose was 5.5 Gy, the treatment was repeated for 4 times in two weeks. A cylinder volume was contoured in each case according to the prescribed treatment length, and then expanded to 5 mm to get a volume Cylinder-5mm-exp. A volume of PTV-Eval was obtained by subtracting the cylinder volume from the Cylinder-5mm-exp. The shell volume, PTV-Eval serves as the target volume for dosimetric evaluation. Results: DVH curves and average doses of PTV-Eval were obtained. Our results indicated that the DVH curves shifted toward higher dose side when larger cylinder was used instead of smaller ones. When 3.0 cm cylinder was used instead of 2.5 cm, for 3.0 cm treatment length, the average dose only increased 1%, from 790 to 799 cGy. However, the average doses for 3.5 and 4 cm cylinders respectively are 932 and 1137 cGy at the same treatment length. For 5.0 cm treatment length, the average dose is 741 cGy for 2.5 cm cylinder, and 859 cGy for 3 cm cylinder. Conclusion: Our data analysis suggests that for the vaginal intracavitary HDRBT, the average dose is at least 35% larger than the prescribed dose in the studied cases; the size of the cylinder will impact the dose delivered to the target volume. The cylinder with bigger diameter tends to deliver larger average dose to the PTV-Eval.

  4. Determination of air kerma standard of high dose rate {sup 192}Ir brachytherapy source; Determinacao da taxa de kerma no ar de referencia para {sup 192}Ir de alta taxa de dose para braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Pires, E.J.; Alves, C.F.E.; Leite, S.P.; Magalhaes, L.A.G.; David, M.G.; Almeida, C.E. de, E-mail: cfealves@gmail.com [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Lab. de Ciencias Radiologicas; Di Prinzio, R. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    This paper presents the methodology developed by the Laboratorio de Ciencias Radiologicas and presently in use for determining of the air kerma standard of {sup 192}Ir high dose rate sources to calibrate well-type chambers. Uncertainty analysis involving the measurements procedure are presented. (author)

  5. External-Beam Radiation Therapy and High-Dose Rate Brachytherapy Combined With Long-Term Androgen Deprivation Therapy in High and Very High Prostate Cancer: Preliminary Data on Clinical Outcome

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Monge, Rafael, E-mail: rmartinezm@unav.es [Department of Radiation Oncology, Clinica Universitaria de Navarra, University of Navarra, Pamplona, Navarre (Spain); Moreno, Marta; Ciervide, Raquel; Cambeiro, Mauricio [Department of Radiation Oncology, Clinica Universitaria de Navarra, University of Navarra, Pamplona, Navarre (Spain); Perez-Gracia, Jose Luis; Gil-Bazo, Ignacio [Department of Medical Oncology, Clinica Universitaria de Navarra, University of Navarra, Pamplona, Navarre (Spain); Gaztanaga, Miren; Arbea, Leire [Department of Radiation Oncology, Clinica Universitaria de Navarra, University of Navarra, Pamplona, Navarre (Spain); Pascual, Ignacio [Department of Urology, Clinica Universitaria de Navarra, University of Navarra, Pamplona, Navarre (Spain); Aristu, Javier [Department of Radiation Oncology, Clinica Universitaria de Navarra, University of Navarra, Pamplona, Navarre (Spain)

    2012-03-01

    Purpose: To determine the feasibility of combined long-term androgen deprivation therapy (ADT) and dose escalation with high-dose-rate (HDR) brachytherapy. Methods and Materials: Between 2001 and 2007, 200 patients with high-risk prostate cancer (32.5%) or very high-risk prostate cancer (67.5%) were prospectively enrolled in this Phase II trial. Tumor characteristics included a median pretreatment prostate-specific antigen of 15.2 ng/mL, a clinical stage of T2c, and a Gleason score of 7. Treatment consisted of 54 Gy of external irradiation (three-dimensional conformal radiotherapy [3DCRT]) followed by 19 Gy of HDR brachytherapy in four twice-daily treatments. ADT started 0-3 months before 3DCRT and continued for 2 years. Results: One hundred and ninety patients (95%) received 2 years of ADT. After a median follow-up of 3.7 years (range, 2-9), late Grade {>=}2 urinary toxicity was observed in 18% of the patients and Grade {>=}3 was observed in 5%. Prior transurethral resection of the prostate (p = 0.013) and bladder D{sub 50} {>=}1.19 Gy (p = 0.014) were associated with increased Grade {>=}2 urinary complications; age {>=}70 (p = 0.05) was associated with Grade {>=}3 urinary complications. Late Grade {>=}2 gastrointestinal toxicity was observed in 9% of the patients and Grade {>=}3 in 1.5%. CTV size {>=}35.8 cc (p = 0.007) and D{sub 100} {>=}3.05 Gy (p = 0.01) were significant for increased Grade {>=}2 complications. The 5-year and 9-year biochemical relapse-free survival (nadir + 2) rates were 85.1% and 75.7%, respectively. Patients with Gleason score of 7-10 had a decreased biochemical relapse-free survival (p = 0.007). Conclusions: Intermediate-term results at the 5-year time point indicate a favorable outcome without an increase in the rate of late complications.

  6. Cervical Gross Tumor Volume Dose Predicts Local Control Using Magnetic Resonance Imaging/Diffusion-Weighted Imaging—Guided High-Dose-Rate and Positron Emission Tomography/Computed Tomography—Guided Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Dyk, Pawel; Jiang, Naomi; Sun, Baozhou; DeWees, Todd A. [Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri (United States); Fowler, Kathryn J.; Narra, Vamsi [Department of Diagnostic Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri (United States); Garcia-Ramirez, Jose L.; Schwarz, Julie K. [Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri (United States); Grigsby, Perry W., E-mail: pgrigsby@wustl.edu [Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri (United States); Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri (United States); Division of Gynecologic Oncology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri (United States); Alvin J. Siteman Cancer Center, Washington University School of Medicine, St Louis, Missouri (United States)

    2014-11-15

    Purpose: Magnetic resonance imaging/diffusion weighted-imaging (MRI/DWI)-guided high-dose-rate (HDR) brachytherapy and {sup 18}F-fluorodeoxyglucose (FDG) — positron emission tomography/computed tomography (PET/CT)-guided intensity modulated radiation therapy (IMRT) for the definitive treatment of cervical cancer is a novel treatment technique. The purpose of this study was to report our analysis of dose-volume parameters predicting gross tumor volume (GTV) control. Methods and Materials: We analyzed the records of 134 patients with International Federation of Gynecology and Obstetrics stages IB1-IVB cervical cancer treated with combined MRI-guided HDR and IMRT from July 2009 to July 2011. IMRT was targeted to the metabolic tumor volume and lymph nodes by use of FDG-PET/CT simulation. The GTV for each HDR fraction was delineated by use of T2-weighted or apparent diffusion coefficient maps from diffusion-weighted sequences. The D100, D90, and Dmean delivered to the GTV from HDR and IMRT were summed to EQD2. Results: One hundred twenty-five patients received all irradiation treatment as planned, and 9 did not complete treatment. All 134 patients are included in this analysis. Treatment failure in the cervix occurred in 24 patients (18.0%). Patients with cervix failures had a lower D100, D90, and Dmean than those who did not experience failure in the cervix. The respective doses to the GTV were 41, 58, and 136 Gy for failures compared with 67, 99, and 236 Gy for those who did not experience failure (P<.001). Probit analysis estimated the minimum D100, D90, and Dmean doses required for ≥90% local control to be 69, 98, and 260 Gy (P<.001). Conclusions: Total dose delivered to the GTV from combined MRI-guided HDR and PET/CT-guided IMRT is highly correlated with local tumor control. The findings can be directly applied in the clinic for dose adaptation to maximize local control.

  7. A comparison of the biological effects of 125I seeds continuous low-dose-rate radiation and 60Co high-dose-rate gamma radiation on non-small cell lung cancer cells.

    Directory of Open Access Journals (Sweden)

    Zhongmin Wang

    Full Text Available To compare the biological effects of 125I seeds continuous low-dose-rate (CLDR radiation and 60Co γ-ray high-dose-rate (HDR radiation on non-small cell lung cancer (NSCLC cells.A549, H1299 and BEAS-2B cells were exposed to 125I seeds CLDR radiation or 60Co γ-ray HDR radiation. The survival fraction was determined using a colony-forming assay. The cell cycle progression and apoptosis were detected by flow cytometry (FCM. The expression of the apoptosis-related proteins caspase-3, cleaved-caspase-3, PARP, cleaved-PARP, BAX and Bcl-2 were detected by western blot assay.After irradiation with 125I seeds CLDR radiation, there was a lower survival fraction, more pronounced cell cycle arrest (G1 arrest and G2/M arrest in A549 and H1299 cells, respectively and a higher apoptotic ratio for A549 and H1299 cells than after 60Co γ-ray HDR radiation. Moreover, western blot assays revealed that 125I seeds CLDR radiation remarkably up-regulated the expression of Bax, cleaved-caspase-3 and cleaved-PARP proteins and down-regulated the expression of Bcl-2 proteins in A549 and H1299 cells compared with 60Co γ-ray HDR radiation. However, there was little change in the apoptotic ratio and expression of apoptosis-related proteins in normal BEAS-2B cells receiving the same treatment.125I seeds CLDR radiation led to remarkable growth inhibition of A549 and H1299 cells compared with 60Co HDR γ-ray radiation; A549 cells were the most sensitive to radiation, followed by H1299 cells. In contrast, normal BEAS-2B cells were relatively radio-resistant. The imbalance of the Bcl-2/Bax ratio and the activation of caspase-3 and PARP proteins might play a key role in the anti-proliferative effects induced by 125I seeds CLDR radiation, although other possibilities have not been excluded and will be investigated in future studies.

  8. SU-F-T-32: Evaluation of the Performance of a Multiple-Array-Diode Detector for Quality Assurance Tests in High-Dose-Rate Brachytherapy with Ir-192 Source

    Energy Technology Data Exchange (ETDEWEB)

    Harpool, K; De La Fuente Herman, T; Ahmad, S; Ali, I [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2016-06-15

    Purpose: To evaluate the performance of a two-dimensional (2D) array-diode- detector for geometric and dosimetric quality assurance (QA) tests of high-dose-rate (HDR) brachytherapy with an Ir-192-source. Methods: A phantom setup was designed that encapsulated a two-dimensional (2D) array-diode-detector (MapCheck2) and a catheter for the HDR brachytherapy Ir-192 source. This setup was used to perform both geometric and dosimetric quality assurance for the HDR-Ir192 source. The geometric tests included: (a) measurement of the position of the source and (b) spacing between different dwell positions. The dosimteric tests include: (a) linearity of output with time, (b) end effect and (c) relative dose verification. The 2D-dose distribution measured with MapCheck2 was used to perform the previous tests. The results of MapCheck2 were compared with the corresponding quality assurance testes performed with Gafchromic-film and well-ionization-chamber. Results: The position of the source and the spacing between different dwell-positions were reproducible within 1 mm accuracy by measuring the position of maximal dose using MapCheck2 in contrast to the film which showed a blurred image of the dwell positions due to limited film sensitivity to irradiation. The linearity of the dose with dwell times measured from MapCheck2 was superior to the linearity measured with ionization chamber due to higher signal-to-noise ratio of the diode readings. MapCheck2 provided more accurate measurement of the end effect with uncertainty < 1.5% in comparison with the ionization chamber uncertainty of 3%. Although MapCheck2 did not provide absolute calibration dosimeter for the activity of the source, it provided accurate tool for relative dose verification in HDR-brachytherapy. Conclusion: The 2D-array-diode-detector provides a practical, compact and accurate tool to perform quality assurance for HDR-brachytherapy with an Ir-192 source. The diodes in MapCheck2 have high radiation sensitivity and

  9. The evaluation of a 2D diode array in "magic phantom" for use in high dose rate brachytherapy pretreatment quality assurance.

    Science.gov (United States)

    Espinoza, A; Petasecca, M; Fuduli, I; Howie, A; Bucci, J; Corde, S; Jackson, M; Lerch, M L F; Rosenfeld, A B

    2015-02-01

    High dose rate (HDR) brachytherapy is a treatment method that is used increasingly worldwide. The development of a sound quality assurance program for the verification of treatment deliveries can be challenging due to the high source activity utilized and the need for precise measurements of dwell positions and times. This paper describes the application of a novel phantom, based on a 2D 11 × 11 diode array detection system, named "magic phantom" (MPh), to accurately measure plan dwell positions and times, compare them directly to the treatment plan, determine errors in treatment delivery, and calculate absorbed dose. The magic phantom system was CT scanned and a 20 catheter plan was generated to simulate a nonspecific treatment scenario. This plan was delivered to the MPh and, using a custom developed software suite, the dwell positions and times were measured and compared to the plan. The original plan was also modified, with changes not disclosed to the primary authors, and measured again using the device and software to determine the modifications. A new metric, the "position-time gamma index," was developed to quantify the quality of a treatment delivery when compared to the treatment plan. The MPh was evaluated to determine the minimum measurable dwell time and step size. The incorporation of the TG-43U1 formalism directly into the software allows for dose calculations to be made based on the measured plan. The estimated dose distributions calculated by the software were compared to the treatment plan and to calibrated EBT3 film, using the 2D gamma analysis method. For the original plan, the magic phantom system was capable of measuring all dwell points and dwell times and the majority were found to be within 0.93 mm and 0.25 s, respectively, from the plan. By measuring the altered plan and comparing it to the unmodified treatment plan, the use of the position-time gamma index showed that all modifications made could be readily detected. The MPh was able to

  10. A generic high-dose rate {sup 192}Ir brachytherapy source for evaluation of model-based dose calculations beyond the TG-43 formalism

    Energy Technology Data Exchange (ETDEWEB)

    Ballester, Facundo, E-mail: Facundo.Ballester@uv.es [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Carlsson Tedgren, Åsa [Department of Medical and Health Sciences (IMH), Radiation Physics, Faculty of Health Sciences, Linköping University, Linköping SE-581 85, Sweden and Department of Medical Physics, Karolinska University Hospital, Stockholm SE-171 76 (Sweden); Granero, Domingo [Department of Radiation Physics, ERESA, Hospital General Universitario, Valencia E-46014 (Spain); Haworth, Annette [Department of Physical Sciences, Peter MacCallum Cancer Centre and Royal Melbourne Institute of Technology, Melbourne, Victoria 3000 (Australia); Mourtada, Firas [Department of Radiation Oncology, Helen F. Graham Cancer Center, Christiana Care Health System, Newark, Delaware 19713 (United States); Fonseca, Gabriel Paiva [Instituto de Pesquisas Energéticas e Nucleares – IPEN-CNEN/SP, São Paulo 05508-000, Brazil and Department of Radiation Oncology (MAASTRO), GROW, School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Zourari, Kyveli; Papagiannis, Panagiotis [Medical Physics Laboratory, Medical School, University of Athens, 75 MikrasAsias, Athens 115 27 (Greece); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Siebert, Frank-André [Clinic of Radiotherapy, University Hospital of Schleswig-Holstein, Campus Kiel, Kiel 24105 (Germany); Sloboda, Ron S. [Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada and Department of Oncology, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); and others

    2015-06-15

    Purpose: In order to facilitate a smooth transition for brachytherapy dose calculations from the American Association of Physicists in Medicine (AAPM) Task Group No. 43 (TG-43) formalism to model-based dose calculation algorithms (MBDCAs), treatment planning systems (TPSs) using a MBDCA require a set of well-defined test case plans characterized by Monte Carlo (MC) methods. This also permits direct dose comparison to TG-43 reference data. Such test case plans should be made available for use in the software commissioning process performed by clinical end users. To this end, a hypothetical, generic high-dose rate (HDR) {sup 192}Ir source and a virtual water phantom were designed, which can be imported into a TPS. Methods: A hypothetical, generic HDR {sup 192}Ir source was designed based on commercially available sources as well as a virtual, cubic water phantom that can be imported into any TPS in DICOM format. The dose distribution of the generic {sup 192}Ir source when placed at the center of the cubic phantom, and away from the center under altered scatter conditions, was evaluated using two commercial MBDCAs [Oncentra{sup ®} Brachy with advanced collapsed-cone engine (ACE) and BrachyVision ACUROS{sup TM}]. Dose comparisons were performed using state-of-the-art MC codes for radiation transport, including ALGEBRA, BrachyDose, GEANT4, MCNP5, MCNP6, and PENELOPE2008. The methodologies adhered to recommendations in the AAPM TG-229 report on high-energy brachytherapy source dosimetry. TG-43 dosimetry parameters, an along-away dose-rate table, and primary and scatter separated (PSS) data were obtained. The virtual water phantom of (201){sup 3} voxels (1 mm sides) was used to evaluate the calculated dose distributions. Two test case plans involving a single position of the generic HDR {sup 192}Ir source in this phantom were prepared: (i) source centered in the phantom and (ii) source displaced 7 cm laterally from the center. Datasets were independently produced by

  11. A generic high-dose rate (192)Ir brachytherapy source for evaluation of model-based dose calculations beyond the TG-43 formalism.

    Science.gov (United States)

    Ballester, Facundo; Carlsson Tedgren, Åsa; Granero, Domingo; Haworth, Annette; Mourtada, Firas; Fonseca, Gabriel Paiva; Zourari, Kyveli; Papagiannis, Panagiotis; Rivard, Mark J; Siebert, Frank-André; Sloboda, Ron S; Smith, Ryan L; Thomson, Rowan M; Verhaegen, Frank; Vijande, Javier; Ma, Yunzhi; Beaulieu, Luc

    2015-06-01

    In order to facilitate a smooth transition for brachytherapy dose calculations from the American Association of Physicists in Medicine (AAPM) Task Group No. 43 (TG-43) formalism to model-based dose calculation algorithms (MBDCAs), treatment planning systems (TPSs) using a MBDCA require a set of well-defined test case plans characterized by Monte Carlo (MC) methods. This also permits direct dose comparison to TG-43 reference data. Such test case plans should be made available for use in the software commissioning process performed by clinical end users. To this end, a hypothetical, generic high-dose rate (HDR) (192)Ir source and a virtual water phantom were designed, which can be imported into a TPS. A hypothetical, generic HDR (192)Ir source was designed based on commercially available sources as well as a virtual, cubic water phantom that can be imported into any TPS in DICOM format. The dose distribution of the generic (192)Ir source when placed at the center of the cubic phantom, and away from the center under altered scatter conditions, was evaluated using two commercial MBDCAs [Oncentra(®) Brachy with advanced collapsed-cone engine (ACE) and BrachyVision ACUROS™ ]. Dose comparisons were performed using state-of-the-art MC codes for radiation transport, including ALGEBRA, BrachyDose, GEANT4, MCNP5, MCNP6, and PENELOPE2008. The methodologies adhered to recommendations in the AAPM TG-229 report on high-energy brachytherapy source dosimetry. TG-43 dosimetry parameters, an along-away dose-rate table, and primary and scatter separated (PSS) data were obtained. The virtual water phantom of (201)(3) voxels (1 mm sides) was used to evaluate the calculated dose distributions. Two test case plans involving a single position of the generic HDR (192)Ir source in this phantom were prepared: (i) source centered in the phantom and (ii) source displaced 7 cm laterally from the center. Datasets were independently produced by different investigators. MC results were then

  12. A generic TG-186 shielded applicator for commissioning model-based dose calculation algorithms for high-dose-rate 192 Ir brachytherapy.

    Science.gov (United States)

    Ma, Yunzhi; Vijande, Javier; Ballester, Facundo; Tedgren, Åsa Carlsson; Granero, Domingo; Haworth, Annette; Mourtada, Firas; Fonseca, Gabriel Paiva; Zourari, Kyveli; Papagiannis, Panagiotis; Rivard, Mark J; Siebert, Frank André; Sloboda, Ron S; Smith, Ryan; Chamberland, Marc J P; Thomson, Rowan M; Verhaegen, Frank; Beaulieu, Luc

    2017-11-01

    A joint working group was created by the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy and Oncology (ESTRO), and the Australasian Brachytherapy Group (ABG) with the charge, among others, to develop a set of well-defined test case plans and perform calculations and comparisons with model-based dose calculation algorithms (MBDCAs). Its main goal is to facilitate a smooth transition from the AAPM Task Group No. 43 (TG-43) dose calculation formalism, widely being used in clinical practice for brachytherapy, to the one proposed by Task Group No. 186 (TG-186) for MBDCAs. To do so, in this work a hypothetical, generic high-dose rate (HDR) 192 Ir shielded applicator has been designed and benchmarked. A generic HDR 192 Ir shielded applicator was designed based on three commercially available gynecological applicators as well as a virtual cubic water phantom that can be imported into any DICOM-RT compatible treatment planning system (TPS). The absorbed dose distribution around the applicator with the TG-186 192 Ir source located at one dwell position at its center was computed using two commercial TPSs incorporating MBDCAs (Oncentra® Brachy with Advanced Collapsed-cone Engine, ACE™, and BrachyVision ACUROS™) and state-of-the-art Monte Carlo (MC) codes, including ALGEBRA, BrachyDose, egs_brachy, Geant4, MCNP6, and Penelope2008. TPS-based volumetric dose distributions for the previously reported "source centered in water" and "source displaced" test cases, and the new "source centered in applicator" test case, were analyzed here using the MCNP6 dose distribution as a reference. Volumetric dose comparisons of TPS results against results for the other MC codes were also performed. Distributions of local and global dose difference ratios are reported. The local dose differences among MC codes are comparable to the statistical uncertainties of the reference datasets for the "source centered in water" and "source displaced" test

  13. Therapeutic analysis of high-dose-rate {sup 192}Ir vaginal cuff brachytherapy for endometrial cancer using a cylindrical target volume model and varied cancer cell distributions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hualin, E-mail: hualin.zhang@northwestern.edu; Donnelly, Eric D.; Strauss, Jonathan B. [Department of Radiation Oncology, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Northwestern Memorial Hospital, Chicago, Illinois 60611 (United States); Qi, Yujin [Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia)

    2016-01-15

    Purpose: To evaluate high-dose-rate (HDR) vaginal cuff brachytherapy (VCBT) in the treatment of endometrial cancer in a cylindrical target volume with either a varied or a constant cancer cell distributions using the linear quadratic (LQ) model. Methods: A Monte Carlo (MC) technique was used to calculate the 3D dose distribution of HDR VCBT over a variety of cylinder diameters and treatment lengths. A treatment planning system (TPS) was used to make plans for the various cylinder diameters, treatment lengths, and prescriptions using the clinical protocol. The dwell times obtained from the TPS were fed into MC. The LQ model was used to evaluate the therapeutic outcome of two brachytherapy regimens prescribed either at 0.5 cm depth (5.5 Gy × 4 fractions) or at the vaginal mucosal surface (8.8 Gy × 4 fractions) for the treatment of endometrial cancer. An experimentally determined endometrial cancer cell distribution, which showed a varied and resembled a half-Gaussian distribution, was used in radiobiology modeling. The equivalent uniform dose (EUD) to cancer cells was calculated for each treatment scenario. The therapeutic ratio (TR) was defined by comparing VCBT with a uniform dose radiotherapy plan in term of normal cell survival at the same level of cancer cell killing. Calculations of clinical impact were run twice assuming two different types of cancer cell density distributions in the cylindrical target volume: (1) a half-Gaussian or (2) a uniform distribution. Results: EUDs were weakly dependent on cylinder size, treatment length, and the prescription depth, but strongly dependent on the cancer cell distribution. TRs were strongly dependent on the cylinder size, treatment length, types of the cancer cell distributions, and the sensitivity of normal tissue. With a half-Gaussian distribution of cancer cells which populated at the vaginal mucosa the most, the EUDs were between 6.9 Gy × 4 and 7.8 Gy × 4, the TRs were in the range from (5.0){sup 4} to (13

  14. Commissioning of applicator-guided stereotactic body radiation therapy boost with high-dose-rate brachytherapy for advanced cervical cancer using radiochromic film dosimetry.

    Science.gov (United States)

    Aldelaijan, Saad; Wadi-Ramahi, Shada; Nobah, Ahmad; Moftah, Belal; Devic, Slobodan; Jastaniyah, Noha

    To describe an EBT3 GAFCHROMIC film-based dosimetry method to be used in commissioning of a combined HDR brachytherapy (HDRB) and stereotactic body radiation therapy (SBRT) boost for treatment of advanced cervical cancer involving extensive residual disease after external beam treatment. A cube phantom was designed to firmly fit an intrauterine tandem applicator and EBT3 radiochromic film pieces. A high-risk clinical target volume (CTVHR, Total) was contoured with an extended arm at one side. The HDRB treatment was planned to cover the proximal CTVHR, Total with 7 Gy and the distal volume, referred to as CTVHR, Distal, was planned by SBRT for dose augmentation. After HDRB treatment delivery, SBRT treatment was delivered within 1 hour by image guidance using the applicator geometry. Intentional 1D and 2D misalignments were introduced to evaluate the effect on target volumes. In addition, effect of film reirradiation at different time gaps and dose levels was evaluated. Film dosimetric accuracy, with up to 2 hours gap between irradiations, was shown to be unaffected. A 2%/2 mm gamma analysis between measured and planned doses showed agreement of >99%. Misalignments of more than 2 mm between applicator and SBRT isocenter resulted in suboptimal dose-volume histogram affecting mostly D98% and D90% of CTVHR, Distal. Visualizing how target dose-volume metrics are affected by minor misalignments between SBRT and HDRB dose gradients, in light of achievable phantom-based experimental quality assurance level, encourages the clinical applicability of this technique. Radiochromic film was shown to be a valuable tool to commission procedures combining two different treatment planning systems and modalities with varying dose rates and energy ranges. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  15. Dose error from deviation of dwell time and source position for high dose-rate 192Ir in remote afterloading system.

    Science.gov (United States)

    Okamoto, Hiroyuki; Aikawa, Ako; Wakita, Akihisa; Yoshio, Kotaro; Murakami, Naoya; Nakamura, Satoshi; Hamada, Minoru; Abe, Yoshihisa; Itami, Jun

    2014-07-01

    The influence of deviations in dwell times and source positions for (192)Ir HDR-RALS was investigated. The potential dose errors for various kinds of brachytherapy procedures were evaluated. The deviations of dwell time ΔT of a (192)Ir HDR source for the various dwell times were measured with a well-type ionization chamber. The deviations of source position ΔP were measured with two methods. One is to measure actual source position using a check ruler device. The other is to analyze peak distances from radiographic film irradiated with 20 mm gap between the dwell positions. The composite dose errors were calculated using Gaussian distribution with ΔT and ΔP as 1σ of the measurements. Dose errors depend on dwell time and distance from the point of interest to the dwell position. To evaluate the dose error in clinical practice, dwell times and point of interest distances were obtained from actual treatment plans involving cylinder, tandem-ovoid, tandem-ovoid with interstitial needles, multiple interstitial needles, and surface-mold applicators. The ΔT and ΔP were 32 ms (maximum for various dwell times) and 0.12 mm (ruler), 0.11 mm (radiographic film). The multiple interstitial needles represent the highest dose error of 2%, while the others represent less than approximately 1%. Potential dose error due to dwell time and source position deviation can depend on kinds of brachytherapy techniques. In all cases, the multiple interstitial needles is most susceptible. © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  16. Evaluation of failure modes of computerized planning phase of interstitial implants with high dose rate brachytherapy using HFMEA; Avaliacao dos modos de falha do planejamento computadorizado em implantes intersticiais com braquiterapia de alta taxa de dose usando HFMEA

    Energy Technology Data Exchange (ETDEWEB)

    Biazotto, Bruna; Tokarski, Marcio, E-mail: bruna@ceb.unicamp.br [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Centro de Engenharia Biomedica

    2014-08-15

    This paper evaluates the failure modes of the computerized planning step in interstitial implants with high dose rate brachytherapy. The prospective tool of risk management Health Care Failure Mode and Effects Analysis (HFMEA) was used. Twelve subprocesses were identified, and 33 failure modes of which 21 justified new safety actions, and 9 of them were intolerable risks. The method proved itself useful in identifying failure modes, but laborious and subjective in their assessment. The main risks were due to human factors, which require training and commitment of management to their mitigation. (author)

  17. Verification of the calculation program for brachytherapy planning system of high dose rate (PLATO); Programa de verificacion del calculo para un sistema de planificacion de braquiterapia de alta tasa de dosis (PLATO)

    Energy Technology Data Exchange (ETDEWEB)

    Almansa, J.; Alaman, C.; Perez-Alija, J.; Herrero, C.; Real, R. del; Ososrio, J. L.

    2011-07-01

    In our treatments are performed brachytherapy high dose rate since 2007. The procedures performed include gynecological intracavitary treatment and interstitial. The treatments are performed with a source of Ir-192 activity between 5 and 10 Ci such that small variations in treatment times can cause damage to the patient. In addition the Royal Decree 1566/1998 on Quality Criteria in radiotherapy establishes the need to verify the monitor units or treatment time in radiotherapy and brachytherapy. All this justifies the existence of a redundant system for brachytherapy dose calculation that can reveal any abnormality is present.

  18. Concomitant chemoradiotherapy with high dose rate brachytherapy ...

    African Journals Online (AJOL)

    Tamer Refaat

    2011-06-12

    Jun 12, 2011 ... The mean age was 48.49 years. EBR to the whole pelvis TO 45 Gy in 25 fractions .... with radio-opaque seeds or a radio-opaque vaginal tampon. Barium or another radio-opaque device was used to ..... A common language has been developed that allows differ- ent BT traditions to communicate. Important ...

  19. Computed tomography-based treatment planning for high-dose-rate brachytherapy using the tandem and ring applicator: influence of applicator choice on organ dose and inter-fraction adaptive planning

    Directory of Open Access Journals (Sweden)

    Vishruta A. Dumane

    2017-06-01

    Full Text Available Three dimensional planning for high-dose-rate (HDR brachytherapy in cervical cancer has been highly recommended by consensus guidelines such as the American Brachytherapy Society (ABS and the Groupe Européen de Curiethérapie – European Society for Radiotherapy and Oncology (GEC-ESTRO. In this document, we describe our experience with computed tomography (CT-based planning using the tandem/ring applicator. We discuss the influence of applicator geometry on doses to organs at risk (OARs, namely the bladder, rectum, and sigmoid. Through example cases with dose prescribed to point A, we demonstrate how adaptive planning can help achieve constraints to the OARs as per guidelines.

  20. SU-F-P-39: End-To-End Validation of a 6 MV High Dose Rate Photon Beam, Configured for Eclipse AAA Algorithm Using Golden Beam Data, for SBRT Treatments Using RapidArc

    Energy Technology Data Exchange (ETDEWEB)

    Ferreyra, M; Salinas Aranda, F; Dodat, D; Sansogne, R; Arbiser, S [Vidt Centro Medico, Ciudad Autonoma De Buenos Aires, Ciudad Autonoma de Buenos Aire (Argentina)

    2016-06-15

    Purpose: To use end-to-end testing to validate a 6 MV high dose rate photon beam, configured for Eclipse AAA algorithm using Golden Beam Data (GBD), for SBRT treatments using RapidArc. Methods: Beam data was configured for Varian Eclipse AAA algorithm using the GBD provided by the vendor. Transverse and diagonals dose profiles, PDDs and output factors down to a field size of 2×2 cm2 were measured on a Varian Trilogy Linac and compared with GBD library using 2% 2mm 1D gamma analysis. The MLC transmission factor and dosimetric leaf gap were determined to characterize the MLC in Eclipse. Mechanical and dosimetric tests were performed combining different gantry rotation speeds, dose rates and leaf speeds to evaluate the delivery system performance according to VMAT accuracy requirements. An end-to-end test was implemented planning several SBRT RapidArc treatments on a CIRS 002LFC IMRT Thorax Phantom. The CT scanner calibration curve was acquired and loaded in Eclipse. PTW 31013 ionization chamber was used with Keithley 35617EBS electrometer for absolute point dose measurements in water and lung equivalent inserts. TPS calculated planar dose distributions were compared to those measured using EPID and MapCheck, as an independent verification method. Results were evaluated with gamma criteria of 2% dose difference and 2mm DTA for 95% of points. Results: GBD set vs. measured data passed 2% 2mm 1D gamma analysis even for small fields. Machine performance tests show results are independent of machine delivery configuration, as expected. Absolute point dosimetry comparison resulted within 4% for the worst case scenario in lung. Over 97% of the points evaluated in dose distributions passed gamma index analysis. Conclusion: Eclipse AAA algorithm configuration of the 6 MV high dose rate photon beam using GBD proved efficient. End-to-end test dose calculation results indicate it can be used clinically for SBRT using RapidArc.

  1. Single dose irradiation response of pig skin: a comparison of brachytherapy using a single, high dose rate iridium-192 stepping source with 200 kV X-rays

    NARCIS (Netherlands)

    P.C.J. Hamm; E.J. Bakker (Erik Jan); A.P. van den Berg (Aad); G.J.M.J. van den Aardweg (Gerard J. M.); A.G. Visser (Andries); P.C. Levendag (Peter)

    2000-01-01

    textabstractAn experimental brachytherapy model has been developed to study acute and late normal tissue reactions as a tool to examine the effects of clinically relevant multifractionation schedules. Pig skin was used as a model since its morphology, structure, cell

  2. Erratum: Attenuation measurements show that the presence of a TachoSil surgical patch will not compromise target irradiation in intra-operative electron radiation therapy or high-dose-rate brachytherapy.

    Science.gov (United States)

    Sarmento, Sandra; Costa, Filipa; Pereira, Alexandre; Lencart, Joana; Dias, Anabela; Cunha, Luís; Sousa, Olga; Silva, José Pedro; Santos, Lúcio

    2015-12-15

    After publication of this study [1], the authors noticed that the funding was incorrectly acknowledged. The correct Acknowledgements section can be found below: “This work was partly funded by Fundação para a Ciência e Tecnologia (FCT), in the framework of the project PTDC/SAU-ENB/117631/2010, which is cofinanced by FEDER, through Programa Operacional Fatores de Competitividade - COMPETE of QREN (reference FCOMP-01-0124-FEDER-021141).”

  3. Determinants of Toxicity, Patterns of Failure, and Outcome Among Adult Patients With Soft Tissue Sarcomas of the Extremity and Superficial Trunk Treated With Greater Than Conventional Doses of Perioperative High-Dose-Rate Brachytherapy and External Beam Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    San Miguel, Inigo [Department of Radiation Oncology, Clinica Universidad de Navarra, University of Navarra, Navarre (Spain); San Julian, Mikel [Department of Orthopedic Surgery, Clinica Universidad de Navarra, University of Navarra, Navarre (Spain); Cambeiro, Mauricio [Department of Radiation Oncology, Clinica Universidad de Navarra, University of Navarra, Navarre (Spain); Sanmamed, Miguel Fernandez [Department of Medical Oncology, Clinica Universidad de Navarra, University of Navarra, Navarre (Spain); Vazquez-Garcia, Blanca [Department of Orthopedic Surgery, Clinica Universidad de Navarra, University of Navarra, Navarre (Spain); Pagola, Maria; Gaztanaga, Miren [Department of Radiation Oncology, Clinica Universidad de Navarra, University of Navarra, Navarre (Spain); Martin-Algarra, Salvador [Department of Medical Oncology, Clinica Universidad de Navarra, University of Navarra, Navarre (Spain); Martinez-Monge, Rafael, E-mail: rmartinezm@unav.es [Department of Radiation Oncology, Clinica Universidad de Navarra, University of Navarra, Navarre (Spain)

    2011-11-15

    Purpose: The present study was undertaken to determine factors predictive of toxicity, patterns of failure, and survival in 60 adult patients with soft tissue sarcomas of the extremity and superficial trunk treated with combined perioperative high-dose-rate brachytherapy and external beam radiotherapy. Methods and Materials: The patients were treated with surgical resection and perioperative high-dose-rate brachytherapy (16 or 24 Gy) for negative and close/microscopically positive resection margins, respectively. External beam radiotherapy (45 Gy) was added postoperatively to reach a 2-Gy equivalent dose of 62.9 and 72.3 Gy, respectively. Adjuvant chemotherapy with ifosfamide and doxorubicin was given to patients with advanced high-grade tumors. Results: Grade 3 toxic events were observed in 18 patients (30%) and Grade 4 events in 6 patients (10%). No Grade 5 events were observed. A location in the lower limb was significant for Grade 3 or greater toxic events on multivariate analysis (p = .013), and the tissue volume encompassed by the 150% isodose line showed a trend toward statistical significance (p = .086). The local control, locoregional control, and distant control rate at 9 years was 77.4%, 69.5%, and 63.8%, respectively. On multivariate analysis, microscopically involved margins correlated with local control (p = .036) and locoregional control (p = .007) and tumor size correlated with distant metastases (p = .004). The 9-year disease-free survival and overall survival rate was 47.0% and 61.5%, respectively. Multivariate analysis showed poorer disease-free survival rates for patients with tumors >6 cm (p = .005) and microscopically involved margins (p = .043), and overall survival rates decreased with increasing tumor size (p = .011). Conclusions: Grade 3 or greater wound complications can probably be decreased using meticulous treatment planning to decrease the tissue volume encompassed by the 150% isodose line, especially in lower limb locations

  4. Computed Tomography–Guided Interstitial High-Dose-Rate Brachytherapy in Combination With Regional Positive Lymph Node Intensity-Modulated Radiation Therapy in Locally Advanced Peripheral Non–Small Cell Lung Cancer: A Phase 1 Clinical Trial

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Li; Zhang, Jian-wen; Lin, Sheng; Luo, Hui-Qun; Wen, Qing-Lian; He, Li-Jia; Shang, Chang-Ling; Ren, Pei-Rong; Yang, Hong-Ru; Pang, Hao-Wen; Yang, Bo; He, Huai-Lin [Department of Oncology, Affiliated Hospital of Luzhou Medical College, Luzhou (China); Chen, Yue, E-mail: chenyue5523@126.com [Department of Nuclear Medicine, Affiliated Hospital of Luzhou Medical College, Luzhou (China); Wu, Jing-Bo, E-mail: wjb6147@163.com [Department of Oncology, Affiliated Hospital of Luzhou Medical College, Luzhou (China)

    2015-08-01

    Purpose: To assess the technical safety, adverse events, and efficacy of computed tomography (CT)-guided interstitial high-dose-rate (HDR) brachytherapy in combination with regional positive lymph node intensity modulated radiation therapy in patients with locally advanced peripheral non–small cell lung cancer (NSCLC). Methods and Materials: Twenty-six patients with histologically confirmed NSCLC were enrolled in a prospective, officially approved phase 1 trial. Primary tumors were treated with HDR brachytherapy. A single 30-Gy dose was delivered to the 90% isodose line of the gross lung tumor volume. A total dose of at least 70 Gy was administered to the 95% isodose line of the planning target volume of malignant lymph nodes using 6-MV X-rays. The patients received concurrent or sequential chemotherapy. We assessed treatment efficacy, adverse events, and radiation toxicity. Results: The median follow-up time was 28 months (range, 7-44 months). There were 3 cases of mild pneumothorax but no cases of hemothorax, dyspnea, or pyothorax after the procedure. Grade 3 or 4 acute hematologic toxicity was observed in 5 patients. During follow-up, mild fibrosis around the puncture point was observed on the CT scans of 2 patients, but both patients were asymptomatic. The overall response rates (complete and partial) for the primary mass and positive lymph nodes were 100% and 92.3%, respectively. The 1-year and 2-year overall survival (OS) rates were 90.9% and 67%, respectively, with a median OS of 22.5 months. Conclusion: Our findings suggest that HDR brachytherapy is safe and feasible for peripheral locally advanced NSCLC, justifying a phase 2 clinical trial.

  5. Rectal Bleeding After High-Dose-Rate Brachytherapy Combined With Hypofractionated External-Beam Radiotherapy for Localized Prostate Cancer: The Relationship Between Dose-Volume Histogram Parameters and the Occurrence Rate

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Masahiko, E-mail: masaoka@showa.gunma-u.ac.jp [Department of Radiation Oncology, Gunma University Graduate School of Medicine, Gunma (Japan); Ishikawa, Hitoshi; Ebara, Takeshi; Kato, Hiroyuki; Tamaki, Tomoaki [Department of Radiation Oncology, Gunma University Graduate School of Medicine, Gunma (Japan); Akimoto, Tetsuo [Department of Radiation Oncology, Tokyo Women' s Medical University, Tokyo (Japan); Ito, Kazuto; Miyakubo, Mai; Yamamoto, Takumi; Suzuki, Kazuhiro [Department of Urology, Gunma University Graduate School of Medicine, Gunma (Japan); Takahashi, Takeo; Nakano, Takashi [Department of Radiation Oncology, Gunma University Graduate School of Medicine, Gunma (Japan)

    2012-02-01

    Purpose: To determine the predictive risk factors for Grade 2 or worse rectal bleeding after high-dose-rate brachytherapy (HDR-BT) combined with hypofractionated external-beam radiotherapy (EBRT) for prostate cancer using dose-volume histogram analysis. Methods and Materials: The records of 216 patients treated with HDR-BT combined with EBRT were analyzed. The treatment protocols for HDR-BT were 5 Gy Multiplication-Sign five times in 3 days or 7 Gy Multiplication-Sign three, 10.5 Gy Multiplication-Sign two, or 9 Gy Multiplication-Sign two in 2 days. The EBRT doses ranged from 45 to 51 Gy with a fractional dose of 3 Gy. Results: In 20 patients Grade 2 or worse rectal bleeding developed, and the cumulative incidence rate was 9% at 5 years. By converting the HDR-BT and EBRT radiation doses into biologic effective doses (BED), the BED{sub 3} at rectal volumes of 5% and 10% in the patients who experienced bleeding were significantly higher than those in the remaining 196 patients. Univariate analysis showed that a higher rectal BED{sub 3-5%} and the use of fewer needles in brachytherapy were correlated with the incidence of bleeding, but BED{sub 3-5%} was found to be the only significant factor on multivariate analysis. Conclusions: The radiation dose delivered to small rectal lesions as 5% is important for predicting Grade 2 or worse rectal bleeding after HDR-BT combined with EBRT for prostate cancer.

  6. The relationship between the biochemical control outcomes and the quality of planning of high-dose rate brachytherapy as a boost to external beam radiotherapy for locally and locally advanced prostate cancer using the RTOG-ASTRO Phoenix definition.

    Science.gov (United States)

    Pellizzon, Antonio Cassio Assis; Salvajoli, João; Novaes, Paulo; Maia, Maria; Fogaroli, Ricardo; Gides, Doglas; Horriot, Rodrigues

    2008-06-04

    To evaluated prognostic factors and impact of the quality of planning of high dose rate brachytherapy (HDR-BT) for patients with local or locally advanced prostate cancer treated with external beam radiotherapy (EBRT) and HDR-BT. Between 1997 and 2005, 209 patients with biopsy proven prostate adenocarcinoma were treated with localized EBRT and HDR-BT at the Department of Radiation-Oncology, Hospital A. C. Camargo, Sao Paulo, Brazil. Patient's age, Gleason score (GS), clinical stage (CS), initial PSA (iPSA), risk group for biochemical failure (GR), doses of EBRT and HDR-BT, use of three-dimensional planning for HDR-BT (3DHDR) and the Biological Effective Dose (BED) were evaluated as prognostic factors for biochemical control (bC). Median age and median follow-up time were 68 and 5.3 years, respectively. Median EBRT and HDR-BT doses were 45 Gy and 20 Gy. The crude bC at 3.3 year was 94.2%. For the Low, intermediate and high risk patients the bC rates at 3.3 years were 91.5%, 90.2% and 88.5%, respectively. Overall survival (OS) and disease specific survival rates at 3.3 years were 97.8% and 98.4%, respectively. On univariate analysis the prognostic factors related bC were GR (p= 0.040), GS or = 20 Gy (p or = 99 Gy(1.5) (p or = 185 (p or = 20 Gy (p=0.008) and 3DHDR (p<0.001). we observed that the bC rates correlates with the generally accepted risk factors described in the literature. Dose escalation, evaluated through the BED, and the quality of planning of HDR-BT are also important predictive factors when treating prostate cancer.

  7. Triple-tandem high-dose-rate brachytherapy for early-stage medically inoperable endometrial cancer: Initial report on acute toxicity and dosimetric comparison to stereotactic body radiation therapy.

    Science.gov (United States)

    Kauffmann, Greg; Wu, Tianming; Al-Hallaq, Hania; Hasan, Yasmin

    Stereotactic body radiotherapy (SBRT) may be appealing in medically inoperable endometrial cancer to avoid procedural risks. We performed a dosimetric comparison to triple-tandem, high-dose-rate (HDR) brachytherapy. Six consecutive clinical stage I, grade 1-2, medically inoperable endometrial cancer patients were treated with triple-tandem HDR brachytherapy. We report patient factors and acute toxicity. Also, we performed dosimetric comparison to SBRT using both 3D conformal arc (3DArc) and volumetric-modulated arc therapy. D2cc values for normal tissues were calculated and compared to the HDR plans. Median age was 57 years. Patient comorbidities included morbid obesity, congestive heart failure, diabetes, and pulmonary emboli. In three patients who received prior external beam radiation (EBRT), median EBRT and HDR doses were 46 Gy and 20 Gy, respectively. The median dose with HDR brachytherapy monotherapy was 35 Gy. Acute toxicities during EBRT included gastrointestinal (3/3 with grade 1-2) and genitourinary (3/3 with grade 1-2). Acute toxicities during HDR brachytherapy were gastrointestinal (2/6 total with grade 1-2) and genitourinary (2/6 total with grade 1). The mean D2cc/Gy of prescription dose for rectum, sigmoid, and bladder were 0.58, 0.40, and 0.47 respectively. Overall, doses to normal tissues were higher for SBRT plans as compared to HDR. Also, the R50 (ratio of the 50% prescription isodose volume to the PTV) was lowest with HDR brachytherapy. In medically inoperable, clinical stage I endometrial cancer patients with multiple comorbidities, definitive triple-tandem, HDR brachytherapy results in mild acute toxicity. In addition, HDR brachytherapy achieves relatively lower doses to surrounding normal tissues as compared to SBRT. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  8. Urethra low-dose tunnels: validation of and class solution for generating urethra-sparing dose plans using inverse planning simulated annealing for prostate high-dose-rate brachytherapy.

    Science.gov (United States)

    Cunha, J Adam M; Pouliot, Jean; Weinberg, Vivian; Wang-Chesebro, Alice; Roach, Mack; Hsu, I-Chow

    2012-01-01

    Urethral dose is related to severity of genitourinary toxicity in patients treated with brachytherapy for prostate cancer. This work describes a dose planning method that uses inverse planning to create a low-dose tunnel around the urethra and presents a class solution to achieve this additional dose sparing of the urethra. Fifteen patients on the Radiation Therapy Oncology Group (RTOG) 0321 protocol were treated for prostate cancer with a high-dose-rate brachytherapy dose boost to an external beam radiation treatment regimen. All were treated with 9.5Gy for each of the two fractions after 45Gy of the external beam radiation. The inverse-planning algorithm, inverse planning simulated annealing (IPSA), was used to create both the standard RTOG protocol (SRP) plan for treatment and the a posteriori urethra dose sparing (UDS) plan consisting of a dose tunnel along the urethra. Both plans maintained the protocol parameters: prostate V(100) (volume receiving 100% of prescribed dose)>90% and bladder and rectum V(75)90%, with mean for the SRP V(100)=93% versus UDS plan V(100)=90%. Prostate D(90) for SRP was 104% versus UDS plan D(90)=101%. For all patients, the UDS achieved a dose tunnel surrounding the length of the intraprostatic urethra. The class solution for generating UDS is presented. A urethral sparing-focused planning solution using IPSA reduces mean urethral dose by 34%, as compared with IPSA-generated plans based on the RTOG 0321 protocol. This is done while maintaining prostate coverage and critical structure dose. This technique can be applied to all patients in whom urethra toxicity is of particular concern. Copyright © 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  9. Acute and late vaginal toxicity after adjuvant high-dose-rate vaginal brachytherapy in patients with intermediate risk endometrial cancer: is local therapy with hyaluronic acid of clinical benefit?

    Directory of Open Access Journals (Sweden)

    Concetta Laliscia

    2016-12-01

    Full Text Available Purpose : The aim of the present study was to evaluate the effectiveness of hyaluronic acid (HA in the prevention of acute and late vaginal toxicities after high-dose-rate (HDR vaginal brachytherapy (BT. Material and methods : Between January 2011 and January 2015, we retrospectively analyzed 126 patients with endometrial cancer who underwent extrafascial hysterectomy with or without lymphadenectomy and adjuvant HDR-vaginal BT +/– adjuvant chemotherapy. The total dose prescription was 21 Gy in 3 fractions (one fraction for week. Vaginal ovules containing 5 mg of HA were given for whole duration of vaginal BT and for the two following weeks. Acute and late toxicities were evaluated according to CTCAE vs 4.02. Results : According to the revised FIGO 2009 classification, most tumors were in stage IA (30.9% and in stage IB (57.9%. Thirty-three patients (26.2% received adjuvant chemotherapy before vaginal BT. Five-year disease-free survival (DFS and five-year overall survival (OS were 88% and 93%, respectively. The most common grade 1-2 acute toxicities were vaginal inflammation (18 patients, 14.3% and dyspareunia (7 patients, 5.5%. Two patients (1.6% had more than one toxicity. Late toxicity occurred in 20 patients (15.9%. Grade 1-2 late toxicities were fibrosis (14 patients, 11.1% and telangiectasias (7 patients, 5.5%. Six patients (4.8% had more than one late toxicity. No grade 3 or higher acute or late toxicities were observed. Conclusions : These results appear to suggest that the local therapy with HA is of clinical benefit for intermediate risk endometrial cancer patients who receive adjuvant HDR-vaginal BT after surgery. A randomized trial comparing HA treatment vs. no local treatment in this clinical setting is warranted to further evaluate the efficacy of HA in preventing vaginal BT-related vaginal toxicity.

  10. Single-fraction high-dose-rate brachytherapy using real-time transrectal ultrasound based planning in combination with external beam radiotherapy for prostate cancer: dosimetrics and early clinical results

    Directory of Open Access Journals (Sweden)

    Olivier Lauche

    2016-04-01

    Full Text Available Purpose : To validate the feasibility of a single-fraction high-dose-rate brachytherapy (HDRBT boost for prostate cancer using real-time transrectal ultrasound (TRUS based planning. Material and methods : From August 2012 to September 2015, 126 patients underwent a single-fraction HDRBT boost of 15 Gy using real-time TRUS based planning. External beam radiation therapy (EBRT (37.5 Gy/15 fractions, 44 Gy/22 fractions, or 45 Gy/25 fractions was performed before (31% or after (69% HDRBT boost. Genito-urinary (GU and gastro-intestinal (GI toxicity were assessed 4 and 12 months after the end of combined treatment using the international prostate symptom score scale (IPSS and the common terminology criteria for adverse events (CTCAE v3.0. Results : All dose-planning objectives were achieved in 90% of patients. Prostate D 90 ≥ 105% and ≤ 115% was achieved in 99% of patients, prostate V 150 ≤ 40% in 99%, prostate V 200 < 11% in 96%, urethra D 10 < 120% for 99%, urethra V 125 = 0% in 100%, and rectal V 75 < 1 cc in 93% of patients. Median IPSS score was 4 at baseline and did not change at 4 and 12 months after combined treatment. No patients developed ≥ grade 2 GI toxicity. With a median follow-up of 10 months, only two patients experienced biochemical failure. Among patients who didn’t receive ADT, cumulative percentage of patients with PSA ≤ 1 ng/ml at 4 and 18 months was respectively 23% and 66%. Conclusions : Single-fraction HDRBT boost of 15 Gy using real-time TRUS based planning achieves consistently high dosimetry quality. In combination with EBRT, toxicity outcomes appear promising. A longer follow-up is needed to assess long-term outcome and toxicities.

  11. Combination of high-dose rate brachytherapy and external beam radiotherapy for the treatment of advanced scalp angiosarcoma - case report; Braquiterapia de alta taxa de dose associada a radioterapia externa no tratamento de angiossarcoma extenso do couro cabeludo - relato de caso

    Energy Technology Data Exchange (ETDEWEB)

    Gentil, Andre Cavalcanti; Lima Junior, Carlos Genesio Bezerra [Instituto Nacional do Cancer, Rio de Janeiro, RJ (Brazil). Dept. de Radioterapia]. E-mail: andregentil@hotmail.com; Soboll, Danyel Scheidegger; Novaes, Paulo Eduardo R.S.; Pereira, Adelino Jose; Pellizon, Antonio Carlos Assis [Hospital do Cancer A.C. Camargo, Sao Paulo, SP (Brazil). Centro de Tratamento e Pequisa

    2001-10-01

    The authors report a case of a patient with an extensive angiosarcoma of the scalp that was submitted only to radiotherapy with a combination of orthovoltage roentgentherapy and high-dose rate brachytherapy, using a mould. The clinical and technical features as well as the therapeutic outcome are presented, and the usefulness and peculiarities of high-dose rate brachytherapy for this particular indication is discussed. A comparative analysis of the difficulties and limitations of employing low-dose rate brachytherapy is also presented. The authors concluded that high-dose rate brachytherapy might be an useful, practical and safe option to treat neoplastic lesions of the scalp, and an alternative treatment to electrontherapy. (author)

  12. Building lab-scale x-ray tube based irradiators

    Science.gov (United States)

    The construction of economical x-ray tube based irradiators in a variety of configurations is described using 1000 Watt x-ray tubes. Single tube, double tube, and four tube designs are described, as well as various cabinet construction techniques. Relatively high dose rates were achieved for small s...

  13. Film-substrate hydrodynamic interaction initiated by femtosecond laser irradiation

    Science.gov (United States)

    Khokhlov, V. A.; Inogamov, N. A.; Zhakhovsky, V. V.; Ilnitsky, D. K.; Migdal, K. P.; Shepelev, V. V.

    2017-01-01

    Action of an ultrashort single laser pulse onto a thin metal film is considered. Disruption of a plane freestanding film quickly heated by a laser is the simplest model of the laser thermomechanical spallation. There is a sharp spallation (ablation) threshold Fabl dividing dynamics of a freestanding film to two regimes: below or above the threshold Fabl. Problem of significant importance is: how this picture will change when a film is deposited onto a substrate? We have solved this problem. It is found that there are two thresholds Fdelam waves into substrate. For Fdelam wave achieves the film-substrate contact boundary and overcomes adhesion strength of a contact. The addition ΔF to the freestanding case is small in the case when the ratio η of the acoustic impedances of substrate to a film is small. This is the case of the gold or silver films on a glass. The third is the complicated regime with interacting delamination and spallation processes when F ≈ Fabl + ΔF. In the fourth regime Fabl + ΔF one remains on substrate.

  14. Schistosoma mansoni: interactive effects of irradiation and cryopreservation on parasite maturation and immunization of mice

    Energy Technology Data Exchange (ETDEWEB)

    James, E.R.; Dobinson, A.R.

    1984-06-01

    Mechanically transformed schistosomula of Schistosoma mansoni were irradiated with levels of 60Co irradiation between 2.5 and 54 krad, cryopreserved by the two-step addition of ethanediol and rapid cooling technique, and were injected intramuscularly into groups of mice which were perfused 40 days later. The schistosomula were either irradiated and then cryopreserved (IC) or cryopreserved and then irradiated in the frozen state (CI). Development into adult worms was prevented with 4 krad for IC schistosomula, but for CI schistosomula a small number of worms (1.6%) was recovered using 8.8 krad. A dose of 4 krad was sufficient to prevent development of unfrozen controls (I), but for schistosomula irradiated while exposed to ethanediol (EI), a dose of 7 krad was required. Using the different protocols, the peak levels of protection against a challenge infection were achieved with 9 (IC) and 16 krad (CI), compared to 20 krad for unfrozen schistosomula (I) reported previously. The highest level of protection (65%) was achieved with CI schistosomula. Possible interactions between the radioprotective and damaging effects of cryopreservation are discussed.

  15. Prostate Specific Antigen (PSA as Predicting Marker for Clinical Outcome and Evaluation of Early Toxicity Rate after High-Dose Rate Brachytherapy (HDR-BT in Combination with Additional External Beam Radiation Therapy (EBRT for High Risk Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Thorsten H. Ecke

    2016-11-01

    Full Text Available High-dose-rate brachytherapy (HDR-BT with external beam radiation therapy (EBRT is a common treatment option for locally advanced prostate cancer (PCa. Seventy-nine male patients (median age 71 years, range 50 to 79 with high-risk PCa underwent HDR-BT following EBRT between December 2009 and January 2016 with a median follow-up of 21 months. HDR-BT was administered in two treatment sessions (one week interval with 9 Gy per fraction using a planning system and the Ir192 treatment unit GammaMed Plus iX. EBRT was performed with CT-based 3D-conformal treatment planning with a total dose administration of 50.4 Gy with 1.8 Gy per fraction and five fractions per week. Follow-up for all patients was organized one, three, and five years after radiation therapy to evaluate early and late toxicity side effects, metastases, local recurrence, and prostate-specific antigen (PSA value measured in ng/mL. The evaluated data included age, PSA at time of diagnosis, PSA density, BMI (body mass index, Gleason score, D’Amico risk classification for PCa, digital rectal examination (DRE, PSA value after one/three/five year(s follow-up (FU, time of follow-up, TNM classification, prostate volume, and early toxicity rates. Early toxicity rates were 8.86% for gastrointestinal, and 6.33% for genitourinary side effects. Of all treated patients, 84.81% had no side effects. All reported complications in early toxicity were grade 1. PSA density at time of diagnosis (p = 0.009, PSA on date of first HDR-BT (p = 0.033, and PSA on date of first follow-up after one year (p = 0.025 have statistical significance on a higher risk to get a local recurrence during follow-up. HDR-BT in combination with additional EBRT in the presented design for high-risk PCa results in high biochemical control rates with minimal side-effects. PSA is a negative predictive biomarker for local recurrence during follow-up. A longer follow-up is needed to assess long-term outcome and toxicities.

  16. 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

    can thus be an alternative to {sup 192}Ir-only in high-dose-rate prostate brachytherapy.

  17. Prostate Specific Antigen (PSA) as Predicting Marker for Clinical Outcome and Evaluation of Early Toxicity Rate after High-Dose Rate Brachytherapy (HDR-BT) in Combination with Additional External Beam Radiation Therapy (EBRT) for High Risk Prostate Cancer.

    Science.gov (United States)

    Ecke, Thorsten H; Huang-Tiel, Hui-Juan; Golka, Klaus; Selinski, Silvia; Geis, Berit Christine; Koswig, Stephan; Bathe, Katrin; Hallmann, Steffen; Gerullis, Holger

    2016-11-10

    High-dose-rate brachytherapy (HDR-BT) with external beam radiation therapy (EBRT) is a common treatment option for locally advanced prostate cancer (PCa). Seventy-nine male patients (median age 71 years, range 50 to 79) with high-risk PCa underwent HDR-BT following EBRT between December 2009 and January 2016 with a median follow-up of 21 months. HDR-BT was administered in two treatment sessions (one week interval) with 9 Gy per fraction using a planning system and the Ir192 treatment unit GammaMed Plus iX. EBRT was performed with CT-based 3D-conformal treatment planning with a total dose administration of 50.4 Gy with 1.8 Gy per fraction and five fractions per week. Follow-up for all patients was organized one, three, and five years after radiation therapy to evaluate early and late toxicity side effects, metastases, local recurrence, and prostate-specific antigen (PSA) value measured in ng/mL. The evaluated data included age, PSA at time of diagnosis, PSA density, BMI (body mass index), Gleason score, D'Amico risk classification for PCa, digital rectal examination (DRE), PSA value after one/three/five year(s) follow-up (FU), time of follow-up, TNM classification, prostate volume, and early toxicity rates. Early toxicity rates were 8.86% for gastrointestinal, and 6.33% for genitourinary side effects. Of all treated patients, 84.81% had no side effects. All reported complications in early toxicity were grade 1. PSA density at time of diagnosis (p = 0.009), PSA on date of first HDR-BT (p = 0.033), and PSA on date of first follow-up after one year (p = 0.025) have statistical significance on a higher risk to get a local recurrence during follow-up. HDR-BT in combination with additional EBRT in the presented design for high-risk PCa results in high biochemical control rates with minimal side-effects. PSA is a negative predictive biomarker for local recurrence during follow-up. A longer follow-up is needed to assess long-term outcome and toxicities.

  18. High-dose rate brachytherapy of prostatic adenocarcinoma in combination with external beam radiotherapy. A long-term follow-up of the first 50 patients at one center

    Energy Technology Data Exchange (ETDEWEB)

    Lennernaes, B. [Dept. of Oncology, Sahlgrenska Univ. Hospital (Sweden); Holmaeng, S. [Dept. of Urology, Sahlgrenska Univ. Hospital (Sweden); Hedelin, H. [Kaernsjukhuset, Skoevde (Sweden)

    2002-10-01

    Aim: To report the long-term follow-up of 50 patients with prostatic adenocarcinoma (PAC) by high-dose rate brachytherapy in combination with external beam radiotherapy. Patients and methods: Between 1988 and 1995, 50 patients were treated with external beam radiotherapy delivered in 2 Gy fractions to a total dose of 50 Gy. Brachytherapy was delivered in two 10 Gy fractions. The mean follow-up time was 7.2 years. Results: 42 patients are alive and four patients have deceased of prostatic adenocarcinoma. Of the remaining patients, 40 have a PSA<1 ng/l. 41 patients were interviewed during the year 2000 and 91% of these were satisfied with the treatment. Four (8%) patients reported grade III/IV side effects. Ten of the 41 patients reported that they still had an erection allowing intercourse. Half of those who developed an erectile dysfunction did so in direct connection with the treatment. In the others erectile dysfunction developed gradually during the first 48 months after the treatment. Conclusion: The combined treatment gave an exceptionally good local control (86%). The method represents a promising curative treatment, but the effect can be double edged. The small number of patients in this study restricts a more conclusive statement concerning this treatment modality. (orig.) [German] Ziel: Monoinstitutioneller Erfahrungsbericht zur Behandlung des Prostatakarzinoms mit kombinierter externer und HDR-Brachytherapie. Patienten und Methoden: Von 1988 bis 1995 wurden 50 Patienten mit einem Prostataadenokarzinom kombiniert extern und interstitiell behandelt. Die perkutane Radiotherapie erfolgte bei einer Einzeldosis von 2 Gy bis zu einer Gesamtreferenzdosis von 50 Gy. Die Brachtherapie folgte mittels zweier HDR-Fraktionen von je 10 Gy. Die mediane Nachbeobachtungszeit betrug 7,2 Jahre. Ergebnisse: 42 Patienten sind am Leben, vier starben am Prostataadenokarzinom. Von den ueberlebenden Patienten haben 40 einen PSA-Wert <1 ng/l. 41 Patienten wurden waehrend des Jahres

  19. Proposal of a high dose rate brachytherapy model for radiobiology studies in vitro; Proposta de um modelo de braquiterapia de alta taxa de dose para estudos de radiobiologia in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Jony M.; Andrade, Lidia M., E-mail: jony.marques@mariopenna.org.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Departamento de Fisica; Trindade, Cassia [Hospital Luxemburgo, Belo Horizonte, MG (Brazil); Nogueira, Luciana B. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Faculdade de Medicina; Furtado, Clascidia A.; Ladeira, Luiz Orlando [Centro de Desenvolvimento da Tecnologia Nuclear (CTDN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2016-07-01

    The aim of this research was to develop an easy and reproducible approach for experimental HDR brachytherapy allowing in vitro irradiation studies based on clinical parameters. An acrylic platform was designed to attach T25 tissue culture flasks and multi-well tissue culture plates as well as kept the catheters in a fixed position during irradiation. CT images were taken and the irradiation was planned for 550cGy dose applied on adherent tumor cells. Dosimetric measurements were done and all relevant uncertainties were taken into account in order to figure out the correct dose range received by the cells. Tumor cells were irradiated two times over an interval of 24h between irradiations. Proof of concepts of this approach was carried out by biological effects analysis using a radioresistant human epidermoid carcinoma A431 cell line. Cellular proliferation and cell cycle phase were assessed by Trypan blue exclusion assay and DNA content analysis by flow cytometry, respectively. This approach allowed uniform dose distribution around the arrangement in all types of tissue culture plastics evaluated. Corrections due to uncertainties were managed. Regarding in vitro assays there was a significant (p<0.05) decreasing of cellular proliferation rate in irradiated cells. Moreover, increased percentage of cells arrested in G2/M phase (32.3 ± 1.5%) were observed for treated group compared with untreated cells. (author)

  20. Proposal of a high dose rate brachytherapy model for in vitro radiobiology studies; Proposta de um modelo de braquiterapia de alta taxa de dose para estudos de radiobiologia in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Jony M.; Nogueira, Luciana B.; Andrade, Lidia M. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Trindade, Cassia [Hospital Luxemburgo, Belo Horizonte, MG (Brazil); Furtado, Clascidia A.; Ladeira, Luiz Orlando, E-mail: jony.marques@mariopenna.org.br [Centro de Desenvolvimento da Tecnologia Nuclear (CTDN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2016-07-01

    The aim of this research was to develop an easy and reproducible approach for experimental HDR brachytherapy allowing in vitro irradiation studies based on clinical parameters. An acrylic platform was designed to attach T25 tissue culture flasks and multi-well tissue culture plates as well as kept the catheters in a fixed position during irradiation. CT images were taken and the irradiation was planned for 550cGy dose applied on adherent tumor cells. Dosimetric measurements were done and all relevant uncertainties were taken into account in order to figure out the correct dose range received by the cells. Tumor cells were irradiated two times over an interval of 24h between irradiations. Proof of concepts of this approach was carried out by biological effects analysis using a radioresistant human epidermoid carcinoma A431 cell line. Cellular proliferation and cell cycle phase were assessed by Trypan blue exclusion assay and DNA content analysis by flow cytometry, respectively. This approach allowed uniform dose distribution around the arrangement in all types of tissue culture plastics evaluated. Corrections due to uncertainties were managed. Regarding in vitro assays there was a significant (p<0.05) decreasing of cellular proliferation rate in irradiated cells. Moreover, increased percentage of cells arrested in G2/M phase (32.3 ± 1.5%) were observed for treated group compared with untreated cells. (author)

  1. Interactive effects of nitrogen and irradiance on growth and partitioning of dry mass and nitrogen in young tomato plants

    NARCIS (Netherlands)

    Groot, de C.C.; Marcelis, L.F.M.; Boogaard, van der R.; Lambers, H.

    2002-01-01

    The interactive effects of irradiance and N on growth of young tomato plants (Lycopersicon esculentum Mill.) were studied. Plants were grown at 70 or 300 μmol photons m–2 s–1, hereafter referred to as 'low' and 'high' irradiance, and at a range of exponential N supply rates (70–370 mg g–1 d–1) or at

  2. Comparison of absorbed dose in the cervix carcinoma therapy by brachytherapy of high dose rate using the conventional planning and Monte Carlo simulation; Comparacao da dose absorvida no tratamento do cancer ginecologico por braquiterapia de alta taxa de dose utilizando o planejamento convencional do tratamento e simulacao de Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Aneli Oliveira da

    2010-07-01

    This study aims to compare the doses received for patients submitted to brachytherapy High Dose Rate (HDR) brachytherapy, a method of treatment of the cervix carcinoma, performed in the planning system PLATO BPS with the doses obtained by Monte Carlo simulation using the radiation transport code MCNP 5 and one female anthropomorphic phantom based on voxel, the FAX. The implementation of HDR brachytherapy treatment for the cervix carcinoma consists of the insertion of an intrauterine probe and an intravaginal probe (ring or ovoid) and then two radiographs are obtained, anteroposterior (AP) and lateral (LAT) to confirm the position of the applicators in the patient and to allow the treatment planning and the determination of the absorbed dose at points of interest: rectum, bladder, sigmoid and point A, which corresponds anatomically to the crossings of the uterine arteries with ureters The absorbed doses obtained with the code MCNP 5, with the exception of the absorbed dose in the rectum and sigmoid for the simulation considering a point source of {sup 192}Ir, are lower than the absorbed doses from PLATO BPS calculations because the MCNP 5 considers the chemical compositions and densities of FAX body, not considering the medium as water. When considering the Monte Carlo simulation for a source with dimensions equal to that used in the brachytherapy irradiator used in this study, the values of calculated absorbed dose to the bladder, to the rectum, to the right point A and to the left point A were respectively lower than those determined by the treatment planning system in 33.29, 5.01, 22.93 and 19.04%. These values are almost all larger than the maximum acceptable deviation between patient planned and administered doses (5 %). With regard to the rectum and bladder, which are organs that must be protected, the present results are in favor of the radiological protection of patients. The point A, that is on the isodose of 100%, used to tumor treatment, the results

  3. In Situ Studies on the Irradiation-Induced Twin Boundary-Defect Interactions in Cu

    Science.gov (United States)

    Fan, C.; Li, Jin; Fan, Zhe; Wang, H.; Zhang, X.

    2017-11-01

    Polycrystalline Cu films with nanoscale annealing twins are subjected to in situ Kr++ ion irradiation at room temperature inside a transmission electron microscope up to a dose of 1 displacement-per-atom. Radiation induces prominent migration of incoherent twin boundaries. Depending on twin thickness, three types of twin boundary evolutions are observed, including rapid detwinning, gradual detwinning, and self-healing. The mechanism of twin thickness-dependent evolution of microstructures is discussed. This study provides further evidence on twin boundary-defect interactions and may assist the design of radiation-tolerant twinned metallic materials.

  4. Gamma irradiation on canola seeds affects herbivore-plant and host-parasitoid interactions

    Energy Technology Data Exchange (ETDEWEB)

    Akandeh, M.; Kocheili, F.; Rasekh, A. [Dept. of Entomology, Shahid Chamran Univ of Ahvaz (Iran, Islamic Republic of); Soufbaf, M., E-mail: msoufbaf@nrcam.org [Agricultural, Medical and Industrial Research School, Karaj (Iran, Islamic Republic of)

    2017-06-15

    As an agricultural modernization, gamma irradiation is an important method for enhancing crop yield and quality. Nevertheless, its use can alter other plant traits such as nutrition and resistance to different biotic/abiotic stresses that consequently affect plant-insect interactions. A tritrophic system was utilized based on two canola mutant lines produced through gamma irradiation (RGS 8-1 and Talaye 8-3). Plutella xylostella (L.), as a worldwide pest of Brassicaceae and Cotesia vestalis (Holiday) as a key biocontrol agent of P. xylostella were examined for the potential indirect effects of canola seed irradiation on the experimental insects' performance when acting on the respective mutant lines. This study showed that physical mutation did not affect plant nitrogen and herbivore-damaged total phenolics; however, phenolic compounds showed greater concentration in damaged leaves than undamaged leaves of both mutant and control plants. The relative growth rate and pupal weight of P. xylostella reared on RGS 8-1 were significantly higher than those reared on the control RGS. There was no significant difference by performance parameters of the parasitoid, C. vestalis, including total pre-oviposition period, adult longevity, adult fresh body weight of males and females, pupal weight, forewing area, and total longevity of both sexes on tested canola cultivars in comparison with their mutant lines. Life table parameters of C. vestalis on mutant lines of both cultivars, RGS and Talaye, were not significantly different from their control treatments. Comprehensive studies should be conducted to find out the mechanisms under which gamma rays affect plant-insect interactions. (author)

  5. Characterization of TLD-100 in powders for dosimetric quality control of {sup 192} Ir sources used in brachytherapy of high dose rate; Caracterizacion de TLD-100 en polvo para control de calidad dosimetrico de fuentes de Ir{sup 192} usadas en braquiterapia de alta tasa de dosis

    Energy Technology Data Exchange (ETDEWEB)

    Loaiza C, S.P

    2007-07-01

    The Secondary Standard Dosimetric at the National Institute of Nuclear Research (ININ) calibrated a lot of powdered TLD-100 (LiF:Mg,Ti) in terms of absorbed dose to water D{sub w} for the energy of: {sup 60}Co, {sup 137C}s, X rays of 250 and 50 kVp. Later on, it is carried out an interpolation of the calibration for the energy of the {sup 192}Ir. This calibration is part of a dosimetric quality control program, to solve the problems of traceability for the measurements carried out by the users of {sup 192}Ir sources employed in the treatments of High Dose Rate Brachytherapy (HDR) at the Mexican Republic. The calibrations of the radiation beams are made with the following protocols: IAEA TRS-398 for the {sup 60}Co for D{sub w}, using a secondary standard ionization chamber PTW N30013 calibrated in D{sub w} by the National Research Council (NRC, Canada). AAPM TG-43 for D{sub w} in terms of the strength kerma Sk, calibrating this last one quantity for the {sup 137}Cs radioactive source, with a well chamber HDR 1000 PLUS traceable to the University of Wisconsin (US). AAPM TG-61 for X ray of 250 and 50 kVp for D{sub w} start to Ka using field standard a Farmer chamber PTW 30001 traceable to K for the Central Laboratory of Electric Industries (CLEI, France). The calibration curves (CC) they built for the response of the powder TLD: R{sub TLD} vs D{sub w}: For the energy of {sup 60}Co, {sup 137}Cs, X rays of 250 and 50 kVp. Fitting them with the least square method weighed by means of a polynomial of second grade that corrects the supra linearity of the response. iii. Each one of the curves was validated with a test by lack of fitting and for the Anderson Darling normality test, using the software MINITAB in both cases. iv. The sensibility factor (F{sub s}) for each energy corresponds to the slope of the CC, v. The F{sub s} for the two {sup 192}Ir sources used are interpolated: one for a Micro Selectron source and the other one a Vari Source source. Finally, a couple of

  6. Effect of gamma irradiation on hyaluronic acid and dipalmitoylphosphatidylcholine (DPPC) interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Ainee Fatimah; Mohd, Hur Munawar Kabir; Taqiyuddin Mawardi bin Ayob, Muhammad; Rosli, Nur Ratasha Alia Md; Mohamed, Faizal; Radiman, Shahidan; Rahman, Irman Abdul [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2014-09-03

    DPPC lipids are the major component constituting the biological membrane, and their importances in various physiological functions are well documented. Hyaluronic acid (HA) in the synovial joint fluid functions as a lubricant, shock absorber and a nutrient carrier. Gamma irradiation has also been found to be effective in depolymerizing and cleaving molecular chains related to free radicals, thus extends with changes in chemical composition as well as its physiological functions. This research are conducted to investigate the hyaluronic acid (HA) and 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) interaction in form of vesicles and its effect to gamma radiation. The size of DPPC vesicles formed via gentle hydration method is between 100 to 200 nm in diameter. HA (0.1, 0.5 and 1.0 mg/ml) was added into the vesicles and characterized by using TEM to determine vesicle size distributions, fusion and rupture of DPPC structure. The results demonstrated that the size of the vesicles approximately between 200 to 300 nm which caused by vesicles fusion with HA and formed even larger vesicles. After being irradiated by 0 to 200 Gy, the size of vesicles decreased as HA was degraded. To elucidate the mechanism of these effects, FTIR spectra were carried out and have shown that at absorption bands at 1700–1750 cm{sup −1} due to formation of carboxylic acid and leads to alteration of HA structure.

  7. Influence of irradiation conditions on plasma evolution in laser-surface interaction

    Science.gov (United States)

    Hermann, J.; Boulmer-Leborgne, C.; Dubreuil, B.; Mihailescu, I. N.

    1993-09-01

    The plasma plume induced by pulsed CO2 laser irradiation of a Ti target at power densities up to 4×108 W cm-2 was studied by emission spectroscopy. Time- and space-resolved measurements were performed by varying laser intensity, laser temporal pulse shape, ambient gas pressure, and the nature of the ambient gas. Experimental results are discussed by comparison with usual models. We show that shock wave and plasma propagation depend critically on the ratio Ivap/Ii, Ivap being the intensity threshold for surface vaporization and Ii the plasma ignition threshold of the ambient gas. Spectroscopic diagnostics of the helium breakdown plasma show maximum values of electron temperature and electron density in the order of kTe˜10 eV and ne=1018 cm-3, respectively. The plasma cannot be described by local thermodynamic equilibrium modeling. Nevertheless, excited metal atoms appear to be in equilibrium with electrons, hence, they can be used like a probe to measure the electron temperature. In order to get information on the role of the plasma in the laser-surface interaction, Ti surfaces were investigated by microscopy after irradiation. Thus an enhanced momentum transfer from the plasma to the target due to the recoil pressure of the breakdown plasma could be evidenced.

  8. Status Report on the Fabrication of Fuel Cladding Chemical Interaction Test Articles for ATR Irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Field, Kevin G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Howard, Richard H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-28

    FeCrAl alloys are a promising new class of alloys for light water reactor (LWR) applications due to their superior oxidation and corrosion resistance in high temperature environments. The current R&D efforts have focused on the alloy composition and processing routes to generate nuclear grade FeCrAl alloys with optimized properties for enhanced accident tolerance while maintaining properties needed for normal operation conditions. Therefore, the composition and processing routes must be optimized to maintain the high temperature steam oxidation (typically achieved by increasing the Cr and Al content) while still exhibiting properties conducive to normal operation in a LWR (such as radiation tolerance where reducing Cr content is favorable). Within this balancing act is the addition of understanding the influence on composition and processing routes on the FeCrAl alloys for fuel-cladding chemical interactions (FCCI). Currently, limited knowledge exists on FCCI for the FeCrAl-UO2 clad-fuel system. To overcome the knowledge gaps on the FCCI for the FeCrAl-UO2 clad-fuel system a series of fueled irradiation tests have been developed for irradiation in the Advanced Test Reactor (ATR) housed at the Idaho National Laboratory (INL). The first series of tests has already been reported. These tests used miniaturized 17x17 PWR fuel geometry rodlets of second-generation FeCrAl alloys fueled with industrial Westinghouse UO2 fuel. These rodlets were encapsulated within a stainless steel housing.To provide high fidelity experiments and more robust testing, a new series of rodlets have been developed deemed the Accident Tolerant Fuel Experiment #1 Oak Ridge National Laboratory FCCI test (ATF-1 ORNL FCCI). The main driving factor, which is discussed in detail, was to provide a radiation environment where prototypical fuel-clad interface temperatures are met while still maintaining constant contact between industrial fuel and the candidate cladding alloys

  9. Identification of novel direct protein-protein interactions by irradiating living cells with femtosecond UV laser pulses.

    Science.gov (United States)

    Itri, Francesco; Monti, Daria Maria; Chino, Marco; Vinciguerra, Roberto; Altucci, Carlo; Lombardi, Angela; Piccoli, Renata; Birolo, Leila; Arciello, Angela

    2017-10-07

    The identification of protein-protein interaction networks in living cells is becoming increasingly fundamental to elucidate main biological processes and to understand disease molecular bases on a system-wide level. We recently described a method (LUCK, Laser UV Cross-linKing) to cross-link interacting protein surfaces in living cells by UV laser irradiation. By using this innovative methodology, that does not require any protein modification or cell engineering, here we demonstrate that, upon UV laser irradiation of HeLa cells, a direct interaction between GAPDH and alpha-enolase was "frozen" by a cross-linking event. We validated the occurrence of this direct interaction by co-immunoprecipitation and Immuno-FRET analyses. This represents a proof of principle of the LUCK capability to reveal direct protein interactions in their physiological environment. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Braquiterapia de alta taxa de dose associada a radioterapia externa no tratamento de angiossarcoma extenso do couro cabeludo: relato de caso Combination of high-dose rate brachytherapy and external beam radiotherapy for the treatment of advanced scalp angiosarcoma: case report

    Directory of Open Access Journals (Sweden)

    André Cavalcanti Gentil

    2001-10-01

    Full Text Available Os autores apresentam um caso de extenso angiossarcoma do couro cabeludo submetido a radioterapia exclusiva, pela associação de roentgenterapia de ortovoltagem e braquiterapia de alta taxa de dose utilizando um molde. Descrevem os aspectos clínicos, técnicos e a evolução terapêutica. Destacam as particularidades e a utilidade da braquiterapia de alta taxa de dose, nesta situação em particular, e fazem uma análise comparativa das dificuldades e limitações caso a braquiterapia de baixa taxa de dose fosse empregada. Concluem ser a braquiterapia de alta taxa de dose uma opção útil, prática e segura para as lesões neoplásicas superficiais do escalpe, podendo ser considerada uma alternativa ao tratamento com elétrons.The authors report a case of a patient with an extensive angiosarcoma of the scalp that was submitted only to radiotherapy with a combination of orthovoltage roentgentherapy and high-dose rate brachytherapy, using a mould. The clinical and technical features as well as the therapeutic outcome are presented, and the usefulness and peculiarities of high-dose rate brachytherapy for this particular indication is discussed. A comparative analysis of the difficulties and limitations of employing low-dose rate brachytherapy is also presented. The authors concluded that high-dose rate brachytherapy might be an useful, practical and safe option to treat neoplastic lesions of the scalp, and an alternative treatment to electrontherapy.

  11. Temperature dependence of the rate constant of hydrogen isotope interactions with a lithium capillary-porous system under reactor irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tazhibayeva, Irina, E-mail: tazhibayeva@ntsc.kz [Institute of Atomic Energy NNC RK, Kurchatov (Kazakhstan); Kulsartov, Timur; Gordienko, Yuri [Institute of Atomic Energy NNC RK, Kurchatov (Kazakhstan); Mukanova, Aliya [Al’ Farabi Kazakh National University, Almaty (Kazakhstan); Ponkratov, Yuri; Barsukov, Nikolay; Tulubaev, Evgeniy [Institute of Atomic Energy NNC RK, Kurchatov (Kazakhstan); Platacis, Erik [University of Latvia (IPUL), Riga (Latvia); Kenzhin, Ergazy [Shakarim Semey State University, Semey (Kazakhstan)

    2013-10-15

    Highlights: • The experiments with Li CPS sample were carried out at reactor IVG-1.M. • The gas absorption technique was used to study hydrogen isotope interaction with lithium CPS. • The temperature dependence of constants of interaction rate was obtained for various power rates of the reactor. • Determination of the activation energies, and pre-exponents of Arrhenius dependence. • The effect of increase of the rate constant under reaction irradiation. -- Abstract: Experiments with a sample of a lithium capillary-porous system (CPS) were performed at the reactor IVG-1.M of the Institute of Atomic Energy NNC RK to study the effects of neutron irradiation on the parameters of hydrogen isotope interactions with a lithium CPS. The absorption technique was used during the experiments, and this technique allowed the temperature dependences of the hydrogen isotope interaction rate constants with the lithium CPS to be obtained under various reactor powers. The obtained dependencies were used to determine the main interaction parameters: the activation energies and the pre-exponents of the Arrhenius dependence of the hydrogen interaction rate constants with lithium and the lithium CPS. An increase of the hydrogen isotope interaction rate with the lithium CPS was observed under reactor irradiation.

  12. Interaction of post harvest disease control treatments and gamma irradiation on mangoes

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, G.I.; Cooke, A.W. (Department of Primary Industries, Indooroopilly (Australia)); Boag, T.S. (Riverina-Murray Inst. of Higher Education, Wagga Wagga (Australia). School of Agriculture); Izard, M. (Australian Nuclear Science and Technology Organisation, Lucas Heights (Australia)); Panitz, M. (Committee of Direction of Fruit Marketing, Brisbane Markets (Australia)); Sangchote, S. (Kasetsart Univ., Bangkok (Thailand))

    1990-04-01

    The effects of gamma irradiation and disease control treatments on disease severity and post harvest quality of several mango cultivars were investigated. In mangoes cv. Kensington Pride, irradiation doses ranging from 300-1200 Gy reduced disease, but the level of control was not commercially acceptable. Hot benomyl immediately followed by irradiation provided effective control of anthracnose (Colletotrichum gloeosporioides) and stem end rot (Dothiorella dominicana) during short-term storage (15 days at 20degC). The effects of the two treatments were additive. Satisfactory disease control was achieved during long-term controlled atmosphere storage when mangoes were treated with hot benomyl followed by prochloraz and then irradiated. Effects of fungicide treatment and irradiation were additive. Fungicide, or irradiation treatments alone, were unsatisfactory. Irradiation of cv. Kensington Pride at doses in excess of 600 Gy caused unacceptable surface damage. (author).

  13. Four-color laser irradiation system for laser-plasma interaction experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pennington, D.M.; Henesian, M.A.; Wilcox, R.B. [and others

    1996-06-01

    Since 1986, optical smoothing of the laser irradiance on targets for Inertial Confinement Fusion (ICF) has gained increasing attention. Optical smoothing can significantly reduce wavefront aberrations that produce nonuniformities in the energy distribution of the focal spot. Hot spots in the laser irradiance can induce local self focusing of the light, producing filamentation of the plasma. Filamentation can have detrimental consequences on the hydrodynamics of an ICF plasma, and can affect the growth of parametric instabilities, as well as add to the complexity of the study of such instabilities as stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS). As experiments approach and exceed breakeven (i.e., where driver energy = fusion yield), the likelihood of significant excitation of these processes increases. As a result, the authors are including a scheme for implementing optical-beam smoothing for target experiments in the baseline design for the proposed next-generation ICF facility--the National Ignition Facility (NIF). To verify the efficacy of this design for the suppression of parametric instabilites in NIF-like indirect-drive targets, the authors successfully modified a Nova beamline to simulate the proposed NIF conditions. In this article, they discuss the laser science associated with a four-color target campaign on Nova to test the effect of f-number (ratio of focal length to beam diameter) and temporal smoothing on the scaling of SBS with a four-segment interaction beam using NIF-like parameters. The results of the target series associated with the four-color configuration are discussed elsewhere.

  14. Conditioned instrumental behaviour in the rat: Effects of prenatal irradiation with various low dose-rate doses. Instrumentelle Verhaltensuntersuchungen an der Ratte: Ueber die Wirkung verschiedener Dosen einer praenatalen Bestrahlung niedriger Dosisleistung

    Energy Technology Data Exchange (ETDEWEB)

    Klug, H.

    1986-01-01

    4 groups of rats of the Wistar-strain were subjected to ..gamma..-irradiation on the 16th day of gestation. 5 rats received 0,6 Gy low dose rate irradiation, 5 animals received 0,9 Gy low dose and 6 high dose irradiation, 3 females were shamirradiated. The male offspring of these 3 irradiation groups and 1 control group were tested for locomotor coordination on parallel bars and in a water maze. The female offspring were used in an operant conditioning test. The locomotor test showed slight impairment of locomotor coordination in those animals irradiated with 0,9 Gy high dose rate. Swimming ability was significantly impaired by irradiation with 0,9 Gy high dose rate. Performance in the operant conditioning task was improved by irradiation with 0,9 Gy both low and high dose rate. The 0,9 Gy high dose rate group learned faster than all the other groups. For the dose of 0,9 Gy a significant dose rate effect could be observed. For the dose of 0,6 Gy a similar tendency was observed, differences between 0,6 Gy high and low dose rate and controls not being significant.

  15. Schedule-dependent interaction between vinblastine and irradiation in experimental sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Cemazar, Maja [Institute of Oncology Ljubljana, Ljubljana (Slovenia); University of Primorska, Faculty of Health Sciences, Izola (Slovenia); Dolinsek, Tanja; Markelc, Bostjan; Sersa, Gregor; Kloboves, Veronika; Strojan, Primoz [Institute of Oncology Ljubljana, Ljubljana (Slovenia); Kosjek, Tina [J. Stefan Institute, Ljubljana (Slovenia)

    2014-07-15

    Prolonged vinblastine (VLB) infusion and irradiation (IR) lead to favourable results in certain tumours types; however the underlying biological mechanisms of interaction are not well known. The aim of our study was to evaluate the dose- and time-dependent interactions between split-dose VLB treatment (mimicking prolonged infusion) and IR of sarcoma SA-1 tumours in A/J mice. Antitumor effectiveness of different VLB-IR schedules was determined by a tumour growth delay assay, the VLB amount in the tumours by liquid chromatography coupled to mass spectrometry and DNA cell cycle analysis. A positive antitumor effect was obtained when tumours were irradiated immediately after the first (0 h) or second (4 h) injection of VLB treatment, despite the lower amount of VLB in the tumours as well as decreased number of cells in the IR-sensitive G2M phase at these times points as opposed to the second half of VLB split-dose scheduling. Preferential binding of VLB to microtubules (with consequent lack of available VLB to bind to DNA where it acts as a radioprotector) and the absence of radiobiologically relevant hypoxia are presumably leading to the observed therapeutic benefit of applying IR at the beginning of the prolonged VLB infusion. (orig.) [German] Eine Verlaengerung der Vinblastin-(VLB-)Infusion sowie der Bestrahlung (IR) fuehrt bei einigen Tumorarten zu vorteilhaften Ergebnissen, wobei aber die biologischen Grundelemente dieser Interaktion noch nicht genuegend aufgeklaert sind. Unsere Untersuchung setzte sich zum Ziel, an den SA-1-Sarkomen der A/J-Maeuse dosis- sowie zeitabhaengige Interaktionen zwischen der VLB-Teildosentherapie (d. h. einer Nachahmung der Infusionsverlaengerung) und der IR festzustellen. Die Antitumorwirkung verschiedener VLB-IR-Schemata wurde mit einem Tumorwachstumsverzoegerungs-Assay (''tumor growth delay assay''), durch Messung der in den Tumoren befindlichen VLB-Menge mittels Fluessigkeitschromatographie sowie anhand der DNA

  16. Interactions between impurities and defects created by irradiation in iron; Interactions entre les impuretes et les defauts crees par irradiation dans le fer

    Energy Technology Data Exchange (ETDEWEB)

    Vigier, P. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1968-07-01

    Chapter 1 is a brief review of the most important properties of point defects: the author is particularly interested in radiation damage; the different models proposed until now to explain the five annealing stages are exposed. Chapter 2 describes the experimental processes insisting on how fruitful is the magnetic after-effect to investigate point-defects. In chapter 3, new experimental results are exposed and discussed. Owing to addition of impurities to iron, magnetic after effect, stored energy, resistivity and length measurements have allowed to establish that stage I is correctly explained by the Granato-Nilan model (90): only the last stage, I{sub E}, is related to the interstitial-vacancy annihilation after the interstitial have freely migrated into the network. Several models are discussed for stage II; though it is highly probable that di-interstitials have been observed after electron irradiation, after neutron irradiation none of the after-effect zones can be connected with them. Special phenomena are observed in irradiated iron containing such impurities as nickel, silicium (appearance of new after effect zones, their transformation); they show the successive complication of an elementary defect: iron interstitial associated with an impurity atom. In the last section, the author describes some experiments on iron-carbon alloy; these show that carbon atoms (having precipitated at a temperature lower than 300 deg. C return to solid solution when the alloy is heated above 330 deg. C. (author) [French] Au cours du premier chapitre consacre a un bref rappel des principales proprietes des defauts ponctuels, l'auteur s'attache particulierement a l'effet de l'irradiation; les divers modeles proposes jusqu'alors pour expliquer les cinq stades de disparition des defauts sont exposes. Le deuxieme chapitre decrit les techniques experimentales en insistant sur la richesse du trainage magnetique comme moyen d'investigation. Le troisieme

  17. Wall interactions with plasma generated by vacuum arcs and targets irradiated by intense laser beams

    Energy Technology Data Exchange (ETDEWEB)

    Beilis, Isak I [Electrical Discharge and Plasma Laboratory, School of Electrical Engineering, Fleischman Faculty of Engineering Tel Aviv University, PO Box 39040, Tel Aviv 69978 (Israel)

    2009-02-01

    The theory of plasma-wall interactions in vacuum arc spots and in laser irradiated spots is reviewed in light of Langmuir's fundamental contributions to the theory of plasmas, sheaths, evaporation and electron emission. The mechanisms of plasma generation in the electrode and laser-target vapors are described. Models of sheath structures at surfaces which emit vapor and electrons are presented and the influence of the relation between the rates of electron and vapor emission on the electrical current continuity at the plasma-electrode boundary is discussed. The mechanisms of current continuity in the vacuum arc anode region, in the short vacuum arc, and in transient cathode spots are described. The important role of the near-target sheath in laser generated plasma is shown, indicating the effect of converting laser radiation absorbed in plasma into kinetic and potential energy of charged particles that impinge on the target. The description is summarized showing that understanding these phenomena relies on Langmuir's pioneering work.

  18. Imaging method for monitoring delivery of high dose rate brachytherapy

    Science.gov (United States)

    Weisenberger, Andrew G; Majewski, Stanislaw

    2012-10-23

    A method for in-situ monitoring both the balloon/cavity and the radioactive source in brachytherapy treatment utilizing using at least one pair of miniature gamma cameras to acquire separate images of: 1) the radioactive source as it is moved in the tumor volume during brachytherapy; and 2) a relatively low intensity radiation source produced by either an injected radiopharmaceutical rendering cancerous tissue visible or from a radioactive solution filling a balloon surgically implanted into the cavity formed by the surgical resection of a tumor.

  19. Status Report on Irradiation Capsules Designed to Evaluate FeCrAl-UO2 Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Field, Kevin G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Howard, Richard H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-06-24

    This status report provides the background and current status of a series of irradiation capsules that were designed and are being built to test the interactions between candidate FeCrAl cladding for enhanced accident tolerant applications and prototypical enriched commercial UO2 fuel in a neutron radiation environment. These capsules will test the degree, if any, of fuel cladding chemical interactions (FCCI) between FeCrAl and UO2. The capsules are to be irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory to burn-ups of 10, 30, and 50 GWd/MT with a nominal target temperature at the interfaces between the pellets and clad of 350°C.

  20. Examining the base stacking interaction in a dinucleotide context via reversible cyclobutane dimer analogue formation under UV irradiation.

    Science.gov (United States)

    Liu, Degang; Li, Lei

    2013-11-14

    Substituted tolyl groups are considered as close isosteres of the thymine (T) residue. They can be recognized by DNA polymerases as if they were thymine. Although these toluene derivatives are relatively inert toward radical additions, our recent finding suggests that the dinucleotide analogue TpTo (To = 2'-deoxy-1-(3-tolyl)-β-D-ribofuranose) supports an ortho photocycloaddition reaction upon UV irradiation, producing two cyclobutane pyrimidine dimer (CPD) analogues 2 and 3. Our report here further shows that formation of these CPD species is reversible under UVC irradiation, resembling the photochemical property of the CPD species formed between two Ts. Analyzing the stability of these CPD analogues suggests that one (2) is more stable than the other (3). The TpTo conformer responsible for 2 formation is also more stable than that responsible for 3 formation, as indicated by the Gibbs free energy change calculated from the constructed Bordwell thermodynamic cycle. These different stabilities are not due to the varying photochemical properties, as proved by quantum yields determined from the corresponding photoreactions. Instead, they are ascribed to the different stacking interaction between the T and the To rings both in the TpTo dinucleotide as well as in the formed CPD analogues. Factors contributing to the ring stacking interactions are also discussed. Our proof-of-concept approach suggests that a carefully designed Bordwell cycle coupled with reversible CPD formations under UV irradiation can be very useful in studying DNA base interactions.

  1. Accelerated Irradiations for High Dose Microstructures in Fast Reactor Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Zhijie [Univ. of Michigan, Ann Arbor, MI (United States)

    2017-03-31

    The objective of this project is to determine the extent to which high dose rate, self-ion irradiation can be used as an accelerated irradiation tool to understand microstructure evolution at high doses and temperatures relevant to advanced fast reactors. We will accomplish the goal by evaluating phase stability and swelling of F-M alloys relevant to SFR systems at very high dose by combining experiment and modeling in an effort to obtain a quantitative description of the processes at high and low damage rates.

  2. Investigation of the interaction of copper(II) oxide and electron beam irradiation crosslinkable polyethylene

    Science.gov (United States)

    Bee, Soo-Tueen; Sin, Lee Tin; Ratnam, C. T.; Haraveen, K. J. S.; Tee, Tiam-Ting; Rahmat, A. R.

    2015-10-01

    In this study, the effects of electron beam irradiation on the properties of copper(II) oxide when added to low-density polyethylene (LDPE) blends were investigated. It was found that the addition of low loading level of copper(II) oxide (⩽2 phr) to LDPE results in significantly poorer gel content and hot set results. However, the incorporation of higher loading level of copper(II) oxide (⩾3 phr) could slightly increase the degree of crosslinking in all irradiated LDPE composites. This is due to the fact that higher amounts of copper(II) oxide could slightly induce the formation of free radicals in LDPE matrix. Besides, increasing irradiation doses was also found to gradually increase the gel content of LDPE composites by generating higher amounts of free radicals. As a consequence, these higher amounts of free radicals released in the LDPE matrix could significantly increase the degree of crosslinking. The addition of copper(II) oxide could reduce the tensile strength and fracture strain (elongation at break) of LDPE composites because of poorer interfacial adhesion effect between copper(II) oxide particles and LDPE matrix. Meanwhile, increasing irradiation doses on all copper(II) oxide added LDPE composites could marginally increase the tensile strength. In addition, increasing irradiation dose could enhance the thermal stability of LDPE composites by increasing the decomposition temperature. The oxidation induction time (OIT) analysis showed that, because of the crosslinking network in the copper(II) oxide added LDPE composites, oxidation reaction is much delayed.

  3. Interaction between Mesodinium rubrum and its prey: importance of prey concentration, irradiance and pH

    DEFF Research Database (Denmark)

    Moldrup, Morten; Hansen, Per Juel

    2007-01-01

    ABSTRACT: The functional and numerical responses for the marine obligate mixotrophic ciliate Mesodinium rubrum Lohmann, 1908 (=Myrionecta rubra Jankowsky, 1976) were studied at 2 irradiances (20 and 100 µE m2 s-1). Furthermore, its tolerance to high pH levels and response to starvation were studied...

  4. Análises de protocolos de braquiterapia, por alta taxa de dose, do controle de qualidade de alguns serviços locais, baseados no TG40, TG56 e ARCAL XXX Analysis of the high dose rate brachytherapy protocols of quality assurance programs of some local services, based on TG40, TG56 and ARCAL XXX.

    Directory of Open Access Journals (Sweden)

    Carmen S. Guzmán Calcina

    2001-08-01

    Full Text Available A braquiterapia por alta taxa de dose está recebendo atenção considerável na maioria dos países. Por isso, nos serviços que utilizam este equipamento exige-se que o desenvolvimento de um programa de controle de qualidade seja cada vez mais rigoroso, para garantir não apenas a segurança aos pacientes, mas também aos operadores e demais envolvidos. Este trabalho tem por objetivos fazer um levantamento dos tipos de testes para um equipamento de braquiterapia por alta taxa de dose, propostos pelos protocolos oficiais publicados (TG40, TG56 e ARCAL XXX e avaliar os tipos de testes que atualmente são realizados por alguns serviços de radioterapia, comparando-os com aqueles apresentados nos protocolos citados. Das análises feitas, observou-se que: a quanto aos protocolos oficiais, o TG56 é mais completo que o TG40 e o ARCAL XXX; b quanto às instituições analisadas, estas em geral se basearam no TG56 para elaborar seus próprios protocolos, os quais demonstraram ter também concordância com os outros já citados. Nestes protocolos, a inexistência dos testes anuais foi notada, o que pode ser explicado por sua aparição nas freqüências trimestral e semestral. Do produto deste estudo são apresentadas tabelas dos tipos de testes com suas respectivas freqüências de utilização, das quais um protocolo pode ser inferido para auxiliar na implementação, pelo menos, dos tipos de testes de controle de qualidade básicos e indispensáveis para o equipamento, garantindo, assim, um tratamento adequado aos pacientes e uma melhor segurança ao pessoal envolvido e, conseqüentemente, assegurando a garantia de qualidade na braquiterapia por alta taxa de dose.High dose rate brachytherapy has been increasingly recognized in most countries, and radiotherapy services using this equipment are encouraged to have a very efficient quality assurance program to ensure protection for patients, workers and other personnel involved. The objective of this

  5. Evaluation of irradiation hardening and microstructure evolution under the synergistic interaction of He and subsequent Fe ions irradiation in CLAM steel

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Y.P.; Liu, P.P.; Zhu, Y.M.; Wang, Z.Q.; Wan, F.R.; Zhan, Q., E-mail: qzhan@mater.ustb.edu.cn

    2016-08-15

    Sequential dual-ion irradiation is a useful technique for experimental exploration on the synergistic effects of ion accumulation and cascade damage. In this research, the helium-ion accumulation concomitant with displacement damage induced by helium and iron ions irradiation in China low active martensitic (CLAM) steel was studied by ion-irradiation, transmission electron microscopy and nano-indentation technique. The helium bubbles formed under continuous implantation of helium ions at room temperature and the helium dose forming observed bubbles resolved by TEM clearly in CLAM steel is around 0.7 × 10{sup 17}–1.0 × 10{sup 17} He{sup +}/cm{sup 2} under single 100 keV He{sup +} irradiation. Significant irradiation hardening was observed in the samples with various ion- and dose-irradiations. Positive correlation between the hardening increment and the helium-ion dose has been established in single helium-ion irradiated samples. On the other hand, the subsequent Fe-ion irradiation greatly promoted the formation and growth of helium bubbles as well as dislocation loops in sequential dual-ion irradiated samples. No significant contribution of the subsequent Fe-ion irradiation on the hardness increment was found for the sequential dual-ion irradiated samples. It is suggested that the defects recombination, the combination effects of size and density of defects contribute to the degree of irradiation hardening. The calculated hardness increment based on dispersion strengthening model and the experimental microstructure analysis followed the same trend as the experimental nano-indentation data. - Highlights: • Sequential dual-ion irradiation was used to study the synergistic effects of helium accumulation and cascade damage. • The critical helium dose for notable growth of bubbles is around 1.0 × 10{sup 17} He{sup +}/cm{sup 2}. • Bubbles and dislocation loops grew greatly after subsequent Fe-ions irradiation. • The tested and calculated hardness increments

  6. Impact of creep-fatigue interaction on the lifetime of a dispersion strengthened copper alloy in unirradiated and irradiated conditions

    DEFF Research Database (Denmark)

    Singh, B.N.; Stubbins, J.F.; Toft, P.

    2001-01-01

    Creep-fatigue interaction behaviour of a dispersion strengthened copper alloy was investigated at 22 and 250 deg.C. To determine the effect of irradiation a number of fatigue specimens were irradiated at 250 deg.C to a dose level of 0.3 dpa and weretested at 250 deg.C. The creep-fatigue interaction...... was simulated by applying a certain holdtime on both tension and compression sides of the cyclic loading with a frequency of 0.5 Hz. Holdtimes of 0,2, 5, 10, 100, and 1000 seconds were used. For a givenholdtime, the real lifetime and a number of cycles to failure were determined at different strain amplitudes...... the present work is that a holdtime of 10 seconds or less causes a drastic decrease in the reallifetime as well as in the number of cycles to failure, particularly at low levels of strain amplitudes. A combination of higher temperature, higher strain amplitude and longer holdtime, on the other hand, may lead...

  7. Atomic level simulations of interaction between edge dislocations and irradiation induced ellipsoidal voids in alpha-iron

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Bida [Department of Mechanics, Huazhong University of Science and Technology, Wuhan 430074 (China); Huang, Minsheng, E-mail: mshuang@hust.edu.cn [Department of Mechanics, Huazhong University of Science and Technology, Wuhan 430074 (China); Hubei Key Laboratory of Engineering Structural Analysis and Safety Assessment, Luoyu Road 1037, Wuhan 430074 (China); Li, Zhenhuan [Department of Mechanics, Huazhong University of Science and Technology, Wuhan 430074 (China); Hubei Key Laboratory of Engineering Structural Analysis and Safety Assessment, Luoyu Road 1037, Wuhan 430074 (China)

    2017-04-15

    High concentrations of vacancies tend to be formed inside the metal materials under irradiation, and then accumulate and cluster together gradually to promote the formation of nanovoids. Generally, these voids act as obstacles for dislocation glide and thereby change/degrade the mechanical behavior of irradiated materials. In this work, the interaction between ellipsoidal nanovoids with edge dislocations in alpha-iron has been studied by atomic simulations. The results illuminate that the ellipsoidal void’s semi-major axis on the slip plane and parallel to the dislocation line is the dominant factor controlling the obstacle strength of ellipsoidal nanovoids. Two other semi-major axes, which are perpendicular to the glide plane and parallel to the Burgers vector, respectively, can also influence the critical resolved shear stress (CRSS) for dislocation shearing the ellipsoidal void. The intrinsic atomic mechanisms controlling above phenomena, such as nanovoid-geometry spatial constraint and nanovoid-surface curvature on dislocation evolution, have been discussed carefully. The classical continuum model has been amended to describe the dislocation-ellipsoidal nanovoid interaction base on current results. In addition, the influence of temperature on the CRSS of ellipsoidal nanovoids has also been investigated.

  8. Atomic force microscopy investigation of the interaction of low-level laser irradiation of collagen thin films in correlation with fibroblast response.

    Science.gov (United States)

    Stylianou, Andreas; Yova, Dido

    2015-12-01

    Low-level red laser (LLRL)-tissue interactions have a wide range of medical applications and are garnering increased attention. Although the positive effects of low-level laser therapy (LLLT) have frequently been reported and enhanced collagen accumulation has been identified as one of the most important mechanisms involved, little is known about LLRL-collagen interactions. In this study, we aimed to investigate the influence of LLRL irradiation on collagen, in correlation with fibroblast response. Atomic force microscopy (AFM) and fluorescence spectroscopy were used to characterize surfaces and identify conformational changes in collagen before and after LLRL irradiation. Irradiated and non-irradiated collagen thin films were used as culturing substrates to investigate fibroblast response with fluorescence microscopy. The results demonstrated that LLRL induced small alterations in fluorescence emission and had a negligible effect on the topography of collagen thin films. However, fibroblasts cultured on LLRL-irradiated collagen thin films responded to LRLL. The results of this study show for the first time the effect of LLRL irradiation on pure collagen. Although irradiation did not affect the nanotopography of collagen, it influenced cell behavior. The role of collagen appears to be crucial in the LLLT mechanism, and our results demonstrated that LLRL directly affects collagen and indirectly affects cell behavior.

  9. Dosimetric comparison of (192)Ir high-dose-rate brachytherapy vs. 50 kV x-rays as techniques for breast intraoperative radiation therapy: conceptual development of image-guided intraoperative brachytherapy using a multilumen balloon applicator and in-room CT imaging.

    Science.gov (United States)

    Jones, Ryan; Libby, Bruce; Showalter, Shayna L; Brenin, David R; Wilson, David D; Schroen, Anneke; Morris, Monica; Reardon, Kelli A; Morrison, John; Showalter, Timothy N

    2014-01-01

    At our institution, the availability of a shielded procedure room with in-room CT-on-rails imaging allows for the exploration of a high-dose-rate (HDR) brachytherapy approach for breast intraoperative radiation therapy (IORT). We hypothesize that HDR brachytherapy will permit a higher prescription dose without increasing toxicity. In this study, we compare the dosimetry of intraoperative HDR brachytherapy, using multilumen balloon applicator, to IORT with a 50 kV source and then select a prescription dose for a subsequent clinical trial. The CT scans of 14 patients who had previously received multilumen balloon-based breast brachytherapy were replanned to a standard prescription to the target volume. The same 14 cases were planned to the specifications of a 50 kV x-ray system. Uniform volume optimization and prescription doses were used to permit direct comparisons. All plans were evaluated for the dose homogeneity index, tumor coverage, and dose to normal tissues, including skin, ribs, and heart (for left breast plans). The HDR brachytherapy plans were superior to 50 kV superficial photon plans for IORT in all dosimetric parameters except for the heart and rib dosimetric parameters. Prescription dose of 12.5 Gy to the planning target volume for evaluation yielded a dose to 95 percent of the balloon surface of 19.7 Gy. Image-guided HDR intraoperative brachytherapy with a multilumen balloon applicator provides superior target volume coverage compared with 50 kV photons, while maintaining doses within tolerance limits for normal tissues. An ongoing prospective clinical trial will evaluate the safety and feasibility of this technique. Copyright © 2014 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  10. Adjuvant radiation therapy for the treatment of endometrial cancer: experience with combination of external radiation therapy and high-dose rate brachytherapy; Radioterapia adjuvante no tratamento do cancer de endometrio: experiencia com a associacao de radioterapia externa e braquiterapia de alta taxa de dose

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Michael Jenwei; Novaes, Paulo Eduardo Ribeiro Soares; Pellizzon, Antonio Cassio de Assis; Ferrigno, Robson; Fogaroli, Ricardo Cesar; Maia, Maria Aparecida Conte; Salvajoli, Joao Victor [Hospital do Cancer A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Radioterapia]. E-mail: michael.chen@ig.com.br; Nishimoto, Ines Nobuko [Hospital do Cancer A.C. Camargo, Sao Paulo, SP (Brazil). Centro de Estudos

    2005-12-01

    Objective: To review the results of adjuvant external beam radiation therapy (EBRT) combined with high-dose rate brachytherapy (HDR-BT) for the treatment of endometrial carcinoma. Materials and methods: We retrospectively evaluated 141 patients treated with EBRT and HDR-BT after surgery between January 1993 and January 2001. EBRT was performed with a median dose of 45 Gy, and HDR-BT was performed with a median dose of 24 Gy, with four weekly insertions of 6 Gy. The median age of the patients was 63 years and the disease stage distribution was: CS I (FIGO), 52.4%; CS II, 13.5%; CS III, 29.8%; CS IV, 4.3%. Results: With a median follow-up of 53.7 months, the disease free survival (DFS) at five years was: CS I, 88.0%; CS II, 70.8%; CS III, 55.1%; CS IV, 50.0% (p = 0.0003). Global survival after five years was: CS I, 79.6%; CS II, 74.0%; CS III, 53.6%; CS IV, 100.0% (p = 0.0062). Factors affecting the DFS were histological grade and serous-papillary histology. Recurrence of the disease was observed in 33 cases, 13 (9.2%) of these occurred in the pelvis, vagina or vaginal vault. EBRT + HDR-BT of the vaginal vault allowed disease control in 90.8% of the cases. Conclusion: Radiation therapy is essential for loco-regional control of endometrial cancer and can achieve excellent cure rates in the initial stages. In more advanced stages, therapeutic failure frequently appears as distant metastases suggesting the need for complementary systemic therapy using new treatment modalities, particularly chemotherapy. (author)

  11. Identification of CEA-interacting proteins in colon cancer cells and their changes in expression after irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Byong Chul [Colorectal Cancer Branch, Research Institute, National Cancer Center, Goyang (Korea, Republic of); Yeo, Seung Gu [Dept. of Radiation Oncology, Soonchunhyang University College of Medicine, Soonchunhyang University Hospital, Cheonan (Korea, Republic of)

    2017-09-15

    The serum carcinoembryonic antigen (CEA) level has been recognized as a prognostic factor in colorectal cancer, and associated with response of rectal cancer to radiotherapy. This study aimed to identify CEA-interacting proteins in colon cancer cells and observe post-irradiation changes in their expression. CEA expression in colon cancer cells was examined by Western blot analysis. Using an anti-CEA antibody or IgG as a negative control, immunoprecipitation was performed in colon cancer cell lysates. CEA and IgG immunoprecipitates were used for liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis. Proteins identified in the CEA immunoprecipitates but not in the IgG immunoprecipitates were selected as CEA-interacting proteins. After radiation treatment, changes in expression of CEA-interacting proteins were monitored by Western blot analysis. CEA expression was higher in SNU-81 cells compared with LoVo cells. The membrane localization of CEA limited the immunoprecipitation results and thus the number of CEA-interacting proteins identified. Only the Ras-related protein Rab-6B and lysozyme C were identified as CEA-interacting proteins in LoVo and SNU-81 cells, respectively. Lysozyme C was detected only in SNU-81, and CEA expression was differently regulated in two cell lines; it was down-regulated in LoVo but up-regulated in SNU-81 in radiation dosage-dependent manner. CEA-mediated radiation response appears to vary, depending on the characteristics of individual cancer cells. The lysozyme C and Rab subfamily proteins may play a role in the link between CEA and tumor response to radiation, although further studies are needed to clarify functional roles of the identified proteins.

  12. Interaction of NO2 with TiO2 surface under UV irradiation: measurements of the uptake coefficient

    Directory of Open Access Journals (Sweden)

    Y. Bedjanian

    2012-01-01

    Full Text Available The interaction of NO2 with TiO2 solid films was studied under UV irradiation using a low pressure flow reactor (1–10 Torr combined with a modulated molecular beam mass spectrometer for monitoring of the gaseous species involved. The NO2 to TiO2 reactive uptake coefficient was measured from the kinetics of NO2 loss on TiO2 coated Pyrex rods as a function of NO2 concentration, irradiance intensity (JNO2 = 0.002–0.012 s−1, relative humidity (RH = 0.06–69 %, temperature (T = 275–320 K and partial pressure of oxygen (0.001–3 Torr. TiO2 surface deactivation upon exposure to NO2 was observed. The initial uptake coefficient of NO2 on illuminated TiO2 surface (with 90 ppb of NO2 and JNO2≅0.006 s−1 was found to be γ0 = (1.2±0.4 ×10−4 (calculated using BET surface area under dry conditions at T = 300 K. The steady state uptake, γ, was several tens of times lower than the initial one, independent of relative humidity, and was found to decrease in the presence of molecular oxygen. In addition, it was shown that γ is not linearly dependent on the photon flux and seems to level off under atmospheric conditions. Finally, the following expression for γ was derived, γ = 2.3×10−3 exp(−1910/T/(1 + P0.36 (where P is O2 pressure in Torr, and recommended for atmospheric applications (for any RH, near 90 ppb of NO2 and JNO2 = 0.006 s−1.

  13. PtRu/C Electrocatalysts Prepared Using Gamma and Electron Beam Irradiation for Methanol Electrooxidation

    Directory of Open Access Journals (Sweden)

    Dionisio F. Silva

    2012-01-01

    Full Text Available PtRu/C electrocatalysts (carbon-supported PtRu nanoparticles were prepared in a single step submitting water/2-propanol mixtures containing Pt(IV and Ru(III ions and the carbon support to gamma and electron beam irradiation. The electrocatalysts were characterized by energy dispersive X-ray analysis (EDX, X-ray diffraction (XRD, transmission electron microscopy (TEM, and cyclic voltammetry and tested for methanol electrooxidation. PtRu/C electrocatalyst can be prepared in few minutes using high dose rate electron beam irradiation while using low dose rate gamma irradiation some hours were necessary to prepare it. The obtained materials showed the face-centered cubic (fcc structure of Pt and Pt alloys with average nanoparticle sizes of around 3 nm. The material prepared using electron beam irradiation was more active for methanol electrooxidation than the material prepared using gamma irradiation.

  14. Thermoluminescent dosimetry in total body irradiation.

    Science.gov (United States)

    Rodríguez-Cortés, J; Rivera-Montalvo, T; Villaseñor Navarro, L F; Flores-López, O; Roman, J; Hernandez-Oviedo, J O

    2012-12-01

    The aim of this paper was to develop a thermoluminescent dosimetry method for the absorbed dose determination of 6 MeV high-energy electron beams by thermoluminescent dosimetry. Total body irradiation (TBI) was performed using four dual fields angled at 252° and 285° in high-dose rate (HDR) mode. TBI measurements were investigated to estimate the absorbed dose in different anatomical parts of the patient. Experimental results were obtained using thermoluminescent detectors and solid water phantoms. The TL response of the dosimeters, as a function of the high-energy electron beam (HEEB) absorbed dose, was linear, from 0.1 to 500 cGy. The entrance skin dose (ESD) and isodose distribution on the surface of the treatment were investigated graphically. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Cirurgia conservadora, radioterapia externa e reforço de dose com braquiterapia de alta taxa de dose: uma nova perspectiva no tratamento de sarcomas de partes moles do adulto Limb-sparing surgery, external beam radiotherapy and boost with high-dose rate brachytherapy: a new perspective for the treatment of soft tissue sarcomas in adults

    Directory of Open Access Journals (Sweden)

    Antonio Cássio Assis Pellizzon

    2002-03-01

    Full Text Available OBJETIVO: Avaliar a influência no controle local de pacientes adultos e portadores de sarcoma de partes moles em extremidades e submetidos a cirurgia conservadora do membro, com braquiterapia de alta taxa de dose (BATD como reforço para a radioterapia externa (RT. MATERIAL E MÉTODOS: Foram avaliados 16 pacientes tratados, de 1993 até 1999. A RT foi utilizada com finalidade pré ou pós-operatória (30--55 Gy e BATD com dose de 18--36 Gy (fx 3--6 Gy BID. Com base no modelo linear quadrático calculou-se a dose efetiva biológica ("biological effective dose" - BED para o tumor e comparou-se seu valor a dados da literatura internacional, que utiliza tratamentos com RT e braquiterapia de baixa taxa de dose (BBTD. RESULTADOS: Os valores médios e medianos da BED para os sarcomas de partes moles foram de 78,5 Gy7 e 80 Gy7. A análise univariada mostrou que a BED para o tumor, quando utilizada BATD, era semelhante ao valor de 83 Gy7 quando utilizada BBTD (p = 0,008. As taxas de controle local, sobrevida livre de doença e sobrevida global atuarial em cinco anos foram de 83,2%, 75% e 93,7%, respectivamente. CONCLUSÕES: A BATD, quando utilizada como método complementar no reforço de dose da RT no tratamento conservador dos sarcomas de partes moles, apresenta taxas de controle local equiparáveis às da literatura internacional; no entanto, estudos com número maior de pacientes e período maior de seguimento são ainda necessários para determinar o verdadeiro potencial da BATD em substituir a BBTD.PURPOSE: To evaluate the influence on local control in adult patients with soft tissue sarcomas of the limbs that underwent limb-sparing surgery and high-dose rate brachytherapy (HDRB in association with teletherapy. MATERIAL AND METHODS: Sixteen patients treated from 1993 to 1999 were reviewed. Teletherapy was used pre- or postoperatively (30--55 Gy in association with HDRB in a dose range of 18--36 Gy (fx 3--6 Gy BID. The linear quadratic model was

  16. Breast conserving treatment of breast carcinoma T2 ({<=} 4 cm) and T3 by neoadjuvant chemotherapy, quadrantectomy, high dose rate brachytherapy as a boost, external beam radiotherapy and adjuvant chemotherapy: local control and overall survival analysis; Tratamento conservador do cancer de mama T2 ({<=} 4 cm) e T3 por quimioterapia neoadjuvante, quadrantectomia, braquiterapia com alta taxa de dose como reforco de dose, teleterapia complementar e quimioterapia adjuvante: analise de controle local e sobrevida global

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Celia Regina; Miziara Filho, Miguel Abrao; Fogaroli, Ricardo Cesar; Baraldi, Helena Espindola; Pellizzon, Antonio Cassio Assis; Pelosi, Edilson Lopes [Instituto do Cancer Dr. Arnaldo Vieira de Carvalho (ICAVC), Sao Paulo, SP (Brazil). Servico de Radioterapia], e-mail: celiarsoares@terra.com.br; Fristachi, Carlos Elias [Instituto do Cancer Dr. Arnaldo Vieira de Carvalho (ICAVC), Sao Paulo, SP (Brazil). Servico de Onco-Ginecologia e Mastologia; Paes, Roberto Pinto [Instituto do Cancer Dr. Arnaldo Vieira de Carvalho (ICAVC), Sao Paulo, SP (Brazil)

    2008-12-15

    Objective: to assess the treatment of breast cancer T2 ({<=} 4 cm) and T3 through neoadjuvant chemotherapy, quadrantectomy and high dose rate brachytherapy as a boost, complementary radiotherapy and adjuvant chemotherapy, considering local control and overall survival. Material and method: this clinical prospective descriptive study was based on the evaluation of 88 patients ranging from 30 to 70 years old, with infiltrating ductal carcinoma, clinical stage IIb and IIIa, responsive to the neoadjuvant chemotherapy, treated from June/1995 to December/2006. Median follow-up was 58 months. Using clinical methods the tumor was evaluated before and after three or four cycles of chemotherapy based on anthracyclines. Overall survival and local control were assessed according to Kaplan-Meier methodology. Results: Local control and overall survival in five years were 90% and 73.5%, respectively. Conclusion: local control and overall survival were comparable to other forms of treatment. (author)

  17. Metallography and fuel cladding chemical interaction in fast flux test facility irradiated metallic U-10Zr MFF-3 and MFF-5 fuel pins

    Energy Technology Data Exchange (ETDEWEB)

    Carmack, W.J., E-mail: jon.carmack@inl.gov [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415 (United States); Chichester, H.M., E-mail: heather.chichester@inl.gov [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415 (United States); Porter, D.L., E-mail: douglas.porter@inl.gov [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415 (United States); Wootan, D.W., E-mail: david.wootan@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99354 (United States)

    2016-05-15

    The Mechanistic Fuel Failure (MFF) series of metal fuel irradiations conducted in the Fast Flux Test Facility (FFTF) provides an important comparison between data generated in the Experimental Breeder Reactor (EBR-II) and that expected in a larger-scale fast reactor. The MFF fuel operated with a peak cladding temperature at the top of the fuel column, but developed peak burnup at the centerline of the core. This places the peak fuel temperature midway between the core center and the top of fuel, lower in the fuel column than in EBR-II experiments. Data from the MFF-3 and MFF-5 assemblies are most comparable to the data obtained from the EBR-II X447 experiment. The two X447 pin breaches were strongly influenced by fuel/cladding chemical interaction (FCCI) at the top of the fuel column. Post irradiation examination data from MFF-3 and MFF-5 are presented and compared to historical EBR-II data. - Highlights: • Irradiation and post irradiation examination of full-length metallic fast reactor fuel. • Fuel cladding chemical interaction formation in full-length metallic fast reactor fuel. • Correlation of FCCI with temperature and burnup. • Comparison of full-length reactor fuel performance with test reactor fuel performance.

  18. Radioterapia adjuvante no tratamento do câncer de endométrio: experiência com a associação de radio-terapia externa e braquiterapia de alta taxa de dose Adjuvant radiation therapy for the treatment of endometrial cancer: experience with combination of external radiation therapy and high-dose rate brachytherapy

    Directory of Open Access Journals (Sweden)

    Michael Jenwei Chen

    2005-12-01

    Full Text Available OBJETIVO: Analisar, retrospectivamente, os resultados da radioterapia externa (RT combinada a braquiterapia de alta taxa de dose (BATD, adjuvantes à cirurgia para o carcinoma de endométrio. MATERIAIS E MÉTODOS: Avaliamos 141 pacientes tratados com RT e BATD adjuvantes à cirurgia, no período de janeiro de 1993 a janeiro de 2001. RT pélvica foi realizada com dose mediana de 45 Gy, e BATD realizada na dose mediana de 24 Gy, em quatro inserções semanais de 6 Gy. A idade mediana das pacientes foi de 63 anos e a distribuição por estádio clínico (EC foi: EC I (FIGO, 52,4%; EC II, 13,5%; EC III, 29,8%; EC IV, 4,3%. RESULTADOS: Com seguimento mediano de 53,7 meses, a sobrevida livre de doença (SLD em cinco anos foi: EC I, 88,0%; EC II, 70,8%; EC III, 55,1%; EC IV, 50,0% (p = 0,0003. A sobrevida global em cinco anos foi: EC I, 79,6%; EC II, 74,0%; EC III, 53,6%; EC IV, 100,0% (p = 0,0062. Fatores que influíram na SLD foram grau histológico e histologia seropapilífera. Dos 33 casos que apresentaram recidiva da doença, em 13 (9,2% esta ocorreu na pelve, vagina ou cúpula vaginal. RT + BATD do fundo vaginal permitiram o controle da doença em 90,8% dos casos. CONCLUSÃO: A RT exerce papel fundamental no controle loco-regional do câncer de endométrio e permite excelentes taxas de cura nos estádios iniciais. Para os estádios mais avançados, a falha terapêutica tende a ser a distância, sugerindo a necessidade de complementação terapêutica sistêmica, com introdução de novas modalidades de tratamento, em particular a quimioterapia.OBJECTIVE: To review the results of adjuvant external beam radiation therapy (EBRT combined with high-dose rate brachytherapy (HDR-BT for the treatment of endometrial carcinoma. MATERIALS AND METHODS: We retrospectively evaluated 141 patients treated with EBRT and HDR-BT after surgery between January 1993 and January 2001. EBRT was performed with a median dose of 45 Gy, and HDR-BT was performed with a

  19. Arabidopsis DNA ligase IV is induced by gamma-irradiation and interacts with an Arabidopsis homologue of the double strand break repair protein XRCC4.

    Science.gov (United States)

    West, C E; Waterworth, W M; Jiang, Q; Bray, C M

    2000-10-01

    Rejoining of single- and double-strand breaks (DSBs) introduced in DNA during replication, recombination, and DNA damage is catalysed by DNA ligase enzymes. Eukaryotes possess multiple DNA ligase enzymes, each having distinct roles in cellular metabolism. Double-strand breaks in DNA, which can occur spontaneously in the cell or be induced experimentally by gamma-irradiation, represent one of the most serious threats to genomic integrity. Non-homologous end joining (NHEJ) rather than homologous recombination is the major pathway for repair of DSBs in organisms with complex genomes, including humans and plants. DNA ligase IV in Saccharomyces cerevisiae and humans catalyses the final step in the NHEJ pathway of DSB repair. In this study we identify an Arabidopsis thaliana homologue (AtLIG4) of human and S. cerevisiae DNA ligase IV which is shown to encode an ATP-dependent DNA ligase with a theoretical molecular mass of 138 kDa and 48% similarity in amino-acid sequence to the human DNA ligase IV. Yeast two-hybrid analysis demonstrated a strong interaction between A. thaliana DNA ligase IV and the A. thaliana homologue of the human DNA ligase IV-binding protein XRCC4. This interaction is shown to be mediated via the tandem BRCA C-terminal domains of A. thaliana DNA ligase IV protein. Expression of AtLIG4 is induced by gamma-irradiation but not by UVB irradiation, consistent with an in vivo role for the A. thaliana DNA ligase IV in DSB repair.

  20. The dinoflagellate Akashiwo sanguinea will benefit from future climate change: The interactive effects of ocean acidification, warming and high irradiance on photophysiology and hemolytic activity.

    Science.gov (United States)

    Ou, Guanyong; Wang, Hong; Si, Ranran; Guan, Wanchun

    2017-09-01

    Due to global climate change, marine phytoplankton will likely experience low pH (ocean acidification), high temperatures and high irradiance in the future. Here, this work report the results of a batch culture experiment conducted to study the interactive effects of elevated CO 2 , increased temperature and high irradiance on the harmful dinoflagellate Akashiwo sanguinea, isolated at Dongtou Island, Eastern China Sea. The A. sanguinea cells were acclimated in high CO 2 condition for about three months before testing the responses of cells to a full factorial matrix experimentation during a 7-day period. This study measured the variation in physiological parameters and hemolytic activity in 8 treatments, representing full factorial combinations of 2 levels each of exposure to CO 2 (400 and 1000μatm), temperature (20 and 28°C) and irradiance (50 and 200μmol photons m -2 s -1 ). Sustained growth of A. sanguinea occurred in all treatments, but high CO 2 (HC) stimulated faster growth than low CO 2 (LC). The pigments (chlorophyll a and carotenoid) decreased in all HC treatments. The quantum yield (F v /F m ) declined slightly in all high-temperature (HT) treatments. High irradiance (HL) induced the accumulation of ultraviolet-absorbing compounds (UV abc ) irrespective of temperature and CO 2 . The hemolytic activity in the LC treatments, however, declined when exposed to HT and HL, but HC alleviated the adverse effects of HT and HL on hemolytic activity. All HC and HL conditions and the combinations of high temperature*high light (HTHL) and high CO 2 *high temperature*high light (HCHTHL) positively affected the growth in comparison to the low CO 2 *low temperature*low light (LCLTLL) treatment. High temperature (HT), high light (HL) and a combination of HT*HL, however, negatively impacted hemolytic activity. CO 2 was the main factor that affected the growth and hemolytic activity. There were no significant interactive effects of CO 2 *temperature*irradiance on growth

  1. ESR study of Na-Colloids in heavily irradiated NaCl : Size effects and inter-precipitate interactions

    NARCIS (Netherlands)

    Vainshtein, DJ; den Hartog, H.W.

    1996-01-01

    Compared with other materials, the radiolysis processes in alkali halides and in particular NaCl have been investigated extensively. From these investigations we have obtained a rather clear picture of the radiolysis processes in these model materials. During irradiation of NaCl crystals at 50-150

  2. Chromosomal Aberrations in Normal and AT Cells Exposed to High Dose of Low Dose Rate Irradiation

    Science.gov (United States)

    Kawata, T.; Shigematsu, N.; Kawaguchi, O.; Liu, C.; Furusawa, Y.; Hirayama, R.; George, K.; Cucinotta, F.

    2011-01-01

    Ataxia telangiectasia (A-T) is a human autosomally recessive syndrome characterized by cerebellar ataxia, telangiectases, immune dysfunction, and genomic instability, and high rate of cancer incidence. A-T cell lines are abnormally sensitive to agents that induce DNA double strand breaks, including ionizing radiation. The diverse clinical features in individuals affected by A-T and the complex cellular phenotypes are all linked to the functional inactivation of a single gene (AT mutated). It is well known that cells deficient in ATM show increased yields of both simple and complex chromosomal aberrations after high-dose-rate irradiation, but, less is known on how cells respond to low-dose-rate irradiation. It has been shown that AT cells contain a large number of unrejoined breaks after both low-dose-rate irradiation and high-dose-rate irradiation, however sensitivity for chromosomal aberrations at low-dose-rate are less often studied. To study how AT cells respond to low-dose-rate irradiation, we exposed confluent normal and AT fibroblast cells to up to 3 Gy of gamma-irradiation at a dose rate of 0.5 Gy/day and analyzed chromosomal aberrations in G0 using fusion PCC (Premature Chromosomal Condensation) technique. Giemsa staining showed that 1 Gy induces around 0.36 unrejoined fragments per cell in normal cells and around 1.35 fragments in AT cells, whereas 3Gy induces around 0.65 fragments in normal cells and around 3.3 fragments in AT cells. This result indicates that AT cells can rejoin breaks less effectively in G0 phase of the cell cycle? compared to normal cells. We also analyzed chromosomal exchanges in normal and AT cells after exposure to 3 Gy of low-dose-rate rays using a combination of G0 PCC and FISH techniques. Misrejoining was detected in the AT cells only? When cells irradiated with 3 Gy were subcultured and G2 chromosomal aberrations were analyzed using calyculin-A induced PCC technique, the yield of unrejoined breaks decreased in both normal and AT

  3. Radiolesão vascular como efeito deletério da braquiterapia intra-arterial com dose elevada de Samário-153 em coelhos hipercolesterolêmicos Vascular radiolesion as a deleterious effect of high-dose-rate intraarterial brachytherapy with Samarium-153 in hypercholesterolemic rabbits

    Directory of Open Access Journals (Sweden)

    Dalton Bertolim Précoma

    2006-10-01

    Full Text Available OBJETIVO: Este estudo tem por objetivo avaliar as alterações vasculares morfológicas e morfométricas induzidas pela braquiterapia com Samário-153 (153 Sm em coelhos hipercolesterolêmicos, com doses elevadas. MÉTODOS: Foram analisados 43 coelhos hipercolesterolêmicos, brancos, da raça New Zealand, e o total de 86 artérias ilíacas submetidas a lesão por balão de angioplastia. Divididos em três grupos: dois (GI irradiados com as doses de 15Gy (n=14 e 60Gy (n=36 e um grupo controle (n=36. Foram realizadas avaliação histológica morfométrica e análise histológica qualitativa para análise tecidual. RESULTADOS: Foram observadas uma redução significativa da neoproliferação intimal (NPI no GI 15 Gy (pOBJECTIVE: This study was designed to evaluate vascular morphological and morphometric changes induced by brachytherapy with samarium-153 (Sm-153 at high doses in hypercholesterolemic rabbits. METHODS: Forty-three New Zealand White hypercholesterolemic rabbits were analyzed, and the total of 86 iliac arteries underwent balloon angioplasty injury. The rabbits were divided into three different groups: two irradiation groups (IG assigned to 15 Gy (n=14 and 60 Gy (n=36 irradiation doses, respectively, and a control group (n = 36. Histomorphometric and qualitative histological analyses were performed for tissue evaluation. RESULTS: Significant reductions were found in neointimal proliferation (NIP (p< 0.0001, media area (MA (p<0.0001 and percent stenosis (p<0.0001 in the 15-Gy IG, compared to the other groups. The 60-Gy IG had the higher rate of NIP, increase in media and vessel areas (VA and percent stenosis. The 60-Gy IG also showed the greatest number of xanthomatous cells (60-Gy IG: 86.11% and 15-Gy IG: 14.29%, p<0.0001 and the highest amount of hyaline amorphous tissue (60-Gy IG:58.33% and 15-Gy IG:0%, p=0.0001 and vascular proliferation (60-Gy IG:30.56% and 15-Gy IG:0%, p=0.0221. No statistically significant differences were found

  4. The lethal interaction of x ray and penicillin induced lesions following x-irradiation of Escherichia coli B/r in the presence of hypoxic cell sensitizers

    Energy Technology Data Exchange (ETDEWEB)

    Gillies, N.E.; Obioha, F.I.

    1982-03-01

    When Escherichia coli B/r were x-irradiated under anoxia in the presence of different electron-affinic sensitizers and then incubated in broth containing penicillin (at a concentration that did not kill unirradiated cells) additional killing of the bacteria occurred provided the sensitizers were of relatively high lipophilicity. The overall effect was to increase the efficiency of these sensitizers. It is concluded that sensitizer-dependent latent radiation lesions(s) are produced in membrane components of the cell envelope that interact with damage caused by penicillin in the peptidoglycan layer and this causes the additional lethality.

  5. Interactions of secondary particles with thorium samples in the setup QUINTA irradiated with 6 GeV deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Khushvaktov, J., E-mail: khushvaktov@jinr.ru [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute of Nuclear Physics ASRU, Tashkent (Uzbekistan); Adam, J. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Nuclear Physics Institute ASCR PRI (Czech Republic); Baldin, A.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute for Advanced Studies “OMEGA”, Dubna (Russian Federation); Chilap, V.V. [Center of Physical and Technical Projects “Atomenergomash”, Moscow (Russian Federation); Furman, V.I.; Sagimbaeva, F.; Solnyshkin, A.A.; Stegailov, V.I.; Tichy, P.; Tsoupko-Sitnikov, V.M.; Tyutyunnikov, S.I.; Vespalec, R. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Vrzalova, J. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Nuclear Physics Institute ASCR PRI (Czech Republic); Yuldashev, B.S. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute of Nuclear Physics ASRU, Tashkent (Uzbekistan); Wagner, V. [Nuclear Physics Institute ASCR PRI (Czech Republic); Zavorka, L.; Zeman, M. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

    2016-08-15

    The natural uranium assembly, QUINTA, was irradiated with 6 GeV deuterons. The {sup 232}Th samples were placed at the central axis of the setup QUINTA. The spectra of gamma rays emitted by the activated {sup 232}Th samples have been analysed and more than one hundred nuclei produced have been identified. For each of those products, reaction rates have been determined. The ratio of the weight of produced {sup 233}U to {sup 232}Th is presented. Experimental results were compared with the results of Monte Carlo simulations by FLUKA code.

  6. Breast conserving treatment of locally advanced carcinoma T2 and T3 after neoadjuvant chemotherapy followed by quadrantectomy and high dose-rate brachytherapy, as a boost, complementary teletherapy and adjuvant chemotherapy; Tratamento conservador dos carcinomas de mama localmente avancados T2 e T3, apos quimioterapia neoadjuvante, com quadrantectomia e braquiterapia de alta taxa de dose como reforco de dose, teleterapia complementar e quimioterapia adjuvante

    Energy Technology Data Exchange (ETDEWEB)

    Fristachi, Carlos Elias [Instituto do Cancer Dr. Arnaldo Vieira de Carvalho (ICAVC), Sao Paulo, SP (Brazil). Servico de Onco-Ginecologia e Mastologia]. E-mail: cefristachi@uol.com.br; Miziara Filho, Miguel Abrao; Soares, Celia Regina; Fogaroli, Ricardo Cesar; Pelosi, Edilson Lopes; Martins, Homero Lavieri Martins [Instituto do Cancer Dr. Arnaldo Vieira de Carvalho (ICAVC), Sao Paulo, SP (Brazil). Servico de Radioterapia; Baracat, Fausto Farah [Hospital do Servidor Publico Estadual de Sao Paulo (HSPE), SP (Brazil). Servico de Ginecologia e Mastologia; Piato, Sebastiao [Irmandade da Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Dept. de Obstetricia e Ginecologia (DOGI)

    2005-07-01

    Objective: to assess the treatment of breast cancer T2 and T3(T > = 4 cm), through neoadjuvant chemotherapy, quadrantectomy and high-dose-rate (HDR) brachytherapy as a boost, complementary radiotherapy and adjuvant chemotherapy, considering its method problems, its esthetics results, the aspect of local control, overall survival, and disease-free survival. Patients and method: this clinical prospective descriptive study was based on the evaluation of 26 patients ranging from 30 to 70 years old, with infiltrating ductal carcinoma, clinical stage IIB and IIIA, responsive to the neoadjuvant chemotherapy. Early and late radiotherapy complications were evaluated according to the criteria established by the RTOG/EORTC (Radiotherapy and Oncology Group /European Organization for Research and Treatment of Cancer) groups. Esthetics evaluation was done in accordance with the criteria set by a plastic surgeon. Local control was evaluated by clinical method, mammography and ultrasonography. Overall survival (OS) and the disease-free survival (DFS) were assessed according to Kaplan-Meier methodology. All the patients were treated at the Dr. Arnaldo Vieira de Carvalho Cancer Institute, from June/1995 to November/2001, and evaluated in March, 2002, with median follow-up of 28.7 months. Results: early complications were observed in 8 patients (30.6%). Two patients were classified as G3 and G4 (RTOG/EORTC). Six patients had late complications and three of them (11.5%) were classified as G3 and G4. One patient (3.8%) had local recurrence, 64 months after having local treatment. Esthetics results were considered good or regular in 16 patients (60.5%) out of 24 patients who were examined. Overall survival and disease-free survival in 24, 36 and 60 months were 100%, 92.3% and 83.1% respectively. Conclusion: early and late radiotherapy complications were considerate high when compared to literature, but esthetic results were considered acceptable. RL, OS and DFS were comparable to other

  7. Rotational total skin electron irradiation with a linear accelerator.

    Science.gov (United States)

    Reynard, Eric P; Evans, Michael D C; Devic, Slobodan; Parker, William; Freeman, Carolyn R; Roberge, David; Podgorsak, Ervin B

    2008-11-03

    The rotational total skin electron irradiation (RTSEI) technique at our institution has undergone several developments over the past few years. Replacement of the formerly used linear accelerator has prompted many modifications to the previous technique. With the current technique, the patient is treated with a single large field while standing on a rotating platform, at a source-to-surface distance of 380 cm. The electron field is produced by a Varian 21EX linear accelerator using the commercially available 6 MeV high dose rate total skin electron mode, along with a custom-built flattening filter. Ionization chambers, radiochromic film, and MOSFET (metal oxide semiconductor field effect transistor) detectors have been used to determine the dosimetric properties of this technique. Measurements investigating the stationary beam properties, the effects of full rotation, and the dose distributions to a humanoid phantom are reported. The current treatment technique and dose regimen are also described.

  8. Food irradiation

    Energy Technology Data Exchange (ETDEWEB)

    1987-02-28

    A brief article examines the controversy over food irradiation regarding the wholesomeness of irradiated food, its microbiological safety, loss of vitamins and changes in flavour. The benefits of food irradiation are also outlined including the destruction of certain food-borne pathogens and the prolongation of the shelf-life of food by killing pests and delaying the deterioration process.

  9. TU-H-CAMPUS-TeP2-02: FLASH Irradiation Improves the Therapeutic Index Following GI Tract Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, E; Trovati, S; King, G; Lartey, F; Rafat, M; Loo, B; Maxim, P [Stanford University School of Medicine, Palo Alto, California (United States)

    2016-06-15

    Purpose: To investigate and characterize the radiobiological effectiveness of very high dose rate radiotherapy (FLASH) compared to conventional irradiation in an in vivo model. Methods: The gastrointestinal (GI) tract of C57BL/6 mice were irradiated with doses ranging between 10 and 18 Gy using a custom stereotactic jig. A Varian Clinac 21EX was modified to allow dose rates ranging from 0.05 to 240 Gy/s at the position of the mirror. With the gantry at 180 degrees, the jig holding the individual animals was placed above the mirror to take advantage of the reduced source to target distance. Mice were irradiated with 20MeV electrons. Following irradiation, the mice were monitored twice daily for morbidity and daily for weight changes. Results: Mice irradiated with FLASH irradiation had lower weight loss compared to the mice receiving conventional irradiation. Following FLASH irradiation, a maximum weight loss of ∼20% was observed at day 6 with subsequent recovery, while following conventional irradiation, higher weight losses was observed with fewer instances of recovery. Concerning survival, all mice in the conventionally irradiated groups had a 100% mortality in the range of 15.5–18 Gy, while the mice irradiated with FLASH irradiation had a 100% survival in the same range. Conclusion: These results have demonstrated proof of principle that FLASH irradiations have a dramatic impact on the overall survival of mice following GI tract irradiations. If the increase in the therapeutic window can be validated and understood, this would revolutionize the field of radiation oncology and lead to increased cure rates with reduced side effects following treatment, resulting in increased quality of life for cancer survivors. Funding: DoD, Award#:W81XWH-14-1-0014, Weston Havens Foundation, Bio-X (Stanford University), the Office of the Dean of the Medical School, the Office of the Provost (Stanford University), and the Swedish Childhood Cancer Foundation; BL and PM are

  10. Metallography and fuel cladding chemical interaction in fast flux test facility irradiated metallic U-10Zr MFF-3 and MFF-5 fuel pins

    Energy Technology Data Exchange (ETDEWEB)

    Carmack, W. J.; Chichester, H. M.; Porter, D. L.; Wootan, D. W.

    2016-05-01

    Abstract The Mechanistic Fuel Failure (MFF) series of metal fuel irradiations conducted in the Fast Flux Test Facility (FFTF) provides an important potential comparison between data generated in the Experimental Breeder Reactor (EBR-II) and that expected in a larger-scale fast reactor. The irradiations were the beginning tests to qualify U-10wt%Zr as a driver fuel for FFTF. The FFTF core, with a 91.4 cm tall fuel column and a chopped cosine neutron flux profile, operated with a peak cladding temperature at the top of the fuel column, but developed peak burnup at the centerline of the core. This places the peak fuel temperature midway between the core center and the top of fuel, lower in the fuel column than in previous EBR-II experiments that had a 32-cm height core. The MFF-3 and MFF-5 qualification assemblies operated in FFTF to >10 at% burnup, and performed very well with no cladding breaches. The MFF-3 assembly operated to 13.8 at% burnup with a peak inner cladding temperature of 643°C, and the MFF-5 assembly operated to 10.1 at% burnup with a peak inner cladding temperature of 651°C. Because of the very high operating temperatures for both the fuel and the cladding, data from the MFF assemblies are most comparable to the data obtained from the EBR-II X447 experiment, which experienced two pin breaches. The X447 breaches were strongly influenced by a large amount of fuel/cladding chemical interaction (FCCI). The MFF pins benefitted from different axial locations of high burnup and peak cladding temperature, which helped to reduce interdiffusion between rare earth fission products and stainless steel cladding. Post-irradiation examination evidence illustrates this advantage. Comparing other performance data of the long MFF pins to prior EBR-II test data, the MFF fuel inside the cladding grew less axially, and the gas release data did not reveal a definitive difference.

  11. A flattening filter for brachytherapy skin irradiation

    Science.gov (United States)

    Kron, Tomas; Haque, Mamoon; Foulkes, Kristie; Jeraj, Robert

    2002-03-01

    Radioactive sources in close contact offer an alternative to superficial radiation in the treatment of skin lesions. A flattening filter was designed for a lead surface applicator to improve the skin dose distribution of a high dose rate (HDR) brachytherapy unit (Nucletron). At three heights from the opening (10, 15 and 25 mm) of the cylindrical applicator, the 192Ir source can be driven into the centre of the applicator. Thin sheets of lead foil (0.2 mm) were cut into circular shapes and placed in the opening to build a cylindrical cone that acts as a flattening filter. The shape of the cone was optimized in an iterative process using a spreadsheet and the resulting dose distribution under the applicator was determined using radiosensitive film. The use of the filter improved the dose distribution in a plane perpendicular to the beam axis to be within +/-5% of the central axis dose. The present applicator and flattening filter together with an HDR brachytherapy unit offer an alternative for skin irradiation where a superficial unit is not available or will be replaced with a more flexible device. As the depth dose characteristics can be modified using different source-to-surface distances, the dose throughout the patient's skin can be shaped as desired by the radiation oncologist using a compensator design type approach.

  12. Irradiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Howe, L.M

    2000-07-01

    There is considerable interest in irradiation effects in intermetallic compounds from both the applied and fundamental aspects. Initially, this interest was associated mainly with nuclear reactor programs but it now extends to the fields of ion-beam modification of metals, behaviour of amorphous materials, ion-beam processing of electronic materials, and ion-beam simulations of various kinds. The field of irradiation damage in intermetallic compounds is rapidly expanding, and no attempt will be made in this chapter to cover all of the various aspects. Instead, attention will be focused on some specific areas and, hopefully, through these, some insight will be given into the physical processes involved, the present state of our knowledge, and the challenge of obtaining more comprehensive understanding in the future. The specific areas that will be covered are: point defects in intermetallic compounds; irradiation-enhanced ordering and irradiation-induced disordering of ordered alloys; irradiation-induced amorphization.

  13. External beam radiation and high-dose-rate brachytherapy for elderly patients with gastroesophageal junction adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2017-07-01

    Full Text Available Purpose: The aim of this study was to retrospectively observe and analyze the long-term treatment outcomes of 96 elderly patients with gastroesophageal junction adenocarcinoma (GEJAC who were treated with californium-252 (252Cf neutron brachytherapy (NBT in combination with external beam radiotherapy (EBRT with or without chemotherapy. Material and methods: From January 2002 to November 2012, 96 patients with GEJAC underwent treatment. The total radiation dose to the reference point via NBT was 8-25 Gy-eq in 2 to 5 fractions, with 1 fraction per week. The total dose via EBRT was 40-54 Gy, which was delivered over a period of 4 to 5.5 weeks with normal fraction. Results: The median survival time for the 96 patients was 15.3 months, and the 1-, 2-, 3-, and 5-year rates of overall survival (OS were 62.5%, 33.7%, 20.1%, and 7.9%, respectively. The 1-, 2-, 3-, and 5-year rates for local-regional control (LRC were 78.7%, 57.9%, 41.8%, and 26.4%, respectively. The patients’ age was an independent factor that was significantly associated with OS (p = 0.006 and LRC (p = 0.0005, according to univariate analysis. The 3-year OS (LRC was 31.9% (62.9% for patients aged 70-74 years and 16.1% (19.5% for patients aged ≥ 75 years. From the time of treatment completion to the development of local-regional recurrence or death, 5 (5.2% patients experienced fistula and 7 (7.3% experienced massive bleeding. Conclusions: The clinical data indicated that NBT in combination with EBRT produced favorable local control and long-term survival rates for elderly patients with GEJAC, and that the side effects were tolerable. The patient’s age could be used to select the appropriate treatment in an elderly patient.

  14. Implementation and experimental validation of the high dose rate stereotactic treatment mode at Varian accelerators

    National Research Council Canada - National Science Library

    Hoffmann, Lone

    2009-01-01

    ...) and the Anisotropic Analytical Algorithm (AAA). Additional output factors, profiles and percentage depth dose curves were measured in a water phantom for asymmetric fields and fields defined by the Varian 120 MLC and the BrainLAB m3 MLC...

  15. Implementation and experimental validation of the high dose rate stereotactic treatment mode at Varian accelerators.

    Science.gov (United States)

    Hoffmann, Lone

    2009-01-01

    Treating small tumours in the brain requires usage of small fields. However, it is a challenge for all treatment planning systems (TPS) to modulate small fields (percentage depth dose curves were measured in a water phantom for asymmetric fields and fields defined by the Varian 120 MLC and the BrainLAB m3 MLC. Dose distributions in transverse sections were measured with gafchromic films in a homogeneous phantom. These were compared to those calculated by the Eclipse TPS for 11 stereotactic treatment plans. The plans included non-coplanar, dynamic and arc fields. All comparisons for the film measurements in the phantom were made with a Gamma criterion of 2 mm in distance and 3% in dose. The AAA and the PB algorithms broadened the penumbra of the profiles by approximately 1.5 mm and 2.0 mm, respectively. For static fields defined by the Varian 120 MLC, the measured field size was 1.0 mm broader than the calculated. The output factors were typically within 2% for field sizes > or = 2 x 2 cm(2). More than 95% of the points passed the Gamma criterion. Up to 50% of the points in the low dose regions failed the criterion, but overall the match was satisfactory. The accuracy of calculations performed by the Eclipse TPS for the SRS mode was shown to be within a few percent for most clinical fields. AAA was found to be superior to the PB algorithm in modelling the dose in the penumbra region.

  16. Targeting MRS-Defined Dominant Intraprostatic Lesions with Inverse-Planned High Dose Rate Brachytherapy

    National Research Council Canada - National Science Library

    Pouliot, Jean; Hsu, I-Chow; Kurhanewicz, John; Noworelski, Sue

    2008-01-01

    .... We have also published our results on the class solution for the boost of DIL defined by MRI/MRSI, as well as for the sparing of organs at risk including bladder, rectum, urethra and penile bulb...

  17. Postoperative single-dose interstitial high-dose-rate brachytherapy in therapy-resistant keloids

    NARCIS (Netherlands)

    Hafkamp, C. J. H.; Lapid, O.; Dávila Fajardo, R.; van de Kar, A. L.; Koedooder, C.; Stalpers, L. J.; Pieters, B. R.

    2017-01-01

    Patients with keloids complain of the cosmetic aspect, pain, and pruritus. Many different therapies are being used for keloids. The aim of this study was to evaluate the recurrence rate and outcome after resection followed by a single-dose brachytherapy. Patients treated by resection of the keloid

  18. High-Dose-Rate Brachytherapy for the Treatment of Recalcitrant Keloids: A Unique, Effective Treatment Protocol

    NARCIS (Netherlands)

    van Leeuwen, M.C.E.; Stokmans, S.C.; Bulstra, A.E.J.; Meijer, O.W.M.; van Leeuwen, P.A.M.; Niessen, F.B.

    2014-01-01

    BACKGROUND:: Keloids cause aesthetic disfigurement and physical complaints, mainly pain and pruritus. Treatment of these scars is difficult, with high recurrence rates forming the main issue. Surgical excision with adjuvant radiotherapy is considered the most efficacious treatment. At their

  19. Monte Carlo Study of Radiation Dose Enhancement by Gadolinium in Megavoltage and High Dose Rate Radiotherapy

    OpenAIRE

    Daniel G Zhang; Vladimir Feygelman; Moros, Eduardo G.; Kujtim Latifi; Zhang, Geoffrey G.

    2014-01-01

    MRI is often used in tumor localization for radiotherapy treatment planning, with gadolinium (Gd)-containing materials often introduced as a contrast agent. Motexafin gadolinium is a novel radiosensitizer currently being studied in clinical trials. The nanoparticle technologies can target tumors with high concentration of high-Z materials. This Monte Carlo study is the first detailed quantitative investigation of high-Z material Gd-induced dose enhancement in megavoltage external beam photon ...

  20. Comparison of focal boost high dose rate prostate brachytherapy optimisation methods.

    Science.gov (United States)

    Mason, Josh; Bownes, Peter; Carey, Brendan; Henry, Ann

    2015-12-01

    For HDR prostate brachytherapy treatments of 15 Gy to the whole gland plus focal boost, optimisation to either tumour plus margin (F-PTV) or involved sectors was compared. For 15 patients median F-PTV D90 and V150 were 21.0 Gy and 77.2% for F-PTV optimisation and 19.8 Gy and 75.6% for sector optimisation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Dose optimization of intra-operative high dose rate interstitial brachytherapy implants for soft tissue sarcoma

    Directory of Open Access Journals (Sweden)

    Jamema Swamidas

    2009-01-01

    Full Text Available Objective : A three dimensional (3D image-based dosimetric study to quantitatively compare geometric vs. dose-point optimization in combination with graphical optimization for interstitial brachytherapy of soft tissue sarcoma (STS. Materials and Methods : Fifteen consecutive STS patients, treated with intra-operative, interstitial Brachytherapy, were enrolled in this dosimetric study. Treatment plans were generated using dose points situated at the "central plane between the catheters", "between the catheters throughout the implanted volume", at "distances perpendicular to the implant axis" and "on the surface of the target volume" Geometrically optimized plans had dose points defined between the catheters, while dose-point optimized plans had dose points defined at a plane perpendicular to the implant axis and on the target surface. Each plan was graphically optimized and compared using dose volume indices. Results : Target coverage was suboptimal with coverage index (CI = 0.67 when dose points were defined at the central plane while it was superior when the dose points were defined at the target surface (CI=0.93. The coverage of graphically optimized plans (GrO was similar to non-GrO with dose points defined on surface or perpendicular to the implant axis. A similar pattern was noticed with conformity index (0.61 vs. 0.82. GrO were more conformal and less homogeneous compared to non-GrO. Sum index was superior for dose points defined on the surface of the target and relatively inferior for plans with dose points at other locations (1.35 vs. 1.27. Conclusions : Optimization with dose points defined away from the implant plane and on target results in superior target coverage with optimal values of other indices. GrO offer better target coverage for implants with non-uniform geometry and target volume.

  2. Application of RADPOS in Vivo Dosimetry for QA of High Dose Rate Brachytherapy

    DEFF Research Database (Denmark)

    Cherpak, A.; Kertzscher Schwencke, Gustavo Adolfo Vladimir; Cygler, J.

    2012-01-01

    Purpose: The RADPOS in vivo dosimetry system combines an electromagnetic positioning sensor with MOSFET dosimetry, allowing for simultaneous online measurements of dose and spatial position. In this work, we assess the potential use of RADPOS for measurements of motion and dose during prostate HDR......Gy. Conclusions: In vivo dosimetry can potentially signal errors in catheter placement or numbering before entire dose is delivered. The demonstrated accuracy of RADPOS dose measurements and its ability to simultaneously measure displacement makes it a powerful tool for HDR brachytherapy treatments for prostate...

  3. Radiochromic film-based quality assurance for CT-based high-dose-rate brachytherapy.

    Science.gov (United States)

    Asgharizadeh, Saeid; Bekerat, Hamed; Syme, Alasdair; Aldelaijan, Saad; DeBlois, François; Vuong, Té; Evans, Michael; Seuntjens, Jan; Devic, Slobodan

    2015-01-01

    In the past, film dosimetry was developed into a powerful tool for external beam radiotherapy treatment verification and quality assurance. The objective of this work was the development and clinical testing of the EBT3 model GafChromic film based brachytherapy quality assurance (QA) system. Retrospective dosimetry study was performed to test a patient-specific QA system for preoperative endorectal brachytherapy that uses a radiochromic film dosimetry system. A dedicated phantom for brachytherapy applicator used for rectal cancer treatment was fabricated enabling us to compare calculated-to-measured dose distributions. Starting from the same criteria used for external beam intensity-modulated radiation therapy QA (3%, 3 mm), passing criteria for high- and low-dose gradient regions were subsequently determined. Finally, we investigated the QA system's sensitivity to controlled source positional errors on selected patient plans. In low-dose gradient regions, measured dose distributions with criteria of 3%, 3 mm barely passed the test, as they showed 95% passing pixels. However, in the high-dose gradient region, a more stringent condition could be established. Both criteria of 2%, 3 mm and 3%, 2 mm with gamma function calculated using normalization to the same absolute dose value in both measured and calculated dose distributions, and matrix sizes rescaled to match each other showed more than 95% of pixels passing, on average, for 15 patient plans analyzed. Although the necessity of the patient-specific brachytherapy QA needs yet to be justified, we described a radiochromic film dosimetry-based QA system that can be a part of the brachytherapy commissioning process, as well as yearly QA program. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  4. Use of ultrasound in image-guided high-dose-rate brachytherapy: enumerations and arguments

    OpenAIRE

    Susovan Banerjee; Tejinder Kataria; Deepak Gupta; Shikha Goyal; Shyam Singh Bisht; Trinanjan Basu; Ashu Abhishek

    2017-01-01

    Inherently, brachytherapy is the most conformal radiotherapeutic technique. As an aid to brachytherapy, ultrasonography (USG) serves as a portable, inexpensive, and simple to use method allowing for accurate, reproducible, and adaptive treatments. Some newer brachytherapy planning systems have incorporated USG as the sole imaging modality. Ultrasonography has been successfully used to place applicator and dose planning for prostate, cervix, and anal canal cancers. It can guide placement of br...

  5. A method for restricting intracatheter dwell time variance in high-dose-rate brachytherapy plan optimization.

    Science.gov (United States)

    Cunha, Adam; Siauw, Timmy; Hsu, I-Chow; Pouliot, Jean

    2016-01-01

    To present the algorithm of a modification to the inverse planning simulated annealing (IPSA) optimization engine that allows for restriction of the intracatheter dwell time variance. IPSA was modified to allow user control of dwell time variance within each catheter through a single parameter, the dwell time deviation constraint (DTDC). The minimum DTDC value (DTDC = 0) does not impose any restriction on dwell time variance, and the maximum value (DTDC = 1) restricts all dwell times within each catheter to take on the same value. The final optimization penalty function value was evaluated as a function of DTDC. The algorithm proposed fully preserves the inverse planning nature of the IPSA algorithm along with the penalty-based dose optimization workflow. Increasing DTDC creates less variance in dwell time between dwell positions in each catheter and may be used to induce a more smooth change in dwell time with dwell position in each catheter. Nonzero DTDC values always increased the optimization penalty function value. The DTDC was developed as an extension to IPSA to allow restriction of the difference in dwell time between adjacent dwell positions. This results in less variation between neighboring dwell positions which can be clinically desirable. However, the impact of this restriction needs to be considered for its clinical relevance on a case-by-case basis because considerable degradation in dose-volume histogram metrics can result for large DTDC values. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  6. Very High Dose-Rate Radiobiology and Radiation Therapy for Lung Cancer

    Science.gov (United States)

    2015-02-01

    landmarks, the position of the right lung in mice (Figure 7). With this information, it was possible to position the mice in front of the beamline to...front of the beamline with the mini-incubator on top of it. c) Mini-incubator containing the rotation motor that allowed the flask’s two sided

  7. Anthropomorphic phantom to investigate the bladder dose in gynecological high-dose-rate brachytherapy.

    Science.gov (United States)

    Silva, R M V; Belinato, W; Macedo, L E; Souza, D N

    2015-01-01

    This study presents a prototype of a phantom appropriate for experimental bladder dosimetry. This work presents details of the phantom construction and dosimetric results obtained using radiochromic film and optically stimulated luminescence dosimeters (OSLDs). The phantom was constructed of polymethyl methacrylate. Two artificial bladders were three-dimensional printed using previous computed tomography images. Radiochromic films and OSLDs were positioned on the artificial bladder walls, and the applicators were placed according to the original computed tomography image. The prototype phantom simulated the behavior of the dose on the bladder surface, enabling bladder movement in all directions. The dosimetric study that was performed using radiochromic film and OSLDs exhibited concordance, in most cases, with the results obtained from the planning system. The methodology presented offers conditions for researchers to investigate more accurately the behavior of the dose on the bladder surface during intracavitary brachytherapy procedures. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  8. Advantages of high-dose rate (HDR) brachytherapy in treatment of prostate cancer

    Science.gov (United States)

    Molokov, A. A.; Vanina, E. A.; Tseluyko, S. S.

    2017-09-01

    One of the modern methods of preserving organs radiation treatment is brachytherapy. This article analyzes the results of prostate brachytherapy. These studies of the advantages of high dose brachytherapy lead to the conclusion that this method of radiation treatment for prostate cancer has a favorable advantage in comparison with remote sensing methods, and is competitive, preserving organs in comparison to surgical methods of treatment. The use of the method of polyfocal transperineal biopsy during the brachytherapy session provides information on the volumetric spread of prostate cancer and adjust the dosimetry plan taking into account the obtained data.

  9. PprA Protein Is Involved in Chromosome Segregation via Its Physical and Functional Interaction with DNA Gyrase in Irradiated Deinococcus radiodurans Bacteria

    Science.gov (United States)

    Devigne, Alice; Guérin, Philippe; Lisboa, Johnny; Quevillon-Cheruel, Sophie; Armengaud, Jean; Sommer, Suzanne; Bouthier de la Tour, Claire

    2016-01-01

    ABSTRACT PprA, a radiation-induced Deinococcus-specific protein, was previously shown to be required for cell survival and accurate chromosome segregation after exposure to ionizing radiation. Here, we used an in vivo approach to determine, by shotgun proteomics, putative PprA partners coimmunoprecipitating with PprA when cells were exposed to gamma rays. Among them, we found the two subunits of DNA gyrase and, thus, chose to focus our work on characterizing the activities of the deinococcal DNA gyrase in the presence or absence of PprA. Loss of PprA rendered cells hypersensitive to novobiocin, an inhibitor of the B subunit of DNA gyrase. We showed that treatment of bacteria with novobiocin resulted in induction of the radiation desiccation response (RDR) regulon and in defects in chromosome segregation that were aggravated by the absence of PprA. In vitro, the deinococcal DNA gyrase, like other bacterial DNA gyrases, possesses DNA negative supercoiling and decatenation activities. These two activities are inhibited in vitro by novobiocin and nalidixic acid, whereas PprA specifically stimulates the decatenation activity of DNA gyrase. Together, these results suggest that PprA plays a major role in chromosome decatenation via its interaction with the deinococcal DNA gyrase when D. radiodurans cells are recovering from exposure to ionizing radiation. IMPORTANCE D. radiodurans is one of the most radiation-resistant organisms known. This bacterium is able to cope with high levels of DNA lesions generated by exposure to extreme doses of ionizing radiation and to reconstruct a functional genome from hundreds of radiation-induced chromosomal fragments. Here, we identified partners of PprA, a radiation-induced Deinococcus-specific protein, previously shown to be required for radioresistance. Our study leads to three main findings: (i) PprA interacts with DNA gyrase after irradiation, (ii) treatment of cells with novobiocin results in defects in chromosome segregation

  10. PprA Protein Is Involved in Chromosome Segregation via Its Physical and Functional Interaction with DNA Gyrase in Irradiated Deinococcus radiodurans Bacteria.

    Science.gov (United States)

    Devigne, Alice; Guérin, Philippe; Lisboa, Johnny; Quevillon-Cheruel, Sophie; Armengaud, Jean; Sommer, Suzanne; Bouthier de la Tour, Claire; Servant, Pascale

    2016-01-01

    PprA, a radiation-induced Deinococcus-specific protein, was previously shown to be required for cell survival and accurate chromosome segregation after exposure to ionizing radiation. Here, we used an in vivo approach to determine, by shotgun proteomics, putative PprA partners coimmunoprecipitating with PprA when cells were exposed to gamma rays. Among them, we found the two subunits of DNA gyrase and, thus, chose to focus our work on characterizing the activities of the deinococcal DNA gyrase in the presence or absence of PprA. Loss of PprA rendered cells hypersensitive to novobiocin, an inhibitor of the B subunit of DNA gyrase. We showed that treatment of bacteria with novobiocin resulted in induction of the radiation desiccation response (RDR) regulon and in defects in chromosome segregation that were aggravated by the absence of PprA. In vitro, the deinococcal DNA gyrase, like other bacterial DNA gyrases, possesses DNA negative supercoiling and decatenation activities. These two activities are inhibited in vitro by novobiocin and nalidixic acid, whereas PprA specifically stimulates the decatenation activity of DNA gyrase. Together, these results suggest that PprA plays a major role in chromosome decatenation via its interaction with the deinococcal DNA gyrase when D. radiodurans cells are recovering from exposure to ionizing radiation. IMPORTANCE D. radiodurans is one of the most radiation-resistant organisms known. This bacterium is able to cope with high levels of DNA lesions generated by exposure to extreme doses of ionizing radiation and to reconstruct a functional genome from hundreds of radiation-induced chromosomal fragments. Here, we identified partners of PprA, a radiation-induced Deinococcus-specific protein, previously shown to be required for radioresistance. Our study leads to three main findings: (i) PprA interacts with DNA gyrase after irradiation, (ii) treatment of cells with novobiocin results in defects in chromosome segregation that are

  11. Accelerated partial breast irradiation following breast-conservative surgery. A review; Irradiation partielle du sein apres chirurgie conservatrice revue de la litterature

    Energy Technology Data Exchange (ETDEWEB)

    Calais, G. [Hopital Bretonneau, Clinique d' Oncologie et Radiotherapie, 37 - Tours (France)

    2003-11-01

    After breast-conservative surgery, radiation therapy delivered to the whole breast to 50 Gy with an additional boost of 10 to 16 Gy is the standard of care. Based upon data showing that the vast majority of the recurrences occur within and surrounding the original tumor site and in order to reduce the morbidity of whole breast radiotherapy and to give the treatment in a shorter time, partial breast irradiation has been developed by several institutions. Partial breast radiotherapy is given by intraoperative radiotherapy (photons or electrons), or brachytherapy (low dose rate or high dose rate) or external radiotherapy using 3D conformal radiation therapy. This is a review of the literature data on this topic. (author)

  12. Institutional experience with a rotational total skin electron irradiation (RTSEI) technique-A three decade review (1981-2012).

    Science.gov (United States)

    Evans, Michael D C; Hudon, Christine; Podgorsak, Ervin B; Freeman, Carolyn R

    2014-03-01

    Total skin electron irradiation (TSEI) for patients with cutaneous lymphomas is technically challenging, and numerous approaches have been developed to overcome the many field matching problems associated with such a large and complex treatment volume. Since 1981 we have delivered TSEI using a rotational total skin electron irradiation (RTSEI) technique in conjunction with patch, treat and boost fields in order to provide complete skin and dose coverage. Initially we used a 6 MeV electron beam at an extended source-skin distance (SSD) on a modified linear accelerator. More recently we began using a high dose rate electron mode on a commercially available linear accelerator. The RTSEI technique allows the delivery of a seamless surface dose to the majority of the patient's skin surface in a single treatment. In this review paper we present our three-decade experience with the technical development, dosimetry, treatment delivery and clinical outcomes of our RTSEI technique.

  13. Institutional experience with a rotational total skin electron irradiation (RTSEI) technique—A three decade review (1981–2012)

    Science.gov (United States)

    Evans, Michael D.C.; Hudon, Christine; Podgorsak, Ervin B.; Freeman, Carolyn R.

    2013-01-01

    Total skin electron irradiation (TSEI) for patients with cutaneous lymphomas is technically challenging, and numerous approaches have been developed to overcome the many field matching problems associated with such a large and complex treatment volume. Since 1981 we have delivered TSEI using a rotational total skin electron irradiation (RTSEI) technique in conjunction with patch, treat and boost fields in order to provide complete skin and dose coverage. Initially we used a 6 MeV electron beam at an extended source-skin distance (SSD) on a modified linear accelerator. More recently we began using a high dose rate electron mode on a commercially available linear accelerator. The RTSEI technique allows the delivery of a seamless surface dose to the majority of the patient's skin surface in a single treatment. In this review paper we present our three-decade experience with the technical development, dosimetry, treatment delivery and clinical outcomes of our RTSEI technique. PMID:24936331

  14. Microstructural evaluation of stainless alloys irradiated in the BOR-60 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.; Allen, T.R. [Univ. of Wisconsin-Madison, Madison, Wisconsin (United States); Chen, Y.; Chopra, O.K. [Argonne National Lab., Argonne, Illinois (United States)

    2007-07-01

    The microstructures of austenitic stainless steels, cast steels, and nickel-base alloys irradiated at PWR-relevant dose and temperature have been characterized using transmission electron microscopy. The samples had varied chemical composition, heat treatment, and cold working with associated initial variations in microstructure. They were irradiated at 325{sup o}C to approximately 25 dpa with a dose rate of {approx} 9.4E-7 dpa/s. No voids and no precipitates with sufficient concentration or size for diffraction characterization were observed in the austenitic stainless steels and cast steels, while some voids were found in the nickel-base alloys. The irradiated microstructures were dominated by a high density of dislocation loops. The sizes and densities of the dislocation loops were measured by means of relrod dark field images. The results varied for different heats and were consistent with other published data. The lack of swelling in the irradiated austenitic stainless steels was attributed to the low irradiation temperature and relatively high dose rate. (author)

  15. Irradiation subassembly

    Science.gov (United States)

    Seim, O.S.; Filewicz, E.C.; Hutter, E.

    1973-10-23

    An irradiation subassembly for use in a nuclear reactor is described which includes a bundle of slender elongated irradiation -capsules or fuel elements enclosed by a coolant tube and having yieldable retaining liner between the irradiation capsules and the coolant tube. For a hexagonal bundle surrounded by a hexagonal tube the yieldable retaining liner may consist either of six segments corresponding to the six sides of the tube or three angular segments each corresponding in two adjacent sides of the tube. The sides of adjacent segments abut and are so cut that metal-tometal contact is retained when the volume enclosed by the retaining liner is varied and Springs are provided for urging the segments toward the center of the tube to hold the capsules in a closely packed configuration. (Official Gazette)

  16. An experimental and mathematical analysis of lymphopoiesis dynamics under continuous irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zukhbaya, T.M.; Smirnova, O.A. (Institute of Medicobiological Problems of USSR, Ministry of Health, Moscow (USSR))

    1991-07-01

    A mathematical model describing the dynamics of lymphopoiesis in mammals continuously exposed to ionizing radiation has been developed. It is based on the theory of chalone regulation of hematopoiesis. The model comprises a system of nine differential equations. Results from the model were compared with our experimental data for bone marrow and blood lymphocytes of rats continuously exposed to gamma radiation in a wide range of dose rates. The model reproduces the lymphopoiesis dynamics that we observed in our experiment, in particular, the radiation hormesis at low dose rates, the reduction of lymphopoiesis at intermediate dose rates, and extinction of lymphopoiesis at high dose rates of continuous radiation. The possible explanation of the hormesis is suggested by the framework of the model. The model can be used for predicting the lymphopoiesis dynamics in mammals under continuous irradiation.

  17. First results on cell irradiation with laser-driven protons on the TARANIS system

    Energy Technology Data Exchange (ETDEWEB)

    Kar, S.; Doria, D.; Kakolee, K. F.; Prasad, R.; Litt, S.; Ahmed, H.; Nersisyan, G.; Lewis, C.; Zepf, M. [School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Borghesi, M. [School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN, UK and Institute of Physics of the ASCR, ELI-Beamlines Project, Prague (Czech Republic); Schettino, G.; Prise, K. M. [CCRCB, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Fiorini, F.; Kirby, D.; Green, S. [Dept. of Medical Physics, University Hospital, Birmingham, B15 2TH (United Kingdom); Jeynes, J. C. G.; Merchant, M. J.; Kirkby, K. J. [Ion Beam Centre, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2013-07-26

    The ultra short duration of laser-driven multi-MeV ion bursts offers the possibility of radiobiological studies at extremely high dose rates. Employing the TARANIS Terawatt laser at Queen’s University, the effect of proton irradiation at MeV-range energies on live cells has been investigated at dose rates exceeding 10{sup 9} Gy/s as a single exposure. A clonogenic assay showed consistent lethal effects on V-79 live, cells, which, even at these dose rates, appear to be in line with previously published results employing conventional sources. A Relative Biological Effectiveness (RBE) of 1.4±0.2 at 10% survival is estimated from a comparison with a 225 kVp X-ray source.

  18. Investigating the embryo/larval toxic and genotoxic effects of {gamma} irradiation on zebrafish eggs

    Energy Technology Data Exchange (ETDEWEB)

    Simon, O., E-mail: olivier.simon@irsn.fr [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Massarin, S. [Laboratoire de Modelisation Environnementale, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 159, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Coppin, F. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Hinton, T.G. [Service d' Etude du Comportement des Radionucleides dans les Ecosystemes, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 159, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Gilbin, R. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France)

    2011-11-15

    Eggs/larval of freshwater fish (Danio rerio) were exposed to low dose rates of external gamma radiation (from 1 to 1000 mGy d{sup -1}) over a 20-day period, with the objective of testing the appropriateness of the 10 mGy d{sup -1} guideline suggested by the IAEA. The present study examines different endpoints, mortality and hatching time and success of embryos as well as the genotoxicity of {gamma}-irradiations (after 48 h). The 20-day embryo-larval bioassay showed an enhanced larval resistance to starvation after chronic exposure to {gamma} irradiation (from low 1 mGy d{sup -1} to high dose rate 1000 mGy d{sup -1}) and an acceleration in hatching time. Gamma irradiation led to increased genotoxic damage Ito zebrafish egg (40-50% DNA in tail in Comet assay) from the lowest dose rate (1 mGy d{sup -1}). Possible mechanisms of {gamma} radiotoxicity and implications for radioprotection are discussed. - Highlights: > Relevant information on the {gamma} radiation impact on early life stage biota is scarce. > The eggs of zebrafish Danio rerio were selected as biological model. > We test the appropriateness of the 10 mGy d{sup -1} guideline (IAEA). > We observed effects measured at individual levels (starvation, hatching time). > Chronic gamma irradiation led to increased genotoxic damage to zebrafish egg. > {gamma} radiotoxicity mechanisms and implications for radioprotection are discussed.

  19. The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core

    Energy Technology Data Exchange (ETDEWEB)

    Toivonen, A.; Moilanen, P.; Pyykkoenen, M.; Taehtinen, S.; Rintamaa, R.; Saario, T. [Valtion Teknillinen Tutkimuskeskus, Espoo (Finland)

    1998-11-01

    Environmentally assisted cracking (EAC) of core materials has become an increasingly important issue of downtime and maintenance costs in nuclear power plants. Small size specimens are necessary in stress corrosion testing of irradiated materials because of difficulties in handling high dose rate materials and because of restricted availability of the materials. The drawback of using small size specimens is that in some cases they do not fulfil the requirements of the relevant testing standards. Recently VTT has developed J-R testing with irradiated and non-irradiated sub size 3 PB specimens, both in inert and in LWR environments. Also, a new materials testing system which will enable simultaneous multiple specimen testing both in laboratory conditions and in operating reactor core is under development. The new testing system will utilize Charpy and sub size 3 PB specimens. The feasibility study of the system has been carried out using different materials. Fracture resistance curves of a Cu-Zr-Cr alloy are shown to be independent of the specimen geometry and size, to some extent. Results gained from tests in simulated boiling water reactor (BWR) water are presented for sensitized SIS 2333 stainless steel. The experimental results indicate that the size of the plastic zone or stress triaxiality must be further studied although no significant effect on the environmentally assisted crack growth rate was observed. (orig.)

  20. Accelerated partial breast irradiation for elderly women with early breast cancer: A compromise between whole breast irradiation and omission of radiotherapy.

    Science.gov (United States)

    Sumodhee, Shakeel; Levy, Johan; Chamorey, Emmanuel; Lam Cham Kee, Daniel; Chand, Marie-Eve; Gautier, Mathieu; Peyrottes, Isabelle; Barranger, Emmanuel; Hannoun-Levi, Jean-Michel

    Regarding adjuvant radiation therapy making decision for elderly women, Albert (2013) published a nomogram predicting the mastectomy-free survival (MFS) rate with or without adjuvant irradiation. Based on this approach, we proposed to investigate the use of accelerated partial breast irradiation (APBI) vs. whole breast irradiation (WBI) or endocrine therapy alone in elderly low-risk breast cancer patients. For each elderly woman treated by conserving surgery and APBI (multicatheter interstitial high-dose-rate brachytherapy), 5- and 10-year MFS rates were calculated. For each treated patient, using the Albert nomogram, we calculated the estimated MFS rates at 5 and 10 years, with and without WBI. Then, we compared the estimated MFS rates after no irradiation and WBI vs. observed MFS rates after APBI. From 2005 to 2016, 79 patients were treated. Median followup was 96.8 months [68.6-104.9], median age was 77 years [66-89]. Expected 5- and 10-year mastectomy rates calculated with the Albert nomogram without WBI were 2.95% and 7.25%, respectively, leading to a 10-year MFS rate of 92.7%. Expected 5- and 10-year mastectomy rates after WBI were 1.41% and 3.66%, respectively, leading to a 10-year MFS rate of 96.3%. Regarding observed MFS rate, 1 pt (1.3%) experienced a salvage mastectomy. The 10-year MFS rate after APBI was 97.4% vs. 96.3% after WBI (p = 1) and 92.7% after no irradiation (p = 0.27). No toxicity Grade 3 or more was observed. APBI seems to be an attractive compromise between WBI and no irradiation for elderly women with early stage breast cancer as far as local control, quality of life and cost benefit is concerned. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  1. Phytosanitary Irradiation

    Directory of Open Access Journals (Sweden)

    Guy J. Hallman

    2016-01-01

    Full Text Available Phytosanitary treatments disinfest traded commodities of potential quarantine pests. Phytosanitary irradiation (PI treatments use ionizing radiation to accomplish this, and, since their international commercial debut in 2004, the use of this technology has increased by ~10% annually. Generic PI treatments (one dose is used for a group of pests and/or commodities, although not all have been tested for efficacy are used in virtually all commercial PI treatments, and new generic PI doses are proposed, such as 300 Gy, for all insects except pupae and adult Lepidoptera (moths. Fresh fruits and vegetables tolerate PI better than any other broadly used treatment. Advances that would help facilitate the use of PI include streamlining the approval process, making the technology more accessible to potential users, lowering doses and broadening their coverage, and solving potential issues related to factors that might affect efficacy.

  2. American Brachytherapy Society Task Group Report: Combined external beam irradiation and interstitial brachytherapy for base of tongue tumors and other head and neck sites in the era of new technologies.

    Science.gov (United States)

    Takácsi-Nagy, Zoltán; Martínez-Mongue, Rafael; Mazeron, Jean-Jacques; Anker, Cristopher James; Harrison, Louis B

    Irradiation plays an important role in the treatment of cancers of the head and neck providing a high locoregional tumor control and preservation of organ functions. External beam irradiation (EBI) results in unnecessary radiation exposure of the surrounding normal tissues increasing the incidence of side effects (xerostomy, osteoradionecrosis, and so forth). Brachytherapy (BT) seems to be the best choice for dose escalation over a short treatment period and for minimizing radiation-related normal tissue damage due to the rapid dose falloff around the source. Low-dose-rate BT is being increasingly replaced by pulsed-dose-rate and high-dose-rate BT because the stepping source technology offers the advantage of optimizing dose distribution by varying dwell times. Pulsed-dose and high-dose rates appear to yield local control and complication rates equivalent to those of low-dose rate. BT may be applied alone; but in case of high risk of nodal metastases, it is used together with EBI. This review presents the results and the indications of combined BT and EBI in carcinoma of the base of tongue and other sites of the head and neck region, as well as the role BT plays among other-normal tissue protecting-modern radiotherapy modalities (intensity-modulated radiotherapy, stereotactic radiotherapy) applied in these localizations. Copyright © 2016 American Brachytherapy Society. All rights reserved.

  3. INTERACTION OF LASER RADIATION WITH MATTER AND OTHER LASER APPLICATIONS: Changes in the emission properties of metal targets during pulse-periodic laser irradiation

    Science.gov (United States)

    Konov, Vitalii I.; Pimenov, S. M.; Prokhorov, A. M.; Chapliev, N. I.

    1988-02-01

    A scanning electron microscope was used with a pulse-periodic CO2 laser to discover the laws governing the correlation of the modified microrelief of metal surfaces, subjected to the action of multiple laser pulses, with the emission of charged particles and the luminescence of the irradiated zone. It was established that the influence of sorption and laser-induced desorption on the emission signals may be manifested differently depending on the regime of current generation in the "target-vacuum chamber" circuit.

  4. Irradiation Facilities at CERN

    CERN Document Server

    Gkotse, Blerina; Carbonez, Pierre; Danzeca, Salvatore; Fabich, Adrian; Garcia, Alia, Ruben; Glaser, Maurice; Gorine, Georgi; Jaekel, Martin, Richard; Mateu,Suau, Isidre; Pezzullo, Giuseppe; Pozzi, Fabio; Ravotti, Federico; Silari, Marco; Tali, Maris

    2017-01-01

    CERN provides unique irradiation facilities for applications in many scientific fields. This paper summarizes the facilities currently operating for proton, gamma, mixed-field and electron irradiations, including their main usage, characteristics and information about their operation. The new CERN irradiation facilities database is also presented. This includes not only CERN facilities but also irradiation facilities available worldwide.

  5. Low Dose Rate Irradiation Facility: initial study on chronic exposures to medaka

    Energy Technology Data Exchange (ETDEWEB)

    Hinton, T.G. E-mail: thinton@srel.edu; Coughlin, D.P.; Yi, Yi; Marsh, L.C

    2004-07-01

    Uncertainties associated with the effects from chronic low-level exposures to radiation prompted us to construct a Low Dose Rate Irradiation Facility (LoDIF). The facility was designed specifically to test the appropriateness of the 10 mGy d{sup -1} guideline often espoused as acceptable for protection of aquatic biota from ionizing radiation. Scientists at the 0.4 ha facility use 40 outdoor mesocosms and {sup 137}Cs irradiators of three different source strengths to research the effects of chronic low-level irradiation at different levels of biological organization. A description of the facility is included along with results from a pilot study in which Japanese medaka (a small fish native to Asia) were chronically irradiated at the highest dose rate possible within the facility (350{+-}150 mGy d{sup -1}). Irradiated fish produced fewer eggs per day (p=0.03); had a lower percentage of viable eggs (p=0.04), and produced a lower percentage of hatchlings (p=0.05). Although these data are not surprising based on the relatively high dose rates, they are important to future work at the LoDIF because they confirm the utility of our chosen model organism for detecting population-level responses, and they illustrate the statistical power achieved from using replicated mesocosms, in that statistical significance was achieved with few replicates per treatment. Future directions for the LoDIF are presented, as well as an invitation for interested researchers to participate in our studies.

  6. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    interaction between a human operator and an artificial actor or agent. We can apply insights from puppetry to develop culturally-aware robots. Here we describe the development of a robotic marionette theatre wherein robotic controllers assume the role of human puppeteers. The system has been built, tested...... including puppetry and dance. However, the aesthetics of these traditions vary across cultures and carry different associative and interpretive meanings. Puppetry offers a useful frame for understanding the relationship between abstract and imitative gestures and behavior, and instantiates the complex...

  7. American Brachytherapy Society consensus report for accelerated partial breast irradiation using interstitial multicatheter brachytherapy.

    Science.gov (United States)

    Hepel, Jaroslaw T; Arthur, Douglas; Shaitelman, Simona; Polgár, Csaba; Todor, Dorin; Zoberi, Imran; Kamrava, Mitchell; Major, Tibor; Yashar, Catheryn; Wazer, David E

    To develop a consensus report for the quality practice of accelerated partial breast irradiation (APBI) using interstitial multicatheter brachytherapy (IMB). The American Brachytherapy Society Board appointed an expert panel with clinical and research experience with breast brachytherapy to provide guidance for the current practice of IMB. This report is based on a comprehensive literature review with emphasis on randomized data and expertise of the panel. Randomized trials have demonstrated equivalent efficacy of APBI using IMB compared with whole breast irradiation for select patients with early-stage breast cancer. Several techniques for placement of interstitial catheters are described, and importance of three-dimensional planning with appropriate optimization is reviewed. Optimal target definition is outlined. Commonly used dosing schemas include 50 Gy delivered in pulses of 0.6-0.8 Gy/h using pulsed-dose-rate technique and 34 Gy in 10 fractions, 32 Gy in eight fractions, or 30 Gy in seven fractions using high-dose-rate technique. Potential toxicities and strategies for toxicity avoidance are described in detail. Dosimetric constraints include limiting whole breast volume that receives ≥50% of prescription dose to skin dose to ≤100% of prescription dose (≤60-70% preferred), chest wall dose to ≤125% of prescription dose, Dose Homogeneity Index to >0.75 (>0.85 preferred), V150 Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  8. Evaluation of electron beam irradiation under heating process on vulcanized EPDM

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Leandro; Cardoso, Jessica R.; Moura, Eduardo; Geraldo, Aurea B.C., E-mail: lgabriell@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The Global consumption of rubber is estimated around 30.5 million tons in 2015, when it is expected an increase of 4.3% of this volume in the coming of years. This demand is mainly attributed to the production of elastomeric accessories for the automotive sector. However, the generation of this type of waste also reaches major proportions at the end of its useful life, when it is necessary to dispose the environmental liability. Rubber reprocessing is an alternative where it can be used as filler in other polymer matrices or in other types of materials. The devulcanization process is another alternative and it includes the study of methods that allow economic viability and waste reduction. Therefore, this study aims to recycle vulcanized EPDM rubber with the use of ionizing radiation. In this work we are using the electron beam irradiation process with simultaneous heating at absorbed doses from 150 kGy to 800 kGy, under high dose rate of 22.3 kGy/s on vulcanized EPDM powder and on samples about 4 mm thick. Their characterization, before and after the irradiation process, have been realized by thermal analysis and their changes have been discussed. (author)

  9. SU-E-T-232: Custom High-Dose-Rate Brachytherapy Surface Mold Applicators: The Importance Source to Skin Distance

    Energy Technology Data Exchange (ETDEWEB)

    Park, S; Demanes, J; Kamrava, M [UCLA School of Medicine, Los Angeles, CA (United States)

    2015-06-15

    Purpose: Surface mold applicators can be customized to fit irregular skin surfaces that are difficult to treat with other radiation therapy techniques. Optimal design of customized HDR skin brachytherapy is not well-established. We evaluated the impact of applicator thickness (source to skin distance) on target dosimetry. Methods: 27 patients had 34 treated sites: scalp 4, face 13, extremity 13, and torso 4. Custom applicators were constructed from 5–15 mm thick thermoplastic bolus molded over the skin lesion. A planar array of plastic brachytherapy catheters spaced 5–10 mm apart was affixed to the bolus. CT simulation was used to contour the target volume and to determine the prescription depth. Inverse planning simulated annealing followed by graphical optimization was used to plan and deliver 40–56 Gy in 8–16 fractions. Target coverage parameters (D90, Dmean, and V100) and dose uniformity (V110–200, D0.1cc, D1cc, and D2cc) were studied according to target depth (<5mm vs. ≥5mm) and applicator thickness (5–10mm vs. ≥10mm). Results: The average prescription depth was 4.2±1.5mm. The average bolus thickness was 9.2±2.4mm. The median CTV volume was 10.0 cc (0.2–212.4 cc). Similar target coverage was achieved with prescription depths of <5mm and ≥5mm (Dmean = 113.8% vs. 112.4% and D90 = 100.2% vs. 98.3%). The <5mm prescription depth plans were more uniform (D0.1cc = 131.8% vs. 151.8%). Bolus thickness <10mm vs. ≥10mm plans also had similar target coverage (Dmean = 118.2% vs. 110.7% and D90 = 100.1% vs. 99.0%). Applicators ≥10mm thick, however, provide more uniform target dosimetry (D0.1cc = 146.9% vs. 139.5%). Conclusion: Prescription depth is based upon the thickness of the lesion and upon the clinical needs of the patient. Applicators ≥10mm thick provide more dose uniformity than 5–10mm thick applicators. Applicator thickness is an important variable that should be considered during treatment planning to achieve optimal dose uniformity.

  10. Dosimetric evaluation of PLATO and Oncentra treatment planning systems for High Dose Rate (HDR) brachytherapy gynecological treatments

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Hardev; De La Fuente Herman, Tania; Showalter, Barry; Thompson, Spencer J.; Syzek, Elizabeth J.; Herman, Terence; Ahmad, Salahuddin [Department of Radiation Oncology, Peggy and Charles Stephenson Oklahoma Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104 (United States)

    2012-10-23

    This study compares the dosimetric differences in HDR brachytherapy treatment plans calculated with Nucletron's PLATO and Oncentra MasterPlan treatment planning systems (TPS). Ten patients (1 T1b, 1 T2a, 6 T2b, 2 T4) having cervical carcinoma, median age of 43.5 years (range, 34-79 years) treated with tandem and ring applicator in our institution were selected retrospectively for this study. For both Plato and Oncentra TPS, the same orthogonal films anterior-posterior (AP) and lateral were used to manually draw the prescription and anatomical points using definitions from the Manchester system and recommendations from the ICRU report 38. Data input for PLATO was done using a digitizer and Epson Expression 10000XL scanner was used for Oncentra where the points were selected on the images in the screen. The prescription doses for these patients were 30 Gy to points right A (RA) and left A (LA) delivered in 5 fractions with Ir-192 HDR source. Two arrangements: one dwell position and two dwell positions on the tandem were used for dose calculation. The doses to the patient points right B (RB) and left B (LB), and to the organs at risk (OAR), bladder and rectum for each patient were calculated. The mean dose and the mean percentage difference in dose calculated by the two treatment planning systems were compared. Paired t-tests were used for statistical analysis. No significant differences in mean RB, LB, bladder and rectum doses were found with p-values > 0.14. The mean percent difference of doses in RB, LB, bladder and rectum are found to be less than 2.2%, 1.8%, 1.3% and 2.2%, respectively. Dose calculations based on the two different treatment planning systems were found to be consistent and the treatment plans can be made with either system in our department without any concern.

  11. TU-AB-201-06: Evaluation of Electromagnetically Guided High- Dose Rate Brachytherapy for Ablative Treatment of Lung Metastases

    Energy Technology Data Exchange (ETDEWEB)

    Pinkham, D.W.; Shultz, D.; Loo, B.W.; Sung, A.; Diehn, M.; Fahimian, B.P. [Stanford University, Stanford, CA (United States)

    2015-06-15

    Purpose: The advent of electromagnetic navigation bronchoscopy has enabled minimally invasive access to peripheral lung tumors previously inaccessible by optical bronchoscopes. As an adjunct to Stereotactic Ablative Radiosurgery (SABR), implantation of HDR catheters can provide focal treatments for multiple metastases and sites of retreatments. The authors evaluate a procedure to deliver ablative doses via Electromagnetically-Guided HDR (EMG-HDR) to lung metastases, quantify the resulting dosimetry, and assess its role in the comprehensive treatment of lung cancer. Methods: A retrospective study was conducted on ten patients, who, from 2009 to 2011, received a hypo-fractionated SABR regimen with 6MV VMAT to lesions in various lobes ranging from 1.5 to 20 cc in volume. A CT visible pathway was delineated for EM guided placement of an HDR applicator (catheter) and dwell times were optimized to ensure at least 98% prescription dose coverage of the GTV. Normal tissue doses were calculated using inhomogeneity corrections via a grid-based Boltzmann solver (Acuros-BV-1.5.0). Results: With EMG-HDR, an average of 83% (+/−9% standard deviation) of each patient’s GTV received over 200% of the prescription dose, as compared to SABR where the patients received an average maximum dose of 125% (+/−5%). EMG-HDR enabled a 59% (+/−12%) decrease in the aorta maximum dose, a 63% (+/−26%) decrease in the spinal cord max dose, and 57% (+/−23%) and 70% (+/−17%) decreases in the volume of the body receiving over 50% and 25% of the prescription dose, respectively. Conclusion: EMG-HDR enables delivery of higher ablative doses to the GTV, while concurrently reducing surrounding normal tissue doses. The single catheter approach shown here is limited to targets smaller than 20 cc. As such, the technique enables ablation of small lesions and a potentially safe and effective retreatment option in situations where external beam utility is limited by normal tissue constraints.

  12. Comparison of manual and inverse optimisation techniques in high dose rate intracavitary brachytherapy of cervical cancer: A dosimetric study.

    Science.gov (United States)

    Kannan, Ram Abhinav; Gururajachar, Janaki Manur; Ponni, Arul; Koushik, Kirthi; Kumar, Mohan; Alva, Ram Charith; Harjani, Ritika; Murthy, Arvind

    2015-01-01

    To compare dosimetrically the manual optimisation with IPSA using dose volume histograms (DVH) among patients treated for carcinoma of cervix with intracavitary brachytherapy. With the advent of advanced imaging modalities, there has been a shift from conventional X-ray based planning to three-dimensional planning. Manual optimisation is widely used across various institutions but it is time consuming and operator dependant. Inverse planning simulated annealing (IPSA) is now available in various brachytherapy planning systems. But there is a paucity of studies comparing manual optimisation and IPSA in treatment of carcinoma cervix with intracavitary brachytherapy and hence this study. Fifteen consecutive patients treated between December 2013 and March 2014 with intracavitary brachytherapy for carcinoma of cervix were selected for this study. All patients were initially treated with external beam radiotherapy followed by intracavitary brachytherapy. The DVH was evaluated and compared between manually optimised plans and IPSA in the same set of patients. There was a significant improvement in the HRCTV coverage, mean V100 of 87.75% and 82.37% (p = 0.001) and conformity index 0.67 and 0.6 (p = 0.007) for plans generated using IPSA and manual optimisation, respectively. Homogeneity index and dose to the OARs remained similar between the two groups. The use of inverse planning in intracavitary brachytherapy of cervix has shown a significant improvement in the target volume coverage when compared with manual planning.

  13. Workflow efficiency for the treatment planning process in CT-guided high-dose-rate brachytherapy for cervical cancer.

    Science.gov (United States)

    Michaud, Anthony L; Benedict, Stanley; Montemayor, Eliseo; Hunt, Jon Paul; Wright, Cari; Mathai, Mathew; Mayadev, Jyoti S

    2016-01-01

    To investigate process efficiency, we present a prospective investigation of the treatment planning phase of image-guided brachytherapy (BT) for cervical cancer using a specific checklist. From October 2012 to January 2014, 76 BT procedures were consecutively performed. Prospective data on the CT-based treatment planning process was collected using a specific checklist which details the following steps: (1) dosimetry planning, (2) physician review start, (3) physician review time, (4) dosimetry processing, (5) physics review start, (6) physics review, and (7) procedural pause. Variables examined included the use of a pre-BT MRI, clinic duty conflicts, resident teaching, and the use of specific BT planners. Analysis was performed using descriptive statistics, t-test, and analysis of variance. Seventy-five prospectively gathered checklists comprised this analysis. The mean time for treatment planning was 95 minutes (med 94, std 18). The mean intervals in the above steps were (1) = 42, (2) = 5, (3) = 19, (4) = 10, (5) = 6, (6) = 13, and (7) = 26 minutes. There was no statistical difference in patients who had a pre-BT MRI. Resident teaching did not influence time, p = 0.17. Treatment planning time was decreased with a specific planner, p = 0.0015. A skillful team approach is required for treatment planning efficiency in image-guided BT. We have found that the specific BT planners can have a significant effect on the overall planning efficiency. We continue to examine clinical and workflow-related factors that will enhance our safety and workflow process with BT. Published by Elsevier Inc.

  14. Dosimetry comparison between TG-43 and Monte Carlo calculations using the Freiburg flap for skin high-dose-rate brachytherapy.

    Science.gov (United States)

    Vijande, Javier; Ballester, Facundo; Ouhib, Zoubir; Granero, Domingo; Pujades-Claumarchirant, M Carmen; Perez-Calatayud, Jose

    2012-01-01

    The purpose of this work was to evaluate whether the delivered dose to the skin surface and at the prescription depth when using a Freiburg flap applicator is in agreement with the one predicted by the treatment planning system (TPS) using the TG-43 dose-calculation formalism. Monte Carlo (MC) simulations and radiochromic film measurements have been performed to obtain dose distributions with the source located at the center of one of the spheres and between two spheres. Primary and scatter dose contributions were evaluated to understand the role played by the scatter component. A standard treatment plan was generated using MC- and TG-43-based TPS applying the superposition principle. The MC model has been validated by performing additional simulations in the same conditions but transforming air and Freiburg flap materials into water to match TG-43 parameters. Both dose distributions differ less than 1%. Scatter defect compared with TG-43 data is up to 15% when the source is located at the center of the sphere and up to 25% when the source is between two spheres. Maximum deviations between TPS- and MC-based distributions are of 5%. The deviations in the TG-43-based dose distributions for a standard treatment plan with respect to the MC dose distribution calculated taking into account the composition and shape of the applicator and the surrounding air are lower than 5%. Therefore, this study supports the validity of the TPS used in clinical practice. Copyright © 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  15. A novel conformal superficial high-dose-rate brachytherapy device for the treatment of nonmelanoma skin cancer and keloids.

    Science.gov (United States)

    Ferreira, Clara; Johnson, Daniel; Rasmussen, Karl; Leinweber, Clinton; Ahmad, Salahuddin; Jung, Jae Won

    To develop a novel conformal superficial brachytherapy (CSBT) device as a treatment option for the patient-specific radiation therapy of conditions including superficial lesions, postsurgical positive margins, Dupuytren's contractures, keloid scars, and complex anatomic sites (eyelids, nose, ears, etc.). A preliminary CSBT device prototype was designed, built, and tested using readily available radioactive seeds. Iodine-125 ((125)I) seeds were independently guided to the treatment surface to conform to the target. Treatment planning was performed via BrachyVision Planning System (BPS) and dose distributions measured with Gafchromic EBT3 film. Percent depth dose curves and profiles for Praseodymium-142 ((142)Pr), and Strontium-90/Yttrium-90 ((90)Sr-(90)Y) were also investigated as potential sources. Results achieved with (90)Sr-(90)Y and electron external beam radiation therapy were compared and Monte Carlo N-Particle eXtended 2.6 simulations of (142)Pr seeds were validated. BPS was able to predict clinical dose distributions for a multiple seeds matrix. Calculated and measured doses for the (125)I seed matrix were 500 cGy and 473.5 cGy at 5 mm depth, and 171.0 cGy and 201.0 cGy at 10 mm depth, respectively. Results of (90)Sr-(90)Y tests demonstrate a more conformal dose than electron EBRT (1.6 mm compared to 4.3 mm penumbra). Measured (142)Pr doses were 500 cGy at surface and 17.4 cGy at 5 mm depth. The CSBT device provides a highly conformal dose to small surface areas. Commercially available BPS can be used for treatment planning, and Monte Carlo simulation can be used for plans using beta-emitting sources and complex anatomies. Various radionuclides may be used in this device to suit prescription depths and treatment areas. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  16. A feasibility study of applying thermal imaging to assist quality assurance of high-dose rate brachytherapy

    Directory of Open Access Journals (Sweden)

    Xiaofeng Zhu

    2017-01-01

    Conclusion: Thermal imaging could be a feasible tool to visualize HDR source dwell positions and verify source integrity. Potentially, patient safety and treatment quality may be improved by integrating thermal measurements into HDR QA procedures.

  17. Sexual Functioning Among Endometrial Cancer Patients Treated With Adjuvant High-Dose-Rate Intra-Vaginal Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Damast, Shari, E-mail: shari.damast@yale.edu [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Alektiar, Kaled M. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Goldfarb, Shari [Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Eaton, Anne; Patil, Sujata [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Mosenkis, Jeffrey [Department of Comparative Human Development, University of Chicago, Chicago, Illinois (United States); Bennett, Antonia [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Atkinson, Thomas [Department of Psychiatry, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Jewell, Elizabeth; Leitao, Mario; Barakat, Richard; Carter, Jeanne [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Basch, Ethan [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2012-10-01

    Purpose: We used the Female Sexual Function Index (FSFI) to investigate the prevalence of sexual dysfunction (SD) and factors associated with diminished sexual functioning in early stage endometrial cancer (EC) patients treated with simple hysterectomy and adjuvant brachytherapy. Methods and Materials: A cohort of 104 patients followed in a radiation oncology clinic completed questionnaires to quantify current levels of sexual functioning. The time interval between hysterectomy and questionnaire completion ranged from <6 months to >5 years. Multivariate regression was performed using the FSFI as a continuous variable (score range, 1.2-35.4). SD was defined as an FSFI score of <26, based on the published validation study. Results: SD was reported by 81% of respondents. The mean ({+-} standard deviation) domain scores in order of highest-to-lowest functioning were: satisfaction, 2.9 ({+-}2.0); orgasm, 2.5 ({+-}2.4); desire, 2.4 ({+-}1.3); arousal, 2.2 ({+-}2.0); dryness, 2.1 ({+-}2.1); and pain, 1.9 ({+-}2.3). Compared to the index population in which the FSFI cut-score was validated (healthy women ages 18-74), all scores were low. Compared to published scores of a postmenopausal population, scores were not statistically different. Multivariate analysis isolated factors associated with lower FSFI scores, including having laparotomy as opposed to minimally invasive surgery (effect size, -7.1 points; 95% CI, -11.2 to -3.1; P<.001), lack of vaginal lubricant use (effect size, -4.4 points; 95% CI, -8.7 to -0.2, P=.040), and short time interval (<6 months) from hysterectomy to questionnaire completion (effect size, -4.6 points; 95% CI, -9.3-0.2; P=.059). Conclusions: The rate of SD, as defined by an FSFI score <26, was prevalent. The postmenopausal status of EC patients alone is a known risk factor for SD. Additional factors associated with poor sexual functioning following treatment for EC included receipt of laparotomy and lack of vaginal lubricant use.

  18. Numerical simulation of physicochemical interactions between oxygen atom and phosphatidylcholine due to direct irradiation of atmospheric pressure nonequilibrium plasma to biological membrane with quantum mechanical molecular dynamics

    Science.gov (United States)

    Uchida, Satoshi; Yoshida, Taketo; Tochikubo, Fumiyoshi

    2017-10-01

    Plasma medicine is one of the most attractive applications using atmospheric pressure nonequilibrium plasma. With respect to direct contact of the discharge plasma with a biological membrane, reactive oxygen species play an important role in induction of medical effects. However, complicated interactions between the plasma radicals and membrane have not been understood well. In the present work, we simulated elemental processes at the first stage of physicochemical interactions between oxygen atom and phosphatidylcholine using the quantum mechanical molecular dynamics code in a general software AMBER. The change in the above processes was classified according to the incident energy of oxygen atom. At an energy of 1 eV, the abstraction of a hydrogen atom and recombination to phosphatidylcholine were simultaneously occurred in chemical attachment of incident oxygen atom. The exothermal energy of the reaction was about 80% of estimated one based on the bond energies of ethane. An oxygen atom over 10 eV separated phosphatidylcholine partially. The behaviour became increasingly similar to physical sputtering. The reaction probability of oxygen atom was remarkably high in comparison with that of hydrogen peroxide. These results suggest that we can uniformly estimate various physicochemical dynamics of reactive oxygen species against membrane lipids.

  19. Identification of protein phosphatase interacting proteins from normal and UVA-irradiated HaCaT cell lysates by surface plasmon resonance based binding technique using biotin-microcystin-LR as phosphatase capturing molecule.

    Science.gov (United States)

    Bécsi, Bálint; Dedinszki, Dóra; Gyémánt, Gyöngyi; Máthé, Csaba; Vasas, Gábor; Lontay, Beáta; Erdődi, Ferenc

    2014-09-05

    Identification of the interacting proteins of protein phosphatases is crucial to understand the cellular roles of these enzymes. Microcystin-LR (MC-LR), a potent inhibitor of protein phosphatase-1 (PP1), -2A (PP2A), PP4, PP5 and PP6, was biotinylated, immobilized to streptavidin-coupled sensorchip surface and used in surface plasmon resonance (SPR) based binding experiments to isolate phosphatase binding proteins. Biotin-MC-LR captured PP1 catalytic subunit (PP1c) stably and the biotin-MC-LR-PP1c complex was able to further interact with the regulatory subunit (MYPT1) of myosin phosphatase. Increased biotin-MC-LR coated sensorchip surface in the Surface Prep unit of Biacore 3000 captured PP1c, PP2Ac and their regulatory proteins including MYPT1, MYPT family TIMAP, inhibitor-2 as well as PP2A-A and -Bα-subunits from normal and UVA-irradiated HaCaT cell lysates as revealed by dot blot analysis of the recovered proteins. Biotin-MC-LR was used for the subcellular localization of protein phosphatases in HaCaT cells by identification of phosphatase-bound biotin-MC-LR with fluorescent streptavidin conjugates. Partial colocalization of the biotin-MC-LR signals with those obtained using anti-PP1c and anti-PP2Ac antibodies was apparent as judged by confocal microscopy. Our results imply that biotin-MC-LR is a suitable capture molecule in SPR for isolation of protein phosphatase interacting proteins from cell lysates in sufficient amounts for immunological detection. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Modeling of the PWR fuel mechanical behaviour and particularly study of the pellet-cladding interaction in a fuel rod; Contribution a la modelisation du comportement mecanique des combustibles REP sous irradiation, avec en particulier le traitement de l`interaction pastille-gaine dans un crayon combustible

    Energy Technology Data Exchange (ETDEWEB)

    Hourdequin, N.

    1995-05-01

    In Pressurized Water Reactor (PWR) power plants, fuel cladding constitutes the first containment barrier against radioactive contamination. Computer codes, developed with the help of a large experimental knowledge, try to predict cladding failures which must be limited in order to maintain a maximal safety level. Until now, fuel rod design calculus with unidimensional codes were adequate to prevent cladding failures in standard PWR`s operating conditions. But now, the need of nuclear power plant availability increases. That leads to more constraining operating condition in which cladding failures are strongly influenced by the fuel rod mechanical behaviour, mainly at high power level. Then, the pellet-cladding interaction (PCI) becomes important, and is characterized by local effects which description expects a multidimensional modelization. This is the aim of the TOUTATIS 2D-3D code, that this thesis contributes to develop. This code allows to predict non-axisymmetric behaviour too, as rod buckling which has been observed in some irradiation experiments and identified with the help of TOUTATIS. By another way, PCI is influenced by under irradiation experiments and identified with the help of TOUTATIS which includes a densification model and a swelling model. The latter can only be used in standard operating conditions. However, the processing structure of this modulus provides the possibility to include any type of model corresponding with other operating conditions. In last, we show the result of these fuel volume variations on the cladding mechanical conditions. (author). 25 refs., 89 figs., 2 tabs., 12 photos., 5 appends.

  1. Modelling property changes in graphite irradiated at changing irradiation temperature

    CSIR Research Space (South Africa)

    Kok, S

    2011-01-01

    Full Text Available A new method is proposed to predict the irradiation induced property changes in nuclear; graphite, including the effect of a change in irradiation temperature. The currently used method; to account for changes in irradiation temperature, the scaled...

  2. Irradiation in adulthood as a new model of schizophrenia.

    Directory of Open Access Journals (Sweden)

    Yasuhide Iwata

    Full Text Available BACKGROUND: Epidemiological studies suggest that radiation exposure may be a potential risk factor for schizophrenia in adult humans. Here, we investigated whether adult irradiation in rats caused behavioral abnormalities relevant to schizophrenia. METHODOLOGY/PRINCIPAL FINDINGS: A total dose of 15-Gy irradiation in six fractionations during 3 weeks was exposed to the forebrain including the subventricular zone (SVZ and subgranular zone (SGZ with male rats in the prone position. Behavioral, immunohistochemical, and neurochemical studies were performed three months after fractionated ionizing irradiation. Three months after fractionated ionizing irradiation, the total numbers of BrdU-positive cells in both the SVZ and SGZ zones of irradiated rats were significantly lower than those of control (sham-irradiated rats. Hyperactivity after administration of the dopaminergic agonist methamphetamine, but not the N-methyl-D-aspartate (NMDA receptor antagonist dizocilpine, was significantly enhanced in the irradiated rats although spontaneous locomotion in the irradiated rats was significantly lower than that of controls. Behavioral abnormalities including auditory sensory gating deficits, social interaction deficits, and working memory deficits were observed in the irradiated rats. CONCLUSION/SIGNIFICANCE: The present study suggests that irradiation in adulthood caused behavioral abnormalities relevant to schizophrenia, and that reduction of adult neurogenesis by irradiation may be associated with schizophrenia-like behaviors in rats.

  3. Radiotherapy combined with intracavitary irradiation for uterine cervical cancer. Study of survival rate, patterns of recurrence and complication

    Energy Technology Data Exchange (ETDEWEB)

    Kusuda, Junko; Mizutani, Yoshiyuki; Yoshino, Ayako; Takayama, Makoto; Furuya, Yoshiro (Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine); Takei, Ryoji

    1994-09-01

    Survival rates and patterns of recurrence in 137 patients with uterine cervical cancer were determined. These patients were treated by radiotherapy with high-dose rate intracavitary irradiation using remote afterloading system (RALS) at Kyorin University Hospital from Oct. 1987 to Dec. 1992. Age range was from 29 to 87 years. According to clinical staging of UICC, stages I, II, III, and IV were observed in 29, 62, 33, and 13 cases respectively. Cumulative 5-year survival rate of all cases was 72%. Cumulative 5-year survival rates were 100% for stage I, 81% for stage II, 38% for stage III, and 27% for stage IV. Cumulative 5-year survival rates of the postoperative radiotherapy and radical radiotherapy groups were 75% and 90% respectively. There was significant difference of survival rates between the postoperative radiotherapy group and the radical radiotherapy group. As patterns of recurrence, extrapelvic metastasis was more frequent than local recurrence. In stages II and III, recurrent patterns were extrapelvic matastasis in most cases. Of 18 cases with extrapelvic metastasis, there were 10 cases of paraaortic lymph node metastasis. With increase in the control rate of parraortic lymph node metastasis, survival rate of patients with uterine cervical cancer increased. Four of 5 cases with local recurrence controled by intracavitary irradiation is effective for local recurrence control. Rectal and bladder complications following radiotherapy were observed in 25 cases. However, all cases with complication after radiotherapy were treated conservatively, excluding 1 case (vasicorectal fistula). (author).

  4. Accelerated partial breast irradiation using multicatheter brachytherapy for select early-stage breast cancer: local control and toxicity

    Directory of Open Access Journals (Sweden)

    Kim Ji-Young

    2010-06-01

    Full Text Available Abstract Background To investigate the efficacy and safety of accelerated partial breast irradiation (APBI via high-dose-rate (HDR multicatheter interstitial brachytherapy for early-stage breast cancer. Methods Between 2002 and 2006, 48 prospectively selected patients with early-stage breast cancer received APBI using multicatheter brachytherapy following breast-conserving surgery. Their median age was 52 years (range 36-78. A median of 34 Gy (range 30-34 in 10 fractions given twice daily within 5 days was delivered to the tumor bed plus a 1-2 cm margin. Most (92% patients received adjuvant systemic treatments. The median follow-up was 53 months (range 36-95. Actuarial local control