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Sample records for seed implant brachytherapy

  1. Automated treatment planning engine for prostate seed implant brachytherapy

    International Nuclear Information System (INIS)

    Yu Yan; Zhang, J.B.Y.; Brasacchio, Ralph A.; Okunieff, Paul G.; Rubens, Deborah J.; Strang, John G.; Soni, Arvind; Messing, Edward M.

    1999-01-01

    Purpose: To develop a computer-intelligent planning engine for automated treatment planning and optimization of ultrasound- and template-guided prostate seed implants. Methods and Materials: The genetic algorithm was modified to reflect the 2D nature of the implantation template. A multi-objective decision scheme was used to rank competing solutions, taking into account dose uniformity and conformity to the planning target volume (PTV), dose-sparing of the urethra and the rectum, and the sensitivity of the resulting dosimetry to seed misplacement. Optimized treatment plans were evaluated using selected dosimetric quantifiers, dose-volume histogram (DVH), and sensitivity analysis based on simulated seed placement errors. These dosimetric planning components were integrated into the Prostate Implant Planning Engine for Radiotherapy (PIPER). Results: PIPER has been used to produce a variety of plans for prostate seed implants. In general, maximization of the minimum peripheral dose (mPD) for given implanted total source strength tended to produce peripherally weighted seed patterns. Minimization of the urethral dose further reduced the loading in the central region of the PTV. Isodose conformity to the PTV was achieved when the set of objectives did not reflect seed positioning uncertainties; the corresponding optimal plan generally required fewer seeds and higher source strength per seed compared to the manual planning experience. When seed placement uncertainties were introduced into the set of treatment planning objectives, the optimal plan tended to reach a compromise between the preplanned outcome and the likelihood of retaining the preferred outcome after implantation. The reduction in the volatility of such seed configurations optimized under uncertainty was verified by sensitivity studies. Conclusion: An automated treatment planning engine incorporating real-time sensitivity analysis was found to be a useful tool in dosimetric planning for prostate

  2. Seed Placement in Permanent Breast Seed Implant Brachytherapy: Are Concerns Over Accuracy Valid?

    Energy Technology Data Exchange (ETDEWEB)

    Morton, Daniel, E-mail: dmorton@bccancer.bc.ca [Department of Medical Physics, BC Cancer Agency, Centre for the Southern Interior, Kelowna, British Columbia (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia (Canada); Hilts, Michelle [Department of Medical Physics, BC Cancer Agency, Centre for the Southern Interior, Kelowna, British Columbia (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia (Canada); Batchelar, Deidre [Department of Medical Physics, BC Cancer Agency, Centre for the Southern Interior, Kelowna, British Columbia (Canada); Crook, Juanita [Department of Radiation Oncology, BC Cancer Agency, Centre for the Southern Interior, Kelowna, British Columbia (Canada)

    2016-07-01

    Purpose: To evaluate seed placement accuracy in permanent breast seed implant brachytherapy (PBSI), to identify any systematic errors and evaluate their effect on dosimetry. Methods and Materials: Treatment plans and postimplant computed tomography scans for 20 PBSI patients were spatially registered and used to evaluate differences between planned and implanted seed positions, termed seed displacements. For each patient, the mean total and directional seed displacements were determined in both standard room coordinates and in needle coordinates relative to needle insertion angle. Seeds were labeled according to their proximity to the anatomy within the breast, to evaluate the influence of anatomic regions on seed placement. Dosimetry within an evaluative target volume (seroma + 5 mm), skin, breast, and ribs was evaluated to determine the impact of seed placement on the treatment. Results: The overall mean (±SD) difference between implanted and planned positions was 9 ± 5 mm for the aggregate seed population. No significant systematic directional displacements were observed for this whole population. However, for individual patients, systematic displacements were observed, implying that intrapatient offsets occur during the procedure. Mean displacements for seeds in the different anatomic areas were not found to be significantly different from the mean for the entire seed population. However, small directional trends were observed within the anatomy, potentially indicating some bias in the delivery. Despite observed differences between the planned and implanted seed positions, the median (range) V{sub 90} for the 20 patients was 97% (66%-100%), and acceptable dosimetry was achieved for critical structures. Conclusions: No significant trends or systematic errors were observed in the placement of seeds in PBSI, including seeds implanted directly into the seroma. Recorded seed displacements may be related to intrapatient setup adjustments. Despite observed seed

  3. Dosimetric intercomparison of permanent Ho-166 seed's implants and HDR Ir-192 brachytherapy in breast cancer.

    Science.gov (United States)

    de Campos, Tarcisio Passos Ribeiro; Nogueira, Luciana Batista; Trindade, Bruno; Cuperschmid, Ethel Mizrahy

    2016-01-01

    To provide a comparative dosimetric analysis of permanent implants of Ho(166)-seeds and temporary HDR Ir(192)-brachytherapy through computational simulation. Brachytherapy with Ir(192)-HDR or LDR based on temporary wires or permanent radioactive seed implants can be used as dose reinforcement for breast radiation therapy. Permanent breast implants have not been a practical clinical routine; although, I(125) and Pd(103)-seeds have already been reported. Biodegradable Ho(166)-ceramic-seeds have been addressed recently. Simulations of implants of nine Ho(166)-seeds and equivalent with HDR Ir(192)-brachytherapy were elaborated in MCNP5, shaped in a computational multivoxel simulator which reproduced a female thorax phantom. Spatial dose rate distributions and dose-volume histograms were generated. Protocol's analysis involving exposure time, seed's activities and dose were performed. Permanent Ho(166)-seed implants presented a maximum dose rate per unit of contained activity (MDR) of 1.1601 μGy h(-1) Bq(-1); and, a normalized MDR in standard points (8 mm, equidistant to 03-seeds - SP1, 10 mm - SP2) of 1.0% (SP1) and 0.5% (SP2), respectively. Ir(192)-brachytherapy presented MDR of 4.3945 × 10(-3) μGy h(-1) Bq(-1); and, 30% (SP1), and 20% (SP2). Therefore, seed's implant activities of 333 MBq (Ho(166)) and 259 GBq (Ir(192)) produced prescribed doses of 58 Gy (SP1; 5d) and 56 Gy (SP1, 5 fractions, 6 min), respectively. Breast Ho(166)-implants of 37-111 MBq are attractive due to the high dose rate near 6-10 mm from seeds, equivalent to Ir(192)-brachytherapy of 259 GBq (3 fractions, 6 min) providing similar dose in standard points at a week; however, with spatial dose distribution better confined. The seed positioning can be adjusted for controlling the breast tumor, in stages I and II, in flat and deep tumors, without any breast volumetric limitation.

  4. Effect of permanent 103Pd radioactive seed implantation on brachytherapy of malignant tumor

    International Nuclear Information System (INIS)

    Chen Ping; Wei Xianzhong; Liu Yanmin; Wu Kaijun; Liang Jianxin; Chen Hanzhang

    2003-01-01

    Objective: To investigate and assess the brachytherapeutic effectiveness of 103 Pd radioactive seeds in malignant tumor therapy. Methods: 196.1-2127.5 MBq 103 Pd seeds were implanted in 21 confirmed malignant tumor patients. The seeds were evenly scattered in 15/21 patients' tumors and peripherally in the remaining 6 cases' tumors. The size and shape, local recurrence and remote metastasis of the tumors were observed. Results: The brachytherapy of 103 Pd seeds in tumor patients resulted in obvious efficacy. No local recurrence and remote metastasis were observed. 19/21 (90.5%) patients scored 0 and 2/21 (9.5%) of them scored 1 in skin acute radiation morbidity scoring criteria within the observation period. Conclusion: The 103 Pd seeds can be safely used in brachytherapy of malignant tumors with lower or medium sensitivity to radiation therapy

  5. Iodine-125 seed implantation (permanent brachytherapy) for clinically localized prostate cancer

    International Nuclear Information System (INIS)

    Ebara, Shin; Katayama, Yoshihisa; Tanimoto, Ryuta

    2008-01-01

    From January 2004 to March 2007, 308 patients with clinically localized prostate cancer were treated using iodine-125 ( 125 I) seed implantation (permanent brachytherapy) at Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences. We evaluated the treatment's efficacy and morbidity in 300 prostate cancer patients who were followed up for more than 1 month after brachytherapy. Based on the National Comprehensive Cancer Network (NCCN) guidelines, patients with a prostate volume of less than 40 ml in transrectal ultrasound imaging were classified as low or intermediate risk. The median patient age was 67 years (range 50 to 79 years), the median prostate-specific antigen (PSA) value before biopsy was 6.95 ng/ml (range 1.13 to 24.7 ng/ml), and the median prostate volume was 24.33 ml (range 9.3 to 41.76 ml). The median follow-up was 18 months (range 1 to 36 months) and the PSA levels decreased in almost all patients after brachytherapy. Although 194 of 300 patients (64.7%) complained of difficulty in urination, pollakisuria/urgency, miction pain, and/or urinary incontinence, all of which might be associated with radiation prostatitis during the first month after brachytherapy, these symptoms gradually improved. 125 I seed implantation brachytherapy is safe and effective for localized prostate cancer within short-term follow up. (author)

  6. Investigation on curative efficacy for malignant tumor by implantation '125I permanent brachytherapy seeds

    International Nuclear Information System (INIS)

    Hu Shu; Gao Zhou; Jia Shaowei; Cheng Xianyi; Chen Junhui; Yin Weihua; Sun Desheng

    2011-01-01

    Twenty inpatients suffered from malignant tumors with twenty-four lesions were treated with 125 I permanent brachytherapy seed in Peking University Shenzhen Hospital, and the feasibility, curative effect and adverse effect of the treatment were observed. Before 125 I seeds implantation, the three-dimensional treatment planning was preconcerted. There were two methods to implant 125 I seeds. One was to insert the seeds in the location of residual focus and metastatic lesions of the tumors directly in ordinary operations or through laparoscopy under general anesthesia. The other w as to implant the seeds into the tumors through percutaneous needles by the guidance of CT scanning or color doppler ultrasonography under local anesthesia. The implantations for all of the 20 patients (24 lesions) were performed successfully. During and one week after the implantation, the distributions of the planted seeds were approximately the same as the scheduled three-dimensional treatment planning, and no seed migration was found. Adverse reactions during and after the operation were slight and recovered after correlative treatments. Clinical symptoms were palliated and ser um tumor marker decreased to a different extent among most patients. The complete remission (CR) rate is 20.00% (4/20 patients ), the partial emission (PR) rate is 35.00% (7/20 patients), the stable disease (SD) rate is 30.00% (6/20 patients), the progressive disease (PD) rate is 15.00% (3/20 patients), and the overall response rate (CR + PR) is 53.33% (8 patients). 125 I seeds implantation for targeted therapy is convenient, safe and effective on malignant tumor, and is well worth advanced application. (authors)

  7. Seed Implant Retention Score Predicts the Risk of Prolonged Urinary Retention After Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Lee, Hoon K.; Adams, Marc T.; Shi, Qiuhu; Basillote, Jay; LaMonica, Joanne; Miranda, Luis; Motta, Joseph

    2010-01-01

    Purpose: To risk-stratify patients for urinary retention after prostate brachytherapy according to a novel seed implant retention score (SIRS). Patients and Methods: A total of 835 patients underwent transperineal prostate seed implant from March 1993 to January 2007; 197 patients had 125 I and 638 patients had 103 Pd brachytherapy. Four hundred ninety-four patients had supplemental external-beam radiation. The final downsized prostate volume was used for the 424 patients who had neoadjuvant hormone therapy. Retention was defined as reinsertion of a Foley catheter after the implant. Results: Retention developed in 7.4% of patients, with an average duration of 6.7 weeks. On univariate analysis, implant without supplemental external-beam radiation (10% vs. 5.6%; p = 0.02), neoadjuvant hormone therapy (9.4% vs. 5.4%; p = 0.02), baseline α-blocker use (12.5% vs. 6.3%; p = 0.008), and increased prostate volume (13.4% vs. 6.9% vs. 2.9%, >45 cm 3 , 25-45 cm 3 , 3 ; p = 0.0008) were significantly correlated with increased rates of retention. On multivariate analysis, implant without supplemental external-beam radiation, neoadjuvant hormone therapy, baseline α-blocker use, and increased prostate volume were correlated with retention. A novel SIRS was modeled as the combined score of these factors, ranging from 0 to 5. There was a significant correlation between the SIRS and retention (p < 0.0001). The rates of retention were 0, 4%, 5.6%, 9%, 20.9%, and 36.4% for SIRS of 0 to 5, respectively. Conclusions: The SIRS may identify patients who are at high risk for prolonged retention after prostate brachytherapy. A prospective validation study of the SIRS is planned.

  8. Effects of seed migration on post-implant dosimetry of prostate brachytherapy

    International Nuclear Information System (INIS)

    Gao, M.; Wang, J. Z.; Nag, S.; Gupta, N.

    2007-01-01

    Brachytherapy using permanent seed implants has been an effective treatment for prostate cancer. However, seeds will migrate after implant, thus making the evaluation of post-implant dosimetry difficult. In this study, we developed a computer program to simulate seed migration and analyzed dosimetric changes due to seed migration at various migration amounts. The study was based on 14 patients treated with Pd-103 at the James Cancer Hospital. Modeling of seed migration, including direction, distance as well as day of migration, was based on clinical observations. Changes of commonly used dosimetric parameters as a function of migration amount (2, 4, 6 mm respectively), prostate size (from 20 to 90 cc), and prostate region (central vs peripheral) were studied. Change of biological outcome (tumor control probability) due to migration was also estimated. Migration reduced prostate D90 to 99±2% of original value in 2 mm migration, and the reduction increased to 94±6% in 6 mm migration. The reduction of prostate dose led to a 14% (40%) drop in the tumor control probability for 2 mm (6 mm) migration, assuming radiosensitive tumors. However, migration has less effect on a prostate implanted with a larger number of seeds. Prostate V100 was less sensitive to migration than D90 since its mean value was still 99% of original value even in 6 mm migration. Migration also showed a different effect in the peripheral region vs the central region of the prostate, where the peripheral mean dose tended to drop more significantly. Therefore, extra activity implanted in the peripheral region during pre-plan can be considered. The detrimental effects of migration were more severe in terms of increasing the dose to normal structures, as rectum V50 may be 70% higher and urethra V100 may be 50% higher in the case of 6 mm migration. Quantitative knowledge of these effects is helpful in treatment planning and post-implant evaluation

  9. Conventional Versus Automated Implantation of Loose Seeds in Prostate Brachytherapy: Analysis of Dosimetric and Clinical Results

    International Nuclear Information System (INIS)

    Genebes, Caroline; Filleron, Thomas; Graff, Pierre; Jonca, Frédéric; Huyghe, Eric; Thoulouzan, Matthieu; Soulie, Michel; Malavaud, Bernard; Aziza, Richard; Brun, Thomas; Delannes, Martine; Bachaud, Jean-Marc

    2013-01-01

    Purpose: To review the clinical outcome of I-125 permanent prostate brachytherapy (PPB) for low-risk and intermediate-risk prostate cancer and to compare 2 techniques of loose-seed implantation. Methods and Materials: 574 consecutive patients underwent I-125 PPB for low-risk and intermediate-risk prostate cancer between 2000 and 2008. Two successive techniques were used: conventional implantation from 2000 to 2004 and automated implantation (Nucletron, FIRST system) from 2004 to 2008. Dosimetric and biochemical recurrence-free (bNED) survival results were reported and compared for the 2 techniques. Univariate and multivariate analysis researched independent predictors for bNED survival. Results: 419 (73%) and 155 (27%) patients with low-risk and intermediate-risk disease, respectively, were treated (median follow-up time, 69.3 months). The 60-month bNED survival rates were 95.2% and 85.7%, respectively, for patients with low-risk and intermediate-risk disease (P=.04). In univariate analysis, patients treated with automated implantation had worse bNED survival rates than did those treated with conventional implantation (P<.0001). By day 30, patients treated with automated implantation showed lower values of dose delivered to 90% of prostate volume (D90) and volume of prostate receiving 100% of prescribed dose (V100). In multivariate analysis, implantation technique, Gleason score, and V100 on day 30 were independent predictors of recurrence-free status. Grade 3 urethritis and urinary incontinence were observed in 2.6% and 1.6% of the cohort, respectively, with no significant differences between the 2 techniques. No grade 3 proctitis was observed. Conclusion: Satisfactory 60-month bNED survival rates (93.1%) and acceptable toxicity (grade 3 urethritis <3%) were achieved by loose-seed implantation. Automated implantation was associated with worse dosimetric and bNED survival outcomes

  10. Conventional Versus Automated Implantation of Loose Seeds in Prostate Brachytherapy: Analysis of Dosimetric and Clinical Results

    Energy Technology Data Exchange (ETDEWEB)

    Genebes, Caroline, E-mail: genebes.caroline@claudiusregaud.fr [Radiation Oncology Department, Institut Claudius Regaud, Toulouse (France); Filleron, Thomas; Graff, Pierre [Radiation Oncology Department, Institut Claudius Regaud, Toulouse (France); Jonca, Frédéric [Department of Urology, Clinique Ambroise Paré, Toulouse (France); Huyghe, Eric; Thoulouzan, Matthieu; Soulie, Michel; Malavaud, Bernard [Department of Urology and Andrology, CHU Rangueil, Toulouse (France); Aziza, Richard; Brun, Thomas; Delannes, Martine; Bachaud, Jean-Marc [Radiation Oncology Department, Institut Claudius Regaud, Toulouse (France)

    2013-11-15

    Purpose: To review the clinical outcome of I-125 permanent prostate brachytherapy (PPB) for low-risk and intermediate-risk prostate cancer and to compare 2 techniques of loose-seed implantation. Methods and Materials: 574 consecutive patients underwent I-125 PPB for low-risk and intermediate-risk prostate cancer between 2000 and 2008. Two successive techniques were used: conventional implantation from 2000 to 2004 and automated implantation (Nucletron, FIRST system) from 2004 to 2008. Dosimetric and biochemical recurrence-free (bNED) survival results were reported and compared for the 2 techniques. Univariate and multivariate analysis researched independent predictors for bNED survival. Results: 419 (73%) and 155 (27%) patients with low-risk and intermediate-risk disease, respectively, were treated (median follow-up time, 69.3 months). The 60-month bNED survival rates were 95.2% and 85.7%, respectively, for patients with low-risk and intermediate-risk disease (P=.04). In univariate analysis, patients treated with automated implantation had worse bNED survival rates than did those treated with conventional implantation (P<.0001). By day 30, patients treated with automated implantation showed lower values of dose delivered to 90% of prostate volume (D90) and volume of prostate receiving 100% of prescribed dose (V100). In multivariate analysis, implantation technique, Gleason score, and V100 on day 30 were independent predictors of recurrence-free status. Grade 3 urethritis and urinary incontinence were observed in 2.6% and 1.6% of the cohort, respectively, with no significant differences between the 2 techniques. No grade 3 proctitis was observed. Conclusion: Satisfactory 60-month bNED survival rates (93.1%) and acceptable toxicity (grade 3 urethritis <3%) were achieved by loose-seed implantation. Automated implantation was associated with worse dosimetric and bNED survival outcomes.

  11. Monte Carlo study of LDR seed dosimetry with an application in a clinical brachytherapy breast implant.

    Science.gov (United States)

    Furstoss, C; Reniers, B; Bertrand, M J; Poon, E; Carrier, J-F; Keller, B M; Pignol, J P; Beaulieu, L; Verhaegen, F

    2009-05-01

    A Monte Carlo (MC) study was carried out to evaluate the effects of the interseed attenuation and the tissue composition for two models of 125I low dose rate (LDR) brachytherapy seeds (Medi-Physics 6711, IBt InterSource) in a permanent breast implant. The effect of the tissue composition was investigated because the breast localization presents heterogeneities such as glandular and adipose tissue surrounded by air, lungs, and ribs. The absolute MC dose calculations were benchmarked by comparison to the absolute dose obtained from experimental results. Before modeling a clinical case of an implant in heterogeneous breast, the effects of the tissue composition and the interseed attenuation were studied in homogeneous phantoms. To investigate the tissue composition effect, the dose along the transverse axis of the two seed models were calculated and compared in different materials. For each seed model, three seeds sharing the same transverse axis were simulated to evaluate the interseed effect in water as a function of the distance from the seed. A clinical study of a permanent breast 125I implant for a single patient was carried out using four dose calculation techniques: (1) A TG-43 based calculation, (2) a full MC simulation with realistic tissues and seed models, (3) a MC simulation in water and modeled seeds, and (4) a MC simulation without modeling the seed geometry but with realistic tissues. In the latter, a phase space file corresponding to the particles emitted from the external surface of the seed is used at each seed location. The results were compared by calculating the relevant clinical metrics V85, V100, and V200 for this kind of treatment in the target. D90 and D50 were also determined to evaluate the differences in dose and compare the results to the studies published for permanent prostate seed implants in literature. The experimental results are in agreement with the MC absolute doses (within 5% for EBT Gafchromic film and within 7% for TLD-100

  12. SU-E-T-123: Anomalous Altitude Effect in Permanent Implant Brachytherapy Seeds

    International Nuclear Information System (INIS)

    Watt, E; Spencer, DP; Meyer, T

    2015-01-01

    Purpose: Permanent seed implant brachytherapy procedures require the measurement of the air kerma strength of seeds prior to implant. This is typically accomplished using a well-type ionization chamber. Previous measurements (Griffin et al., 2005; Bohm et al., 2005) of several low-energy seeds using the air-communicating HDR 1000 Plus chamber have demonstrated that the standard temperature-pressure correction factor, P TP , may overcompensate for air density changes induced by altitude variations by up to 18%. The purpose of this work is to present empirical correction factors for two clinically-used seeds (IsoAid ADVANTAGE™ 103 Pd and Nucletron selectSeed 125 I) for which empirical altitude correction factors do not yet exist in the literature when measured with the HDR 1000 Plus chamber. Methods: An in-house constructed pressure vessel containing the HDR 1000 Plus well chamber and a digital barometer/thermometer was pumped or evacuated, as appropriate, to a variety of pressures from 725 to 1075 mbar. Current measurements, corrected with P TP , were acquired for each seed at these pressures and normalized to the reading at ‘standard’ pressure (1013.25 mbar). Results: Measurements in this study have shown that utilization of P TP can overcompensate in the corrected current reading by up to 20% and 17% for the IsoAid Pd-103 and the Nucletron I-125 seed respectively. Compared to literature correction factors for other seed models, the correction factors in this study diverge by up to 2.6% and 3.0% for iodine (with silver) and palladium respectively, indicating the need for seed-specific factors. Conclusion: The use of seed specific altitude correction factors can reduce uncertainty in the determination of air kerma strength. The empirical correction factors determined in this work can be applied in clinical quality assurance measurements of air kerma strength for two previously unpublished seed designs (IsoAid ADVANTAGE™ 103 Pd and Nucletron selectSeed 125 I

  13. SU-E-T-123: Anomalous Altitude Effect in Permanent Implant Brachytherapy Seeds

    Energy Technology Data Exchange (ETDEWEB)

    Watt, E; Spencer, DP; Meyer, T [University of Calgary and Tom Baker Cancer Centre, Calgary, AB (Canada)

    2015-06-15

    Purpose: Permanent seed implant brachytherapy procedures require the measurement of the air kerma strength of seeds prior to implant. This is typically accomplished using a well-type ionization chamber. Previous measurements (Griffin et al., 2005; Bohm et al., 2005) of several low-energy seeds using the air-communicating HDR 1000 Plus chamber have demonstrated that the standard temperature-pressure correction factor, P{sub TP}, may overcompensate for air density changes induced by altitude variations by up to 18%. The purpose of this work is to present empirical correction factors for two clinically-used seeds (IsoAid ADVANTAGE™ {sup 103}Pd and Nucletron selectSeed {sup 125}I) for which empirical altitude correction factors do not yet exist in the literature when measured with the HDR 1000 Plus chamber. Methods: An in-house constructed pressure vessel containing the HDR 1000 Plus well chamber and a digital barometer/thermometer was pumped or evacuated, as appropriate, to a variety of pressures from 725 to 1075 mbar. Current measurements, corrected with P{sub TP}, were acquired for each seed at these pressures and normalized to the reading at ‘standard’ pressure (1013.25 mbar). Results: Measurements in this study have shown that utilization of P{sub TP} can overcompensate in the corrected current reading by up to 20% and 17% for the IsoAid Pd-103 and the Nucletron I-125 seed respectively. Compared to literature correction factors for other seed models, the correction factors in this study diverge by up to 2.6% and 3.0% for iodine (with silver) and palladium respectively, indicating the need for seed-specific factors. Conclusion: The use of seed specific altitude correction factors can reduce uncertainty in the determination of air kerma strength. The empirical correction factors determined in this work can be applied in clinical quality assurance measurements of air kerma strength for two previously unpublished seed designs (IsoAid ADVANTAGE™ {sup 103}Pd and

  14. Prostate brachytherapy postimplant dosimetry: Seed orientation and the impact of dosimetric anisotropy in stranded implants

    International Nuclear Information System (INIS)

    Chng, Nicholas; Spadinger, Ingrid; Rasoda, Rosey; Morris, W. James; Salcudean, Septimiu

    2012-01-01

    Purpose: In postimplant dosimetry for prostate brachytherapy, dose is commonly calculated using the TG-43 1D formalism, because seed orientations are difficult to determine from CT images, the current standard for the procedure. However, the orientation of stranded seeds soon after implantation is predictable, as these seeds tend to maintain their relative spacing, and orient themselves along the implant trajectory. The aim of this study was to develop a method for determining seed orientations from reconstructed strand trajectories, and to use this information to investigate the dosimetric impact of applying the TG-43 2D formalism to clinical postimplant analysis. Methods: Using in-house software, the preplan to postimplant seed correspondence was determined for a cohort of 30 patients during routine day-0 CT-based postimplant dosimetry. All patients were implanted with stranded-seed trains. Spline curves were fit to each set of seeds composing a strand, with the requirement that the distance along the spline between seeds be equal to the seed spacing within the strand. The orientations of the seeds were estimated by the tangents to the spline at each seed centroid. Dose distributions were then determined using the 1D and 2D TG-43 formalisms. These were compared using the TG-137 recommended dose metrics for the prostate, prostatic urethra, and rectum. Results: Seven hundred and sixty one strands were analyzed in total. Defining the z-axis to be cranial-positive and the x-axis to be left-lateral positive in the CT coordinate system, the average seed had an inclination of 21 deg. ± 10 deg. and an azimuth of -81 deg. ± 57 deg. These values correspond to the average strand rising anteriorly from apex to base, approximately parallel to the midsagittal plane. Clinically minor but statistically significant differences in dose metrics were noted. Compared to the 2D calculation, the 1D calculation underestimated prostate V100 by 1.1% and D90 by 2.3 Gy, while

  15. SU-E-T-378: Evaluation of An Analytical Model for the Inter-Seed Attenuation Effect in 103-Pd Multi-Seed Implant Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Safigholi, H; Soliman, A; Song, W [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, U of T, Toronto, Ontario (Canada); Meigooni, A Soleimani [Comprehensive Cancer Center of Nevada, Las Vegas, Nevada (United States); Han, D [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, U of T, Toronto, Ontario (Canada); University of California, San Diego, La Jolla, CA (United States)

    2015-06-15

    Purpose: Brachytherapy treatment planning systems based on TG-43 protocol calculate the dose in water and neglects the heterogeneity effect of seeds in multi-seed implant brachytherapy. In this research, the accuracy of a novel analytical model that we propose for the inter-seed attenuation effect (ISA) for 103-Pd seed model is evaluated. Methods: In the analytical model, dose perturbation due to the ISA effect for each seed in an LDR multi-seed implant for 103-Pd is calculated by assuming that the seed of interest is active and the other surrounding seeds are inactive. The cumulative dosimetric effect of all seeds is then summed using the superposition principle. The model is based on pre Monte Carlo (MC) simulated 3D kernels of the dose perturbations caused by the ISA effect. The cumulative ISA effect due to multiple surrounding seeds is obtained by a simple multiplication of the individual ISA effect by each seed, the effect of which is determined by the distance from the seed of interest. This novel algorithm is then compared with full MC water-based simulations (FMCW). Results: The results show that the dose perturbation model we propose is in excellent agreement with the FMCW values for a case with three seeds separated by 1 cm. The average difference of the model and the FMCW simulations was less than 8%±2%. Conclusion: Using the proposed novel analytical ISA effect model, one could expedite the corrections due to the ISA dose perturbation effects during permanent seed 103-Pd brachytherapy planning with minimal increase in time since the model is based on multiplications and superposition. This model can be applied, in principle, to any other brachytherapy seeds. Further work is necessary to validate this model on a more complicated geometry as well.

  16. Seed loss through the urinary tract after prostate brachytherapy: examining the role of cystoscopy and urine straining post implant

    International Nuclear Information System (INIS)

    Stutz, Michael; Petrikas, James; Raslowsky, Michael; Lee, Plato; Gurel, Michelle; Moran, Brian

    2003-01-01

    This study describes one institution's experience with seed retrieval through the urinary tract and makes recommendations for cystoscopy and urine straining post prostate brachytherapy (PB). 1794 patients from two separate cohorts covering different time periods (early versus late) were analyzed. All patients were preplanned with a modified peripheral loading technique and implanted with preloaded needles ( 125 I or 103 Pd) under ultrasound guidance. A catheter was used to delineate the urethra during the volume study but was not used during the implant. All patients underwent post implant cystoscopy. All patients were instructed to strain their urine for seven days post implant and return any seeds to our center. In our experience, seed loss through the urinary tract is a common event after PB, occurring in 29.7% of patients and was more common in patients from the early cohort, those implanted with 125 I seeds or those patients with prior transurethral resection of the prostate. Average seed loss per case, however, represents only 0.58% of total activity. We continue to recommend routine post implant cystoscopy for seed retrieval and periprocedural management. We no longer recommend that patients strain their urine at home after documenting a low rate of seed loss after discharge

  17. Clinical Significance of Accounting for Tissue Heterogeneity in Permanent Breast Seed Implant Brachytherapy Planning

    Energy Technology Data Exchange (ETDEWEB)

    Mashouf, Shahram [Medical Biophysics Department, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Fleury, Emmanuelle [Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Lai, Priscilla [Medical Biophysics Department, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Merino, Tomas [Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Radiotherapy Unit, School of Medicine, Departamento de Hemato-oncologia, Pontificia Universidad Católica de Chile, Santiago (Chile); Lechtman, Eli [Medical Biophysics Department, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Kiss, Alex [Sunnybrook Research Institute, Toronto, Ontario (Canada); McCann, Claire [Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Pignol, Jean-Philippe, E-mail: j.p.pignol@erasmusmc.nl [Medical Biophysics Department, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Radiation Oncology Department, Erasmus Medical Center, Cancer Institute, Rotterdam (Netherlands)

    2016-03-15

    Purpose: The inhomogeneity correction factor (ICF) method provides heterogeneity correction for the fast calculation TG43 formalism in seed brachytherapy. This study compared ICF-corrected plans to their standard TG43 counterparts, looking at their capacity to assess inadequate coverage and/or risk of any skin toxicities for patients who received permanent breast seed implant (PBSI). Methods and Materials: Two-month postimplant computed tomography scans and plans of 140 PBSI patients were used to calculate dose distributions by using the TG43 and the ICF methods. Multiple dose-volume histogram (DVH) parameters of clinical target volume (CTV) and skin were extracted and compared for both ICF and TG43 dose distributions. Short-term (desquamation and erythema) and long-term (telangiectasia) skin toxicity data were available on 125 and 110 of the patients, respectively, at the time of the study. The predictive value of each DVH parameter of skin was evaluated using the area under the receiver operating characteristic (ROC) curve for each toxicity endpoint. Results: Dose-volume histogram parameters of CTV, calculated using the ICF method, showed an overall decrease compared to TG43, whereas those of skin showed an increase, confirming previously reported findings of the impact of heterogeneity with low-energy sources. The ICF methodology enabled us to distinguish patients for whom the CTV V{sub 100} and V{sub 90} are up to 19% lower compared to TG43, which could present a risk of recurrence not detected when heterogeneity are not accounted for. The ICF method also led to an increase in the prediction of desquamation, erythema, and telangiectasia for 91% of skin DVH parameters studied. Conclusions: The ICF methodology has the advantage of distinguishing any inadequate dose coverage of CTV due to breast heterogeneity, which can be missed by TG43. Use of ICF correction also led to an increase in prediction accuracy of skin toxicities in most cases.

  18. {sup 125}I seed implant brachytherapy for the treatment of parotid gland cancers in children and adolescents

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, L.; Zhang, J.; Song, T.; Zhang, J.; Yu, G.; Zhang, Y. [Peking University School and Hospital of Stomatology, Beijing (China). Dept. of Oral and Maxillofacial Surgery

    2013-05-15

    Background and purpose: There is a lack of optimal treatment strategies for managing salivary gland cancers in children and adolescents. This study is aimed at assessing the effect of {sup 125}I seed implantation for the treatment of parotid cancers in children and adolescents. Patients and methods: A total of 12 patients younger than 16 years with parotid gland malignant tumors underwent {sup 125}I seed implant brachytherapy between October 2003 and November 2008. All patients were assessed after treatment and at the local tumor control appointments. Facial nerve function, maxillofacial development, and radioactive side-effects were assessed. Results: The follow-up period ranged from 41-104 months. One patient with T4b died of pulmonary metastasis. The other patients were alive during the follow-up period. There were no serious radiation-related complications. The treatment did not affect facial nerve function and dentofacial growth in any of the children. Conclusion: For parotid gland cancers in children, {sup 125}I seed implant brachytherapy may be an acceptable treatment without serious complications and with satisfactory short-term effects. (orig.)

  19. Sci-Thur PM – Brachytherapy 02: Positional accuracy in Pd-103 permanent breast seed implant (PBSI) brachytherapy at the Tom Baker Cancer Centre (TBCC)

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, Amy; Watt, Elizabeth; Peacock, Michael; Husain, Siraj; Meyer, Tyler; Roumeliotis, Michael [University of Calgary, Tom Baker Cancer Centre (Canada)

    2016-08-15

    Purpose: This retrospective study aims to quantify the positional accuracy of seed delivery in permanent breast seed implant (PBSI) brachytherapy at the Tom Baker Cancer Centre (TBCC). Methods: Treatment planning and post-implant CT scans for 5 patients were rigidly registered using the MIM Symphony™ software (MIM Software, Cleveland, OH) and used to evaluate differences between planned and implanted seed positions. Total and directional seed displacements were calculated for each patient in a clinically relevant ‘needle coordinate system’, defined relative to the angle of fiducial needle insertion. Results: The overall average total seed displacement was 10±8 mm. Systematic seed displacements were observed in individual patients and the magnitude and direction of these offsets varied among patients. One patient showed a significant directional seed displacement in the shallow-deep direction compared with the other four patients. With the exception of this one patient outlier, no significant systematic directional displacements in the needle coordinate system were observed for this cohort; the average directional displacements were −1±5 mm, 2±3 mm, and −2±4 mm in the shallow-deep, up-down, and right-left directions respectively. Conclusion: With the exception of one patient outlier, the magnitude of seed displacements were relatively consistent among patients. The results indicate that the shallow-deep direction possesses the largest uncertainty for the seed delivery method used at the TBCC. The relatively large uncertainty in seed placement in this direction is expected, as this is the direction of needle insertion. Further work will involve evaluating deflections of delivered needle tracks from their planned positions.

  20. Aspects of an automatic system of implants of radioactive seeds and anatomic object simulator for tests in prostate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Leonardo S.M.; Braga, Viviane V.B.; Campos, Tarcísio P. R. de, E-mail: leonardosantiago.lsms@gmail.com, E-mail: vitoriabraga06@gmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (PCTN/UFMG), Belo Horizonte (Brazil). Pós-Graduação em Ciências e Técnicas Nucleares. Departamento de Engenharia Nuclear

    2017-07-01

    This work presents the state of the art of the research and development of an automatic radioactive seed implantation system (PSIS). PSIS may assist in the procedure of testing permanent implants in the prostate. These tests will be important in measurements of absorbed doses in the pelvic structures, involving the organs and tissues at risk to improve planning, seed positioning and dosimetry. The automated Prostate Seed Implant System (PSIS) has been designed to meet operational needs, which offers the freedom of positioning of the brachytherapy needle within the treatment area and ensures repeatability and fidelity to the planned treatment. Both the ultrasound probe and the seed implant needle are driven by step motors, Atmega microcontroller, bearings, aluminum shafts and a GUI (Graphical User Interface). Movement of both the probe and the needle holder was performed by fixed spindle on a threaded rod rushing to the step motors by a coupling. The step motors used to move the system consist of step motors used in CNC (Computer Numeric Control) machine. The choice of these engines occurred due to the precision in the movements that can be obtained with these types of motors. The ultrasound probe serves to help, through the images acquired during the longitudinal movement, to monitor the application of the seeds. The parts that make up the system infrastructure were made of aluminum and translucent acrylic and cylindrical aluminum bars of different diameters. All these pieces were fixed and adjusted trough screws, washers, nuts and adhesive to metal, composing the final prototype of the PSIS. The project was developed and the PSIS prototype was assembled. The prototype presented acceptable operating characteristics for prostate implants. The advantage of this system is the automation of the application that provides an accurate positioning and movement of both probe and seed application. In addition to this study, seeds implantation tests will be performed, and

  1. Aspects of an automatic system of implants of radioactive seeds and anatomic object simulator for tests in prostate brachytherapy

    International Nuclear Information System (INIS)

    Silva, Leonardo S.M.; Braga, Viviane V.B.; Campos, Tarcísio P. R. de

    2017-01-01

    This work presents the state of the art of the research and development of an automatic radioactive seed implantation system (PSIS). PSIS may assist in the procedure of testing permanent implants in the prostate. These tests will be important in measurements of absorbed doses in the pelvic structures, involving the organs and tissues at risk to improve planning, seed positioning and dosimetry. The automated Prostate Seed Implant System (PSIS) has been designed to meet operational needs, which offers the freedom of positioning of the brachytherapy needle within the treatment area and ensures repeatability and fidelity to the planned treatment. Both the ultrasound probe and the seed implant needle are driven by step motors, Atmega microcontroller, bearings, aluminum shafts and a GUI (Graphical User Interface). Movement of both the probe and the needle holder was performed by fixed spindle on a threaded rod rushing to the step motors by a coupling. The step motors used to move the system consist of step motors used in CNC (Computer Numeric Control) machine. The choice of these engines occurred due to the precision in the movements that can be obtained with these types of motors. The ultrasound probe serves to help, through the images acquired during the longitudinal movement, to monitor the application of the seeds. The parts that make up the system infrastructure were made of aluminum and translucent acrylic and cylindrical aluminum bars of different diameters. All these pieces were fixed and adjusted trough screws, washers, nuts and adhesive to metal, composing the final prototype of the PSIS. The project was developed and the PSIS prototype was assembled. The prototype presented acceptable operating characteristics for prostate implants. The advantage of this system is the automation of the application that provides an accurate positioning and movement of both probe and seed application. In addition to this study, seeds implantation tests will be performed, and

  2. WE-A-17A-11: Implanted Brachytherapy Seed Movement Due to Transrectal Ultrasound Probe-Induced Prostate Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D; Usmani, N; Sloboda, R [Cross Cancer Institute, Edmonton, Alberta (Canada); University of Alberta, Edmonton, Alberta (Canada); Meyer, T; Husain, S; Angyalfi, S [Tom Baker Cancer Centre, Calgary, Alberta (Canada); University of Calgary, Calgary, Alberta (Canada); Kay, I [Canterbury District Health Board, Christchurch (New Zealand)

    2014-06-15

    Purpose: To characterize the movement of implanted brachytherapy seeds due to transrectal ultrasound probe-induced prostate deformation and to estimate the effects on prostate dosimetry. Methods: Implanted probe-in and probe-removed seed distributions were reconstructed for 10 patients using C-arm fluoroscopy imaging. The prostate was delineated on ultrasound and registered to the fluoroscopy seeds using a visible subset of seeds and residual needle tracks. A linear tensor and shearing model correlated the seed movement with position. The seed movement model was used to infer the underlying prostate deformation and to simulate the prostate contour without probe compression. Changes in prostate and surrogate urethra dosimetry were calculated. Results: Seed movement patterns reflecting elastic decompression, lateral shearing, and rectal bending were observed. Elastic decompression was characterized by anterior-posterior expansion and superior-inferior and lateral contractions. For lateral shearing, anterior movement up to 6 mm was observed for extraprostatic seeds in the lateral peripheral region. The average intra-prostatic seed movement was 1.3 mm, and the residual after linear modeling was 0.6 mm. Prostate D90 increased by 4 Gy on average (8 Gy max) and was correlated with elastic decompression. For selected patients, lateral shearing resulted in differential change in D90 of 7 Gy between anterior and posterior quadrants, and increase in whole prostate D90 of 4 Gy. Urethra D10 increased by 4 Gy. Conclusion: Seed movement upon probe removal was characterized. The proposed model captured the linear correlation between seed movement and position. Whole prostate dose coverage increased slightly, due to the small but systematic seed movement associated with elastic decompression. Lateral shearing movement increased dose coverage in the anterior-lateral region, at the expense of the posterior-lateral region. The effect on whole prostate D90 was smaller due to the subset

  3. Permanent Seed Implant Dosimetry (PSID)TM 4.5 version as isodose and Treatment Planning System (TPS) programme for brachytherapy

    International Nuclear Information System (INIS)

    Indra Saptiama; Moch Subechi; Anung Pujiyanto; Hotman Lubis; Herlan Setiawan

    2014-01-01

    The medical treatment using radiation therapy for cancer diseases is increasingly developed. One of the method used in radiotherapy is brachytherapy. Brachytherapy is radiation therapy method in which a radiation source is implanted in cancer cell directly so the dose accepted by cancer cell is the highest dose and the dose accepted by normal cell is the lowest dose. I-125 Seed have been made successfully in domestic. To support the implant of I-125 seed for brachytherapy needs computer programme for the isodose calculation and Treatment Planning System (TPS). Permanent Seed Implant Dosimetry (PSID) 4.5 is one of the isodose calculation and Treatment Planning System (TPS) programme that is owned by Center for Radioisotope and Radiopharmaceutical-BATAN. In isodose calculation, PSID 4.5 uses 1D formalism and 2D formalism based on AAPM-TG43 (Association of American Physicist in Medicine- Task Group No.43). Anisotropic function on 1D formalism depend on distance function while on 2D formalism count on distance and angle function therefore 2D formalism has isodose calculation better than 1D formalism usage. PSID 4.5 can display the isodose contour of the seed I-125 radiation source in 2 dimension (2D) and 3 dimension (3D). The computer programme of isodose calculation and TPS uses PSID 4.5 is expected able to help planning for seed I-125 implantation process for brachytherapy that used by paramedics and to support the usage of seed I-125 as domestic product. (author)

  4. Assessment of I-125 seed implant accuracy when using the live-planning technique for low dose rate prostate brachytherapy

    Directory of Open Access Journals (Sweden)

    Moorrees Joshua

    2012-11-01

    Full Text Available Abstract Background Low risk prostate cancers are commonly treated with low dose rate (LDR brachytherapy involving I-125 seeds. The implementation of a ‘live-planning’ technique at the Royal Adelaide Hospital (RAH in 2007 enabled the completion of the whole procedure (i.e. scanning, planning and implant in one sitting. ‘Live-planning’ has the advantage of a more reliable delivery of the planned treatment compared to the ‘traditional pre-plan’ technique (where patient is scanned and planned in the weeks prior to implant. During live planning, the actual implanted needle positions are updated real-time on the treatment planning system and the dosimetry is automatically recalculated. The aim of this investigation was to assess the differences and clinical relevance between the planned dosimetry and the updated real-time implant dosimetry. Methods A number of 162 patients were included in this dosimetric study. A paired t-test was performed on the D90, V100, V150 and V200 target parameters and the differences between the planned and implanted dose distributions were analysed. Similarly, dosimetric differences for the organs at risk (OAR were also evaluated. Results Small differences between the primary dosimetric parameters for the target were found. Still, the incidence of hotspots was increased with approximately 20% for V200. Statistically significant increases were observed in the doses delivered to the OAR between the planned and implanted data; however, these increases were consistently below 3% thus probably without clinical consequences. Conclusions The current study assessed the accuracy of prostate implants with I-125 seeds when compared to initial plans. The results confirmed the precision of the implant technique which RAH has in place. Nevertheless, geographical misses, anatomical restrictions and needle displacements during implant can have repercussions for centres without live-planning option if dosimetric changes are not

  5. WE-AB-BRA-11: Improved Imaging of Permanent Prostate Brachytherapy Seed Implants by Combining an Endorectal X-Ray Sensor with a CT Scanner

    International Nuclear Information System (INIS)

    Steiner, J; Matthews, K; Jia, G

    2016-01-01

    Purpose: To test feasibility of the use of a digital endorectal x-ray sensor for improved image resolution of permanent brachytherapy seed implants compared to conventional CT. Methods: Two phantoms simulating the male pelvic region were used to test the capabilities of a digital endorectal x-ray sensor for imaging permanent brachytherapy seed implants. Phantom 1 was constructed from acrylic plastic with cavities milled in the locations of the prostate and the rectum. The prostate cavity was filled a Styrofoam plug implanted with 10 training seeds. Phantom 2 was constructed from tissue-equivalent gelatins and contained a prostate phantom implanted with 18 strands of training seeds. For both phantoms, an intraoral digital dental x-ray sensor was placed in the rectum within 2 cm of the seed implants. Scout scans were taken of the phantoms over a limited arc angle using a CT scanner (80 kV, 120–200 mA). The dental sensor was removed from the phantoms and normal helical CT and scout (0 degree) scans using typical parameters for pelvic CT (120 kV, auto-mA) were collected. A shift-and add tomosynthesis algorithm was developed to localize seed plane location normal to detector face. Results: The endorectal sensor produced images with improved resolution compared to CT scans. Seed clusters and individual seed geometry were more discernable using the endorectal sensor. Seed 3D locations, including seeds that were not located in every projection image, were discernable using the shift and add algorithm. Conclusion: This work shows that digital endorectal x-ray sensors are a feasible method for improving imaging of permanent brachytherapy seed implants. Future work will consist of optimizing the tomosynthesis technique to produce higher resolution, lower dose images of 1) permanent brachytherapy seed implants for post-implant dosimetry and 2) fine anatomic details for imaging and managing prostatic disease compared to CT images. Funding: LSU Faculty Start-up Funding

  6. WE-AB-BRA-11: Improved Imaging of Permanent Prostate Brachytherapy Seed Implants by Combining an Endorectal X-Ray Sensor with a CT Scanner

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, J; Matthews, K; Jia, G [Louisiana State University, Baton Rouge, LA (United States)

    2016-06-15

    Purpose: To test feasibility of the use of a digital endorectal x-ray sensor for improved image resolution of permanent brachytherapy seed implants compared to conventional CT. Methods: Two phantoms simulating the male pelvic region were used to test the capabilities of a digital endorectal x-ray sensor for imaging permanent brachytherapy seed implants. Phantom 1 was constructed from acrylic plastic with cavities milled in the locations of the prostate and the rectum. The prostate cavity was filled a Styrofoam plug implanted with 10 training seeds. Phantom 2 was constructed from tissue-equivalent gelatins and contained a prostate phantom implanted with 18 strands of training seeds. For both phantoms, an intraoral digital dental x-ray sensor was placed in the rectum within 2 cm of the seed implants. Scout scans were taken of the phantoms over a limited arc angle using a CT scanner (80 kV, 120–200 mA). The dental sensor was removed from the phantoms and normal helical CT and scout (0 degree) scans using typical parameters for pelvic CT (120 kV, auto-mA) were collected. A shift-and add tomosynthesis algorithm was developed to localize seed plane location normal to detector face. Results: The endorectal sensor produced images with improved resolution compared to CT scans. Seed clusters and individual seed geometry were more discernable using the endorectal sensor. Seed 3D locations, including seeds that were not located in every projection image, were discernable using the shift and add algorithm. Conclusion: This work shows that digital endorectal x-ray sensors are a feasible method for improving imaging of permanent brachytherapy seed implants. Future work will consist of optimizing the tomosynthesis technique to produce higher resolution, lower dose images of 1) permanent brachytherapy seed implants for post-implant dosimetry and 2) fine anatomic details for imaging and managing prostatic disease compared to CT images. Funding: LSU Faculty Start-up Funding

  7. Simulation of measurement absorbed dose on prostate brachytherapy with radius of prostate 2 cm using MCNP5 with seed implant model isoaid AdvantageTM IAPd-103A

    International Nuclear Information System (INIS)

    Poundra Setiawan; Suharyana; Riyatun

    2015-01-01

    Simulation of measurement absorbed dose on prostate brachytherapy with radius of prostate 2 cm using MCNP5 with seed implant model IsoAid Advantage TM IAPd-103A has been conducted. 103 Pd used as a radioactive source in the seed implant and it has energy gamma emission 20,8 keV with half live 16,9 days and has activity 4 mCi. The prostate cancer is modeled with spherical and it has radius 3 cm, after planting the seed implant 103 Pdover 24,4 days, prostate cancer has absorbed dose 2,172Gy. Lethal dose maximum use 103 Pd is 125 Gy and it was reached with 59 seeds. (author)

  8. An analysis of brachytherapy with computed tomography-guided permanent implantation of Iodine-125 seeds for recurrent nonkeratin nasopharyngeal carcinoma

    Directory of Open Access Journals (Sweden)

    Shen X

    2015-05-01

    Full Text Available Xinying Shen,1,2 Yong Li,2 Yanfang Zhang,2 Jian Kong,2 Yanhao Li1 1Department of Interventional Radiology, Nanfang Hospital, Southern Medical University, Guangzhou, 2Department of Interventional Radiology, Shenzhen People’s Hospital, The Second Clinical Medical College of Jinan University, Shenzhen, People’s Republic of China Background: 125I seed implantation is a new method in treatment of nasopharyngeal carcinoma (NPC, and it is worthwhile to evaluate its feasibility. In this study, we performed brachytherapy with computed tomography (CT-guided permanent implantation of 125I seeds in the treatment of patients with the recurrence of NPC.Methods: A total 30 patients (20 male and ten female at the median age of 55 (range 25–80 years were diagnosed with recurrent nonkeratin NPC, with a total 38 lesions and a short disease-free interval (median ~11 months after primary radiotherapy alone or combined with chemotherapy. Patients received CT scan, starting from 2 months after the treatment. Follow-up was conducted for ~2–38 months to observe the local control rate and overall survival rate. We also analyzed the possible correlation between survival periods and the status of recurrent tumors.Results: The local control rates at 6, 12, 24, 30, and 36 months after the procedure of 125I seed implantation were 86.8%, 73.7%, 26.3%, 15.8%, and 5.3%, respectively. The overall 1-, 2-, and 3-year survival rates were 80.0% (24/30, 30.0% (9/30, and 6.7% (2/30, respectively, with a median survival period of 18 months (17.6±8.6 months. Interestingly, the survival periods of the patients who had primary radiotherapy with or without chemotherapy were 15.8±7.9 and 24.3±7.9 months, respectively. Kaplan–Meier survival analysis demonstrated that χ2 (log rank was 7.555, with very significant difference (P<0.01. The survival periods of patients in tumor stages I, II, III, and IV were 25.4±8.7, 19.8±9.4, 16.1±4.5, and 12.8±7.8 months, respectively, with

  9. SU-E-J-215: Towards MR-Only Image Guided Identification of Calcifications and Brachytherapy Seeds: Application to Prostate and Breast LDR Implant Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Elzibak, A; Fatemi-Ardekani, A; Soliman, A; Mashouf, S; Safigholi, H; Ravi, A; Morton, G; Song, WY [Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Han, D [Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); University of California, San Diego, La Jolla, CA (United States)

    2015-06-15

    Purpose: To identify and analyze the appearance of calcifications and brachytherapy seeds on magnitude and phase MRI images and to investigate whether they can be distinguished from each other on corrected phase images for application to prostate and breast low dose rate (LDR) implant dosimetry. Methods: An agar-based gel phantom containing two LDR brachytherapy seeds (Advantage Pd-103, IsoAid, 0.8mm diameter, 4.5mm length) and two spherical calcifications (large: 7mm diameter and small: 4mm diameter) was constructed and imaged on a 3T Philips MR scanner using a 16-channel head coil and a susceptibility weighted imaging (SWI) sequence (2mm slices, 320mm FOV, TR/ TE= 26.5/5.3ms, 15 degree flip angle). The phase images were unwrapped and corrected using a 32×32, 2D Hanning high pass filter to remove background phase noise. Appearance of the seeds and calcifications was assessed visually and quantitatively using Osirix (http://www.osirix-viewer.com/). Results: As expected, calcifications and brachytherapy seeds appeared dark (hypointense) relative to the surrounding gel on the magnitude MRI images. The diameter of each seed without the surrounding artifact was measured to be 0.1 cm on the magnitude image, while diameters of 0.79 and 0.37 cm were measured for the larger and smaller calcifications, respectively. On the corrected phase images, the brachytherapy seeds and the calcifications appeared bright (hyperintense). The diameter of the seeds was larger on the phase images (0.17 cm) likely due to the dipole effect. Conclusion: MRI has the best soft tissue contrast for accurate organ delineation leading to most accurate implant dosimetry. This work demonstrated that phase images can potentially be useful in identifying brachytherapy seeds and calcifications in the prostate and breast due to their bright appearance, which helps in their visualization and quantification for accurate dosimetry using MR-only. Future work includes optimizing phase filters to best identify

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  11. SU-F-J-157: Effect of Contouring Uncertainty in Post Implant Dosimetry of Low-Dose-Rate Prostate Permanent Seed Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mashouf, S; Merino, T; Ravi, A; Morton, G; Song, W [Sunnybrook Health Sciences Center, Odette Cancer Centre, Toronto, ON (Canada); University of Toronto, Dept. of Radiation Oncology, Toronto, ON (Canada); Safigholi, H; Soliman, A [Sunnybrook Research Institute, Toronto, ON (Canada)

    2016-06-15

    Purpose: There is strong evidence relating post-implant dosimetry for low-dose-rate (LDR) prostate seed brachytherapy to local control rates. The delineation of the prostate on CT images, however, represents a challenge due to the lack of soft tissue contrast in order to identify the prostate borders. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to uncertainty in the contouring of prostate. Methods: CT images, post-op plans and contours of a cohort of patients (n=43) (low risk=55.8%, intermediate risk=39.5%, high risk=4.7%), who had received prostate seed brachytherapy, were imported into MIM Symphony treatment planning system. The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00 mm, ±2.00 mm, ±3.00 mm, ±4.00 mm and ±5.00 mm. The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: Significant changes were observed in the values of D90 and V100 as well as the number of suboptimal plans for expansion or contraction margins of only few millimeters. Evaluation of coverage based on D90 was found to be less sensitive to expansion errors compared to V100. D90 led to a lower number of implants incorrectly identified with insufficient coverage for expanded contours which increases the accuracy of post-implant QA using CT images compared to V100. Conclusion: In order to establish a successful post implant QA for LDR prostate seed brachytherapy, it is necessary to identify the low and high thresholds of important dose metrics of the target volume such as D90 and V100. Since these parameters are sensitive to target volume definition, accurate identification of prostate borders would help to improve accuracy and predictive value of the post-implant QA process. In this respect, use of imaging modalities such as MRI where prostate is well delineated should prove useful.

  12. SU-F-J-157: Effect of Contouring Uncertainty in Post Implant Dosimetry of Low-Dose-Rate Prostate Permanent Seed Brachytherapy

    International Nuclear Information System (INIS)

    Mashouf, S; Merino, T; Ravi, A; Morton, G; Song, W; Safigholi, H; Soliman, A

    2016-01-01

    Purpose: There is strong evidence relating post-implant dosimetry for low-dose-rate (LDR) prostate seed brachytherapy to local control rates. The delineation of the prostate on CT images, however, represents a challenge due to the lack of soft tissue contrast in order to identify the prostate borders. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to uncertainty in the contouring of prostate. Methods: CT images, post-op plans and contours of a cohort of patients (n=43) (low risk=55.8%, intermediate risk=39.5%, high risk=4.7%), who had received prostate seed brachytherapy, were imported into MIM Symphony treatment planning system. The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00 mm, ±2.00 mm, ±3.00 mm, ±4.00 mm and ±5.00 mm. The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: Significant changes were observed in the values of D90 and V100 as well as the number of suboptimal plans for expansion or contraction margins of only few millimeters. Evaluation of coverage based on D90 was found to be less sensitive to expansion errors compared to V100. D90 led to a lower number of implants incorrectly identified with insufficient coverage for expanded contours which increases the accuracy of post-implant QA using CT images compared to V100. Conclusion: In order to establish a successful post implant QA for LDR prostate seed brachytherapy, it is necessary to identify the low and high thresholds of important dose metrics of the target volume such as D90 and V100. Since these parameters are sensitive to target volume definition, accurate identification of prostate borders would help to improve accuracy and predictive value of the post-implant QA process. In this respect, use of imaging modalities such as MRI where prostate is well delineated should prove useful.

  13. Epoxy resins used to seal brachytherapy seed

    International Nuclear Information System (INIS)

    Ferreira, Natalia Carolina Camargos; Ferraz, Wilmar Barbosa; Reis, Sergio Carneiro dos; Santos, Ana Maria Matildes dos

    2013-01-01

    Prostate cancer treatment with brachytherapy is recommended for patients with cancer at an early stage. In this treatment, small radioactive seeds are implanted directly in the prostate gland. These seeds are composed at least of one radionuclide carrier and an X-ray marker enclosed within a metallic tube usually sealed by laser process. This process is expensive and, furthermore, it can provoke a partial volatilization of the radionuclide and change the isotropy in dose distribution around the seed. In this paper, we present a new sealing process using epoxy resin. Three kinds of resins were utilized and characterized by scanning electron microscopy (SEM), energy dispersive X ray (EDS) and by differential scanning calorimetry (DSC) after immersion in simulated body fluid (SBF) and in sodium iodine solution (NaI). The sealing process showed excellent potential to replace the sealing laser usually employed. (author)

  14. Comparative studies on permanent prostate brachytherapy: pre-plan and real-time transrectal ultrasound guided iodine-125 seed implants at Korle-Bu Teaching Hospital, Ghana

    International Nuclear Information System (INIS)

    Kalolo, L.T.

    2013-06-01

    This research was carried out to investigate and compare the real-time and pre-plan implant at the Radiotherapy Department of the Korle Bu Teaching Hospital, Ghana. Prowess Panther 4.5 treatment planning system and variseed 7.2 software were used for pre-plan and real-time implant respectively. The study was conducted for eighty three (83) patients treated for prostate cancer through real-time implant brachytherapy between september, 2008 to April, 2013. Thirty one patients (31) patients whose ultrasound images were available were selected for the pre-plan study. The slices of ultrasound images were re-drawn on transparent A-4 sheets and later on scanned, contoured and registered in the treatment planning system (prowess 4.5). After planning, the volume to be implanted, total number of needles, seeds and the total activity of the source were displayed. Comparison was done withe the pre-plan and real-time implant. In both cases the variation was below 5% as recommended in dosimetry. About 30% - 40% of the imported seeds were left un-used due to over-estimation of seeds ordered from the manufacturer (BARD Company-USA). Hence this work (pre-plan) aims to solve this problem. The comparison for dosimetric parameters was assessed for prostate, urethra and rectum as (V 95%, V 100%, V 150%, D90Gy, D90%), (D90Gy, D90%, D30Gy, D30% ) and (V 100%, D30Gy and D30%) respectively and the variation were within the limit of ± 5%. Comparison of dosimetric values for this work were done with other institutions, like Karolinska university hospital, Sweden, The institute of Curie/ hospital Cochin Group Paris-France and European recommendations. The values reported at Korle - Bu teaching hospital (this work) were in good agreement with the international guidelines. (au)

  15. Dosimetric results in implant and post-implant and low rate in brachytherapy prostate cancer with loose seeds and attached; Resultados dosimetricos en el implante y post-impante en braquiterapia de baja tasa en cancer de prostata con semillas sueltas y unidas

    Energy Technology Data Exchange (ETDEWEB)

    Juan-Senabre, X. J.; Albert Antequera, M.; Lopez-Tarjuelo, J.; Santos Serra, A.; Perez-Mestre, M.; Sanchez Iglesias, A. L.; Conde Moreno, A. J.; Gonzalez Vidal, V.; Beltran Persiva, J.; Muelas Soria, R.; Ferrer Albiach, C.

    2015-07-01

    The objective is determine differences dosimetry statistics on the dosimetry of the implant and post-implant in brachytherapy of low rate with implants permanent in prostate using seed of 125-I loose and attached Both in lives and in the post-prostatic plans dosimetric coverage is good and restrictions in urethra and rectum for both groups of patients are met. Not migrating with joined is evident, as well as better dosimetric homogeneity. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-01

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

  17. Optimal matching for prostate brachytherapy seed localization with dimension reduction.

    Science.gov (United States)

    Lee, Junghoon; Labat, Christian; Jain, Ameet K; Song, Danny Y; Burdette, Everette C; Fichtinger, Gabor; Prince, Jerry L

    2009-01-01

    In prostate brachytherapy, x-ray fluoroscopy has been used for intra-operative dosimetry to provide qualitative assessment of implant quality. More recent developments have made possible 3D localization of the implanted radioactive seeds. This is usually modeled as an assignment problem and solved by resolving the correspondence of seeds. It is, however, NP-hard, and the problem is even harder in practice due to the significant number of hidden seeds. In this paper, we propose an algorithm that can find an optimal solution from multiple projection images with hidden seeds. It solves an equivalent problem with reduced dimensional complexity, thus allowing us to find an optimal solution in polynomial time. Simulation results show the robustness of the algorithm. It was validated on 5 phantom and 18 patient datasets, successfully localizing the seeds with detection rate of > or = 97.6% and reconstruction error of < or = 1.2 mm. This is considered to be clinically excellent performance.

  18. Radioactive seed immobilization techniques for interstitial brachytherapy

    International Nuclear Information System (INIS)

    Yan, K.; Podder, T.; Buzurovic, I.; Hu, Y.; Dicker, A.; Valicenti, R.; Yu, Y.; Messing, E.; Rubens, D.; Sarkar, N.; Ng, W.

    2008-01-01

    In prostate brachytherapy, seeds can detach from their deposited sites and move locally in the pelvis or migrate to distant sites including the pulmonary and cardiac regions. Undesirable consequences of seed migration include inadequate dose coverage of the prostate and tissue irradiation effects at the site of migration. Thus, it is clinically important to develop seed immobilization techniques. We first analyze the possible causes for seed movement, and propose three potential techniques for seed immobilization: (1) surgical glue, (2) laser coagulation and (3) diathermy coagulation. The feasibility of each method is explored. Experiments were carried out using fresh bovine livers to investigate the efficacy of seed immobilization using surgical glue. Results have shown that the surgical glue can effectively immobilize the seeds. Evaluation of the radiation dose distribution revealed that the non-immobilized seed movement would change the planned isodose distribution considerably; while by using surgical glue method to immobilize the seeds, the changes were negligible. Prostate brachytherapy seed immobilization is necessary and three alternative mechanisms are promising for addressing this issue. Experiments for exploring the efficacy of the other two proposed methods are ongoing. Devices compatible with the brachytherapy procedure will be designed in future. (orig.)

  19. Methodology of quality control for brachytherapy {sup 125}I seeds

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Eduardo S.; Zeituni, Carlos A.; Manzoli, Jose E.; Rostelato, Maria Elisa C.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: esmoura@ipen.br

    2007-07-01

    This paper presents the methodology of quality control of {sup 125}I seeds used for brachytherapy. The {sup 125}I seeds are millimeter titanium capsules widely used in permanent implants of prostate cancer, allowing a high dose within the tumour and a low dose on the surrounding tissues, with very low harm to the other tissues. Besides, with this procedure, the patients have a low impotence rate and a small incidence of urinary incontinence. To meet the medical standards, an efficient quality control is necessary, showing values with the minimum uncertainness possible, concerning the seeds dimensions and their respective activities. The medical needles are used to insert the seeds inside the prostate. The needles used in brachytherapy have an internal diameter of 1.0 mm, so it is necessary {sup 125}I seeds with an external maximum diameter of 0.85 mm. For the seeds and the spacer positioning on the planning sheet, the seeds must have a length between 4.5 and 5.0 mm. The activities must not vary more than 5% in each batch of {sup 125}I seeds. For this methodology, we used two ionization chamber detectors and one caliper. In this paper, the methodology using one control batch with 75 seeds manufactured by GE Health care Ltd is presented. (author)

  20. Complementary method of analyzing the quality of the implant I-125 seeds for prostate brachytherapy using ultrasound imaging post-implant

    International Nuclear Information System (INIS)

    Jimenez Dominguez, M.; Carrasco Herrera, M.; Baeza Trujillo, M.; Herrador Cordoba, M.

    2011-01-01

    In this paper we propose a complementary method based on Longitudinal mode ultrasound images acquired the same day of surgery, at the end of the implant. This option will allow us to evaluate the dosimetry end of treatment with the patient in the same position he was planning and to the rectum and bladder just as full. This will permit the identification of bodies and the seeds of interest more easily and will have a reference with which to compare one month later, when the CT images can also detect whether there has been some migration.

  1. WE-A-17A-09: Exploiting Electromagnetic Technologies for Real-Time Seed Drop Position Validation in Permanent Implant Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Racine, E [Departement de Radio-Oncologie et Centre de Recherche du CHU de Quebec, Quebec, QC (Canada); Hautvast, G [Biomedical Systems, Philips Group Innovation, Eindhoven, North Brabant (Netherlands); Binnekamp, D [Integrated Clinical Solutions and Marketing, Philips Healthcare, Best, DA (Netherlands); Beaulieu, L [Centre Hospitalier University de Quebec, Quebec, QC (Canada)

    2014-06-15

    Purpose: To report on preliminary results validating the performance of a specially designed LDR brachytherapy needle prototype possessing both electromagnetic (EM) tracking and seed drop detection abilities. Methods: An EM hollow needle prototype has been designed and constructed in collaboration with research partner Philips Healthcare. The needle possesses conventional 3D tracking capabilities, along with a novel seed drop detection mechanism exploiting local changes of electromagnetic properties generated by the passage of seeds in the needle's embedded sensor coils. These two capabilities are exploited by proprietary engineering and signal processing techniques to generate seed drop position estimates in real-time treatment delivery. The electromagnetic tracking system (EMTS) used for the experiment is the NDI Aurora Planar Field Generator. The experiment consisted of dropping a total of 35 seeds in a prismatic agarose phantom, and comparing the 3D seed drop positions of the EMTS to those obtained by an image analysis of subsequent micro-CT scans. Drop position error computations and statistical analysis were performed after a 3D registration of the two seed distributions. Results: Of the 35 seeds dropped in the phantom, 32 were properly detected by the needle prototype. Absolute drop position errors among the detected seeds ranged from 0.5 to 4.8 mm with mean and standard deviation values of 1.6 and 0.9 mm, respectively. Error measurements also include undesirable and uncontrollable effects such as seed motion upon deposition. The true accuracy performance of the needle prototype is therefore underestimated. Conclusion: This preliminary study demonstrates the potential benefits of EM technologies in detecting the passage of seeds in a hollow needle as a means of generating drop position estimates in real-time treatment delivery. Such tools could therefore represent a potentially interesting addition to existing brachytherapy protocols for rapid dosimetry

  2. WE-A-17A-09: Exploiting Electromagnetic Technologies for Real-Time Seed Drop Position Validation in Permanent Implant Brachytherapy

    International Nuclear Information System (INIS)

    Racine, E; Hautvast, G; Binnekamp, D; Beaulieu, L

    2014-01-01

    Purpose: To report on preliminary results validating the performance of a specially designed LDR brachytherapy needle prototype possessing both electromagnetic (EM) tracking and seed drop detection abilities. Methods: An EM hollow needle prototype has been designed and constructed in collaboration with research partner Philips Healthcare. The needle possesses conventional 3D tracking capabilities, along with a novel seed drop detection mechanism exploiting local changes of electromagnetic properties generated by the passage of seeds in the needle's embedded sensor coils. These two capabilities are exploited by proprietary engineering and signal processing techniques to generate seed drop position estimates in real-time treatment delivery. The electromagnetic tracking system (EMTS) used for the experiment is the NDI Aurora Planar Field Generator. The experiment consisted of dropping a total of 35 seeds in a prismatic agarose phantom, and comparing the 3D seed drop positions of the EMTS to those obtained by an image analysis of subsequent micro-CT scans. Drop position error computations and statistical analysis were performed after a 3D registration of the two seed distributions. Results: Of the 35 seeds dropped in the phantom, 32 were properly detected by the needle prototype. Absolute drop position errors among the detected seeds ranged from 0.5 to 4.8 mm with mean and standard deviation values of 1.6 and 0.9 mm, respectively. Error measurements also include undesirable and uncontrollable effects such as seed motion upon deposition. The true accuracy performance of the needle prototype is therefore underestimated. Conclusion: This preliminary study demonstrates the potential benefits of EM technologies in detecting the passage of seeds in a hollow needle as a means of generating drop position estimates in real-time treatment delivery. Such tools could therefore represent a potentially interesting addition to existing brachytherapy protocols for rapid dosimetry

  3. Iodine-125 thin seeds decrease prostate swelling during transperineal interstitial permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    Beydoun, Nadine; Bucci, Joseph A.; Chin, Yaw S.; Malouf, David

    2014-01-01

    Prostate swelling following seed implantation is a well-recognised phenomenon. The purpose of this intervention was to assess whether using thinner seeds reduces post-implant swelling with permanent prostate brachytherapy. Eighteen consecutive patients eligible for prostate seed brachytherapy underwent seed implantation using iodine-125 (I-125) thin seeds. Operative time, dosimetry, prostate swelling and toxicity were assessed and compared with standard I-125 stranded seed controls, sourced from the department's brachytherapy database. A learning curve was noted with the thin seeds in terms of greater bending and deviation of needles from their intended path. This translated into significantly longer total operative time (88 vs 103 minutes; P=0.009, 95% confidence interval (CI) 4.1-24.3) and time per needle insertion (2.6 vs 3.7 minutes; P<0.001, 95% CI 0.5-1.3) for the thin seeds. Day 30 prostate volumes were significantly smaller in the thin seed group compared with standard seeds (40.9cc vs 46.8cc; P=0.001, 95% CI 1.5-5.6). The ratio of preoperative transrectal ultrasound to day 30 post-implant CT volume was also smaller in the thin seed group (1.2±0.1 for standard seeds vs 1.1±0.1 for thin seeds). Post-implant dosimetric parameters were comparable for both groups. No significant differences were seen in acute urinary morbidity or quality of life between the two groups. I-125 thin seeds are associated with an initial learning curve, with longer operative time, even for experienced brachytherapists. The significant reduction in day 30 prostate volumes with the thin seeds has useful implications in terms of optimising dose coverage to the prostate in the early period post-implantation, as well as improving the accuracy of post-implant dosimetric assessments.

  4. Factors influencing upon the incidence of seed migration in I-125 seed transperineal prostate implantation

    International Nuclear Information System (INIS)

    Itami, Jun; Onishi, Kayoko; Kanemura, Mikio

    2005-01-01

    Transperineal I-125 seed brachytherapy for prostate cancer is rapidly expanding in Japan. Seed migrations to lung and abdomen are well known complication in the seed brachytherapy. The rate of incidence and the predisposing factors were studied. From April 2004 through January 2005, 36 patients underwent transperineal I-125 seed brachytherapy for prostate cancer. In all patients loose I-125 seeds were inserted with Mick applicator according to modified peripheral loading pattern. One day, 1 week, and 1 month after the procedure, posteroanterior and lateral chest X-rays and abdominal X-ray were performed. Abdominal and chest seed migrations were seen in 11 (30.6%) and 14 (38.9%) patients, respectively. In total, 20 patients (55.6%) showed seed migrations. Forty-two I-125 seeds migrated out of 2,508 implanted seeds. Most of the migrations were seen until 1 month after the procedure. The preplanned number of the extraprostatic seeds had a statistically significant influence upon the incidence of seed migration. Seed migration is not a rare phenomenon in transperineal I-125 seed brachytherapy for prostate cancer. To confirm seed migration, X-ray examinations 1 month after the procedure are suited. At the preplanning, the number of extraprostatic seeds should be limited to minimal to decrease the incidence of seed migration. In future, the introduction of linked I-125 seeds is preferred. (author)

  5. Iodine-125 orbital brachytherapy with a prosthetic implant in situ

    Energy Technology Data Exchange (ETDEWEB)

    Stannard, Clare [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Radiation Oncology; Maree, Gert; Munro, Roger [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Medical Physics; Lecuona, Karin [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Ophthalmology; Sauerwein, Wolfgang [Universitaetsklinikum Essen (Germany). Strahlenklinik, NCTeam

    2011-05-15

    Purpose: Brachytherapy is one method of irradiating the orbit after enucleation of an eye with a malignant tumor that has a potential to recur. It consists of 6 trains of I-125 seeds placed around the periphery of the orbit, a shorter central train, and a metal disc, loaded with seeds, placed beneath the eyelids. The presence of a prosthetic orbital implant requires omission of the central train and adjustment of the activity of the seeds in the anterior orbit around the prosthesis. Patients and Methods: This is a retrospective review of the technical modifications and outcome of 12 patients treated in this manner: 6 with retinoblastoma, 5 with malignant melanoma, and 1 with an intraocular rhabdomyosarcoma. The median dose was 35.5 Gy in 73 hours for retinoblastoma and 56 Gy in 141 hours for malignant melanoma. Patients with retinoblastoma and rhabdomyosarcoma also received chemotherapy. Results: The tubes can be placed satisfactorily around the prosthesis. The increased activity in the anterior half of the tubes produced comparable dose distributions. There have been no orbital recurrences, no extrusion of the prosthesis, and cosmesis is good. Conclusion: Insertion of a prosthetic implant at the time of enucleation greatly enhances the subsequent cosmetic appearance. This should be encouraged unless there is frank tumor in the orbit. Orbital brachytherapy without the central train continues to give excellent local control. The short treatment time and good cosmesis are added advantages. The patient is spared the expense and inconvenience of removing and replacing the prosthetic implant. (orig.)

  6. Dose reduction in LDR brachytherapy by implanted prostate gold fiducial markers.

    Science.gov (United States)

    Landry, Guillaume; Reniers, Brigitte; Lutgens, Ludy; Murrer, Lars; Afsharpour, Hossein; de Haas-Kock, Danielle; Visser, Peter; van Gils, Francis; Verhaegen, Frank

    2012-03-01

    The dosimetric impact of gold fiducial markers (FM) implanted prior to external beam radiotherapy of prostate cancer on low dose rate (LDR) brachytherapy seed implants performed in the context of combined therapy was investigated. A virtual water phantom was designed containing a single FM. Single and multi source scenarios were investigated by performing Monte Carlo dose calculations, along with the influence of varying orientation and distance of the FM with respect to the sources. Three prostate cancer patients treated with LDR brachytherapy for a recurrence following external beam radiotherapy with implanted FM were studied as surrogate cases to combined therapy. FM and brachytherapy seeds were identified on post implant CT scans and Monte Carlo dose calculations were performed with and without FM. The dosimetric impact of the FM was evaluated by quantifying the amplitude of dose shadows and the volume of cold spots. D(90) was reported based on the post implant CT prostate contour. Large shadows are observed in the single source-FM scenarios. As expected from geometric considerations, the shadows are dependent on source-FM distance and orientation. Large dose reductions are observed at the distal side of FM, while at the proximal side a dose enhancement is observed. In multisource scenarios, the importance of shadows appears mitigated, although FM at the periphery of the seed distribution caused underdosage (LDR brachytherapy seed implant dose distributions. Therefore, reduced tumor control could be expected from FM implanted in tumors, although our results are too limited to draw conclusions regarding clinical significance.

  7. Radiation exposure to operating room staff during prostate brachytherapy using iodine-125 seeds; Exposition radiologique de l'equipe operatoire au cours de curietherapies de prostate par implants permanents d'iode-125

    Energy Technology Data Exchange (ETDEWEB)

    Gagna, G.; Amabile, J.C.; Laroche, P. [Service de protection radiologique des armees (SPRA), 1 bis rue du Lieutenant Raoul Batany, 92141 Clamart Cedex (France); Gauron, C. [Institut national de recherche et de securite (INRS), Departement Etudes et Assistance Medicales, 30 rue Olivier Noyer, 75680 Paris Cedex 14 (France)

    2011-04-15

    The French defense radiation protection service (SPRA) and the French national institute for research and safety (INRS) conducted a joint study to assess the radiation exposure to operating room staff during prostate brachytherapy using iodine-125 seeds at the Val-de-Grace military hospital. The purpose of the study was the assessment of the effective doses, the equivalent doses to the extremities and lens received by a novice team, the different ambient dose equivalent rates measurements and the delineation of areas. After six brachy-therapies, all the recorded doses with whole-body InLight{sup R} OSL and nanoDot{sup R} dosimeters remained below the detection limit for the whole staff. The dose rate measured at the end of implantation by an AT1123{sup R} survey meter is about 170 {mu}Sv/h at the perineum of the patient. The controlled area limit is estimated to be about 20 cm from the patient perineum. From these results, the authors propose recommendations for the categorization of workers, the delineation of areas and the dose monitoring procedures. This study demonstrates that real-time ultrasound-guided trans-perineal prostate brachytherapy delivers low dose to the operators because of the radioactive source characteristics and the instrumentation providing an effective radiation protection for the surgical team. (authors)

  8. Short-lag spatial coherence beamforming of photoacoustic images for enhanced visualization of prostate brachytherapy seeds

    OpenAIRE

    Lediju Bell, Muyinatu A.; Kuo, Nathanael; Song, Danny Y.; Boctor, Emad M.

    2013-01-01

    Prostate brachytherapy, administered by implanting tiny radioactive seeds to treat prostate cancer, currently relies on transrectal ultrasound imaging for intraoperative visualization of the metallic seeds. Photoacoustic (PA) imaging has been suggested as a feasible alternative to ultrasound imaging due to its superior sensitivity to metal surrounded by tissue. However, PA images suffer from poor contrast when seeds are distant from the light source. We propose a transperineal light delivery ...

  9. Incidence of seed migration to the chest, abdomen, and pelvis after transperineal interstitial prostate brachytherapy with loose 125I seeds

    International Nuclear Information System (INIS)

    Sugawara, Akitomo; Shigematsu, Naoyuki; Nakashima, Jun; Kunieda, Etsuo; Nagata, Hirohiko; Mizuno, Ryuichi; Seki, Satoshi; Shiraishi, Yutaka; Kouta, Ryuichi; Oya, Mototsugu

    2011-01-01

    The aim was to determine the incidence of seed migration not only to the chest, but also to the abdomen and pelvis after transperineal interstitial prostate brachytherapy with loose 125 I seeds. We reviewed the records of 267 patients who underwent prostate brachytherapy with loose 125 I seeds. After seed implantation, orthogonal chest radiographs, an abdominal radiograph, and a pelvic radiograph were undertaken routinely to document the occurrence and sites of seed migration. The incidence of seed migration to the chest, abdomen, and pelvis was calculated. All patients who had seed migration to the abdomen and pelvis subsequently underwent a computed tomography scan to identify the exact location of the migrated seeds. Postimplant dosimetric analysis was undertaken, and dosimetric results were compared between patients with and without seed migration. A total of 19,236 seeds were implanted in 267 patients. Overall, 91 of 19,236 (0.47%) seeds migrated in 66 of 267 (24.7%) patients. Sixty-nine (0.36%) seeds migrated to the chest in 54 (20.2%) patients. Seven (0.036%) seeds migrated to the abdomen in six (2.2%) patients. Fifteen (0.078%) seeds migrated to the pelvis in 15 (5.6%) patients. Seed migration occurred predominantly within two weeks after seed implantation. None of the 66 patients had symptoms related to the migrated seeds. Postimplant prostate D90 was not significantly different between patients with and without seed migration. We showed the incidence of seed migration to the chest, abdomen and pelvis. Seed migration did not have a significant effect on postimplant prostate D90

  10. Prostate brachytherapy - discharge

    Science.gov (United States)

    Implant therapy - prostate cancer - discharge; Radioactive seed placement - discharge ... You had a procedure called brachytherapy to treat prostate cancer. Your treatment lasted 30 minutes or more, ...

  11. Study on interstitial brachytherapy using 103Pd seeds on tumor-bearing rats

    International Nuclear Information System (INIS)

    Feng Huiru; Zhang Jingming; Tian Jiahe; Ding Weimin; Bai Hongsheng; Jin Xiaohai

    2003-01-01

    The effects of low-dose-rate brachytherapy are investigated in tumor-bearing rat. Walker 256 cells are transplanted subcutaneously with a trocar in the left leg of rats (Wistar). Two weeks later, rats with a tumor of 10 mm in mean diameter are divided into three groups (10 per group). Two groups are given 1 seed and 2 seeds implantation of 103 Pd, respectively, the third group is as an untreated control. Tumor size is measured twice a week until the 25th day when the rats are killed. Tumor is monitored either by palpation or further confirmed by histopathology. Kaplan-Meier statistic method is performed for survival analysis. The results show that the average weight of rats in untreated group is lower than in radiation groups (P 0.05). Tumor volumes in all treatment groups increase more obviously than in control till 16 days post-implantation. Tumor regression rate in 1 seed group is higher than in control group and in 2 seeds group. Although survival analysis show that the median survival time in 1 seed, 2 seeds and control groups are 24±0, 21±2 and 19±2 days with survival rate of 80%, 60% and 50% respectively, no significant differences are seen in all groups. So, brachytherapy with 103 Pd seed is effective on tumor-bearing rats. The implantation of seed can cause tumor edema in a self-limited way. A reasonable doses chosen for brachytherapy may play a role in treatment success

  12. First symposium seed implant 125I and high rate of prostate

    International Nuclear Information System (INIS)

    2012-01-01

    The First symposium seed implant 125 I and high rate of prostate, was organized by the Marie Curie Foundation, between the 12 to april 2012, in the Cordoba city of Argentina. In this event were presented several documents in different topics: patients selection for impacts of 125 I seeds; high doses radiation in radiotherapy; brachytherapy for prostate cancer; prostate implant technique with 125 I seeds; implant dosimetric aspects; radioprotection of 125 I seeds.

  13. Prostate brachytherapy seed migration to the heart seen on cardiovascular computed tomographic angiography

    Directory of Open Access Journals (Sweden)

    Shilpa Sachdeva, MD

    2017-03-01

    Full Text Available Brachytherapy consists of placing radioactive sources into or adjacent to tumors, to deliver conformal radiation treatment. The technique is used for treatment of primary malignancies and for salvage in recurrent disease. Permanent prostate brachytherapy seeds are small metal implants containing radioactive sources of I-125, Pd-103, or Cs-131 encased in a titanium shell. They can embolize through the venous system to the lungs or heart and subsequently be detected by cardiovascular computed tomography. Cardiovascular imagers should be aware of the appearance of migrated seeds, as their presence in the chest is generally benign, so that unnecessary worry and testing are avoided. We report a case of a patient who underwent brachytherapy for prostate cancer and developed a therapeutic seeds embolus to the right ventricle.

  14. SU-G-JeP1-10: Feasibility of CyberKnife Tracking Using the Previously-Implanted Permanent Brachytherapy Seed Cloud

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, J; Cunha, J; Sudhyadhom, A; McGuinness, C; Roach, M; Descovich, M [University of California San Francisco, San Francisco, CA (United States)

    2016-06-15

    Purpose: Robotic radiosurgery is a salvage treatment option for patients with recurrent prostate cancer. We explored the feasibility of tracking the bolus of permanent prostate implants (PPI) using image recognition software optimized to track spinal anatomy. Methods: Forty-five inert iodine seeds were implanted into a gelatin-based prostate phantom. Four superficial gold seeds were inserted to provide ground-truth alignment. A CT scan of the phantom (120 kVp, 1 mm slice thickness) was acquired and a single-energy iterative metal artifact reduction (MAR) algorithm was used to enhance the quality of the DRR used for tracking. CyberKnife treatment plans were generated from the MAR CT and regular CT (no-MAR) using spine tracking. The spine-tracking grid was centered on the bolus of seeds and resized to encompass the full seed cloud. A third plan was created from the regular CT scan, using fiducial tracking based on the 4 superficial gold seeds with identical align-center coordinates. The phantom was initially aligned using the fiducial-tracking plan. Then the MAR and no-MAR spine-tracking plans were loaded without moving the phantom. Differences in couch correction parameters were recorded in the case of perfect alignment and after the application of known rotations and translations (roll/pitch of 2 degrees; translations XYZ of 2 cm). Results: The spine tracking software was able to lock on to the bolus of seeds and provide couch corrections both in the MAR and no-MAR plans. In all cases, differences in the couch correction parameters from fiducial alignment were <0.5 mm in translations and <1 degree in rotations. Conclusion: We were able to successfully track the bolus of seeds with the spine-tracking grid in phantom experiments. For clinical applications, further investigation and developments to adapt the spine-tracking algorithm to optimize for PPI seed cloud tracking is needed to provide reliable tracking in patients. One of the authors (MD) has received research

  15. SU-G-JeP1-10: Feasibility of CyberKnife Tracking Using the Previously-Implanted Permanent Brachytherapy Seed Cloud

    International Nuclear Information System (INIS)

    Cheung, J; Cunha, J; Sudhyadhom, A; McGuinness, C; Roach, M; Descovich, M

    2016-01-01

    Purpose: Robotic radiosurgery is a salvage treatment option for patients with recurrent prostate cancer. We explored the feasibility of tracking the bolus of permanent prostate implants (PPI) using image recognition software optimized to track spinal anatomy. Methods: Forty-five inert iodine seeds were implanted into a gelatin-based prostate phantom. Four superficial gold seeds were inserted to provide ground-truth alignment. A CT scan of the phantom (120 kVp, 1 mm slice thickness) was acquired and a single-energy iterative metal artifact reduction (MAR) algorithm was used to enhance the quality of the DRR used for tracking. CyberKnife treatment plans were generated from the MAR CT and regular CT (no-MAR) using spine tracking. The spine-tracking grid was centered on the bolus of seeds and resized to encompass the full seed cloud. A third plan was created from the regular CT scan, using fiducial tracking based on the 4 superficial gold seeds with identical align-center coordinates. The phantom was initially aligned using the fiducial-tracking plan. Then the MAR and no-MAR spine-tracking plans were loaded without moving the phantom. Differences in couch correction parameters were recorded in the case of perfect alignment and after the application of known rotations and translations (roll/pitch of 2 degrees; translations XYZ of 2 cm). Results: The spine tracking software was able to lock on to the bolus of seeds and provide couch corrections both in the MAR and no-MAR plans. In all cases, differences in the couch correction parameters from fiducial alignment were <0.5 mm in translations and <1 degree in rotations. Conclusion: We were able to successfully track the bolus of seeds with the spine-tracking grid in phantom experiments. For clinical applications, further investigation and developments to adapt the spine-tracking algorithm to optimize for PPI seed cloud tracking is needed to provide reliable tracking in patients. One of the authors (MD) has received research

  16. Comparison of CT- and radiograph-based post-implant dosimetry for transperineal 125I prostate brachytherapy using single seeds and a commercial treatment-planning software

    International Nuclear Information System (INIS)

    Siebert, F.A.; Kohr, P.; Kovacs, G.

    2006-01-01

    Background and purpose: the objective of this investigation was a direct comparison of the dosimetry of CT-based and radiograph-based postplanning procedures for seed implants. Patients and methods: CT- and radiograph-based postplans were carried out for eight iodine-125 ( 125 I) seed implant patients with a commercial treatment-planning system (TPS). To assess a direct comparison of the dosimetric indices (D90, V100, V400), the radiograph-based seed coordinates were transformed to the coordinate system of the CT postplan. Afterwards, the CT-based seed positions were replaced by the radiograph-based coordinates in the TPS and the dose distribution was recalculated. Results: the computations demonstrated that the radiograph-based dosimetric values for the prostate (D p 90, V p 100, and V p 400) were on average lower than the values of the CT postplan. Normalized to the CT postplan the following mean values were found: D p 90: 90.6% (standard deviation [SD]: 9.0%), V p 100: 86.1% (SD: 14.7%), and V p 400: 79.4% (SD: 14.4%). For three out of the eight patients the D p 90 decreased to 90% of the initial CT postplan values. The reason for this dosimetric difference is supposed to be evoked by an error of the reconstruction software used. It was detected that the TPS algorithm assigned some sources to wrong coordinates, partly out of the prostate gland. Conclusion: the radiograph-based postplanning technique of the investigated TPS should only be used in combination with CT postplanning. Furthermore, complex testing procedures of reconstruction algorithms are recommended to minimize calculation errors. (orig.)

  17. Iodine 125 seed migration after prostate brachytherapy: a study of 170 patients

    International Nuclear Information System (INIS)

    Chauveinc, L.; Osseili, A.; Rosenwald, J.C.; Cosset, J.M.; Flam, T.; Thiounn, N.; Savignoni, A.

    2004-01-01

    Purpose. To study the number of migrating seeds, the anatomical site of migration and possible predictive parameters of migration, after prostate cancer brachytherapy using a loose-seed (I125) implantation technique. Patients and methods. The charts of the 170 patients consecutively treated by the Institut Curie/Hospital Cochin/Hospital Necker Group between September 1, 2001 and August 31, 2002, were analysed. All seeds having migrated to the lungs and seen on the chest X-ray systematically performed at 2 months, have been recorded, as well as the seeds lost by the urines (after sieving) or in the sperm (condom). Results. Among 12,179 implanted seeds, 44 were found to have migrated (0.36%). Most of the migrating seeds (32/44; 73%), were found in the lungs. Overall, one or several seed migrations were observed in 35 patients (21% of the total number of patients in this series). In the majority of cases (77< r i. only one seed migrated. A significant relationship (P = 0.04) vs as found between the number of migrating seeds and the number of implanted ones (or with the prostate volume, but those two parameters were closely linked in our series). More specifically, a significant relationship (P = 0.02) could be demonstrated between the number of seeds implanted at the periphery of the prostate and the number of seeds migrating to the lungs. Conclusion. The percentage of migrating seeds observed in this series is low. actually one of the lowest found in the literature when using the loose-seed technique. There was no clinical consequences and the loss of-usually only one seed is very unlikely to alter the quality of the dose distribution. However, the predominance of pulmonary migrations in our series led us to slightly modify our implantation technique. We now try to avoid too 'peripheral' seed implantations, due to the risk of migration towards the peri-prostatic veins, and subsequently to the lungs. (author)

  18. Automatic seed picking for brachytherapy postimplant validation with 3D CT images.

    Science.gov (United States)

    Zhang, Guobin; Sun, Qiyuan; Jiang, Shan; Yang, Zhiyong; Ma, Xiaodong; Jiang, Haisong

    2017-11-01

    Postimplant validation is an indispensable part in the brachytherapy technique. It provides the necessary feedback to ensure the quality of operation. The ability to pick implanted seed relates directly to the accuracy of validation. To address it, an automatic approach is proposed for picking implanted brachytherapy seeds in 3D CT images. In order to pick seed configuration (location and orientation) efficiently, the approach starts with the segmentation of seed from CT images using a thresholding filter which based on gray-level histogram. Through the process of filtering and denoising, the touching seed and single seed are classified. The true novelty of this approach is found in the application of the canny edge detection and improved concave points matching algorithm to separate touching seeds. Through the computation of image moments, the seed configuration can be determined efficiently. Finally, two different experiments are designed to verify the performance of the proposed approach: (1) physical phantom with 60 model seeds, and (2) patient data with 16 cases. Through assessment of validated results by a medical physicist, the proposed method exhibited promising results. Experiment on phantom demonstrates that the error of seed location and orientation is within ([Formula: see text]) mm and ([Formula: see text])[Formula: see text], respectively. In addition, the most seed location and orientation error is controlled within 0.8 mm and 3.5[Formula: see text] in all cases, respectively. The average process time of seed picking is 8.7 s per 100 seeds. In this paper, an automatic, efficient and robust approach, performed on CT images, is proposed to determine the implanted seed location as well as orientation in a 3D workspace. Through the experiments with phantom and patient data, this approach also successfully exhibits good performance.

  19. The effects of metallic implants on electroporation therapies: feasibility of irreversible electroporation for brachytherapy salvage.

    Science.gov (United States)

    Neal, Robert E; Smith, Ryan L; Kavnoudias, Helen; Rosenfeldt, Franklin; Ou, Ruchong; Mclean, Catriona A; Davalos, Rafael V; Thomson, Kenneth R

    2013-12-01

    Electroporation-based therapies deliver brief electric pulses into a targeted volume to destabilize cellular membranes. Nonthermal irreversible electroporation (IRE) provides focal ablation with effects dependent on the electric field distribution, which changes in heterogeneous environments. It should be determined if highly conductive metallic implants in targeted regions, such as radiotherapy brachytherapy seeds in prostate tissue, will alter treatment outcomes. Theoretical and experimental models determine the impact of prostate brachytherapy seeds on IRE treatments. This study delivered IRE pulses in nonanimal, as well as in ex vivo and in vivo tissue, with and in the absence of expired radiotherapy seeds. Electrical current was measured and lesion dimensions were examined macroscopically and with magnetic resonance imaging. Finite-element treatment simulations predicted the effects of brachytherapy seeds in the targeted region on electrical current, electric field, and temperature distributions. There was no significant difference in electrical behavior in tissue containing a grid of expired radiotherapy seeds relative to those without seeds for nonanimal, ex vivo, and in vivo experiments (all p > 0.1). Numerical simulations predict no significant alteration of electric field or thermal effects (all p > 0.1). Histology showed cellular necrosis in the region near the electrodes and seeds within the ablation region; however, there were no seeds beyond the ablation margins. This study suggests that electroporation therapies can be implemented in regions containing small metallic implants without significant changes to electrical and thermal effects relative to use in tissue without the implants. This supports the ability to use IRE as a salvage therapy option for brachytherapy.

  20. Occupational exposure of professionals during interstitial permanent prostate brachytherapy implants

    International Nuclear Information System (INIS)

    Pirraco, R.; Pereira, A.; Viterbo, T.; Cavaco, A.

    2006-01-01

    Full text of publication follows: Introduction: In this study we present dose measurements for professionals exposed during interstitial 125 I permanent prostate brachytherapy implants. Methods and Materials: The implant technique used was intra operative real time using strand and loose seeds. The professionals inside the operating room are an oncologist, a radiologist, a physicist, a nurse and an anesthesiologist. The oncologist and the physicist contact directly the loaded needle with radioactive seeds and two types of measurements were taken: total body and extremities (finger) dose. The rest of the team operates at long distances, but measurements were made. To measure total body equivalent dose we use a Berthold Umo LB 123 coupled with a LB 1236-H10 detector, and we recorded dose, time and distance from implant location. Finger dosemeters are thermo -luminescent dosimeter (TLD) rings that were controlled over one month. Results: 50 cases (average number of applications per year) were analysed for extremities measurements and 9 cases for total body measurements (in this case, the results were extrapolated for 50 cases), with an average of 26.1 mCi total activity per implant (in a range of 17.4 - 40.3 mCi). The finger dose was 1.8 mSv for the oncologist and 1.9 mSv for the physicist. The interpolation of total body equivalent dose for the oncologist was 24 mSv, for the radiologist 6 mSv and 9 mSv for the physicist. The rest of the team did not receive anything but background radiation. The annual national limit dose for workers is 20 mSv for total body irradiation, and 500 mSv for extremities. Conclusion: In conclusion we may say that during interstitial permanent prostate brachytherapy implants, total doses received for all groups are not significant when compared to annual limits for Portuguese laws 1. Even so, our main goal is always to get the less possible dose (ALARA principle). References: 1. Decreto Lei n. 180/2002 de 8 de Agosto. (authors)

  1. Occupational exposure of professionals during interstitial permanent prostate brachytherapy implants

    Energy Technology Data Exchange (ETDEWEB)

    Pirraco, R.; Pereira, A.; Viterbo, T.; Cavaco, A. [Instituto Portugues de Oncologia Francisco Gentil, Centro R egional de Oncologia do Porto, SA, Porto (Portugal)

    2006-07-01

    Full text of publication follows: Introduction: In this study we present dose measurements for professionals exposed during interstitial 125 I permanent prostate brachytherapy implants. Methods and Materials: The implant technique used was intra operative real time using strand and loose seeds. The professionals inside the operating room are an oncologist, a radiologist, a physicist, a nurse and an anesthesiologist. The oncologist and the physicist contact directly the loaded needle with radioactive seeds and two types of measurements were taken: total body and extremities (finger) dose. The rest of the team operates at long distances, but measurements were made. To measure total body equivalent dose we use a Berthold Umo LB 123 coupled with a LB 1236-H10 detector, and we recorded dose, time and distance from implant location. Finger dosemeters are thermo -luminescent dosimeter (TLD) rings that were controlled over one month. Results: 50 cases (average number of applications per year) were analysed for extremities measurements and 9 cases for total body measurements (in this case, the results were extrapolated for 50 cases), with an average of 26.1 mCi total activity per implant (in a range of 17.4 - 40.3 mCi). The finger dose was 1.8 mSv for the oncologist and 1.9 mSv for the physicist. The interpolation of total body equivalent dose for the oncologist was 24 mSv, for the radiologist 6 mSv and 9 mSv for the physicist. The rest of the team did not receive anything but background radiation. The annual national limit dose for workers is 20 mSv for total body irradiation, and 500 mSv for extremities. Conclusion: In conclusion we may say that during interstitial permanent prostate brachytherapy implants, total doses received for all groups are not significant when compared to annual limits for Portuguese laws 1. Even so, our main goal is always to get the less possible dose (ALARA principle). References: 1. Decreto Lei n. 180/2002 de 8 de Agosto. (authors)

  2. Three-dimensional seed reconstruction from an incomplete data set for prostate brachytherapy

    International Nuclear Information System (INIS)

    Narayanan, Sreeram; Cho, Paul S; MarksII, Robert J

    2004-01-01

    Intra-operative dosimetry in prostate brachytherapy requires 3D coordinates of the implanted, radioactive seeds. Since CT is not readily available during the implant operation, projection x-rays are commonly used for intra-operative seed localization. Three x-ray projections are usually used. The requirement of the current seed reconstruction algorithms is that the seeds must be identified on all three projections. However, in practice this is often difficult to accomplish due to the problem of heavily clustered and overlapping seeds. We have developed an algorithm that permits seed reconstruction from an incomplete data set. Instead of all three projections, the new algorithm requires only one of the three projections to be complete. Furthermore, even if all three projections are incomplete, it can reconstruct 100% of the implanted seeds depending on how the undetected seeds are distributed among the projections. The method utilizes the principles of epipolar imaging geometry and pseudo-matching of the undetected seeds. The algorithm was successfully applied to a large number of clinical cases where seeds imperceptibly overlap in some projections

  3. Image fusion techniques in permanent seed implantation

    Directory of Open Access Journals (Sweden)

    Alfredo Polo

    2010-10-01

    image fusion for permanent seed implantation.

  4. [Technique of intraoperative planning in prostatic brachytherapy with permanent implants of 125I or 103Pd].

    Science.gov (United States)

    Prada Gómez, Pedro José; Juan Rijo, Germán; Hevia Suarez, Miguel; Abascal García, José María; Abascal García, Ramón

    2002-12-01

    Prostatic brachytherapy with permanent 125I or 123Pd seeds implantation is a therapeutic option for organ-confined prostate cancer. We analyze the technique based on previous planning, our current intraoperative planning procedure and the reasons that moved us to introduce this change. Changes in prostate volume and spatial localization observed between previous planning and intraoperative images, and possible difficulties for seed implantation due to pubic arch interference are some of the reasons that induce us to change technique. Before the operation, we calculate the prostatic volume by transrectal ultrasound; with this information we determine the total implant activity following Wu's nomogram, and per-seed activity; therefore, it is an individual process for each patient. We perform a peripheral implant, placing 75-80% of the seeds within the peripheral prostatic zone, generally through 12-15 needles, the rest of the seeds are placed in the central prostatic zone using a maximum of 3-4 needles in high volume prostates. The day of intervention, after positioning and catheter insertion, volumetry is re-checked. Ultrasound images (from base to apex every 5 mm) are transferred to the planner were a suitable seed distribution is determined. Implantation is then performed placing all needles unloaded, and then intraoperative post-planning to allow us to check implant precision is performed after cistoscopically check that there is no urethral or bladder penetration by any needle. We finish with the insertion of seeds into the prostate. Total time for the procedure is around 90 minutes. Intraoperative planning is an additional step for the treatment of prostate cancer with permanent seeds brachytherapy, which avoids the disadvantages of previous planning and improves tumor inclusion in the ideal irradiation dose area, which will translate into better local disease control.

  5. Radiation protection after interstitial permanent prostate brachytherapy implants

    Energy Technology Data Exchange (ETDEWEB)

    Pirraco, R.; Pereira, A.; Cavaco, A. [Instituto Portugues de Oncologia Francisco Gentil - Centro R egional de Oncologia do Porto, SA, Porto (Portugal)

    2006-07-01

    Full text of publication follows: In this study we measure patients radiation exposure dose after interstitial {sup 125}I permanent prostate Brachytherapy implants, and correlate it with dose limits for public, total activity implanted, patient preoperative weight(1), distance between prostate walls and anterior skin surface. Methods and Material: We analyse 20 patients who were implanted with {sup 125}I seeds. The instrument used to measure radiation is a calibrated Berthold Umo LB 123 aco-plated to a LB 1236-H10 detector. Three measurements were taken: at the perineal and anterior pelvic zones on contact with the skin and at 1 m from the patient. The maximum value was taken for all measurements. The dose at a distance of one meter is obtained at anterior pelvic zone, perpendicular to the skin, according to the recommendations of A.A.P.M.(1). The distance between prostate walls was determined using post -operative CT images. Results: The doses at the perineal zone have determined an average of 186 {mu}Sv/h (range: 110 340 {mu}Sv/h) and at surface pelvic zone of 41 {mu}Sv/h (range: 15 103 {mu}Sv/h). The dose at a distance of 1 meter has an average value of 0.4 {mu}Sv/h (range: 0.2 1.0 {mu}Sv/h). The average total activity implanted was 25 mCi (range: 17 38 mCi). The distance between prostate walls and skin pelvic surface of the patients has an average value of 8.9 cm (range: 6.6 -11.5 cm). At a distance of 1 meter from the pelvic zone the dose measured is very low and below dose limits imposed by the European Directive EURATOM 2 and the Portuguese law. For general public to reach annual dose limit (EURATOM - 1 mSv/year) when contacting the pelvic zone, we extrapolate that 4 days (range: 1.6 11.1 days) would be needed, assuming a daily contact period of 6 hours. Conclusion: We established a correlation between the distance of prostate walls to the skin perineal surface and the total dose, but we find no correlation between measured doses, total activity implanted

  6. A study on image reconstruction for seed localization for permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    Hong, Ju Young; Rah, Jeong Eun; Suh, Tae Suk

    2007-01-01

    This study was to design and fabricate a phantom for prostate cancer brachytherapy to validate a developed program applying a 3-film technique, and to compare it with the conventional 2-film technique for determining the location of an implanted seed. The images were obtained from overlapped seeds by randomly placing a maximum of 63 seeds in the interior-posterior (AP) position and at -30 .deg. to 30 .deg. at 15 .deg. intervals. Images obtained by use of the phantom were applied to the image processing procedure, and were then processed into the development program for seed localization. In this study, cases were set where one seed overlapped, where two seeds overlapped and where none of the three views resolved all seeds. The distance between the centers of each seed to the reference seed was calculated in a prescribed region. This distance determined the location of each seed in a given band. The location of the overlapped seeds was compared with that of the 2-film technique. With this program, the detection rate was 92.2% (at ± 15 .deg. ), 94.1% (at ± 30 .deg.) and 70.6% (compared to the use of the 2-film technique). The overlaps were caused by one or more than two seeds that overlapped; the developed program can identify the location of each seed perfectly. However, for the third case the program was not able to resolve the overlap of the seeds. This program can be used to improve treatment outcome for the brachytherapy of prostate cancer by reducing the number of errors in the process of reconstructing the locations of perfectly overlapped seeds

  7. Seed displacements after permanent brachytherapy for prostate cancer in dependence on the prostate level

    International Nuclear Information System (INIS)

    Pinkawa, M.; Gagel, B.; Asadpour, B.; Piroth, M.D.; Klotz, J.; Eble, M.J.; Borchers, H.; Jakse, G.

    2008-01-01

    Purpose: to evaluate seed displacements after permanent prostate brachytherapy considering different prostate levels. Patients and methods: in 61 patients, postimplant CT scans were performed 1 day and 1 month after an implant with stranded seeds. Seed and prostate surface displacements were determined relative to pelvic bones. Four groups of seed locations were selected: seeds at the base (n = 305; B), at the apex (n = 305; A), close to the urethra (n = 306; U), and close to the rectal wall (n = 204; R). The length of two strands (always containing four seeds) per patient was measured in all CT scans and compared. Results: the largest inferior seed displacements were found at the base: mean 5.3 mm (B), 2.2 mm (A), 2.7 mm (U), 3.3 mm (R; p 3 vs. 41 cm 3 ; p < 0.001), a mean caudal prostate base displacement of 3.9 mm was found, whereas the mean inward displacement ranged from 1.2 to 1.6 mm at the remaining borders (lateral, anterior, posterior, apical). The analysis of the strand lengths revealed an implant compression between day 1 and 30 (mean 1.7 mm; p < 0.001). Conclusion: the largest prostate tissue and seed displacements were observed at the prostate base, associated with an implant compression. Predominantly inferior and posterior displacements implicate consequential smaller preplanning margins at the apex and the posterior prostate. (orig.)

  8. Detection and correction of patient movement in prostate brachytherapy seed reconstruction

    Science.gov (United States)

    Lam, Steve T.; Cho, Paul S.; Marks, Robert J., II; Narayanan, Sreeram

    2005-05-01

    Intraoperative dosimetry of prostate brachytherapy can help optimize the dose distribution and potentially improve clinical outcome. Evaluation of dose distribution during the seed implant procedure requires the knowledge of 3D seed coordinates. Fluoroscopy-based seed localization is a viable option. From three x-ray projections obtained at different gantry angles, 3D seed positions can be determined. However, when local anaesthesia is used for prostate brachytherapy, the patient movement during fluoroscopy image capture becomes a practical problem. If uncorrected, the errors introduced by patient motion between image captures would cause seed mismatches. Subsequently, the seed reconstruction algorithm would either fail to reconstruct or yield erroneous results. We have developed an algorithm that permits detection and correction of patient movement that may occur between fluoroscopy image captures. The patient movement is decomposed into translational shifts along the tabletop and rotation about an axis perpendicular to the tabletop. The property of spatial invariance of the co-planar imaging geometry is used for lateral movement correction. Cranio-caudal movement is corrected by analysing the perspective invariance along the x-ray axis. Rotation is estimated by an iterative method. The method can detect and correct for the range of patient movement commonly seen in the clinical environment. The algorithm has been implemented for routine clinical use as the preprocessing step for seed reconstruction.

  9. Dosimetric study of permanent prostate brachytherapy utilizing 131Cs, 125I and 103Pd seeds

    International Nuclear Information System (INIS)

    Yang Ruijie; Wang Junjie; Zhang Hongzhi

    2009-01-01

    Objective: To compare the dosimetric differences of permanent prostate brachytherapy utilizing 131 Cs, 125 I and 103 Pd seeds. Methods: Twenty-five patients with T 1 -T 2 c prostate cancer who had previously implanted with 125 I seeds were randomly selected in our study. The patients were re-planned with 131 Cs, 125 I and 103 Pd seeds by using the Prowess Brachytherapy 3.1 planning system to the prescription doses of 115 Gy, 145 Gy and 125 Gy, respectively. The seed strengths were 1.8 U,0.5 U and 1.8 U, respectively. The prostate, prostatic urethra and anterior wall of the rectum were contoured on trans-rectal ultrasound images. PTV was outlined based on the prostate volume with no margin applied. The attempted planning goals were that V 100 (the percentage volume of the prostate receiving at least 100% of the prescription doses)= 95%, D 90 (the minimum percentage dose covering 90% of the prostate volume) ≥100%, and prostatic urethra UD 10 (the maximum percentage dose receiving by 10% of the contoured urethra) ≤150%. For the plan comparison, we also computed prostate V 150 , prostatic urethra UV 120 , rectum RV 100 , and the number of implanted seeds and needles. The significance of the differences was tested using one way analysis of variance. Results: The average V 200 in the 103 Pd, 125 I and 131 Cs plans were 28.7%, 20.9% and 19.6% (F=42.50, P=0.000); the average V 150 were 51.9%, 42.1% and 39.4% (F=26.15, P=0.000); the average UV 120 were 26.9%, 29.5% and 23.8% (F=0.37, P=0.691); and the average rectum RV 100 were 0.31 cm 3 , 0.22 cm 3 and 0.19 cm 3 (F=0.43, P=0.652). For 103 Pd, 125 I and 131 Cs, the average number of implanted seeds per cm 3 prostate were 2.02, 2.01 and 1.87 (F=1.92, P=0.154), and the average number of needles were 33.6, 32.9 and 31.6 (F=0.26,P=0.772). Conclusions: Comparing to 125 I and 103 Pd seeds used in permanent prostate brachytherapy, 131 Cs seeds has better dose homogeneity, and possible better sparing of the urethra and rectum

  10. Production of Pd 103 seed from Rh targets for brachytherapy

    International Nuclear Information System (INIS)

    Afarideh, H.; Ardaneh, K.; Sadeghi, M.

    2000-01-01

    The suitability of a given radionuclide for brachytherapy is determined by its half-life, the type of energy, and abundance (number per decay) of its emission. The half-life of a radionuclide must be long enough to permit shipping and implant preparation with an acceptable loss of source strength due to decay, but it must also be short enough to permit source sizes sufficiently small for the intended application. Pd-103 is a low energy photon emitter available for permanent interstitial implantation. Pd-103 has energy and safety characteristics similar to I-125, but its initial peripheral dose rate is approximately three times greater. This may provide improved control of rapidly proliferating tumours. Although Pd-103 has been used for various kinds of cancers, it is almost exclusively used for prostate cancer, the most common cancer, and the death rate from this cancer is the highest. There are two cyclotron production routes for Pd-103, Ag (p,xn) 103 Pd and Rh (p,n) 103 Pd. For a cyclotron with low energy (such as 30Mev that we have in Iran, Karaj, NRCAM) only Rh target can be used. The target material should be deposited on a special designed Cu substrate and the separation process should isolate the desired radionuclide from target material as well as Cu. Our work plan for production of Pd 103 in Karaj, Iran, is as follows: In the first year of the CRP we are going to complete the literature survey of Pd production and perform the relevant experiments as described later. In the second year of the CRP we will construct suitable hot cells for Pd production and also do research for development of Pd seeds. In the last year of the CRP we are going to finalise all the work done during the last two years and propose the automation system for routine production

  11. Demonstration of a forward iterative method to reconstruct brachytherapy seed configurations from x-ray projections

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Martin J; Todor, Dorin A [Department of Radiation Oncology, Virginia Commonwealth University, Richmond VA 23298 (United States)

    2005-06-07

    By monitoring brachytherapy seed placement and determining the actual configuration of the seeds in vivo, one can optimize the treatment plan during the process of implantation. Two or more radiographic images from different viewpoints can in principle allow one to reconstruct the configuration of implanted seeds uniquely. However, the reconstruction problem is complicated by several factors: (1) the seeds can overlap and cluster in the images; (2) the images can have distortion that varies with viewpoint when a C-arm fluoroscope is used; (3) there can be uncertainty in the imaging viewpoints; (4) the angular separation of the imaging viewpoints can be small owing to physical space constraints; (5) there can be inconsistency in the number of seeds detected in the images; and (6) the patient can move while being imaged. We propose and conceptually demonstrate a novel reconstruction method that handles all of these complications and uncertainties in a unified process. The method represents the three-dimensional seed and camera configurations as parametrized models that are adjusted iteratively to conform to the observed radiographic images. The morphed model seed configuration that best reproduces the appearance of the seeds in the radiographs is the best estimate of the actual seed configuration. All of the information needed to establish both the seed configuration and the camera model is derived from the seed images without resort to external calibration fixtures. Furthermore, by comparing overall image content rather than individual seed coordinates, the process avoids the need to establish correspondence between seed identities in the several images. The method has been shown to work robustly in simulation tests that simultaneously allow for unknown individual seed positions, uncertainties in the imaging viewpoints and variable image distortion.

  12. Sequential evaluation of prostate edema after permanent seed prostate brachytherapy using CT-MRI fusion

    International Nuclear Information System (INIS)

    Taussky, Daniel; Austen, Lyn; Toi, Ants; Yeung, Ivan; Williams, Theresa; Pearson, Shannon; McLean, Michael; Pond, Gregory; Crook, Juanita

    2005-01-01

    Purpose: To analyze the extent and time course of prostate edema and its effect on dosimetry after permanent seed prostate brachytherapy. Methods and Materials: Twenty patients scheduled for permanent seed 125 I prostate brachytherapy agreed to a prospective study on postimplant edema. Implants were preplanned using transrectal ultrasonography. Postimplant dosimetry was calculated using computed tomography-magnetic resonance imaging (CT-MRI) fusion on the day of the implant (Day 1) and Days 8 and 30. The prostate was contoured on MRI, and the seeds were located on CT. Factors investigated for an influence on edema were the number of seeds and needles, preimplant prostate volume, transitional zone index (transition zone volume divided by prostate volume), age, and prostate-specific antigen level. Prostate dosimetry was evaluated by the percentage of the prostate volume receiving 100% of the prescribed dose (V 100 ) and percentage of prescribed dose received by 90% of the prostate volume (D 90 ). Results: Prostate edema was maximal on Day 1, with the median prostate volume 31% greater than preimplant transrectal ultrasound volume (range, 0.93-1.72; p 100 on Day 1 was 93.6% (range, 86.0-98.2%) and was 96.3% (range, 85.7-99.5%) on Day 30 (p = 0.079). Patients with a Day 1 V 100 >93% were less affected by edema resolution, showing a median increase in V 100 of 0.67% on Day 30 compared with 2.77% for patients with a V 100 100 >93%)

  13. Pulmonary embolization of permanently implanted radioactive palladium-103 seeds for carcinoma of the prostate

    International Nuclear Information System (INIS)

    Nag, Subir; Vivekanandam, Singhavajhala; Martinez-Monge, Rafael

    1997-01-01

    Purpose: It has been reported that permanently implanted iodine-125 seeds can embolize to the lungs. There is little data on the embolization of palladium-103 seeds. The purpose of this study is to collect and evaluate data on the embolization of Pd-103 seeds. Methods and Materials: The records of 112 patients implanted with Pd-103 for carcinoma of the prostate were reviewed to systemically study the incidence and dynamics of pulmonary embolism of Pd-103 seeds. Five patients had no postoperative chest radiograph and were thus excluded, leaving 107 patients for review. Results: Chest radiographs of 19 of the 107 patients showed embolized seeds in the lungs (18%). Two patients had three seeds each, nine patients had two seeds each; and in the remaining eight patients, a single seed migrated to the lungs. The seeds migrated mainly (84%) to the lower lobes. None of the eight patients who had their first postoperative chest radiograph on the day of the implant showed any embolized seeds. The embolized seed appeared only on subsequent chest radiographs taken 27 to 40 days later. Ten of the other 11 patients who had their first radiograph 1 to 97 days after brachytherapy had embolized seeds on their first chest radiograph. In the other patient, the embolized seed appeared only on a subsequent chest radiograph taken after 127 days. There were no clinical pulmonary or cardiac effects evident on routine follow-up of these patients with pulmonary embolized seeds. Conclusion: Embolization of Pd-103 seeds to the lungs after implantation for carcinoma of the prostate is an unusual event. In this study only 0.3% of the seeds implanted migrated to the lungs. Although it was previously thought that pulmonary seed migration mainly occurred on the day of brachytherapy, our experience shows that seeds usually migrated to the lungs after the day of the implant. There were no clinical pulmonary or cardiac effects attributable to embolized seeds in the lungs on routine follow-up

  14. Seed loss in prostate brachytherapy. Operator dependency and impact on dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    El-Bared, Nancy; Sebbag, Natanel; Beliveau-Nadeau, Dominic; Hervieux, Yannick; Larouche, Renee; Taussky, Daniel; Delouya, Guila [Centre hospitalier de l' Universite de Montreal - Hopital Notre-Dame, Departement de Radio-Oncologie, Montreal, QC (Canada)

    2016-05-15

    The aim of our study was to review seed loss and its impact on dosimetry as well as the influence of the treating physician on seed loss and dosimetry in patients treated with prostate brachytherapy using permanent loose {sup 125}I implant. We analyzed 1087 consecutive patients treated by two physicians between July 2005 and April 2015 at a single institution. Pelvic fluoroscopic imaging was done 30 days post implant and a chest X-ray when seed loss was observed. Seed loss occurred in 19.4 % of patients: in 20.0 % of implants done by the most experienced physician and in 17.2 % by the less experienced physician (p = 0.4) and migration to the thorax occurred in 5.9 % (6.9 vs. 2.2 %, p = 0.004). The mean seed loss rate was 0.57 % [standard deviation (SD) 1.39] and the mean rate of seeds in the thorax was 0.14 % (SD 0.65). The most experienced physician had a higher mean number of seeds lost: 0.36 versus 0.25 (p = 0.055), and a higher mean number of seed migration to the thorax: 0.1 versus 0.02 (p < 0.001). When at least one seed was lost, a decrease of 4.2 Gy (p < 0.001) in the D90 and a decrease of 3.5 % (p = 0.002) in the V150 was observed. We found a significant decrease in V150 and D90 with the occurrence of seed loss. Furthermore, we found a difference in seed migration among the physicians demonstrating that seed loss is operator dependant. (orig.) [German] Wir analysierten den Prozentsatz des Seed-Verlusts sowie den Einfluss von Arzterfahrung und Seed-Abgang auf die Dosimetrie bei Patienten, die mit einer Prostata-Brachytherapie mit permanent beweglichen {sup 125}I-Implantaten behandelt wurden. Eingeschlossen in diese Studie wurden alle zwischen Juli 2005 und April 2015 an unserem Krankenhaus von zwei Aerzten konsekutiv behandelten 1087 Patienten. Anhand fluoroskopischer Bilder wurden noch vorhandene Seeds 30 Tage nach dem Eingriff gezaehlt. Bei unvollstaendiger Seed-Anzahl wurde ein Thorax-Roentgenbild angefertigt. In 19% der Patienten ging mindestens ein

  15. Monte Carlo-aided dosimetry of the new Bebig IsoSeed registered 103Pd Interstitial Brachytherapy Seed

    International Nuclear Information System (INIS)

    Daskalov, George M.; Williamson, J.F.

    2001-01-01

    A new model 103 Pd interstitial brachytherapy source, the IsoSeed registered 103 Pd, was recently introduced by Bebig Isotopentechnik und Umweltdiagnostik GmbH for permanent implant applications. This study presents the first quantitative theoretical study of the seed's dosimetric quantities. Monte Carlo photon transport (MCPT) simulation techniques have been used to evaluate the dose-rate distributions around the model IsoSeed registered 103 Pd source in liquid water and air phantoms. These results have been used to calculate and tabulate the anisotropy function, F(r,θ), radial dose function, g(r), and anisotropy factors, φ(r), and dose-rate constant as defined by AAPM Task Group 43 (TG-43) Report. Cartesian 'away' and 'along' tables, giving the dose rates per unit air-kerma strength in water in the range 0.1-3 cm distance around the seed have also been tabulated. The dose-rate constant, Λ, was evaluated by simulating the wide-angle, free-air chamber (WAFAC) calibration geometry recently implemented by NIST (National Institute of Standards and Technology) to realize the primary standard of air-kerma strength (S K,N99 ) for low-energy photon-emitting brachytherapy sources. The dose-rate constant has been found to be Λ=0.660±0.017 in units of dose-rate per unit air-kerma strength (cGy·h-1·U-1)

  16. Permanent interstitial implantation of 125Iodine seed for thoracic malignant tumors

    International Nuclear Information System (INIS)

    Xu Zhongheng; Qian Yongyue; Wu Jinchang; Liu Zengli

    2002-01-01

    Objective: To observe effect of 125 Iodine sed on interstitial brachytherapy of patient with thoracic malignant tumor. Methods: 125 Iodine seed were inserted into the target tissue and permanent left there for brachytherapy in 6 cases of thoracic malignant tumors, which including lung cancer, Pancoast's tumour, mediastinal malignant schwannoma. Results: All cases were rehabilitated shortly after operation. The implanted lesions remained controlled now and in dead patients. No radiation-related and 125 Iodine seed-related complications occurred. Conclusion: Brachytherapy by implantation of 125 Iodine seeds of remained tumor tissue in patients with thoracic malignant tumor after operation has a satisfactory outcome. This therapy can control local recurrent of thoracic malignant tumor. But the results in long term should be studied further

  17. Indication of brachytherapy of prostate with permanent implants

    International Nuclear Information System (INIS)

    Chauveinc, L.; Solignac, S.; Rosenwald, J.C.; Firmin, F.; Cosset, J.M.; Flam, T.; Thiounn, N.

    2002-01-01

    In the last decade, brachytherapy emerged as a particularly appealing new way of treating localized prostate cancer. Recently published 10-12 years biochemical control results appear to be superimposable to the best percentages achieved by surgery or conformal radiotherapy, with a small percentage of complications. This applied to severely patients. Only patients with T1/T2, PSA 60 g, hip mobility limitations, a urinary obstructive syndrome and previous trans-urethral resection lead to difficulties in technical implantation and therefore must be taken into account when discussing brachytherapy. In conclusion, for adequately selected patients, brachytherapy offers a particularly applied alternative to surgery and external radiotherapy, with satisfactory long term biochemical control rates and limited complications. (author)

  18. WE-DE-201-12: Thermal and Dosimetric Properties of a Ferrite-Based Thermo-Brachytherapy Seed

    International Nuclear Information System (INIS)

    Warrell, G; Shvydka, D; Parsai, E I

    2016-01-01

    Purpose: The novel thermo-brachytherapy (TB) seed provides a simple means of adding hyperthermia to LDR prostate permanent implant brachytherapy. The high blood perfusion rate (BPR) within the prostate motivates the use of the ferrite and conductive outer layer design for the seed cores. We describe the results of computational analyses of the thermal properties of this ferrite-based TB seed in modelled patient-specific anatomy, as well as studies of the interseed and scatter (ISA) effect. Methods: The anatomies (including the thermophysical properties of the main tissue types) and seed distributions of 6 prostate patients who had been treated with LDR brachytherapy seeds were modelled in the finite element analysis software COMSOL, using ferrite-based TB and additional hyperthermia-only (HT-only) seeds. The resulting temperature distributions were compared to those computed for patient-specific seed distributions, but in uniform anatomy with a constant blood perfusion rate. The ISA effect was quantified in the Monte Carlo software package MCNP5. Results: Compared with temperature distributions calculated in modelled uniform tissue, temperature distributions in the patient-specific anatomy were higher and more heterogeneous. Moreover, the maximum temperature to the rectal wall was typically ∼1 °C greater for patient-specific anatomy than for uniform anatomy. The ISA effect of the TB and HT-only seeds caused a reduction in D90 similar to that found for previously-investigated NiCu-based seeds, but of a slightly smaller magnitude. Conclusion: The differences between temperature distributions computed for uniform and patient-specific anatomy for ferrite-based seeds are significant enough that heterogeneous anatomy should be considered. Both types of modelling indicate that ferrite-based seeds provide sufficiently high and uniform hyperthermia to the prostate, without excessively heating surrounding tissues. The ISA effect of these seeds is slightly less than that

  19. WE-DE-201-12: Thermal and Dosimetric Properties of a Ferrite-Based Thermo-Brachytherapy Seed

    Energy Technology Data Exchange (ETDEWEB)

    Warrell, G; Shvydka, D; Parsai, E I [University of Toledo Medical Center, Toledo, OH (United States)

    2016-06-15

    Purpose: The novel thermo-brachytherapy (TB) seed provides a simple means of adding hyperthermia to LDR prostate permanent implant brachytherapy. The high blood perfusion rate (BPR) within the prostate motivates the use of the ferrite and conductive outer layer design for the seed cores. We describe the results of computational analyses of the thermal properties of this ferrite-based TB seed in modelled patient-specific anatomy, as well as studies of the interseed and scatter (ISA) effect. Methods: The anatomies (including the thermophysical properties of the main tissue types) and seed distributions of 6 prostate patients who had been treated with LDR brachytherapy seeds were modelled in the finite element analysis software COMSOL, using ferrite-based TB and additional hyperthermia-only (HT-only) seeds. The resulting temperature distributions were compared to those computed for patient-specific seed distributions, but in uniform anatomy with a constant blood perfusion rate. The ISA effect was quantified in the Monte Carlo software package MCNP5. Results: Compared with temperature distributions calculated in modelled uniform tissue, temperature distributions in the patient-specific anatomy were higher and more heterogeneous. Moreover, the maximum temperature to the rectal wall was typically ∼1 °C greater for patient-specific anatomy than for uniform anatomy. The ISA effect of the TB and HT-only seeds caused a reduction in D90 similar to that found for previously-investigated NiCu-based seeds, but of a slightly smaller magnitude. Conclusion: The differences between temperature distributions computed for uniform and patient-specific anatomy for ferrite-based seeds are significant enough that heterogeneous anatomy should be considered. Both types of modelling indicate that ferrite-based seeds provide sufficiently high and uniform hyperthermia to the prostate, without excessively heating surrounding tissues. The ISA effect of these seeds is slightly less than that

  20. Operator-free, film-based 3D seed reconstruction in brachytherapy

    International Nuclear Information System (INIS)

    Todor, D.A.; Cohen, G.N.; Amols, H.I.; Zaider, M.

    2002-01-01

    In brachytherapy implants, the accuracy of dose calculation depends on the ability to localize radioactive sources correctly. If performed manually using planar images, this is a time-consuming and often error-prone process - primarily because each seed must be identified on (at least) two films. In principle, three films should allow automatic seed identification and position reconstruction; however, practical implementation of the numerous algorithms proposed so far appears to have only limited reliability. The motivation behind this work is to create a fast and reliable system for real-time implant evaluation using digital planar images obtained from radiotherapy simulators, or mobile x-ray/fluoroscopy systems. We have developed algorithms and code for 3D seed coordinate reconstruction. The input consists of projections of seed positions in each of three isocentric images taken at arbitrary angles. The method proposed here consists of a set of heuristic rules (in a sense, a learning algorithm) that attempts to minimize seed misclassifications. In the clinic, this means that the system must be impervious to errors resulting from patient motion as well as from finite tolerances accepted in equipment settings. The software program was tested with simulated data, a pelvic phantom and patient data. One hundred and twenty permanent prostate implants were examined (105 125 I and 15 103 Pd) with the number of seeds ranging from 35 to 138 (average 79). The mean distance between actual and reconstructed seed positions is in the range 0.03-0.11 cm. On a Pentium III computer at 600 MHz the reconstruction process takes 10-30 s. The total number of seeds is independently validated. The process is robust and able to account for errors introduced in the clinic. (author)

  1. Seed displacements after permanent brachytherapy for prostate cancer in dependence on the prostate level

    Energy Technology Data Exchange (ETDEWEB)

    Pinkawa, M.; Gagel, B.; Asadpour, B.; Piroth, M.D.; Klotz, J.; Eble, M.J. [Dept. of Radiotherapy, RWTH Aachen (Germany); Borchers, H.; Jakse, G. [Dept. of Urology, RWTH Aachen (Germany)

    2008-10-15

    Purpose: to evaluate seed displacements after permanent prostate brachytherapy considering different prostate levels. Patients and methods: in 61 patients, postimplant CT scans were performed 1 day and 1 month after an implant with stranded seeds. Seed and prostate surface displacements were determined relative to pelvic bones. Four groups of seed locations were selected: seeds at the base (n = 305; B), at the apex (n = 305; A), close to the urethra (n = 306; U), and close to the rectal wall (n = 204; R). The length of two strands (always containing four seeds) per patient was measured in all CT scans and compared. Results: the largest inferior seed displacements were found at the base: mean 5.3 mm (B), 2.2 mm (A), 2.7 mm (U), 3.3 mm (R; p < 0.001). Posterior displacements predominated both at the base and the central region: mean 2.2 mm (B), 2.0 mm (U), 0.8 mm (A), -0.6 mm (R; p < 0.001). With a decreasing edema between day 1 and 30 (mean prostate volume of 51 cm{sup 3} vs. 41 cm{sup 3}; p < 0.001), a mean caudal prostate base displacement of 3.9 mm was found, whereas the mean inward displacement ranged from 1.2 to 1.6 mm at the remaining borders (lateral, anterior, posterior, apical). The analysis of the strand lengths revealed an implant compression between day 1 and 30 (mean 1.7 mm; p < 0.001). Conclusion: the largest prostate tissue and seed displacements were observed at the prostate base, associated with an implant compression. Predominantly inferior and posterior displacements implicate consequential smaller preplanning margins at the apex and the posterior prostate. (orig.)

  2. Operator-free, film-based 3D seed reconstruction in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Todor, D.A.; Cohen, G.N.; Amols, H.I.; Zaider, M. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2002-06-21

    In brachytherapy implants, the accuracy of dose calculation depends on the ability to localize radioactive sources correctly. If performed manually using planar images, this is a time-consuming and often error-prone process - primarily because each seed must be identified on (at least) two films. In principle, three films should allow automatic seed identification and position reconstruction; however, practical implementation of the numerous algorithms proposed so far appears to have only limited reliability. The motivation behind this work is to create a fast and reliable system for real-time implant evaluation using digital planar images obtained from radiotherapy simulators, or mobile x-ray/fluoroscopy systems. We have developed algorithms and code for 3D seed coordinate reconstruction. The input consists of projections of seed positions in each of three isocentric images taken at arbitrary angles. The method proposed here consists of a set of heuristic rules (in a sense, a learning algorithm) that attempts to minimize seed misclassifications. In the clinic, this means that the system must be impervious to errors resulting from patient motion as well as from finite tolerances accepted in equipment settings. The software program was tested with simulated data, a pelvic phantom and patient data. One hundred and twenty permanent prostate implants were examined (105{sup 125}I and 15{sup 103}Pd) with the number of seeds ranging from 35 to 138 (average 79). The mean distance between actual and reconstructed seed positions is in the range 0.03-0.11 cm. On a Pentium III computer at 600 MHz the reconstruction process takes 10-30 s. The total number of seeds is independently validated. The process is robust and able to account for errors introduced in the clinic. (author)

  3. Dosimetric comparison of seed strength for I-125 prostate implants

    International Nuclear Information System (INIS)

    Elliott, S.; Droege, J.; Beaufort, C.

    2004-01-01

    Full text: The strength of 1-125 seeds for prostate brachytherapy has been a topic of increasing popularity in the literature over the last few years. Recent reports, which include planning and clinical studies, compare dosimetry between plans and implants using higher (0.5 - 0.8 U, where IU = I μGym 2 h -1 ) or lower (0.3 - 0.4 U) seed strength. The majority of these studies support higher seed strengths for obtaining optimal dosimetry. At the WBRC, a seed air kerma strength of just under 0.4 U is currently used for seed implants. The purpose of this work is to investigate the use of higher strength seeds for our prostate implants. Twenty-four patients were selected according to prostate size, and re-planned using a seed strength of 0.5 U or 0.6 U. Planning was performed following our standard preplanning guidelines as closely as possible; that is, manual planning using a modified Seattle approach and dosimetry limits for the target volume of D 100 : > 95 Gy, v 100 > 98 %, V 150 : 52 - 62 % and V 200 : 11 - 16 %. Dosimetry from the original preplans was then compared to the dosimetry from the re-planned cases. Satisfactory dosimetry was obtained using 0.5 U or 0.6 U strength seeds. Seed placement was typically around the periphery of the target on all slices, to avoid overdosing the urethra. The mean D 100 (Gy) is marginally improved with the higher seed strength. As expected, the V200 (%) is also higher. The mean number of seeds required per implant decreased by 16 % and 28 % for 0.5 U and 0.6 U seeds respectively. The mean number of needles decreased by 7 needles for 0.6 U seeds, however only by 3 needles for 0.5 U seeds. Rectal doses, when using the higher strength seeds, were easily constrained to less than the original preplan doses. Although there was no apparent trend in dosimetry statistics with volume size, as a function of seed strength, it was noted that the reduction in needle and seed number was most significant for medium and large target volumes. A

  4. Prostate cancer brachytherapy

    International Nuclear Information System (INIS)

    Abreu, Carlos Eduardo Vita; Silva, Joao L. F.; Srougi, Miguel; Nesrallah, Adriano

    1999-01-01

    The transperineal brachytherapy with 125 I/Pd 103 seed implantation guided by transurethral ultrasound must be presented as therapeutical option of low urinary morbidity in patients with localized prostate cancer. The combined clinical staging - including Gleason and initial PSA - must be encouraged, for definition of a group of low risk and indication of exclusive brachytherapy. Random prospective studies are necessary in order to define the best role of brachytherapy, surgery and external beam radiation therapy

  5. Computational and Experimental Evaluations of a Novel Thermo-Brachytherapy Seed for Treatment of Solid Tumors

    Science.gov (United States)

    Warrell, Gregory R.

    Hyperthermia has long been known as a radiation therapy sensitizer of high potential; however successful delivery of this modality and integrating it with radiation have often proved technically difficult. We present the dual-modality thermobrachytherapy (TB) seed, based on the ubiquitous low dose-rate (LDR) brachytherapy permanent implant, as a simple and effective combination of hyperthermia and radiation therapy. Heat is generated from a ferromagnetic or ferrimagnetic core within the seed, which produces Joule heating by eddy currents. A strategically-selected Curie temperature provides thermal self-regulation. In order to obtain a uniform and sufficiently high temperature distribution, additional hyperthermia-only (HT-only) seeds are proposed to be used in vacant spots within the needles used to implant the TB seeds; this permits a high seed density without the use of additional needles. Experimental and computational studies were done both to optimize the design of the TB and HT-only seeds and to quantitatively assess their ability to heat and irradiate defined, patient-specific targets. Experiments were performed with seed-sized ferromagnetic samples in tissue-mimicking phantoms heated by an industrial induction heater. The magnetic and thermal properties of the seeds were studied computationally in the finite element analysis (FEA) solver COMSOL Multiphysics, modelling realistic patient-specific seed distributions. These distributions were derived from LDR permanent prostate implants previously conducted at our institution; various modifications of the seeds' design were studied. The calculated temperature distributions were analyzed by generating temperature-volume histograms, which were used to quantify coverage and temperature homogeneity for a range of blood perfusion rates, as well as for a range of seed Curie temperatures and thermal power production rates. The impact of the interseed attenuation and scatter (ISA) effect on radiation dose distributions

  6. Radioactive ceramic seeds with Ho-166 and Sm-153 with perspective of use in brachytherapy

    International Nuclear Information System (INIS)

    Valente, Eduardo Sarmento

    2010-01-01

    rates calculated at a distance of one meter ranged between 0.081 and 0.159.μS/h.seed. The results showed that the ceramic seeds produced have physical and chemical characteristics suitable for the proposed use in brachytherapy as small dimensions, appropriate concentration of target atoms of samarium and holmium or no dispersal of radioactive material in body fluid during the first ten days of immersion. The experiments also showed that the concentration of these elements in the ceramic matrix is sufficient to be activated in low neutron flux reactors, generating sufficient radioactivity for brachytherapy in high dose rates. The results obtained in vitro experiments were encouraging and demonstrated the ability that seeds, with β-emitting elements, have to eliminate tumor cells. The range of β radiation in biological experiments in vitro was consistent with the theoretical value and may be used as reference for the seed spacing when implanted in vivo. The solubility characteristics of radioactive nuclides in simulated body fluid in the short and long term, demonstrated that in the early days, there is no measurable solubilization. Indications were obtained that the seed dissolves measurably after a few months immersed in simulated body fluid. Finally it could be seen that the radioactive ceramic seeds with β emitters have favorable perspectives for use in high dose rate brachytherapy. (author)

  7. Prostate-specific antigen density is predictive of outcome in suboptimal prostate seed brachytherapy.

    Science.gov (United States)

    Benzaquen, David; Delouya, Guila; Ménard, Cynthia; Barkati, Maroie; Taussky, Daniel

    In prostate seed brachytherapy, a D 90 of prostate-specific antigen + 2). Univariate and multivariate analyses were performed, adjusting for known prognostic factors such as D 90 and prostate-specific antigen density (PSAD) of ≥0.15 ng/mL/cm 3 , to evaluate their ability to predict BF. Median followup for patients without BF was 72 months (interquartile range 56-96). BF-free recurrence rate at 5 years was 95% and at 8 years 88%. In univariate analysis, PSAD and cancer of the prostate risk assessment score were predictive of BF. On multivariate analysis, none of the factors remained significant. The best prognosis had patients with a low PSAD (<0.15 ng/mL/cm 3 ) and an optimal implant at 30 days after implantation (as defined by D 90  ≥ 130 Gy) compared to patients with both factors unfavorable (p = 0.006). A favorable PSAD was associate with a good prognosis, independently of the D 90 (<130 Gy vs. ≥130 Gy, p = 0.7). Patients with a PSAD of <0.15 ng/mL/cm 3 have little risk of BF, even in the case of a suboptimal implant. These results need to be validated in other patients' cohorts. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  8. On the use of Kodak CR film for quality assurance of needle loading in I-125 seed prostate brachytherapy.

    Science.gov (United States)

    Fog, L S; Nicholls, R; van Doom, T

    2007-09-01

    Low dose rate brachytherapy using implanted I-125 seeds as a monotherapy for prostate cancer is now in use in many hospitals. In contrast to fractionated brachytherapy treatments, where the effect of incorrect positioning of the source in one treatment fraction can be diminished by correcting the position in subsequent fractions, the I-125 seed implant is permanent, making correct positioning of the seeds in the prostate essential. The seeds are inserted into the prostate using needles. Correct configuration of seeds in the needles is essential in order to deliver the planned treatment. A comparison of an autoradiograph obtained by exposing film to the seed-loaded needles with the patient treatment plan is a valuable quality assurance tool. However, the time required to sufficiently expose Kodak XOMAT V film, currently used in this department is significant. This technical note presents the use of Kodak CR film for acquisition of the radiograph. The digital radiograph can be acquired significantly faster, has superior signal-to-noise ratio and contrast and has the usual benefits of digital film, e.g. a processing time which is shorter than that required for non-digital film, the possibility of image manipulation, possibility of paper printing and electronic storage.

  9. Deterministic calculations of radiation doses from brachytherapy seeds

    International Nuclear Information System (INIS)

    Reis, Sergio Carneiro dos; Vasconcelos, Vanderley de; Santos, Ana Maria Matildes dos

    2009-01-01

    Brachytherapy is used for treating certain types of cancer by inserting radioactive sources into tumours. CDTN/CNEN is developing brachytherapy seeds to be used mainly in prostate cancer treatment. Dose calculations play a very significant role in the characterization of the developed seeds. The current state-of-the-art of computation dosimetry relies on Monte Carlo methods using, for instance, MCNP codes. However, deterministic calculations have some advantages, as, for example, short computer time to find solutions. This paper presents a software developed to calculate doses in a two-dimensional space surrounding the seed, using a deterministic algorithm. The analysed seeds consist of capsules similar to IMC6711 (OncoSeed), that are commercially available. The exposure rates and absorbed doses are computed using the Sievert integral and the Meisberger third order polynomial, respectively. The software also allows the isodose visualization at the surface plan. The user can choose between four different radionuclides ( 192 Ir, 198 Au, 137 Cs and 60 Co). He also have to enter as input data: the exposure rate constant; the source activity; the active length of the source; the number of segments in which the source will be divided; the total source length; the source diameter; and the actual and effective source thickness. The computed results were benchmarked against results from literature and developed software will be used to support the characterization process of the source that is being developed at CDTN. The software was implemented using Borland Delphi in Windows environment and is an alternative to Monte Carlo based codes. (author)

  10. Deformable registration of x-ray to MRI for post-implant dosimetry in prostate brachytherapy

    Science.gov (United States)

    Park, Seyoun; Song, Danny Y.; Lee, Junghoon

    2016-03-01

    Post-implant dosimetric assessment in prostate brachytherapy is typically performed using CT as the standard imaging modality. However, poor soft tissue contrast in CT causes significant variability in target contouring, resulting in incorrect dose calculations for organs of interest. CT-MR fusion-based approach has been advocated taking advantage of the complementary capabilities of CT (seed identification) and MRI (soft tissue visibility), and has proved to provide more accurate dosimetry calculations. However, seed segmentation in CT requires manual review, and the accuracy is limited by the reconstructed voxel resolution. In addition, CT deposits considerable amount of radiation to the patient. In this paper, we propose an X-ray and MRI based post-implant dosimetry approach. Implanted seeds are localized using three X-ray images by solving a combinatorial optimization problem, and the identified seeds are registered to MR images by an intensity-based points-to-volume registration. We pre-process the MR images using geometric and Gaussian filtering. To accommodate potential soft tissue deformation, our registration is performed in two steps, an initial affine transformation and local deformable registration. An evolutionary optimizer in conjunction with a points-to-volume similarity metric is used for the affine registration. Local prostate deformation and seed migration are then adjusted by the deformable registration step with external and internal force constraints. We tested our algorithm on six patient data sets, achieving registration error of (1.2+/-0.8) mm in < 30 sec. Our proposed approach has the potential to be a fast and cost-effective solution for post-implant dosimetry with equivalent accuracy as the CT-MR fusion-based approach.

  11. Comparative dosimetry of prostate brachytherapy with I-125 and Pd-103 seeds via SISCODES/MCNP

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, Bruno Machado; Falcao, Patricia Lima, E-mail: bmtrindade@yahoo.com [Nucleo de Radiacoes Ionizantes - Universidade Federal de Minas Gerais (NRI/UFMG), Belo Horizonte, MG (Brazil); Christovao, Marilia Tavares [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Trindade, Daniela de Fatima Maia [Centro Universitario Una, Belo Horizonte, MG (Brazil); Campos, Tarcisio Passos Ribeiro de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2012-09-15

    Objective: The present paper is aimed at presenting a comparative dosimetric study of prostate brachytherapy with I-125 and Pd-103 seeds. Materials and Methods: A protocol for both implants with 148 seeds was simulated on a heterogeneous three-dimensional pelvic phantom by means of the SISCODES/MCNP5 codes. Dose-volume histograms on prostate, rectum and bladder, dose indexes D10, D30, D90, D0.5cc, D2cc and D7cc, and representations of the spatial dose distribution were evaluated. Results: For a D90 index equivalent to the prescription dose, the initial activity of each I-125 seed was calculated as 0.42 mCi and of Pd-103 as 0.94 mCi. The maximum dose on the urethra was 90% and 108% of the prescription dose for I-125 and Pd-103, respectively. The D2cc for I-125 was 30 Gy on the rectum and 127 Gy on the bladder; for Pd-103 was 29 Gy on the rectum and 189 Gy on the bladder. The D10 on the pubic bone was 144 Gy for I-125 and 66 Gy for Pd-103. Conclusion: The results indicate that Pd-103 and I-125 implants could deposit the prescribed dose on the target volume. Among the findings of the present study, there is an excessive radiation exposure of the pelvic bones, particularly with the I-125 protocol. (author)

  12. Histology study on the dorsal root ganglia of rats with 125I seed brachytherapy at intervertebral foramen

    International Nuclear Information System (INIS)

    Zhang Wenyi; Wang Huixing; Ding Yanqiu; Qu Ximei; Wang Liqin; Liu Zhongchao; Cui Songye; Jiao Ling

    2012-01-01

    Objective: To investigate the effect of the histological changes on rat dorsal root ganglia (DRG) after 125 I seed brachytherapy.Methods Twelve adult male Sprague-Dawley rats (150-180 g each) were randomly divided into 6 groups, 125 I seeds with different activities of 0 (Titanium shell), 14.8, 18.5, 22.2, 25.9 and 29.6 MBq were implanted to 6 groups of rats respectively and the behavioral changes of rats were observed. The rats were killed in different periods after implantation,the morphological changes in DRG and surrounding muscle tissue were observed with an Olympus BX51 optical microscope and then the irradiation doses were estimated. Results: After 125 I seed implantation, the movement function of rats was not affected and the weight of rats gained after 7 days. After the titanium shell implantation, very few mild swelling was induced in neuroganglion cells that still had clear nucleolus and normal cytoplasm. At 14 days after 18.5 MBq seed implantation, cell swelling was more serious and cell dehydrating, nuclear condensation and nuclear fragmentation appeared after 30 days. At 60 days after 29.6 MBq of seed implantation, nuclear dissolution and cytoplasmic shrinkage were induced in a large number of cells.In general, the severity of fibrosis was aggravated with the time post-irradiation and the dose in the muscles around the ganglion. Conclusions: After 125 I seed implantation,the injury degree of DRG tissue is dose-dependent, and the 125 I seed irradiation would have analgesic effect on releasing intractable pain. (authors)

  13. Complementary method of analyzing the quality of the implant I-125 seeds for prostate brachytherapy using ultrasound imaging post-implant; Metodo complementario de analisis de la calidad del implante de semillas de I-125 para braquiterapia de prostata mediante la adquisicion de imagenes ecograficas post-implante

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Dominguez, M.; Carrasco Herrera, M.; Baeza Trujillo, M.; Herrador Cordoba, M.

    2011-07-01

    In this paper we propose a complementary method based on Longitudinal mode ultrasound images acquired the same day of surgery, at the end of the implant. This option will allow us to evaluate the dosimetry end of treatment with the patient in the same position he was planning and to the rectum and bladder just as full. This will permit the identification of bodies and the seeds of interest more easily and will have a reference with which to compare one month later, when the CT images can also detect whether there has been some migration.

  14. Dose optimization in simulated permanent interstitial implant of prostate brachytherapy

    International Nuclear Information System (INIS)

    Faria, Fernando Pereira de

    2006-01-01

    Any treatment of cancer that uses some modality of radiotherapy is planned before being executed. In general the goal in radiotherapy is to irradiate the target to be treated minimizing the incidence of radiation in healthy surrounding tissues. The planning differ among themselves according to the modality of radiotherapy, the type of cancer and where it is located. This work approaches the problem of dose optimization for the planning of prostate cancer treatment through the modality of low dose-rate brachytherapy with Iodine 125 or Palladium 103 seeds. An algorithm for dose calculation and optimization was constructed to find the seeds configuration that better fits the relevant clinical criteria such as as the tolerated dose by the urethra and rectum and the desired dose for prostate. The algorithm automatically finds this configuration from the prostate geometry established in two or three dimensions by using images of ultrasound, magnetic resonance or tomography and from the establishment of minimum restrictions to the positions of the seeds in the prostate and needles in a template. Six patterns of seeds distribution based on clinical criteria were suggested and tested in this work. Each one of these patterns generated a space of possible seeds configurations for the prostate tested by the dose calculation and optimization algorithm. The configurations that satisfied the clinical criteria were submitted to a test according to an optimization function suggested in this work. The configuration that produced maximum value for this function was considered the optimized one. (author)

  15. Clinical application and validation of an iterative forward projection matching algorithm for permanent brachytherapy seed localization from conebeam-CT x-ray projections

    Energy Technology Data Exchange (ETDEWEB)

    Pokhrel, Damodar; Murphy, Martin J.; Todor, Dorin A.; Weiss, Elisabeth; Williamson, Jeffrey F. [Department of Radiation Oncology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

    2010-09-15

    Purpose: To experimentally validate a new algorithm for reconstructing the 3D positions of implanted brachytherapy seeds from postoperatively acquired 2D conebeam-CT (CBCT) projection images. Methods: The iterative forward projection matching (IFPM) algorithm finds the 3D seed geometry that minimizes the sum of the squared intensity differences between computed projections of an initial estimate of the seed configuration and radiographic projections of the implant. In-house machined phantoms, containing arrays of 12 and 72 seeds, respectively, are used to validate this method. Also, four {sup 103}Pd postimplant patients are scanned using an ACUITY digital simulator. Three to ten x-ray images are selected from the CBCT projection set and processed to create binary seed-only images. To quantify IFPM accuracy, the reconstructed seed positions are forward projected and overlaid on the measured seed images to find the nearest-neighbor distance between measured and computed seed positions for each image pair. Also, the estimated 3D seed coordinates are compared to known seed positions in the phantom and clinically obtained VariSeed planning coordinates for the patient data. Results: For the phantom study, seed localization error is (0.58{+-}0.33) mm. For all four patient cases, the mean registration error is better than 1 mm while compared against the measured seed projections. IFPM converges in 20-28 iterations, with a computation time of about 1.9-2.8 min/iteration on a 1 GHz processor. Conclusions: The IFPM algorithm avoids the need to match corresponding seeds in each projection as required by standard back-projection methods. The authors' results demonstrate {approx}1 mm accuracy in reconstructing the 3D positions of brachytherapy seeds from the measured 2D projections. This algorithm also successfully localizes overlapping clustered and highly migrated seeds in the implant.

  16. Clinical application and validation of an iterative forward projection matching algorithm for permanent brachytherapy seed localization from conebeam-CT x-ray projections.

    Science.gov (United States)

    Pokhrel, Damodar; Murphy, Martin J; Todor, Dorin A; Weiss, Elisabeth; Williamson, Jeffrey F

    2010-09-01

    To experimentally validate a new algorithm for reconstructing the 3D positions of implanted brachytherapy seeds from postoperatively acquired 2D conebeam-CT (CBCT) projection images. The iterative forward projection matching (IFPM) algorithm finds the 3D seed geometry that minimizes the sum of the squared intensity differences between computed projections of an initial estimate of the seed configuration and radiographic projections of the implant. In-house machined phantoms, containing arrays of 12 and 72 seeds, respectively, are used to validate this method. Also, four 103Pd postimplant patients are scanned using an ACUITY digital simulator. Three to ten x-ray images are selected from the CBCT projection set and processed to create binary seed-only images. To quantify IFPM accuracy, the reconstructed seed positions are forward projected and overlaid on the measured seed images to find the nearest-neighbor distance between measured and computed seed positions for each image pair. Also, the estimated 3D seed coordinates are compared to known seed positions in the phantom and clinically obtained VariSeed planning coordinates for the patient data. For the phantom study, seed localization error is (0.58 +/- 0.33) mm. For all four patient cases, the mean registration error is better than 1 mm while compared against the measured seed projections. IFPM converges in 20-28 iterations, with a computation time of about 1.9-2.8 min/ iteration on a 1 GHz processor. The IFPM algorithm avoids the need to match corresponding seeds in each projection as required by standard back-projection methods. The authors' results demonstrate approximately 1 mm accuracy in reconstructing the 3D positions of brachytherapy seeds from the measured 2D projections. This algorithm also successfully localizes overlapping clustered and highly migrated seeds in the implant.

  17. A novel curvilinear approach for prostate seed implantation

    Energy Technology Data Exchange (ETDEWEB)

    Podder, Tarun K.; Dicker, Adam P.; Hutapea, Parsaoran; Darvish, Kurosh; Yu Yan [Department of Radiation Oncology, Leo Jenkins Cancer Center, Brody School of Medicine, East Carolina University, Greenville, North Carolina 27834 (United States); Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Department of Mechanical Engineering, Temple University, Philadelphia, Pennsylvania 19122 (United States); Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States)

    2012-04-15

    Purpose: A new technique called ''curvilinear approach'' for prostate seed implantation has been proposed. The purpose of this study is to evaluate the dosimetric benefit of curvilinear distribution of seeds for low-dose-rate (LDR) prostate brachytherapy. Methods: Twenty LDR prostate brachytherapy cases planned intraoperatively with VariSeed planning system and I-125 seeds were randomly selected as reference rectilinear cases. All the cases were replanned by using curved-needle approach keeping the same individual source strength and the volume receiving 100% of prescribed dose 145 Gy (V{sub 100}). Parameters such as number of needles, seeds, and the dose coverage of the prostate (D{sub 90}, V{sub 150}, V{sub 200}), urethra (D{sub 30}, D{sub 10}) and rectum (D{sub 5}, V{sub 100}) were compared for the rectilinear and the curvilinear methods. Statistical significance was assessed using two-tailed student's t-test. Results: Reduction of the required number of needles and seeds in curvilinear method were 30.5% (p < 0.001) and 11.8% (p < 0.49), respectively. Dose to the urethra was reduced significantly; D{sub 30} reduced by 10.1% (p < 0.01) and D{sub 10} reduced by 9.9% (p < 0.02). Reduction in rectum dose D{sub 5} was 18.5% (p < 0.03) and V{sub 100} was also reduced from 0.93 cc in rectilinear to 0.21 cc in curvilinear (p < 0.001). Also the V{sub 150} and V{sub 200} coverage of prostate reduced by 18.8% (p < 0.01) and 33.9% (p < 0.001), respectively. Conclusions: Significant improvement in the relevant dosimetric parameters was observed in curvilinear needle approach. Prostate dose homogeneity (V{sub 150}, V{sub 200}) improved while urethral dose was reduced, which might potentially result in better treatment outcome. Reduction in rectal dose could potentially reduce rectal toxicity and complications. Reduction in number of needles would minimize edema and thereby could improve postimplant urinary incontinence. This study indicates that the

  18. Dosimetric study in iodine-125 seeds for brachytherapy application

    International Nuclear Information System (INIS)

    Zeituni, Carlos Alberto

    2008-01-01

    The demand for iodine-125 seeds for use in brachytherapy treatments has experienced an increase along recent years in Brazil and all over the world. All iodine-125 seed must have its operational parameters measured and/or calculated every time changes in the production process are carried out. A complete dosimetric measurement is very expensive, and it is recommended that this procedure must be repeated at least once a year. Thus, this work developed a methodology for the entire dosimetric process. This methodology is based on the scarce information available in the literature, once almost all the methodology used in large industrial laboratories is commercial secret. The proposed methodology was tested using seeds of Amersham-Oncura-Ge Healthcare, which is the largest seed manufactory in the world. In this new methodology, an automatic reader was employed in order to reduce the time required in the selection process of the TLD-100 dosimeters used and a postprocessing of the obtained spectra was carried out. A total of 142 dosimeters were used and only 29 have been selected using the new methodology. Measurements were performed using slabs of Solid Water RW1 to simulate measuring in the 'water', using three different experimental apparatus and each measurement was repeated at least three times. The TLD-100 calibration was performed using a Dermopan II - Siemens. The measured values showed a good agreement with the ones available in the literature. Finally, these measured values were compared with calculated ones obtained by a semiempirical simulation program, showing a good agreement and, therefore, demonstrating the validity of the proposed methodology regarding dosimetric calculations. (author)

  19. Radiobiologically based treatment plan evaluation for prostate seed implants

    Directory of Open Access Journals (Sweden)

    Sotirios Stathakis

    2011-07-01

    Full Text Available Purpose: Accurate prostate low dose-rate brachytherapy treatment plan evaluation is important for future care decisions. Presently, an evaluation is based on dosimetric quantifiers for the tumor and organs at risk. However, these do not account for effects of varying dose-rate, tumor repopulation and other biological effects. In this work, incorporation of the biological response is used to obtain more clinically relevant treatment plan evaluation.Material and methods: Eleven patients were evaluated. Each patient received a 145 Gy implant. Iodine-125 seeds were used and the treatment plans were created on the Prowess system. Based on CT images the post-implant plan was created. In the post-plan, the tumor, urethra, bladder and rectum were contoured. The biologically effective dose was used to determine the tumor control probability and the normal tissue complication probabilities for the urethra, bladder, rectum and surrounding tissue. Results: The average tumor control probability and complication probabilities for the urethra, bladder, rectum and surrounding tissue were 99%, 29%, 0%, 12% and 6%, respectively. These measures provide a simpler means for evaluation and since they include radiobiological factors, they provide more reliable estimation of the treatment outcome. Conclusions: The goal of this work was to create more clinically relevant prostate seed-implant evaluation by incorporating radiobiological measures. This resulted in a simpler descriptor of treatment plan quality and was consistent with patient outcomes.

  20. Development of irradiation support devices for production of brachytherapy seeds

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Fabio R.; Rostelato, Maria Elisa C.M.; Zeituni, Carlos A.; Souza, Carla D.; Moura, Joao A.; Peleias Junior, Fernando S.; Karan Junior, Dib; Feher, Anselmo; Oliveira, Tiago B.; Benega, Marcos A.G., E-mail: tiagooliveira298@gmail.com, E-mail: mattos.fr@gmail.com, E-mail: elisaros@ipen.br, E-mail: czeituni@ipen.br, E-mail: carladdsouza@yahoo.com.br, E-mail: jamoura@ipen.br, E-mail: ernandopeleias@gmail.com, E-mail: s, E-mail: dib.karan@usp.br, E-mail: afeher@ipen.br, E-mail: marcosagbenega@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Ophthalmic tumors treatment with brachytherapy sources has been widely used as a primary or secondary therapy for non-malignant or malignant tumors, for example, choroid melanoma, and retinoblastoma. Ruthenium-106, Iodine-125, Palladium -103, Gold-198 and Iridium-192, are some radionuclides that can be applied for treatment of ocular tumors. These sources are in small sizes (a few millimeters) and different shapes (rods, wires, disks). To ensure high accuracy during treatment, they are positioned in eye applicators, specially designed to fit on the surface of tumor. The Nuclear and Energy Research Institute (IPEN/CNEN) in a partnership with Paulista Medicine School (UNIFESP) created a project that aims to develop a prototype of Iridium-192 seeds for treatment of eye cancer. This seed consists in a core of Ir -Pt alloy (20%-80%) with a length of 3 mm, to be activated in IPEN's IEA-R1 Reactor, and a titanium capsule sealing the core. It was imperative to develop a sustainer device for irradiation. This piece is used to avoid overlapping of one cores and, therefore, avoiding the 'shadow effect' that does not allow full activation of each core due to the high density. (author)

  1. Development of irradiation support devices for production of brachytherapy seeds

    International Nuclear Information System (INIS)

    Mattos, Fabio R.; Rostelato, Maria Elisa C.M.; Zeituni, Carlos A.; Souza, Carla D.; Moura, Joao A.; Peleias Junior, Fernando S.; Karan Junior, Dib; Feher, Anselmo; Oliveira, Tiago B.; Benega, Marcos A.G.

    2013-01-01

    Ophthalmic tumors treatment with brachytherapy sources has been widely used as a primary or secondary therapy for non-malignant or malignant tumors, for example, choroid melanoma, and retinoblastoma. Ruthenium-106, Iodine-125, Palladium -103, Gold-198 and Iridium-192, are some radionuclides that can be applied for treatment of ocular tumors. These sources are in small sizes (a few millimeters) and different shapes (rods, wires, disks). To ensure high accuracy during treatment, they are positioned in eye applicators, specially designed to fit on the surface of tumor. The Nuclear and Energy Research Institute (IPEN/CNEN) in a partnership with Paulista Medicine School (UNIFESP) created a project that aims to develop a prototype of Iridium-192 seeds for treatment of eye cancer. This seed consists in a core of Ir -Pt alloy (20%-80%) with a length of 3 mm, to be activated in IPEN's IEA-R1 Reactor, and a titanium capsule sealing the core. It was imperative to develop a sustainer device for irradiation. This piece is used to avoid overlapping of one cores and, therefore, avoiding the 'shadow effect' that does not allow full activation of each core due to the high density. (author)

  2. Development of an encapsulation method using plasma arc welding to produce iodine-125 seeds for brachytherapy

    International Nuclear Information System (INIS)

    Feher, Anselmo; Calvo, Wilson A.P.; Rostelato, Maria E.C.M.; Zeituni, Carlos A.; Somessari, Samir L.; Costa, Osvaldo L.; Moura, Joao A.; Moura, Eduardo S.; Souza, Carla D.; Rela, Paulo R.

    2011-01-01

    The prostate cancer, which is the second cause of death by cancer in men, overcome only by lung cancer is public health problem in Brazil. Brachytherapy is among the possible available treatments for prostate cancer, in which small seeds containing Iodine-125 radioisotope are implanted into the prostate gland. The seed consists of a titanium sealed capsule with 0.8 mm external diameter and 4.5 mm length, containing a central silver wire with adsorbed Iodine-125. The Plasma Arc Welding (PAW) is one of the viable techniques for sealing process. The equipment used in this technique is less costly than in other processes, such as, Laser Beam Welding (LBW). The main purpose of this work was the development of an encapsulation method using PAW. The development of this work has presented the following phases: cutting and cleaning titanium tube, determination of the welding parameters, development of a titanium tube holding device for PAW, sealed sources validation according to ISO 2919 - Sealed Radioactive Sources - General Requirements and Classification, and metallographic assays. The developed procedure to seal Iodine-125 seeds using PAW has shown high efficiency, satisfying all the established requirements of ISO 2919. The results obtained in this work will give the possibility to establish a routine production process according to the orientations presented in resolution RDC 17 - Good Manufacturing Practices to Medical Products defined by the ANVISA - National Agency of Sanitary Surveillance. (author)

  3. Development of an encapsulation method using plasma arc welding to produce iodine-125 seeds for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Feher, Anselmo; Calvo, Wilson A.P.; Rostelato, Maria E.C.M.; Zeituni, Carlos A.; Somessari, Samir L.; Costa, Osvaldo L.; Moura, Joao A.; Moura, Eduardo S.; Souza, Carla D.; Rela, Paulo R., E-mail: afeher@ipen.b, E-mail: wapcalvo@ipen.b, E-mail: elisaros@ipen.b, E-mail: somessar@ipen.b, E-mail: olcosta@ipen.b, E-mail: esmoura@ipen.b, E-mail: cdsouza@ipen.b, E-mail: prela@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The prostate cancer, which is the second cause of death by cancer in men, overcome only by lung cancer is public health problem in Brazil. Brachytherapy is among the possible available treatments for prostate cancer, in which small seeds containing Iodine-125 radioisotope are implanted into the prostate gland. The seed consists of a titanium sealed capsule with 0.8 mm external diameter and 4.5 mm length, containing a central silver wire with adsorbed Iodine-125. The Plasma Arc Welding (PAW) is one of the viable techniques for sealing process. The equipment used in this technique is less costly than in other processes, such as, Laser Beam Welding (LBW). The main purpose of this work was the development of an encapsulation method using PAW. The development of this work has presented the following phases: cutting and cleaning titanium tube, determination of the welding parameters, development of a titanium tube holding device for PAW, sealed sources validation according to ISO 2919 - Sealed Radioactive Sources - General Requirements and Classification, and metallographic assays. The developed procedure to seal Iodine-125 seeds using PAW has shown high efficiency, satisfying all the established requirements of ISO 2919. The results obtained in this work will give the possibility to establish a routine production process according to the orientations presented in resolution RDC 17 - Good Manufacturing Practices to Medical Products defined by the ANVISA - National Agency of Sanitary Surveillance. (author)

  4. SU-F-BRA-03: Integrating Novel Electromagnetic Tracking Hollow Needle Assistance in Permanent Implant Brachytherapy Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Racine, E; Hautvast, G; Binnekamp, D [Philips Group Innovation - Biomedical Systems, Eindhoven (Netherlands); Beaulieu, L [Centre Hospitalier Univ de Quebec, Quebec, QC (Canada)

    2015-06-15

    Purpose: To report on the results of a complete permanent implant brachytherapy procedure assisted by an electromagnetic (EM) hollow needle possessing both 3D tracking and seed drop detection abilities. Methods: End-to-end in-phantom EM-assisted LDR procedures were conducted. The novel system consisted of an EM tracking apparatus (NDI Aurora V2, Planar Field Generator), a 3D US scanner (Philips CX50), a hollow needle prototype allowing 3D tracking and seed drop detection and a specially designed treatment planning software (Philips Healthcare). A tungsten-doped 30 cc spherical agarose prostate immersed in gelatin was used for the treatment. A cylindrical shape of 0.8 cc was carved along its diameter to mimic the urethra. An initial plan of 26 needles and 47 seeds was established with the system. The plan was delivered with the EM-tracked hollow needle, and individual seed drop locations were recorded on the fly. The phantom was subsequently imaged with a CT scanner from which seed positions and contour definitions were obtained. The DVHs were then independently recomputed and compared with those produced by the planning system, both before and after the treatment. Results: Of the 47 seeds, 45 (96%) were detected by the EM technology embedded in the hollow needle design. The executed plan (from CT analysis) differed from the initial plan by 2%, 14% and 8% respectively in terms of V100, D90 and V150 for the prostate, and by 8%, 7% and 10% respectively in terms of D5, V100 and V120 for the urethra. Conclusion: The average DVH deviations between initial and executed plans were within a 5% tolerance imposed for this proof-of-concept assessment. This relatively good concordance demonstrates the feasibility and potential benefits of combining EM tracking and seed drop detection for real-time dosimetry validation and assistance in permanent implant brachytherapy procedures. This project has been entirely funded by Philips Healthcare.

  5. Reconstruction of brachytherapy seed positions and orientations from cone-beam CT x-ray projections via a novel iterative forward projection matching method.

    Science.gov (United States)

    Pokhrel, Damodar; Murphy, Martin J; Todor, Dorin A; Weiss, Elisabeth; Williamson, Jeffrey F

    2011-01-01

    To generalize and experimentally validate a novel algorithm for reconstructing the 3D pose (position and orientation) of implanted brachytherapy seeds from a set of a few measured 2D cone-beam CT (CBCT) x-ray projections. The iterative forward projection matching (IFPM) algorithm was generalized to reconstruct the 3D pose, as well as the centroid, of brachytherapy seeds from three to ten measured 2D projections. The gIFPM algorithm finds the set of seed poses that minimizes the sum-of-squared-difference of the pixel-by-pixel intensities between computed and measured autosegmented radiographic projections of the implant. Numerical simulations of clinically realistic brachytherapy seed configurations were performed to demonstrate the proof of principle. An in-house machined brachytherapy phantom, which supports precise specification of seed position and orientation at known values for simulated implant geometries, was used to experimentally validate this algorithm. The phantom was scanned on an ACUITY CBCT digital simulator over a full 660 sinogram projections. Three to ten x-ray images were selected from the full set of CBCT sinogram projections and postprocessed to create binary seed-only images. In the numerical simulations, seed reconstruction position and orientation errors were approximately 0.6 mm and 5 degrees, respectively. The physical phantom measurements demonstrated an absolute positional accuracy of (0.78 +/- 0.57) mm or less. The theta and phi angle errors were found to be (5.7 +/- 4.9) degrees and (6.0 +/- 4.1) degrees, respectively, or less when using three projections; with six projections, results were slightly better. The mean registration error was better than 1 mm/6 degrees compared to the measured seed projections. Each test trial converged in 10-20 iterations with computation time of 12-18 min/iteration on a 1 GHz processor. This work describes a novel, accurate, and completely automatic method for reconstructing seed orientations, as well as

  6. Reconstruction of brachytherapy seed positions and orientations from cone-beam CT x-ray projections via a novel iterative forward projection matching method

    Energy Technology Data Exchange (ETDEWEB)

    Pokhrel, Damodar; Murphy, Martin J.; Todor, Dorin A.; Weiss, Elisabeth; Williamson, Jeffrey F. [Department of Radiation Oncology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

    2011-01-15

    Purpose: To generalize and experimentally validate a novel algorithm for reconstructing the 3D pose (position and orientation) of implanted brachytherapy seeds from a set of a few measured 2D cone-beam CT (CBCT) x-ray projections. Methods: The iterative forward projection matching (IFPM) algorithm was generalized to reconstruct the 3D pose, as well as the centroid, of brachytherapy seeds from three to ten measured 2D projections. The gIFPM algorithm finds the set of seed poses that minimizes the sum-of-squared-difference of the pixel-by-pixel intensities between computed and measured autosegmented radiographic projections of the implant. Numerical simulations of clinically realistic brachytherapy seed configurations were performed to demonstrate the proof of principle. An in-house machined brachytherapy phantom, which supports precise specification of seed position and orientation at known values for simulated implant geometries, was used to experimentally validate this algorithm. The phantom was scanned on an ACUITY CBCT digital simulator over a full 660 sinogram projections. Three to ten x-ray images were selected from the full set of CBCT sinogram projections and postprocessed to create binary seed-only images. Results: In the numerical simulations, seed reconstruction position and orientation errors were approximately 0.6 mm and 5 deg., respectively. The physical phantom measurements demonstrated an absolute positional accuracy of (0.78{+-}0.57) mm or less. The {theta} and {phi} angle errors were found to be (5.7{+-}4.9) deg. and (6.0{+-}4.1) deg., respectively, or less when using three projections; with six projections, results were slightly better. The mean registration error was better than 1 mm/6 deg. compared to the measured seed projections. Each test trial converged in 10-20 iterations with computation time of 12-18 min/iteration on a 1 GHz processor. Conclusions: This work describes a novel, accurate, and completely automatic method for reconstructing

  7. Implantation of xenon in amorphous carbon and silicon for brachytherapy application

    International Nuclear Information System (INIS)

    Marques, F.C.; Barbieri, P.F.; Viana, G.A.; Silva, D.S. da

    2013-01-01

    We report a procedure to implant high dose of xenon atoms (Xe) in amorphous carbon, a-C, and amorphous silicon, a-Si, for application in brachytherapy seeds. An ion beam assisted deposition (IBAD) system was used for the deposition of the films, where one ion gun was used for sputtering a carbon (or silicon) target, while the other ion gun was used to simultaneously bombard the growing film with a beam of xenon ion Xe + in the 0–300 eV range. Xe atoms were implanted into the film with concentration up to 5.5 at.%, obtained with Xe bombardment energy in the 50–150 eV range. X-ray absorption spectroscopy was used to investigate the local arrangement of the implanted Xe atoms through the Xe L III absorption edge (4.75 keV). It was observed that Xe atoms tend to agglomerate in nanoclusters in a-C and are dispersed in a-Si.

  8. The surgical viability and radiological monitoring of brain implants of bioactive micro-seeds in an animal model

    International Nuclear Information System (INIS)

    Silva, Giane X.O.; Campos, Tarcisio Passos Ribeiro de; Siqueira, Savio Lana; Maciel, Marcelo B.

    2005-01-01

    The interstitial implant is a therapeutic modality in brachytherapy of the head and neck. Presently, the seeds implanted in tumors in the central nervous system are metallic I-125. After the full emission of the radionuclide, the seed remains inert in the implanted area. Bioactive ceramic seeds have been prepared for this research group incorporating Sm-152 to be active in Sm-153. The main goal of the present study is the development of a the surgical technique for implanting the biodegradable radioactive micro-seeds in the brains of rabbits, as well as the observation of the clinical reactions of the animal after implantation of two sets of three seeds. The surgical procedure consisted of performing two separate perforations 10 mm from each other in the skull, permitting the implantation of two groups of three seeds, totaling six seeds. The results of the pilot study showed the effectiveness of the surgical procedure and of the biocompatibility of the seeds and the lack of presence of adverse reactions, functional sequels, or inflammation in a follow up 50 days post-surgery. Such seeds of reduced volume, 0.2 x 1.6 mm, could be monitored by computerized tomography 30 days after implanting. (author)

  9. Long-term erectile function following permanent seed brachytherapy treatment for localized prostate cancer

    International Nuclear Information System (INIS)

    Ong, Wee Loon; Hindson, Benjamin R.; Beaufort, Catherine; Pharoah, Paul; Millar, Jeremy L.

    2014-01-01

    Background and purpose: Erectile function (EF) is commonly affected following prostate cancer treatment. We aim to evaluate the long-term EF following seed brachytherapy (BT) treatment. Materials and methods: The study consisted of 366 patients treated with BT at our institution, who completed the IIEF-5 questionnaire and reported no or mild erectile dysfunction (ED) pre-BT. The probability of EF preservation post-BT was estimated using the Kaplan–Meier methods. The difference in EF preservation by patient-, tumour- and treatment-related factors was assessed using the log-rank test. Multivariate Cox regression was used to estimate the effect of each factor on EF preservation. Results: Of the 366 patients, 277 (76%) reported normal EF, and 89 (24%) reported mild ED. The patients were followed-up for a median of 41 months (range: 3–124), and the 5-year actuarial rate of EF preservation was 59%. Age at BT seed implant, presence of medical comorbidities, Gleason score and the biologically effective dose (BED) are associated with EF preservation (P < 0.005). The association for these four factors remains statistically significant in multivariate analysis, with Gleason score having the strongest effect (HR = 3.7; 95% CI = 2.6–5.4). Conclusion: The 5-year actuarial rate of EF preservation post-BT in our cohort is 59%, and is influenced by multiple factors

  10. Permanent 125I-seed prostate brachytherapy: early prostate specific antigen value as a predictor of PSA bounce occurrence

    Directory of Open Access Journals (Sweden)

    Mazeron Renaud

    2012-03-01

    Full Text Available Abstract Purpose To evaluate predictive factors for PSA bounce after 125I permanent seed prostate brachytherapy and identify criteria that distinguish between benign bounces and biochemical relapses. Materials and methods Men treated with exclusive permanent 125I seed brachytherapy from November 1999, with at least a 36 months follow-up were included. Bounce was defined as an increase ≥ 0.2 ng/ml above the nadir, followed by a spontaneous return to the nadir. Biochemical failure (BF was defined using the criteria of the Phoenix conference: nadir +2 ng/ml. Results 198 men were included. After a median follow-up of 63.9 months, 21 patients experienced a BF, and 35.9% had at least one bounce which occurred after a median period of 17 months after implantation (4-50. Bounce amplitude was 0.6 ng/ml (0.2-5.1, and duration was 13.6 months (4.0-44.9. In 12.5%, bounce magnitude exceeded the threshold defining BF. Age at the time of treatment and high PSA level assessed at 6 weeks were significantly correlated with bounce but not with BF. Bounce patients had a higher BF free survival than the others (100% versus 92%, p = 0,007. In case of PSA increase, PSA doubling time and velocity were not significantly different between bounce and BF patients. Bounces occurred significantly earlier than relapses and than nadir + 0.2 ng/ml in BF patients (17 vs 27.8 months, p Conclusion High PSA value assessed 6 weeks after brachytherapy and young age were significantly associated to a higher risk of bounces but not to BF. Long delays between brachytherapy and PSA increase are more indicative of BF.

  11. Sci-Sat AM(2): Brachy-07: Tomosynthesis-based seed reconstruction in LDR prostate brachytherapy: A clinical study.

    Science.gov (United States)

    Brunet-Benkhoucha, M; Verhaegen, F; Lassalle, S; Béliveau-Nadeau, D; Reniers, B; Donath, D; Taussky, D; Carrier, J-F

    2008-07-01

    To develop a tomosynthesis-based dose assessment procedure that can be performed after an I-125 prostate seed implantation, while the patient is still under anaesthesia on the treatment table. Our seed detection procedure involves the reconstruction of a volume of interest based on the backprojection of 7 seed-only binary images acquired over an angle of 60° with an isocentric imaging system. A binary seed-only volume is generated by a simple thresholding of the volume of interest. Seeds positions are extracted from this volume with a 3D connected component analysis and a statistical classifier that determines the number of seeds in each cluster of connected voxels. A graphical user interface (GUI) allows to visualize the result and to introduce corrections, if needed. A phantom and a clinical study (24 patients) were carried out to validate the technique. A phantom study demonstrated a very good localization accuracy of (0.4+/-0.4) mm when compared to CT-based reconstruction. This leads to dosimetric error on D90 and V100 of respectively 0.5% and 0.1%. In a patient study with an average of 56 seeds per implant, the automatic tomosynthesis-based reconstruction yields a detection rate of 96% of the seeds and less than 1.5% of false-positives. With the help of the GUI, the user can achieve a 100% detection rate in an average of 3 minutes. This technique would allow to identify possible underdosage and to correct it by potentially reimplanting additional seeds. A more uniform dose coverage could then be achieved in LDR prostate brachytherapy. © 2008 American Association of Physicists in Medicine.

  12. Effect of post-implant edema on prostate brachytherapy treatment margins

    International Nuclear Information System (INIS)

    Reed, Daniel R.; Wallner, Kent; Ford, Eric; Mueller, Amy; Merrick, Gregory; Maki, Jeffrey; Sutlief, Steven; Butler, Wayne

    2005-01-01

    Purpose: To determine if postimplant prostate brachytherapy treatment margins calculated on Day 0 differ substantially from those calculated on Day 30. Methods: Thirty patients with 1997 American Joint Commission on Cancer clinical stage T1-T2 prostatic carcinoma underwent prostate brachytherapy with I-125 prescribed to 144 Gy. Treatment planning methods included using loose seeds in a modified peripheral loading pattern and treatment margins (TMs) of 5-8 mm. Postimplant plain radiographs, computed tomography scans, and magnetic resonance scans were obtained 1-4 hours after implantation (Day 0). A second set of imaging studies was obtained at 30 days after implantation (Day 30) and similarly analyzed. Treatment margins were measured as the radial distance in millimeters from the prostate edge to the 100% isodose line. The TMs were measured and tabulated at 90 o intervals around the prostate periphery at 0.6-cm intervals. Each direction was averaged to obtain the mean anterior, posterior, left, and right margins. Results: The mean overall TM increased from 2.6 mm (±2.3) on Day 0 to 3.5 mm (±2.4) on Day 30. The mean anterior margin increased from 1.2 mm on Day 0 to 1.8 mm on Day 30. The posterior margin increased from 1.2 mm on Day 0 to 2.8 mm on Day 30. The lateral treatment margins increased most over time, with mean right treatment margin increasing from 3.9 mm on Day 0 to 4.7 mm on Day 30. Conclusion: Treatment margins appear to be durable in the postimplant period, with a clinically insignificant increase from Day 0 to Day 30

  13. WE-AB-BRA-12: Post-Implant Dosimetry in Prostate Brachytherapy by X-Ray and MRI Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Park, S; Song, D; Lee, J [Johns Hopkins University, Baltimore, MD (United States); Le, Y [Indiana University, Indianapolis, IN (United States)

    2016-06-15

    Purpose: For post-implant dosimetric assessment after prostate brachytherapy, CT-MR fusion approach has been advocated due to the superior accuracy on both seeds localization and soft tissue delineation. However, CT deposits additional radiation to the patient, and seed identification in CT requires manual review and correction. In this study, we propose an accurate, low-dose, and cost-effective post-implant dosimetry approach based on X-ray and MRI. Methods: Implanted seeds are reconstructed using only three X-ray fluoroscopy images by solving a combinatorial optimization problem. The reconstructed seeds are then registered to MR images using an intensity-based points-to-volume registration. MR images are first pre-processed by geometric and Gaussian filtering, yielding smooth candidate seed-only images. To accommodate potential soft tissue deformation, our registration is performed in two steps, an initial affine followed by local deformable registrations. An evolutionary optimizer in conjunction with a points-to-volume similarity metric is used for the affine registration. Local prostate deformation and seed migration are then adjusted by the deformable registration step with external and internal force constraints. Results: We tested our algorithm on twenty patient data sets. For quantitative evaluation, we obtained ground truth seed positions by fusing the post-implant CT-MR images. Seeds were semi-automatically extracted from CT and manually corrected and then registered to the MR images. Target registration error (TRE) was computed by measuring the Euclidean distances from the ground truth to the closest registered X-ray seeds. The overall TREs (mean±standard deviation in mm) are 1.6±1.1 (affine) and 1.3±0.8 (affine+deformable). The overall computation takes less than 1 minute. Conclusion: It has been reported that the CT-based seed localization error is ∼1.6mm and the seed localization uncertainty of 2mm results in less than 5% deviation of prostate D

  14. WE-AB-BRA-12: Post-Implant Dosimetry in Prostate Brachytherapy by X-Ray and MRI Fusion

    International Nuclear Information System (INIS)

    Park, S; Song, D; Lee, J; Le, Y

    2016-01-01

    Purpose: For post-implant dosimetric assessment after prostate brachytherapy, CT-MR fusion approach has been advocated due to the superior accuracy on both seeds localization and soft tissue delineation. However, CT deposits additional radiation to the patient, and seed identification in CT requires manual review and correction. In this study, we propose an accurate, low-dose, and cost-effective post-implant dosimetry approach based on X-ray and MRI. Methods: Implanted seeds are reconstructed using only three X-ray fluoroscopy images by solving a combinatorial optimization problem. The reconstructed seeds are then registered to MR images using an intensity-based points-to-volume registration. MR images are first pre-processed by geometric and Gaussian filtering, yielding smooth candidate seed-only images. To accommodate potential soft tissue deformation, our registration is performed in two steps, an initial affine followed by local deformable registrations. An evolutionary optimizer in conjunction with a points-to-volume similarity metric is used for the affine registration. Local prostate deformation and seed migration are then adjusted by the deformable registration step with external and internal force constraints. Results: We tested our algorithm on twenty patient data sets. For quantitative evaluation, we obtained ground truth seed positions by fusing the post-implant CT-MR images. Seeds were semi-automatically extracted from CT and manually corrected and then registered to the MR images. Target registration error (TRE) was computed by measuring the Euclidean distances from the ground truth to the closest registered X-ray seeds. The overall TREs (mean±standard deviation in mm) are 1.6±1.1 (affine) and 1.3±0.8 (affine+deformable). The overall computation takes less than 1 minute. Conclusion: It has been reported that the CT-based seed localization error is ∼1.6mm and the seed localization uncertainty of 2mm results in less than 5% deviation of prostate D

  15. Impact of oedema on implant geometry and dosimetry for temporary high dose rate brachytherapy of the prostate

    International Nuclear Information System (INIS)

    Kiffer, J.D.; Schumer, W.A.; Mantle, C.A.; McKenzie, B.J.; Feigen, M.; Quong, G.G.; Waterman, F.M.

    2003-01-01

    The optimal timing of dosimetry for permanent seed prostatic implants remains contentious given the half life of post-implant oedema resolution. The aim of this study was to establish whether prostatic oedematous change over the duration of a temporary high dose rate (HDR) interstitial brachytherapy (BR) boost would result in significant needle displacement, and whether this change in geometry would influence dosimetry. Two CT scans, one for dosimetric purposes on the day of the implant and the second just prior to implant removal, were obtained for four patients receiving transperineal interstitial prostate brachytherapy. The relative changes in cross-sectional dimensions of the implants were calculated by establishing the change in mean radial distance (MRD) of the needle positions from the geometric centre of the implant for each patient's pair of CT studies. The treatment plan, as calculated from the first CT scan, was used in the second set of CT images to allow a comparison of dose distribution. The percentage change in MRD over the duration of the temporary implants ranged from -1.91% to 1.95%. The maximum change in estimated volume was 3.94%. Dosimetric changes were negligible. In the four cases studied, the degree of oedematous change and consequent displacement of flexiguide needle positions was negligible and did not impact on the dosimetry. The rate and direction of oedematous change can be extremely variable but on the basis of the four cases studied and the results of a larger recent study, it might not be necessary to re-image patients for dosimetric purposes over the duration of a fractionated HDR BT boost to the prostate where flexiguide needles are utilized. Nevertheless, further investigation with larger patient numbers is required. Copyright (2003) Blackwell Science Pty Ltd

  16. Open magnetic resonance imaging using titanium-zirconium needles: improved accuracy for interstitial brachytherapy implants?

    International Nuclear Information System (INIS)

    Popowski, Youri; Hiltbrand, Emile; Joliat, Dominique; Rouzaud, Michel

    2000-01-01

    Purpose: To evaluate the benefit of using an open magnetic resonance (MR) machine and new MR-compatible needles to improve the accuracy of brachytherapy implants in pelvic tumors. Methods and Materials: The open MR machine, foreseen for interventional procedures, allows direct visualization of the pelvic structures that are to be implanted. For that purpose, we have developed MR- and CT-compatible titanium-zirconium (Ti-Zr) brachytherapy needles that allow implantations to be carried out under the magnetic field. In order to test the technical feasibility of this new approach, stainless steel (SS) and Ti-Zr needles were first compared in a tissue-equivalent phantom. In a second step, two patients implanted with Ti-Zr needles in the brachytherapy operating room were scanned in the open MR machine. In a third phase, four patients were implanted directly under open MR control. Results: The artifacts induced by both materials were significantly different, strongly favoring the Ti-Zr needles. The implantation in both first patients confirmed the excellent quality of the pictures obtained with the needles in vivo and showed suboptimal implant geometry in both patients. In the next 4 patients, the tumor could be punctured with excellent accuracy, and the adjacent structures could be easily avoided. Conclusion: We conclude that open MR using MR-compatible needles is a very promising tool in brachytherapy, especially for pelvic tumors

  17. Dosimetric comparison of interactive planned and dynamic dose calculated prostate seed brachytherapy.

    Science.gov (United States)

    Meijer, Gert J; van den Berg, Hetty A; Hurkmans, Coen W; Stijns, Pascal E; Weterings, Jan H

    2006-09-01

    To compare the dosimetrical results of an interactive planning procedure and a procedure based on dynamic dose calculation for permanent prostate brachytherapy. Between 6/2000 and 11/2005, 510 patients underwent (125)I implants for T1-T2 prostate cancer. Before 4/2003, 187 patients were treated using an interactive technique that included needle updating. After that period, 323 patients were treated with a more refined dynamic technique that included constant updating of the deposited seed position. The comparison is based on postimplant dose - volume parameters such as the V(100) and d(90) for the target, V(100)(r) for the rectum and d(10)(u) for the urethra. Furthermore, the target volume ratios (TVR identical with V(100)(body)/V(100)), and the homogeneity indices (HI identical with [V(100)-V(150)]/V(100)) were calculated as additional quality parameters. The dose outside the target volume was significantly reduced, the V(100)(r) decreased from 1.4 cm(3) for the interactive technique to 0.6 cm(3) for the dynamic technique. Similarly the mean TVR reduced from 1.66 to 1.44. In addition, the mean V(100) increased from 92% for the interactive procedure to 95% for the dynamic procedure. More importantly, the percentage of patients with a V(100) < 80% reduced from 5% to 1%. A slight decline was observed with regard to the d(10)(u) (136% vs. 140%) and the HI (0.58 vs. 0.51). The dynamic implant procedure resulted in improved implants. Almost ideal dose coverage was achieved, while minimizing the dose outside the prostate.

  18. Dosimetric comparison of interactive planned and dynamic dose calculated prostate seed brachytherapy

    International Nuclear Information System (INIS)

    Meijer, Gert J.; Berg, Hetty A. van den; Hurkmans, Coen W.; Stijns, Pascal E.; Weterings, Jan H.

    2006-01-01

    Purpose: To compare the dosimetrical results of an interactive planning procedure and a procedure based on dynamic dose calculation for permanent prostate brachytherapy. Materials and methods: Between 6/2000 and 11/2005, 510 patients underwent 125 I implants for T1-T2 prostate cancer. Before 4/2003, 187 patients were treated using an interactive technique that included needle updating. After that period, 323 patients were treated with a more refined dynamic technique that included constant updating of the deposited seed position. The comparison is based on postimplant dose-volume parameters such as the V 100 and d 90 for the target, V 100 r for the rectum and d 10 u for the urethra. Furthermore, the target volume ratios (TVR=V 100 body /V 100 ), and the homogeneity indices (HI=[V 100 -V 150 ]/V 100 ) were calculated as additional quality parameters. Results: The dose outside the target volume was significantly reduced, the V 100 r decreased from 1.4cm 3 for the interactive technique to 0.6cm 3 for the dynamic technique. Similarly the mean TVR reduced from 1.66 to 1.44. In addition, the mean V 100 increased from 92% for the interactive procedure to 95% for the dynamic procedure. More importantly, the percentage of patients with a V 100 10 u (136% vs. 140%) and the HI (0.58 vs. 0.51). Conclusion: The dynamic implant procedure resulted in improved implants. Almost ideal dose coverage was achieved, while minimizing the dose outside the prostate

  19. SU-F-T-03: Radiobiological Evaluation of a Directional Brachytherapy Device Surgically Implanted Following EBRT

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, MJ [Tufts University School of Medicine, Boston, MA (United States); Emrich, JG; Poli, J [Drexel University College of Medicine, Philadelphia, PA (United States)

    2016-06-15

    Purpose: Preceding surgical implantation following external-beam radiotherapy (EBRT) delivery, a radiobiological evaluation was performed for a new LDR Pd-103 directional brachytherapy device (CivaSheet). As this was the first case with the device used in combination with EBRT, there was concern to determine the appropriate prescription dose. Methods: The radiobiological model of Dale (1985, 1989) was used for a permanent LDR implant including radioactive decay. The biological effective dose (BED) was converted to the equivalent dose in 2 Gy fractions (EQD2) for comparison with EBRT prescription expectations. Given IMRT delivery of 50.4 Gy, an LDR brachytherapy dose of approximately 15–20 Gy EQD2 was desired. To be specific to the treatment site (leiomyosarcoma T2bN0M0, grade 2 with R1 surgical margin), the radiobiological model required several radiobiological parameters with values taken from the literature. A sensitivity analysis was performed to determine their relative importance on the calculated BED and subsequent EQD2. The Pd-103 decay constant (λ=0.0017 h{sup −1}) was also used. DVHs were prepared for pre- and post-surgical geometries to glean the possible and realized implant geometric configuration. DVHs prepared in VariSeed9 were converted to BEDVHs and subsequently EQD2 values for each volume-element. Results: For a physical dose of 28 Gy to a 0.5 cm depth, BED=21.7 Gy and EQD2=17.6 Gy, which was near the center of the desired EQD2 range. Tumor bed (CTV=4 cm{sup 3}) coverage was 99.2% with 48 sources implanted. In order of decreasing importance from the sensitivity analysis, the radiobiological parameters were α=0.25 Gy{sup −1}, T{sub POT}=23 days, α/β=8.6 Gy, and T=1.5 h. Percentage variations in these values produced EQD2 variations of 40%, 20%, 18%, and 1%, respectively. Conclusion: This radiobiological evaluation indicated that prescription dose may be determined for comparison with the desired EQD2, and that radiobiologicalparameter

  20. Occupational exposure in prostate permanent implants with I-125 seeds

    Energy Technology Data Exchange (ETDEWEB)

    Fdez Garcia, J.; Luna, V.; Sancho, J. M. g.; Martinez, J.; Galiano, P. S.; Jimenez, I.; Prada, P.; Juan, G.; Vivanco, J.

    2002-07-01

    Prostate brachytherapy is one of the techniques increasing faster in the environment of the radiotherapy and will probably go on increasing in the future. There are two forms in their use; by means of remote afterloading high dose rate (HDR) with Ir-192 radioactive sources or by means of permanent implant by manual/automatic afterloading of low dose rate (LDR) with seeds of I-125 or Pd-103. Iodine-125 has a half life of 59.4 days and it decays by electron capture with emissions of characteristic photons and electrons. The electrons are absorbed by the titanium wall of the I-125 seed. The principal photon emissions are 27.4 and 31.4 keV X-rays and a 35.5 keV gamma ray. Besides 22.1 and 25.2 keV fluorescent X-rays are also emitted resulting from interactions of the iodine-125 photons with the silver rod. The resulting average photon energy is approximately 27.4 keV. (Author)

  1. 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.

  2. Palliative interstitial HDR brachytherapy for recurrent rectal cancer. Implantation techniques and results

    International Nuclear Information System (INIS)

    Kolotas, C.; Roeddiger, S.; Martin, T.; Tselis, N.; Baltas, D.; Zamboglou, N.; Strassmann, G.; Aebersold, D.M.

    2003-01-01

    Purpose: To report the methods and clinical results of CT-based interstitial high-dose-rate (HDR) brachytherapy procedures for the palliative treatment of recurrent rectal cancer. Patients and Methods: A total of 44 brachytherapy implants were performed in 38 patients. CT-guided catheter implants were performed in 34 patients under local anesthesia and sedation, and four patients were implanted intraoperatively. Of 40 CT-guided implants, 20 were done using metallic needles introduced via the sacrum and 20 were transperineal implants of plastic tubes in the presacral region. Postimplant CT scans were used for three-dimensional (3-D) conformal brachytherapy planning. Patients implanted with metallic needles were given a single fraction of 10-15 Gy using HDR 192 Ir, and those who received transperineal implants of plastic catheters were given fractionated brachytherapy, 5 Gy twice daily to a total dose of 30-40 Gy. The median tumor volume was 225 cm 3 with a range of 41-2,103 cm 3 . Results: After a median follow-up of 23.4 months, a total of 13/38 patients were alive. The median postbrachytherapy survival was 15 months with 18 of the 25 deaths due to distant metastases. Tumor response was as follows: 6/38 partial remission, 28/38 stable disease, and 4/38 local progression. A planning target volume (PTV) coverage > 85% was achieved in 42/44 implants. The treatment was well tolerated, and no acute complications were observed. One patient developed a fistula after 8 months. Pain relief was recorded in 34 patients (89.5%), and the median duration of this palliative effect was 5 months with a range of 1-13 months. Conclusions: Interstitial HDR brachytherapy is a valuable tool for the delivery of high doses and achieves effective palliation in recurrent rectal carcinoma. (orig.)

  3. Palliative interstitial HDR brachytherapy for recurrent rectal cancer. Implantation techniques and results

    Energy Technology Data Exchange (ETDEWEB)

    Kolotas, C. [Dept. of Radiation Oncology, Offenbach Hospital, Offenbach (Germany); Dept. of Radio-Oncology, Univ. of Bern, Inselspital, Bern (Switzerland); Roeddiger, S.; Martin, T.; Tselis, N.; Baltas, D.; Zamboglou, N. [Dept. of Radiation Oncology, Offenbach Hospital, Offenbach (Germany); Strassmann, G. [Dept. of Radiotherapy, Univ. Hospital, Philipps Univ., Marburg (Germany); Aebersold, D.M. [Dept. of Radio-Oncology, Univ. of Bern, Inselspital, Bern (Switzerland)

    2003-07-01

    Purpose: To report the methods and clinical results of CT-based interstitial high-dose-rate (HDR) brachytherapy procedures for the palliative treatment of recurrent rectal cancer. Patients and Methods: A total of 44 brachytherapy implants were performed in 38 patients. CT-guided catheter implants were performed in 34 patients under local anesthesia and sedation, and four patients were implanted intraoperatively. Of 40 CT-guided implants, 20 were done using metallic needles introduced via the sacrum and 20 were transperineal implants of plastic tubes in the presacral region. Postimplant CT scans were used for three-dimensional (3-D) conformal brachytherapy planning. Patients implanted with metallic needles were given a single fraction of 10-15 Gy using HDR {sup 192}Ir, and those who received transperineal implants of plastic catheters were given fractionated brachytherapy, 5 Gy twice daily to a total dose of 30-40 Gy. The median tumor volume was 225 cm{sup 3} with a range of 41-2,103 cm{sup 3}. Results: After a median follow-up of 23.4 months, a total of 13/38 patients were alive. The median postbrachytherapy survival was 15 months with 18 of the 25 deaths due to distant metastases. Tumor response was as follows: 6/38 partial remission, 28/38 stable disease, and 4/38 local progression. A planning target volume (PTV) coverage > 85% was achieved in 42/44 implants. The treatment was well tolerated, and no acute complications were observed. One patient developed a fistula after 8 months. Pain relief was recorded in 34 patients (89.5%), and the median duration of this palliative effect was 5 months with a range of 1-13 months. Conclusions: Interstitial HDR brachytherapy is a valuable tool for the delivery of high doses and achieves effective palliation in recurrent rectal carcinoma. (orig.)

  4. Investigation of palladium-103 production and IR07-103Pd brachytherapy seed preparation

    International Nuclear Information System (INIS)

    Saidi, Pooneh; Sadeghi, Mahdi; Enferadi, Milad; Aslani, Gholamreza

    2011-01-01

    Highlights: → We report the cyclotron production of 103-palladium via 103 Rh(p,n) 103 Pd reaction. → 103 Pd was absorbed on resin beads for brachytherapy seed preparation. → The optimum absorption of 103 Pd in resin was achieved at 0.5 M HCl. → Version 5 of MCNP code was employed to model a new 103 Pd brachytherapy seed. - Abstract: In this study, design and fabrication of 103 Pd brachytherapy seed was investigated. The excitation functions of 103 Rh(p,n) 103 Pd and 103 Rh(d,2n) 103 Pd reactions were calculated using EMPIRE (version 3.1 Rivoli), ALICE/ASH and TALYS-1.2 codes, the TENDL-2010 database and compared with the published data. Production of 103 Pd was done via 103 Rh(p,n) 103 Pd nuclear reaction. The target was bombarded with 18 MeV protons at 200 μA beam current for 15 h. After irradiation and radiochemical separation of the electroplated rhodium target, the optimum condition for absorption of 103 Pd into Amberlite (registered) IR-93 resin was achieved at 0.5 M HCl. Version 5 of the (MCNP) Monte Carlo radiation transport code was employed to calculate the dosimetric parameters around the 103 Pd brachytherapy seed. Finally the calculated results were compared with published results for other commercial sources.

  5. Three-dimensional verification of 125I seed stability after permanent implantation in the parotid gland and periparotid region

    International Nuclear Information System (INIS)

    Fan, Yi; Huang, Ming-Wei; Zheng, Lei; Zhao, Yi-Jiao; Zhang, Jian-Guo

    2015-01-01

    To evaluate seed stability after permanent implantation in the parotid gland and periparotid region via a three-dimensional reconstruction of CT data. Fifteen patients treated from June 2008 to June 2012 at Peking University School and Hospital of Stomatology for parotid gland tumors with postoperative adjunctive 125 I interstitial brachytherapy were retrospectively reviewed in this study. Serial CT data were obtained during follow-up. Mimics and Geomagic Studio software were used for seed reconstruction and stability analysis, respectively. Seed loss and/or migration outside of the treated area were absent in all patients during follow-up (23–71 months). Total seed cluster volume was maximized on day 1 post-implantation due to edema and decreased significantly by an average of 13.5 % (SD = 9.80 %; 95 % CI, 6.82–17.68 %) during the first two months and an average of 4.5 % (SD = 3.60 %; 95 % CI, 2.29–6.29 %) during the next four months. Volume stabilized over the subsequent six months. 125 I seed number and location were stable with a general volumetric shrinkage tendency in the parotid gland and periparotid region. Three-dimensional seed reconstruction of CT images is feasible for visualization and verification of implanted seeds in parotid brachytherapy

  6. Comparison of Intraoperatively Built Custom Linked Seeds Versus Loose Seed Gun Applicator Technique Using Real-Time Intraoperative Planning for Permanent Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Zauls, A. Jason; Ashenafi, Michael S. [Department of Radiation Oncology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC (United States); Onicescu, Georgiana [Department of Biostatistics and Epidemiology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC (United States); Clarke, Harry S. [Department of Urology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC (United States); Marshall, David T., E-mail: marshadt@musc.edu [Department of Radiation Oncology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC (United States)

    2011-11-15

    Purpose: To report our dosimetric results using a novel push-button seed delivery system that constructs custom links of seeds intraoperatively. Methods and Materials: From 2005 to 2007, 43 patients underwent implantation using a gun applicator (GA), and from 2007 to 2008, 48 patientsunderwent implantation with a novel technique allowing creation of intraoperatively built custom links of seeds (IBCL). Specific endpoint analyses were prostate D90% (pD90%), rV100% > 1.3 cc, and overall time under anesthesia. Results: Final analyses included 91 patients, 43 GA and 48 IBCL. Absolute change in pD90% ({Delta}pD90%) between intraoperative and postoperative plans was evaluated. Using GA method, the {Delta}pD90% was -8.1Gy and -12.8Gy for I-125 and Pd-103 implants, respectively. Similarly, the IBCL technique resulted in a {Delta}pD90% of -8.7Gy and -9.8Gy for I-125 and Pd-103 implants, respectively. No statistically significant difference in {Delta}pD90% was found comparing methods. The GA method had two intraoperative and 10 postoperative rV100% >1.3 cc. For IBCL, five intraoperative and eight postoperative plans had rV100% >1.3 cc. For GA, the mean time under anesthesia was 75 min and 87 min for Pd-103 and I-125 implants, respectively. For IBCL, the mean time was 86 and 98 min for Pd-103 and I-125. There was a statistical difference between the methods when comparing mean time under anesthesia. Conclusions: Dosimetrically relevant endpoints were equivalent between the two methods. Currently, time under anesthesia is longer using the IBCL technique but has decreased over time. IBCL is a straightforward brachytherapy technique that can be implemented into clinical practice as an alternative to gun applicators.

  7. On-line implant reconstruction in HDR brachytherapy

    International Nuclear Information System (INIS)

    Kolkman-Deurloo, Inger-Karine K.; Kruijf, Wilhelmus J.M. de; Levendag, Peter C.

    2006-01-01

    Background and purpose: To evaluate the accuracy of on-line planning in an Integrated Brachytherapy Unit (IBU) using dedicated image distortion correction algorithms, correcting the geometric distortion and magnetic distortion separately, and to determine the effect of the reconstruction accuracy on clinical treatment plans in terms of deviations in treatment time and dose. Patients and methods: The reconstruction accuracy has been measured using 20 markers, positioned at well known locations in a QA phantom. Treatment plans of two phantoms representing clinical implant geometries, have been compared with reference plans to determine the effect of the reconstruction accuracy on the treatment plan. Before clinical introduction, treatment plans of three representative patients, based on on-line reconstruction, have been compared with reference plans. Results: The average reconstruction error for 10 in. images reduces from -0.6 mm (range -2.6 to +1.0 mm) to -0.2 mm (range -1.2 to +0.6 mm) after image distortion correction and for 15 in. images from 0.8 mm (range -0.5 to +3.0 mm) to 0.0 mm (range -0.8 to +0.8 mm). The error in case of eccentric positioning of the phantom, i.e. 0.8 mm (range -1.0 to +3.3 mm), reduces to 0.1 mm (range -0.5 to +0.9 mm). Correction of the image distortions reduces the deviation in the calculated treatment time of maximally 2.7% to less than 0.8% in case of eccentrically positioned clinical phantoms. The deviation in the treatment time or reference dose in the plans based on on-line reconstruction with image distortion correction of the three patient examples is smaller than 0.3%. Conclusions: Accurate on-line implant reconstruction using the IBU localiser and dedicated correction algorithms separating the geometric distortion and the magnetic distortion is possible. The results fulfill the minimum requirements as imposed by the Netherlands Commission on Radiation Dosimetry (NCS) without limitations regarding the usable range of the field

  8. Effect of brachytherapy technique and patient characteristics on cervical cancer implant dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Anker, Christopher J., E-mail: chris.anker@hci.utah.edu [Department of Radiation Oncology, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT (United States); O' Donnell, Kristen [Department of Radiation Oncology, The University of Arizona, Tucson, AZ (United States); Boucher, Kenneth M. [Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT (United States); Gaffney, David K. [Department of Radiation Oncology, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT (United States)

    2013-01-01

    Our purpose was to evaluate the relationship between brachytherapy technique and patient characteristics on dose to organs-at-risk (OARs) in patients undergoing high dose rate (HDR) brachytherapy for cervical cancer. From 1998 to 2008, 31 patients with cervical cancer with full dosimetric data were identified who received definitive external-beam radiation and HDR brachytherapy with tandem and ovoid applicators. Doses were recorded at point A, the International Commission on Radiation Units and Measurements (ICRU)-38 rectal point, the ICRU-38 bladder point, the vaginal surface, and the pelvic sidewall. Generalized estimating equations were used to determine the significance of changes in OAR to point A dose ratios with differences in brachytherapy technique or patient characteristics. Patients underwent a median of 5 brachytherapy procedures (range, 3 to 5), with a total of 179 procedures for 31 patients. For all brachytherapy treatments, the average ratios between the doses for the rectal, bladder, vaginal surface, and pelvic sidewall reference points to those at point A were 0.49, 0.59, 1.15, and 0.17, respectively. In general, decreased OAR dose was associated with a lower stage, younger age, increased ovoid size, increased tandem length, and earlier implant number. Increased tandem curvature significantly increased bladder dose and decreased rectal dose. Intravenous anesthesia usage was not correlated with improved dosimetry. This study allowed identification of patient and procedure characteristics influencing OAR dosing. Although the advent of 3-dimensional (3D) image-guided brachytherapy will bring new advances in treatment optimization, the actual technique involved at the time of the brachytherapy implant procedure will remain important.

  9. Is intraoperative real-time dosimetry in prostate seed brachytherapy predictive of biochemical outcome?

    Directory of Open Access Journals (Sweden)

    Daniel Taussky

    2017-06-01

    Full Text Available Purpose : To analyze intraoperative (IO dosimetry using transrectal ultrasound (TRUS, performed before and after prostate low-dose-rate brachytherapy (LDR-BT, and compare it to dosimetry performed 30 days following the LDR-BT implant (Day 30. Material and methods : A total of 236 patients underwent prostate LDR-BT using 125 I that was performed with a three-dimensional TRUS-guided interactive inverse preplanning system (preimplant dosimetry. After the implant procedure, the TRUS was repeated in the operating room, and the dosimetry was recalculated (postimplant dosimetry and compared to dosimetry on Day 30 computed tomography (CT scans. Area under curve (AUC statistics was used for models predictive of dosimetric parameters at Day 30. Results : The median follow-up for patients without BF was 96 months, the 5-year and 8-year biochemical recurrence (BR-free rate was 96% and 90%, respectively. The postimplant median D 90 was 3.8 Gy lower (interquartile range [IQR], 12.4-0.9, and the V 100 only 1% less (IQR, 2.9-0.2% than the preimplant dosimetry. When comparing the postimplant and the Day 30 dosimetries, the postimplant median D 90 was 9.6 Gy higher (IQR [–] 9.5-30.3 Gy, and the V 100 was 3.2% greater (0.2-8.9% than Day 30 postimplant dosimetry. The variables that best predicted the D 90 of Day 30 was the postimplant D 90 (AUC = 0.62, p = 0.038. None of the analyzed values for IO or Day 30 dosimetry showed any predictive value for BR. Conclusions : Although improving the IO preimplant and postimplant dosimetry improved dosimetry on Day 30, the BR-free rate was not dependent on any dosimetric parameter. Unpredictable factors such as intraprostatic seed migration and IO factors, prevented the accurate prediction of Day 30 dosimetry.

  10. 78 FR 41125 - Interim Enforcement Policy for Permanent Implant Brachytherapy Medical Event Reporting

    Science.gov (United States)

    2013-07-09

    ... NUCLEAR REGULATORY COMMISSION [NRC-2013-0114] Interim Enforcement Policy for Permanent Implant Brachytherapy Medical Event Reporting AGENCY: Nuclear Regulatory Commission. ACTION: Policy statement; revision. SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing an interim Enforcement Policy that allows...

  11. Clinical efficacy of CT-guided 125I seed implantation therapy for advanced pancreatic cancer

    International Nuclear Information System (INIS)

    Wang Zhongmin; Lu Jian; Gong Ju; Zheng Yunfeng; Zhang Liyun; Huang Gang; Chen Kemin

    2009-01-01

    Objective: To discuss the clinical efficacy of CT-guided radioactive 125 I seed implantation treatment for unresectable pancreatic cancer. Methods: Forty patients with inoperable pancreatic cancer were enrolled in this study, including 25 males and 15 females with an median age of 69 years (38-89 years). Treatment planning system (TPS) was used to reconstruct 3-dimensional images of pancreatic tumor and to define the quantity and distribution of 125 I seeds. The radioactivity of 125 I seeds was 0.5 - 0.8 mCi / seed. The seeds were implanted into pancreatic tumor under CT guidance at intervals of 1 cm and were kept away from vessels, pancreatic duct and other adjacent important organs. The tumor matched peripheral dose (MPD) was 60-140 Gy. The median amount of implanted 125 I seeds was 36 (18-68) in number. CT scan was performed immediately after the procedure to check the quality of the seeds. In addition, 10 patients received concurrent chemotherapy with arterial infusion of gemcitabin and 5-fluororacil (5-Fu) for 3 to 4 therapeutic courses. Results: The median diameter of the tumors was 4.9 cm. The follow-up period was 2 to 28 months. After the treatment the refractory pain was significantly relieved (P 125 I seed implantation is a safe, effective and minimally-invasive brachytherapy for unresectable pancreatic cancer with reliable short-term efficacy. It has an excellent anti-pain effect. The curative results can be further improved when chemotherapy is employed together. However, its long-term efficacy needs to be observed. (authors)

  12. Development of an automation system for Iodine-125 brachytherapy seed encapsulated by Nd:YAG laser welding

    International Nuclear Information System (INIS)

    Somessari, S.L.; Feher, A.; Sprenger, F.E.; Rostelato, M.E.C.M.; Costa, F.E. da; Calvo, W.A.P.

    2011-01-01

    The aim of this work is to develop an automation system for iodine-125 radioactive seed production by Nd:YAG laser welding, which has been used successfully in low dose rate (LDR) brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8 mm in diameter and 4.5 mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at Institute for Nuclear and Energy Research, Sao Paulo, Brazil (IPEN-CNEN/SP) imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources became a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a larger number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with good manufacturing practices (GMP). The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing a programmable logic controller (PLC), a stepper motor, an Nd:YAG laser welding machine and a supervisory. The statistical repeatability of correctly encapsulated sealed sources with this automation system is greater than 95%. (authors)

  13. Development of an automation system for iodine-125 brachytherapy seed production by ND:YAG laser welding

    International Nuclear Information System (INIS)

    Somessari, Samir L.; Feher, Anselmo; Sprenger, Francisco E.; Rostellato, Maria Elisa C.M.; Costa, Fabio E.; Calvo, Wilson A.P.

    2009-01-01

    The aim of this work is to develop an automation system for iodine-125 radioactive seed production by Nd:YAG laser welding, which has been used successfully in low dose rate brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8 mm in diameter and 4.5 mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at IPEN-CNEN/SP imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources became a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a larger number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with good manufacturing practices. The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing a Programmable Logic Controller, a stepper motor, an Nd:YAG laser welding machine and a supervisory. (author)

  14. Development of an automation system for iodine-125 brachytherapy seed production by (Nd:YAG) laser welding

    International Nuclear Information System (INIS)

    Somessari, Samir Luiz

    2010-01-01

    The aim of this work is to develop an automation system for iodine-125 radioactive seed production by (Nd:YAG) laser welding, which has been used successfully in Low Dose Rate (LDR) brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8mm in diameter and 4.5mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at IPEN-CNEN/SP imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources becomes a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a largest number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with Good Manufacturing Practices (GMP). The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing Programmable Logic Controller (PLC), stepper motors, drivers, (Nd:YAG) laser welding machine, photoelectric sensors and supervisory. (author)

  15. Brachytherapy

    Science.gov (United States)

    ... the use of a type of energy, called ionizing radiation, to kill cancer cells and shrink tumors. External ... In all cases of brachytherapy, the source of radiation is encapsulated ... non-radioactive metallic capsule. This prevents the radioactive materials ...

  16. Fast cross-projection algorithm for reconstruction of seeds in prostate brachytherapy

    International Nuclear Information System (INIS)

    Narayanan, Sreeram; Cho, Paul S.; Marks, Robert J. II

    2002-01-01

    A fast method of seed matching and reconstruction in prostrate brachytherapy is proposed. Previous approaches have required all seeds to be matched with all other seeds in other projections. The fast cross-projection algorithm for the reconstruction of seeds (Fast-CARS) allows for matching of a given seed with a subset of seeds in other projections. This subset lies in a proximal region centered about the projection of a line, connecting the seed to its source, onto other projection planes. The proposed technique permits a significant reduction in computational overhead, as measured by the required number of matching tests. The number of multiplications and additions is also vastly reduced at no trade-off in accuracy. Because of its speed, Fast-CARS can be used in applications requiring real-time performance such as intraoperative dosimetry of prostate brachytherapy. Furthermore, the proposed method makes practical the use of a larger number of views as opposed to previous techniques limited to a maximum use of three views

  17. SU-F-19A-11: Retrospective Evaluation of Thermal Coverage by Thermobrachytherapy Seed Arrangements of Clinical LDR Prostate Implants

    Energy Technology Data Exchange (ETDEWEB)

    Warrell, G; Shvydka, D; Chen, C; Parsai, E [University of Toledo Medical Center, Toledo, OH (United States)

    2014-06-15

    Purpose: The superiority of a properly-administered combination of radiation therapy and hyperthermia over radiation alone in treatment of human cancers has been demonstrated in multiple studies examining radiobiology, local control, and survival. Unfortunately, hyperthermia is not yet a common modality in oncology practice, due in part to the technical difficulty of heating a deep-seated target volume to sufficient temperature. To address this problem, our group has invented a thermobrachytherapy (TB) seed based on a commonly-used low dose-rate permanent brachytherapy seed for implant in solid tumors. Instead of the tungsten radiographic marker of the standard seed, the TB seed contains one of a self-regulating ferromagnetic alloy. Placement of a patient implanted with such seeds in an oscillating magnetic field generates heat via induction of eddy currents. We present the results of studies of the capability of clinically-realistic TB seed arrangements to adequately heat defined target volumes. Methods: Seed distributions for several past LDR prostate permanent implant brachytherapy patients were reproduced in the finite element analysis software package COMSOL Multiphysics 4.4, with the difference that TB seeds were modelled, rather than the radiation-only seeds actually used for their treatments. The implant geometries were mainly of the modified peripheral loading type; a range of prostatic volumes and blood perfusion rates likely to be seen in a clinical setting were examined. Results: According to the simulations, when distributed to optimize radiation dose, TB seeds also produce sufficient heat to provide thermal coverage of the target given proper selection of the magnetic field strength. However, the thermal distributions may be improved by additional use of hyperthermia-only seeds. Conclusion: A dual-modality seed intended as an alternative to and using the same implantation apparatus and technique as the standard LDR permanent implant seed has been

  18. Metallic artifact mitigation and organ-constrained tissue assignment for Monte Carlo calculations of permanent implant lung brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, J. G. H.; Miksys, N.; Thomson, R. M., E-mail: rthomson@physics.carleton.ca [Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa, Ontario K1S 5B6 (Canada); Furutani, K. M. [Department of Radiation Oncology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905 (United States)

    2014-01-15

    assignment within lung contours are employed in generated phantoms, this erroneous assignment is reduced, generally resulting in higher doses. Lung-constrained tissue assignment also results in increased doses in regions of interest due to a reduction in the erroneous assignment of adipose to voxels within lung contours. Differences in dose metrics calculated for different computational phantoms are sensitive to radionuclide photon spectra with the largest differences for{sup 103}Pd seeds and smallest but still considerable differences for {sup 131}Cs seeds. Conclusions: Despite producing differences in CT images, dose metrics calculated using the STR, fan beam + STR, and 3D median filter techniques produce similar dose metrics. Results suggest that the accuracy of dose distributions for permanent implant lung brachytherapy is improved by applying lung-constrained tissue assignment schemes to metallic artifact corrected images.

  19. Monte Carlo simulations and radiation dosimetry measurements of 142Pr capillary tube-based radioactive implant (CTRI). A new structure for brachytherapy sources

    International Nuclear Information System (INIS)

    Bakht, M.K.; Haddadi, A.; Sadeghi, M.; Ahmadi, S.J.; Sadjadi, S.S.; Tenreiro, C.

    2013-01-01

    Previously, a promising β - -emitting praseodymium-142 glass seed was proposed for brachytherapy of prostate cancer. In accordance with the previous study, a 142 Pr capillary tube-based radioactive implant (CTRI) was suggested as a source with a new structure to enhance application of β - -emitting radioisotopes such as 142 Pr in brachytherapy. Praseodymium oxide powder was encapsulated in a glass capillary tube. Then, a thin and flexible fluorinated ethylene propylene Teflon layer sealed the capillary tube. The source was activated in the Tehran Research Reactor by the 141 Pr(n, γ) 142 Pr reaction. Measurements of the dosimetric parameters were performed using GafChromic radiochromic film. In addition, the dose rate distribution of 142 Pr CTRI was calculated by modeling 142 Pr source in a water phantom using Monte Carlo N-Particle Transport (MCNP5) Code. The active source was unreactive and did not leak in water. In comparison with the earlier proposed 142 Pr seed, the suggested source showed similar desirable dosimetric characteristics. Moreover, the 142 Pr CTRI production procedure may be technically and economically more feasible. The mass of praseodymium in CTRI structure could be greater than that of the 142 Pr glass seed; therefore, the required irradiation time and the neutron flux could be reduced. A 142 Pr CTRI was proposed for brachytherapy of prostate cancer. The dosimetric calculations by the experimental measurements and Monte Carlo simulation were performed to fulfill the requirements according to the American Association of Physicists in Medicine recommendations before the clinical use of new brachytherapy sources. The characteristics of the suggested source were compared with those of the previously proposed 142 Pr glass seed. (author)

  20. Ropes eye plaque brachytherapy dosimetry for two models of 103Pd seeds

    International Nuclear Information System (INIS)

    Saidi, P.; Sadeghi, M.; Shirazi, A.; Tenreiro, C.

    2011-01-01

    Full text: Brachytherapy dose distributions are calculated for I5 m m ROPES eye plaque loaded with model Theragenics200 and IR06-103Pd seeds. The effects of stainless steel backing and Acrylic insert on dose distribution along the central axis of the eye plaque and at critical ocular structure are investigated. Monte Carlo simulation was carried out with the Version 5 of the MCNP. The dose at critical ocular structure by considering the eye composition was calculated. Results are compared with the calculated data for CaMS eye plaque loaded with Theragenics200 palladium-103 seeds and model 6711 iodine-125 seed. The air kerma strength of the IR06- 103Pd seed to deliver 85 Gy in apex of tumor in water medium was calculated to be 4.10 U/seed. Along the central axis of stainless steel plaque loaded with new 103Pd seeds in Acrylic insert, the dose reduction relative to water is 6.9% at 5 mm (apex). Removal of the Acrylic insert from the plaque (replacing with water) did not make significantly difference in dose reduction results (O.2%). The presence of the stainless steel backing results in dose enhancement near the plaque relative to water. Doses at points of interest are higher for ROPES eye plaque when compared to CaMS eye plaque. The dosimetric parameters calculated in this work for the new palladium seed, showed that in dosimetry point of view, the IR06-103Pd seed is suitable for use in brachytherapy. The effect of Acrylic insert on dose distribution is negligible and the main effect on dose reduction is due to the presence of stainless steel plaque backing. (author)

  1. Interfraction patient motion and implant displacement in prostate high dose rate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Fox, C. D.; Kron, T.; Leahy, M.; Duchesne, G.; Williams, S.; Tai, K. H.; Haworth, A.; Herschtal, A.; Foroudi, F. [Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002 (Australia); Nursing Service, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002 (Australia); Department of Radiation Oncology, Peter MacCallum Cancer Centre and University of Melbourne, Melbourne, Victoria 3002 (Australia); Department of Physical Sciences, Peter MacCallum Cancer Centre and Royal Melbourne Insititute of Technology, Melbourne, Victoria 3000 (Australia); Department of Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002 (Australia); Department of Radiation Oncology, Peter MacCallum Cancer Centre and University of Melbourne, Melbourne, Victoria 3010 (Australia)

    2011-11-15

    Purpose: To quantify movement of prostate cancer patients undergoing treatment, using an in-house developed motion sensor in order to determine a relationship between patient movement and high dose rate (HDR) brachytherapy implant displacement. Methods: An electronic motion sensor was developed based on a three axis accelerometer. HDR brachytherapy treatment for prostate is delivered at this institution in two fractions 24 h apart and 22 patients were monitored for movement over the interval between fractions. The motion sensors functioned as inclinometers, monitoring inclination of both thighs, and the inclination and roll of the abdomen. The implanted HDR brachytherapy catheter set was assessed for displacement relative to fiducial markers in the prostate. Angle measurements and angle differences over a 2 s time base were binned, and the standard deviations of the resulting frequency distributions used as a metric for patient motion in each monitored axis. These parameters were correlated to measured catheter displacement using regression modeling. Results: The mean implant displacement was 12.6 mm in the caudal direction. A mean of 19.95 h data was recorded for the patient cohort. Patients generally moved through a limited range of angles with a mean of the exception of two patients who spent in excess of 2 h lying on their side. When tested for a relationship between movement in any of the four monitored axes and the implant displacement, none was significant. Conclusions: It is not likely that patient movement influences HDR prostate implant displacement. There may be benefits to patient comfort if nursing protocols were relaxed to allow patients greater freedom to move while the implant is in situ.

  2. Interfraction patient motion and implant displacement in prostate high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Fox, C. D.; Kron, T.; Leahy, M.; Duchesne, G.; Williams, S.; Tai, K. H.; Haworth, A.; Herschtal, A.; Foroudi, F.

    2011-01-01

    Purpose: To quantify movement of prostate cancer patients undergoing treatment, using an in-house developed motion sensor in order to determine a relationship between patient movement and high dose rate (HDR) brachytherapy implant displacement. Methods: An electronic motion sensor was developed based on a three axis accelerometer. HDR brachytherapy treatment for prostate is delivered at this institution in two fractions 24 h apart and 22 patients were monitored for movement over the interval between fractions. The motion sensors functioned as inclinometers, monitoring inclination of both thighs, and the inclination and roll of the abdomen. The implanted HDR brachytherapy catheter set was assessed for displacement relative to fiducial markers in the prostate. Angle measurements and angle differences over a 2 s time base were binned, and the standard deviations of the resulting frequency distributions used as a metric for patient motion in each monitored axis. These parameters were correlated to measured catheter displacement using regression modeling. Results: The mean implant displacement was 12.6 mm in the caudal direction. A mean of 19.95 h data was recorded for the patient cohort. Patients generally moved through a limited range of angles with a mean of the exception of two patients who spent in excess of 2 h lying on their side. When tested for a relationship between movement in any of the four monitored axes and the implant displacement, none was significant. Conclusions: It is not likely that patient movement influences HDR prostate implant displacement. There may be benefits to patient comfort if nursing protocols were relaxed to allow patients greater freedom to move while the implant is in situ.

  3. A greedy heuristic using adjoint functions for the optimization of seed and needle configurations in prostate seed implant

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Sua [Department of Radiation Oncology, Duke University Medical Center, Box 3295, Durham, NC 27710 (United States); Kowalok, Michael E [Department of Radiation Oncology, Virginia Commonwealth University Health System, 401 College St., PO Box 980058, Richmond, VA 23298-0058 (United States); Thomadsen, Bruce R [Department of Medical Physics, University of Wisconsin-Madison, 1530 MSC, 1300 University Ave., Madison, WI 53706 (United States); Henderson, Douglass L [Department of Engineering Physics, University of Wisconsin-Madison, 153 Engineering Research Bldg., 1500 Engineering Dr., Madison, WI 53706 (United States)

    2007-02-07

    We continue our work on the development of an efficient treatment-planning algorithm for prostate seed implants by incorporation of an automated seed and needle configuration routine. The treatment-planning algorithm is based on region of interest (ROI) adjoint functions and a greedy heuristic. As defined in this work, the adjoint function of an ROI is the sensitivity of the average dose in the ROI to a unit-strength brachytherapy source at any seed position. The greedy heuristic uses a ratio of target and critical structure adjoint functions to rank seed positions according to their ability to irradiate the target ROI while sparing critical structure ROIs. Because seed positions are ranked in advance and because the greedy heuristic does not modify previously selected seed positions, the greedy heuristic constructs a complete seed configuration quickly. Isodose surface constraints determine the search space and the needle constraint limits the number of needles. This study additionally includes a methodology that scans possible combinations of these constraint values automatically. This automated selection scheme saves the user the effort of manually searching constraint values. With this method, clinically acceptable treatment plans are obtained in less than 2 min. For comparison, the branch-and-bound method used to solve a mixed integer-programming model took close to 2.5 h to arrive at a feasible solution. Both methods achieved good treatment plans, but the speedup provided by the greedy heuristic was a factor of approximately 100. This attribute makes this algorithm suitable for intra-operative real-time treatment planning.

  4. A greedy heuristic using adjoint functions for the optimization of seed and needle configurations in prostate seed implant

    International Nuclear Information System (INIS)

    Yoo, Sua; Kowalok, Michael E; Thomadsen, Bruce R; Henderson, Douglass L

    2007-01-01

    We continue our work on the development of an efficient treatment-planning algorithm for prostate seed implants by incorporation of an automated seed and needle configuration routine. The treatment-planning algorithm is based on region of interest (ROI) adjoint functions and a greedy heuristic. As defined in this work, the adjoint function of an ROI is the sensitivity of the average dose in the ROI to a unit-strength brachytherapy source at any seed position. The greedy heuristic uses a ratio of target and critical structure adjoint functions to rank seed positions according to their ability to irradiate the target ROI while sparing critical structure ROIs. Because seed positions are ranked in advance and because the greedy heuristic does not modify previously selected seed positions, the greedy heuristic constructs a complete seed configuration quickly. Isodose surface constraints determine the search space and the needle constraint limits the number of needles. This study additionally includes a methodology that scans possible combinations of these constraint values automatically. This automated selection scheme saves the user the effort of manually searching constraint values. With this method, clinically acceptable treatment plans are obtained in less than 2 min. For comparison, the branch-and-bound method used to solve a mixed integer-programming model took close to 2.5 h to arrive at a feasible solution. Both methods achieved good treatment plans, but the speedup provided by the greedy heuristic was a factor of approximately 100. This attribute makes this algorithm suitable for intra-operative real-time treatment planning

  5. Development of an Iridium-192 seed for use in ophthalmic brachytherapy

    International Nuclear Information System (INIS)

    Mattos, Fabio R.; Rostelato, Maria Elisa C.M.; Zeituni, Carlos; Moura, Joao A.; Costa, Osvaldo L.; Feher, Anselmo; Moura, Eduardo S.; Souza, Carla D.; Peleias Junior, Fernando S.

    2011-01-01

    The Institute for Energy and Nuclear Research (IPEN), in partnership with the School or Medicine (UNIFESP), created a project that aims to develop and implement an ophthalmic therapeutic treatment for cancer with Iridium-192 seeds. The School of Medicine treats many cancer cases in the SUS (Brazilian Public Health System), and brachytherapy group of IPEN has extensive experience in prototype sources. The seed to be manufactured will perform as follows: a core of Iridium-192 is packaged inside small cylindrical seeds consist of a titanium capsule of 0.8 mm outer diameter, 0.05 mm wall thickness and 4 5 mm in length. The core is an alloy of platinum-iridium (20/80) of 3.0 mm in length and 0.3 mm in diameter. Material analysis, neutron activation and activity measurements were carried out. (author)

  6. CT and MR image fusion using two different methods after prostate brachytherapy: impact on post-implant dosimetric assessment

    International Nuclear Information System (INIS)

    Servois, V.; El Khoury, C.; Lantoine, A.; Ollivier, L.; Neuenschwander, S.; Chauveinc, L.; Cosset, J.M.; Flam, T.; Rosenwald, J.C.

    2003-01-01

    To study different methods of CT and MR images fusion in patient treated by brachytherapy for localized prostate cancer. To compare the results of the dosimetric study realized on CT slices and images fusion. Fourteen cases of patients treated by 1125 were retrospectively studied. The CT examinations were realized with continuous section of 5 mm thickness, and MR images were obtained with a surface coil with contiguous section of 3 mm thickness. For the images fusion process, only the T2 weighted MR sequence was used. Two processes of images fusion were realized for each patient, using as reference marks the bones of the pelvis and the implanted seeds. A quantitative and qualitative appreciation was made by the operators, for each patient and both methods of images fusion. The dosimetric study obtained by a dedicated software was realized on CT images and all types of images fusion. The usual dosimetric indexes (D90, V 100 and V 150) were compared for each type of image. The quantitative results given by the software of images fusion showed a superior accuracy to the one obtained by the pelvic bony reference marks. Conversely, qualitative and quantitative results obtained by the operators showed a better accuracy of the images fusion based on iodine seeds. For two patients out of three presenting a D90 inferior to 145 Gy on CT examination, the D90 was superior to this norm when the dosimetry was based on images fusion, whatever the method used. The images fusion method based on implanted seed matching seems to be more precise than the one using bony reference marks. The dosimetric study realized on images fusion could allow to rectify possible errors, mainly due to difficulties in surrounding prostate contour delimitation on CT images. (authors)

  7. Side effects of permanent I125 prostate seed implants in 667 patients treated in Leeds

    International Nuclear Information System (INIS)

    Bottomley, David; Ash, Dan; Al-Qaisieh, Bashar; Carey, Brendan; Joseph, Joji; St Clair, Shaun; Gould, Kathy

    2007-01-01

    Purpose: To report the side effects and complications after I-125 seeds prostate implant after 8.5 years experience. Methods and materials: Six hundred and sixty seven (667) patients were treated between March 1995 and December 2001. The median follow up is 31 months with a maximum of 98.2 months. Morbidity data were collected from a review of patient case-notes. Patients also provided prospective data on urinary symptoms using the International Prostate Symptom Score (IPSS) scoring chart before treatment and at regular follow up. Patients were also sent a questionnaire detailing symptoms and side effects following their brachytherapy. This enabled them to record urinary, bowel and sexual function side effects independently. Logistic regression analysis was carried out to identify the risk of catheterisation in relation to the pre-implant prostate volume and potential implant factors such as the number of seeds and needles and implant dose. Result: The urinary symptom score rises in the first few months after implantation and returns to within one or two points of the pre-treatment score within one year. Nine patients reported incontinence prior to treatment and 15, 12 and 10 patients reported incontinence 6, 12 and 24 months after treatment, respectively. Catheterisation was reported in 97 (14.5%) patients. At six months 84.9% of patients reported no change in bowel function and 78.9% at 12 months. 6.4% of patients complained of some increased bowel frequency at 6 months and 5.7% at 12 months. 402 (77.2%) patients reported being fully potent before treatment and that this fell to 32.4% after treatment. Logistic regression showed that the most significant factors which correlate with the probability of catheterisation are the pre-treatment prostate volume and the number of seeds and needles implanted. Conclusion: The side effects and complications after prostate brachytherapy as reported here and elsewhere confirm that the treatment is not only convenient but also

  8. Influence of 125I seed interstitial brachytherapy on recovery of facial nerve function

    International Nuclear Information System (INIS)

    Song Tieli; Zheng Lei; Zhang Jie; Cai Zhigang; Yang Zhaohui; Yu Guangyan; Zhang Jianguo

    2010-01-01

    Objective: To study the influence of 125 I seed interstitial brachytherapy in parotid region on the recovery of facial nerve function. Methods: A total of the data of 21 patients with primary parotid carcinoma were treated with resection and 125 I interstitial brachytherapy. All the patients had no facial palsy before operation and the prescribed dose was 60 Gy. During 4 years of follow-up, the House-Brackmann grading scales and ENoG were used to evaluate the function of facial nerve. According to the modified regional House-Brackmann grading scales, the facial nerve branches of patients in affected side were divided into normal and abnormal groups, and were compared with those in contra-lateral side. Results: Post-operation facial palsy occurred in all the patients, but the facial palsy recovered within 6 months. The latency time differences between affected side and contralateral side were statistically significant in abnormal group from 1 week to 6 months after treatment (t=2.362, P=0.028), and were also different in normal group 1 week after treatment (t=2.522, P=0.027). Conclusions: 125 I interstitital brachytherapy has no influence on recovery of facial nerve function after tumor resection and no delayed facial nerve damage. (authors)

  9. An orthodontic device for retaining implanted radioactive sources during brachytherapy for cancer of the oral cavity

    International Nuclear Information System (INIS)

    Masuko, Noriko; Katsura, Kouji; Sugita, Tadashi; Sakai, Kunio; Sato, Katsurou; Kawana, Masahiro; Nonomura, Naobumi

    2000-01-01

    An orthodontic retainer was devised to keeping implanted radioactive sources in position and improve the quality of life during brachytherapy for cancer of the oral cavity. The retainer was used in 3 patients with oral cancer, one with cancer of the hard palate, one with cancer of the soft palate, and one with cancer of the floor of mouth, during brachytherapy using 198 Au grains and 137 Cs needles. These patients could speak freely. One with cancer of the hard palate could drink water and ingest semi-liquid food during treatment instead of nasal tube feeding. The plaster dental model obtained while making the retainer proved to be useful for training radiation oncologists. (author)

  10. Dosimetry on ocular brachytherapy with ROPES plaque with Iodine-125 and Palladium-103 seeds

    International Nuclear Information System (INIS)

    Mourao, Arnaldo P.; Campos, Tarcisio P.R.

    2010-01-01

    Radiotherapy is an alternative to ocular enucleation. However, the irradiation of ocular region can bring deleterious effects due to the high doses, mainly in the lens, retina and in the bone structures in growth phase. Brachytherapy instead of teletherapy looks for departuring absorbed doses in tumor minimizing doses in the lens and the adjacent tissues of the eyeball (orbital region), avoiding deleterious effects. Thus, a three-dimensional computational model of ocular area was developed to simulate orbital irradiation with ROPES ophthalmologic plaque placed on the sclera surface filled to ten iodine-125 seeds, and palladium-103 seeds. Simulations are performed on the MCNP5 code. The computational simulation allows evaluating how the dose rates are spatially distributed in the orbital volume. The results are normalized to 100% at the maximum dose on the tumor base, and by the applied source activity. The maximum dose is found onto the eyeball, in the vitreous. The present model represents an advance in simulating and predicting absorbed dose on ocular brachytherapy. (author)

  11. 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.

  12. Radiation protective nursing intervene of 125I seed implantation in non-small cell lung carcinoma guided by CT

    International Nuclear Information System (INIS)

    Fu Li; Zhang Zuncheng; Yu Zhaochen; Zheng Guangjun; Tian Meirong

    2009-01-01

    Objective: To research radiation protective nursing intervene and important notice of 125 I seeds minimally invasive implantation in non-small cell lung carcinoma (NSCLC) by CT. Methods: Under the system of therapy planning system (TPS) and posologic validation, 125 I seeds were implanted in 89 cases of NSCLC patients. The consistent radiation protective nursing intervene was used in perioperative period management. The operative successful rate, therapeutic effect and complication rate, therapeutic effect and complication rate was observed. Results: The scientific radiation protective nursing intervene can ensure that the radioactive dose distribution of 125 I seed implantation brachytherapy is consistent with the principles of effective and minimally invasive. The operative successful rate was 100%. The local control rate and 1 year survival rate respectively was 97.4% and 92.2%. But the early and later incidence rate of radioactive damaging effect was 14.6% and 1.1% respectively. Leakage of radioactive contamination has not occurred. Conclusion: The consistent TPS and posologic validation 125 I seeds implantation integrated scientific radiation protective nursing intervene. It is very important to improve the therapeutic effect of NSCLC and reduce the incidence of complications. (authors)

  13. The surgical viability and radiological monitoring of brain implants of bioactive micro-seeds in an animal model

    Directory of Open Access Journals (Sweden)

    Giane X. O. Silva

    2005-10-01

    Full Text Available The interstitial implant is a therapeutic modality in brachytherapy of the head and neck. Presently, the seeds implanted in tumors in the central nervous system are metallic I-125. After the full emission of the radionuclide, the seed remains inert in the implanted area. Bioactive ceramic seeds have been prepared for this research group incorporating Sm-152 to be active in Sm-153. The main goal of the present study is the development of a the surgical technique for implanting the biodegradable radioactive micro-seeds in the brains of rabbits, as well as the observation of the clinical reactions of the animal after implantation of two sets of three seeds. The surgical procedure consisted of performing two separate perforations 10 mm from each other in the skull, permitting the implantation of two groups of three seeds, totaling six seeds. The results of the pilot study showed the effectiveness of the surgical procedure and of the biocompatibility of the seeds and the lack of presence of adverse reactions, functional sequels, or inflammation in a follow up 50 days post-surgery. Such seeds of reduced volume, 0.2 x 1.6 mm, could be monitored by computerized tomography 30 days after implanting.Os implantes intersticiais podem ser utilizados em braquiterapia de cabeça e pescoço. Atualmente as sementes implantadas no CNS são de I-125 metálicas. Após o decaimento do radioisótopo, a semente fica inerte na região implantada. Sementes cerâmicas bioativas tem sido preparadas pelo grupo de pesquisa incorporando Sm-152. O presente estudo tem o objetivo de viabilizar a técnica cirúrgica de implantes de microsementes biodegradáveis não radioativas no cérebro de coelhos, bem como verificar as reações clínicas e funcionais do animal ao corpo estranho implantado. O procedimento cirúrgico compreendeu em proceder duas perfurações separadas em 10mm na calota craniana onde foi possível a implantação de dois conjuntos de três sementes

  14. The incidence of radioepidermitis and the dose-response relationship in parotid gland cancer patients treated with 125I seed brachytherapy. Incidence of radioepidermitis and the dose-response relationship

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Ming-Hui; Zheng, Lei; Gao, Hong; Zhang, Jie; Liu, Shu-ming; Huang, Ming-wei; Shi, Yan [Peking University School and Hospital of Stomatology, Department of Oral and Maxillofacial Surgery, Beijing (China); Zhang, Jian-Guo [Peking University School and Hospital of Stomatology, Department of Oral and Maxillofacial Surgery, Beijing (China); Fujian Provincial Hospital, Fujian (China)

    2014-09-09

    We studied the incidence and dose-response relationship of radioepidermitis in parotid gland carcinoma patients treated with [{sup 125}I] seed brachytherapy in the hopes of designing an optimized pre-implant treatment plan that would reduce the incidence and severity of radioepidermitis in patients receiving this therapy. Between January 2007 and May 2010, 100 parotid gland cancer patients were treated postoperatively with [{sup 125}I] seed brachytherapy. The matched peripheral dose (MPD) was 80-140 Gy, and [{sup 125}I] seed activity was 0.7-0.8 mCi. The mean dose delivered to the skin was calculated in the post-implant CT on day 0 following implantation. Grades of acute and late dermatitis were evaluated at 2, 6, 12, and 18 months post-implantation. Most patients experienced grade 0-2 acute and late skin side effects (86 and 97 %, respectively), though a small subset developed severe complications. Most grade 1-3 effects resolved within 6 months of implantation, though some grade 1-3 effects and all grade 4 effects remained unchanged throughout the 18-month follow-up period. Grade 3 and 4 effects were most prominent (75 and 25 %, respectively) with doses of 110-140 Gy; doses higher than 140 Gy produced only grade 4 effects. [{sup 125}I] seed brachytherapy produced acceptable levels of acute and late radioepidermitis with a good clinical outcome. A mean dose under 100 Gy delivered to the skin was safe, though doses of 110-140 Gy should be given with caution and extra monitoring; doses greater than 140 Gy are dangerous and likely to produce grade 4-5 effects. (orig.) [German] Wir untersuchten die Inzidenz und die Dosis-Wirkung-Beziehung bei Patienten mit Ohrspeicheldruesenkrebs, die mit [{sup 125}I]-Seed-Brachytherapie behandelt wurden, in der Hoffnung, eine optimierte praeimplantologische Behandlung zu entwickeln, welche die Inzidenz und Schwere der Radioepidermitis bei Patienten, die diese Therapie erhalten haben, reduziert. Zwischen Januar 2007 und Mai 2010

  15. Seed-migration detector for embolized seeds to the lung in the context of permanent iodine-125 prostate brachytherapy

    International Nuclear Information System (INIS)

    Morrier, J.; Chretien, M.; Beaulieu, L.

    2008-01-01

    Full text: Purpose: To evaluate the efficacy of a seed-migration detector for embolized seeds to the lung in the context of permanent iodine-125 prostate brachytherapy and to compare its performance to fluoroscopy and to the postoperative chest radiographs generally recommended. Materials and Methods: A low energy gamma scintillation survey meter, Victoreen Model 425-110 was used together with a Victoreen count rate meter (model 190). It was converted to a seed-migration detector by adding a shield on the scintillation probe detection window, following the method proposed by Chen and Blair in 2003 [Med Phys 2003;30:785790]. The detector response to three seeds activities of iodine 125 (0.42, 0.22 and 0.06 mCi) was measured for different source-to-detector distances in air and in water. The detector was used to perform a chest evaluation on 579 patients at their first postoperative visit, for a total of 31 826 seeds. When the detector showed activity around a patients chest, it was confirmed by taking an antero-posterior chest radiograph and by looking at the region with fluoroscopy. Results: 79 patients (13.6%) present at least one embolized seed in the chest area. This account for 94 of the 31 826 seeds, that is a 0.30% seed migration rate. Sixty-eight, seven and four patients had respectively a single, two and three seeds embolization. In three cases, a seed had migrated in the kidney, which was confirmed with a CT scan. Of the 94 seeds, 67 (71%) were visible under fluoroscopy and 55 (59%) appeared on the chest radiograph. Rapid movement of the seeds in the chest area, due to breathing or to a location close to the heart or the diaphragm, makes nine seeds to be visible with fluoroscopy but not on the radiograph. This also explains why twenty-seven seeds were not visible with fluoroscopy neither with radiograph. In comparison to the seed-migration detector, detection based on fluoroscopy would have led to twenty-seven false-negative detections while the radiograph

  16. Use of brachytherapy with permanent implants of iodine-125 in localized prostate cancer

    International Nuclear Information System (INIS)

    Bladou, F.; Serment, G.; Salem, N.; Simonian, M.; Rosello, R.; Ternier, F.

    2002-01-01

    Approximately 15,000 cases of early stage prostate cancer T1 and T2 are diagnosed every year in France by testing for PSA and performing prostatic biopsies. The treatment of these localized forms is based in most cases on radical prostatectomy or nn external beam radiotherapy. Although the ontological results obtained by these two therapeutic methods are satisfactory and equivalent in the long term, the side effects can be important. For a number of years, trans-perineal brachytherapy using permanent implants of iodine -125 or palladium-103 has proved itself as an alternative therapy with equivalent medium to long-term results. The low urinary, digestive and sexual side effects of prostate brachytherapy are important reasons for the enthusiasm among patients and the medical community for this therapy and the growing number of applications and centres which practice it. In September 1998 we started the prostate brachytherapy programmes- in Marseilles with close collaboration between the department of urology of the Hopital Salvator, and the departments of radiotherapy, medical imaging and medical physics of the Institut Paoli-Calmettes. To date, around 250 patients with localized adenocarcinoma of the prostate have benefited from this alternative therapy in our centre. Preliminary results, with a 3 year-follow-up, are comparable to results published in the literature by pioneer teams. (authors)

  17. Three dimensional implementation of anisotropy corrected fast fourier transform dose calculation around brachytherapy seeds

    International Nuclear Information System (INIS)

    Kyeremeh, P.O.

    2011-01-01

    Current-available brachytherapy dose computation algorithms ignore heterogeneities such as tissue-air interfaces, shielded gynaecological colpostats, and tissue-composition variations in source implants despite dose computation errors as large as 40%. A convolution kernel, which takes into consideration anisotropy of the dose distribution around a brachytherapy source, and to compute dose in the presence of tissue and applicator heterogeneities, has been established. Resulting from the convolution kernel are functions with polynomial and exponential terms. the solution to the convolution integral was represented by the Fast Fourier transform. The Fast Fourier transform has shown enough potency in accounting for errors due to these heterogeneities and the versatility of this Fast Fourier transform is evident from its capability of switching in between fields. Thus successful procedures in external beam could be adopted in brachytherapy to a yield similar effect. A dose deposition kernel was developed for a 64x64x64 matrix size with wrap around ordering and convoluted with the distribution of the sources in 3D. With MatLab's inverse Fast Fourier transform, dose rate distribution for a given array of interstitial sources, typical of brachytherapy was calculated. The shape of the dose rate distribution peaks appeared comparable with the output expected from computerized treatment planning systems for brachytherapy. Subsequently, the study confirmed the speed and accuracy of dose computation using the FFT convolution as well juxtaposed. Although, dose rate peaks from both the FFT convolution and the TPS(TG43) did not compare quantitatively, which was mainly due to the TPS(TG43) initiation computations from the origin (0,0,0) unlike the FFT convolution which uses sampling points; N=1,2,3..., there is a strong basis for establishing parity since the dose rate peaks compared qualitatively. With both modes compared, the discrepancies in the dose rates ranged between 3.6% to

  18. Comparison of intraoperative dosimetric implant representation with postimplant dosimetry in patients receiving prostate brachytherapy.

    Science.gov (United States)

    Stone, Nelson N; Hong, Suzanne; Lo, Yeh-Chi; Howard, Victor; Stock, Richard G

    2003-01-01

    To compare the results of intraoperative dosimetry with those of CT-based postimplant dosimetry in patients undergoing prostate seed implantation. Seventy-seven patients with T1-T3 prostate cancer received an ultrasound-guided permanent seed implant (36 received (125)I, 7 (103)Pd, and 34 a partial (103)Pd implant plus external beam radiation therapy). The implantation was augmented with an intraoperative dosimetric planning system. After the peripheral needles were placed, 5-mm axial images were acquired into the treatment planning system. Soft tissue structures (prostate, urethra, and rectum) were contoured, and exact needle positions were registered. Seeds were placed with an applicator, and their positions were entered into the planning system. The dose distributions for the implant were calculated after interior needle and seed placement. Postimplant dosimetry was performed 1 month later on the basis of CT imaging. Prostate and urethral doses were compared, by using paired t tests, for the real-time dosimetry in the operating room (OR) and the postimplant dosimetry. The mean preimplant prostate volume was 39.8 cm(3), the postneedle planning volume was 41.5 cm(3) (psystem provides a close match to the actual delivered doses. These data support the use of this system to modify the implant during surgery to achieve more consistent dosimetry results.

  19. SU-E-J-233: Effect of Brachytherapy Seed Artifacts in T2 and Proton Density Maps in MR Images

    Energy Technology Data Exchange (ETDEWEB)

    Mashouf, S [Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); University of Toronto, Dept of Radiation Oncology, Toronto, Ontario (Canada); Fatemi-Ardekani, A [Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Sunnybrook Research Institute, Toronto, Ontario (Canada); Song, W [Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); University of Toronto, Dept of Radiation Oncology, Toronto, Ontario (Canada); Sunnybrook Research Institute, Toronto, Ontario (Canada)

    2015-06-15

    Purpose: This study aims at investigating the influence of brachytherapy seeds on T2 and proton density (PD) maps generated from MR images. Proton density maps can be used to extract water content. Since dose absorbed in tissue surrounding low energy brachytherapy seeds are highly influenced by tissue composition, knowing the water content is a first step towards implementing a heterogeneity correction algorithm using MR images. Methods: An LDR brachytherapy (IsoAid Advantage Pd-103) seed was placed in the middle of an agar-based gel phantom and imaged using a 3T Philips MR scanner with a 168-channel head coil. A multiple echo sequence with TE=20, 40, 60, 80, 100 (ms) with large repetition time (TR=6259ms) was used to extract T2 and PD maps. Results: Seed artifacts were considerably reduced on T2 maps compared to PD maps. The variation of PD around the mean was obtained as −97% to 125% (±1%) while for T2 it was recorded as −71% to 24% (±1%). Conclusion: PD maps which are required for heterogeneity corrections are susceptible to artifacts from seeds. Seed artifacts on T2 maps, however, are significantly reduced due to not being sensitive to B0 field variation.

  20. American brachytherapy society recommends no change for prostate permanent implant dose prescriptions using iodine-125 or palladium-103

    International Nuclear Information System (INIS)

    Rivard, M.J.; Butler, W.M.; Merrick, G.S.; Devlin, P.M.; Hayes, J.K.; Hearn, R.A.; Lief, E.P.; Meigooni, A.S.; Williamson, J.F.

    2008-01-01

    Purpose - In 2004, the American Association of Physicists in Medicine (AAPM) issued a report outlining recommended 125 I and 103 Pd datasets for consistency in calculating brachytherapy dose distributions. In 2005, to aid evaluating the clinical impact of implementing these datasets, the AAPM assessed the historical dependence of how prescribed doses differed from administered doses for 125 I and 103 Pd for permanent implantation of the prostate. Consequently, the American Brachytherapy Society (ABS) considered the nature of these changes towards issuing recommended dose prescriptions for 125 I and 103 Pd interstitial brachytherapy implants for mono-therapy and standard boosts. Methods and materials - An investigation was performed of the 2005 AAPM analysis to determine changes in administered dose while affixing prescribed dose using 2004 AAPM 125 I and 103 Pd brachytherapy dosimetry datasets for prostate implants. For 125 I and 103 Pd, administered dose would change by +1.4% and +4.2%, respectively. The biological and societal impact of changing prescribed dose was considered. Results - Based on the need for clinical constancy and in recognition of overall uncertainties, the ABS recommends immediate implementation of the 2004 AAPM consensus brachytherapy dosimetry datasets and no changes to 125 I and 103 Pd dose prescriptions at this time. Conclusions - Radiation oncologists should continue to prescribe mono-therapy doses of 145 Gy and 125 Gy for 125 I and 105 Pd, respectively, and standard boost doses of 100-110 Gy and 90-100 Gy for 125 I and 103 Pd, respectively. (authors)

  1. Twelve-Month Prostate-Specific Antigen Values and Perineural Invasion as Strong Independent Prognostic Variables of Long-Term Biochemical Outcome After Prostate Seed Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ding, William, E-mail: billyding888@gmail.com [Department of Radiation Oncology, California Pacific Medical Center, San Francisco, California (United States); Lee, John [Department of Radiation Oncology, California Pacific Medical Center, San Francisco, California (United States); Chamberlain, David [Department of Radiation Oncology, St. Mary' s Regional Medical Center, Reno, Nevada (United States); Cunningham, James [Carson Urology, Carson City, Nevada (United States); Yang Lixi [Department of Radiation Oncology, California Pacific Medical Center, San Francisco, California (United States); Tay, Jonathan [Department of Radiation Oncology, St. Mary' s Regional Medical Center, Reno, Nevada (United States)

    2012-11-15

    Purpose: To determine whether post-treatment prostate-specific antigen (ptPSA) values at 12 months and other clinical parameters predict long-term PSA relapse-free survival (PRFS) following prostate seed brachytherapy. Methods and Materials: Records of 204 hormone-naieve patients with localized adenocarcinoma of the prostate treated at St. Mary's Regional Medical Center in Reno, NV, and at Carson Tahoe Regional Medical Center in Carson City, NV, between 1998 and 2003, using I-125 or Pd-103 seed brachytherapy, were retrospectively analyzed. Treatment planning was done using a preplanned, modified peripheral loading technique. A total of 185 of 204 patients had PSA records at 12 months after implant. Variables included were age, initial pretreatment PSA, Gleason score, T stage, National Comprehensive Cancer Network (NCCN) risk group (RG), perineural invasion (PNI), external beam boost, dose, and ptPSA levels at 12 months with cutpoints at {<=}1, 1.01 to 2.00, 2.01 to 3.00, and >3.00 ng/ml. Results: Median follow-up was 80 months, and median age was 69 years. The numbers of patients stratified by NCCN low, intermediate, and high RG were 110:65:10, respectively. Monotherapy and boost prescription doses were 145 Gy and 110 Gy for I-125, and 125 Gy and 100 Gy for Pd-103 seeds, respectively. The median dose (D90) was 95.4% of the prescribed dose. The 5-year PRFS at the 12-months ptPSA levels of {<=}1, 1.01 to 2.00, 2.01 to 3.00, and >3.00 ng/ml were 98.5%, 85.7%, 61.5%, and 22.2%, respectively. The 10-year PRFS at the 12-months ptPSA levels of {<=}1 and 1.01 to 2.00 ng/ml were 90.5% and 85.7%, respectively. In multivariate analysis, both ptPSA and PNI were significant independent predictors of PRFS. Hazard ratios (HR) for ptPSA levels at {<=}1, 1.01 to 2.00, 2.01 to 3.00, and >3.00 ng/ml at 12 months were 1, 4.96, 27.57, and 65.10, respectively. PNI had an HR of 6.1 (p = 0.009). Conclusions: Presence of PNI and ptPSA values at 12 months are strong prognostic

  2. Twelve-Month Prostate-Specific Antigen Values and Perineural Invasion as Strong Independent Prognostic Variables of Long-Term Biochemical Outcome After Prostate Seed Brachytherapy

    International Nuclear Information System (INIS)

    Ding, William; Lee, John; Chamberlain, David; Cunningham, James; Yang Lixi; Tay, Jonathan

    2012-01-01

    Purpose: To determine whether post-treatment prostate-specific antigen (ptPSA) values at 12 months and other clinical parameters predict long-term PSA relapse-free survival (PRFS) following prostate seed brachytherapy. Methods and Materials: Records of 204 hormone-naïve patients with localized adenocarcinoma of the prostate treated at St. Mary’s Regional Medical Center in Reno, NV, and at Carson Tahoe Regional Medical Center in Carson City, NV, between 1998 and 2003, using I-125 or Pd-103 seed brachytherapy, were retrospectively analyzed. Treatment planning was done using a preplanned, modified peripheral loading technique. A total of 185 of 204 patients had PSA records at 12 months after implant. Variables included were age, initial pretreatment PSA, Gleason score, T stage, National Comprehensive Cancer Network (NCCN) risk group (RG), perineural invasion (PNI), external beam boost, dose, and ptPSA levels at 12 months with cutpoints at ≤1, 1.01 to 2.00, 2.01 to 3.00, and >3.00 ng/ml. Results: Median follow-up was 80 months, and median age was 69 years. The numbers of patients stratified by NCCN low, intermediate, and high RG were 110:65:10, respectively. Monotherapy and boost prescription doses were 145 Gy and 110 Gy for I-125, and 125 Gy and 100 Gy for Pd-103 seeds, respectively. The median dose (D90) was 95.4% of the prescribed dose. The 5-year PRFS at the 12-months ptPSA levels of ≤1, 1.01 to 2.00, 2.01 to 3.00, and >3.00 ng/ml were 98.5%, 85.7%, 61.5%, and 22.2%, respectively. The 10-year PRFS at the 12-months ptPSA levels of ≤1 and 1.01 to 2.00 ng/ml were 90.5% and 85.7%, respectively. In multivariate analysis, both ptPSA and PNI were significant independent predictors of PRFS. Hazard ratios (HR) for ptPSA levels at ≤1, 1.01 to 2.00, 2.01 to 3.00, and >3.00 ng/ml at 12 months were 1, 4.96, 27.57, and 65.10, respectively. PNI had an HR of 6.1 (p = 0.009). Conclusions: Presence of PNI and ptPSA values at 12 months are strong prognostic variables for

  3. SU-F-T-09: In Phantom Full-Implant Validation of Plastic Scintillation Detectors for in Vivo Dosimetry During Low Dose Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Therriault-Proulx, F; Bruno, T; Beddar, S [UT MD Anderson Cancer Center, Houston, TX (United States); Beaulieu, L [CHU de Quebec, Quebec, QC, CA (Canada)

    2016-06-15

    Purpose: To validate in a water phantom the use of plastic scintillation detectors to measure dose to the urethra and the rectal wall during a clinically realistic low dose rate (LDR) brachytherapy implant. Methods: A template was designed to replicate a clinically realistic LDR brachytherapy prostate implant inside a water phantom. Twenty-two catheters were inserted, including one mimicking the urethra and another the rectal wall. The needles inserted in the remaining 20 catheters were composed of thin-walled nylon tubes in which I-125 radioactive seeds (Air Kerma Strengths of (0.328±0.020)U) were abutted together with plastic spacers to replicate a typical loading. A plastic scintillation detector (PSD) with a 5-mm long × 1-mm diameter sensitive element was first placed inside the urethra and 1-second measurements were performed for 60s after each needle implant. Measurements were also performed at multiple positions along the urethra once all the needles were inserted. The procedure was then repeated with the PSD placed at the rectal wall. Results: Individual dose-rates ranging from 0.07µGy/s to 1.5µGy/s were measured after each needle implant. The average absolute relative differences were (6.2±3.6)% and (6.9±6.5)% to the values calculated with the TG-43 formalism, for the urethra and rectal wall respectively. These results are within expectations from the error uncertainty budget once accounting for uncertainties in seeds’ strength and positioning. Interestingly, the PSD allowed for unplanned error detection as the study was performed. Finally, the measured dose after the full implant at different positions along the mimicked organs at risk were in agreement with TG-43 values for all of the positions tested. Conclusion: Plastic scintillation detectors could be used as in vivo detectors for LDR brachytherapy as they would provide accurate dose information after each needle implant as well as along the organs at risk at the end of the implant.

  4. Poster - Thur Eve - 06: Comparison of an open source genetic algorithm to the commercially used IPSA for generation of seed distributions in LDR prostate brachytherapy.

    Science.gov (United States)

    McGeachy, P; Khan, R

    2012-07-01

    In early stage prostate cancer, low dose rate (LDR) prostate brachytherapy is a favorable treatment modality, where small radioactive seeds are permanently implanted throughout the prostate. Treatment centres currently rely on a commercial optimization algorithm, IPSA, to generate seed distributions for treatment plans. However, commercial software does not allow the user access to the source code, thus reducing the flexibility for treatment planning and impeding any implementation of new and, perhaps, improved clinical techniques. An open source genetic algorithm (GA) has been encoded in MATLAB to generate seed distributions for a simplified prostate and urethra model. To assess the quality of the seed distributions created by the GA, both the GA and IPSA were used to generate seed distributions for two clinically relevant scenarios and the quality of the GA distributions relative to IPSA distributions and clinically accepted standards for seed distributions was investigated. The first clinically relevant scenario involved generating seed distributions for three different prostate volumes (19.2 cc, 32.4 cc, and 54.7 cc). The second scenario involved generating distributions for three separate seed activities (0.397 mCi, 0.455 mCi, and 0.5 mCi). Both GA and IPSA met the clinically accepted criteria for the two scenarios, where distributions produced by the GA were comparable to IPSA in terms of full coverage of the prostate by the prescribed dose, and minimized dose to the urethra, which passed straight through the prostate. Further, the GA offered improved reduction of high dose regions (i.e hot spots) within the planned target volume. © 2012 American Association of Physicists in Medicine.

  5. Stereotactic iodine-125 brachytherapy for brain tumors: temporary versus permanent implantation

    Directory of Open Access Journals (Sweden)

    Ruge Maximilian I

    2012-06-01

    Full Text Available Abstract Stereotactic brachytherapy (SBT has been described in several publications as an effective, minimal invasive and safe highly focal treatment option in selected patients with well circumscribed brain tumors 40 cGy/h in combination with adjuvant external beam radiation and/or chemotherapy for the treatment of malignant gliomas and metastases resulted in increased rates of radiation induced adverse tissue changes requiring surgical intervention. Vice versa, such effects have been only minimally observed in numerous studies applying low dose rate (LDR regiments (3–8 cGy/h for low grade gliomas, metastases and other rare indications. Besides these observations, there are, however, no data available directly comparing the long term incidences of tissue changes after HDR and LDR and there is, furthermore, no evidence regarding a difference between temporary or permanent LDR implantation schemes. Thus, recommendations for effective and safe implantation schemes have to be investigated and compared in future studies.

  6. Development of virtual patient models for permanent implant brachytherapy Monte Carlo dose calculations: interdependence of CT image artifact mitigation and tissue assignment.

    Science.gov (United States)

    Miksys, N; Xu, C; Beaulieu, L; Thomson, R M

    2015-08-07

    This work investigates and compares CT image metallic artifact reduction (MAR) methods and tissue assignment schemes (TAS) for the development of virtual patient models for permanent implant brachytherapy Monte Carlo (MC) dose calculations. Four MAR techniques are investigated to mitigate seed artifacts from post-implant CT images of a homogeneous phantom and eight prostate patients: a raw sinogram approach using the original CT scanner data and three methods (simple threshold replacement (STR), 3D median filter, and virtual sinogram) requiring only the reconstructed CT image. Virtual patient models are developed using six TAS ranging from the AAPM-ESTRO-ABG TG-186 basic approach of assigning uniform density tissues (resulting in a model not dependent on MAR) to more complex models assigning prostate, calcification, and mixtures of prostate and calcification using CT-derived densities. The EGSnrc user-code BrachyDose is employed to calculate dose distributions. All four MAR methods eliminate bright seed spot artifacts, and the image-based methods provide comparable mitigation of artifacts compared with the raw sinogram approach. However, each MAR technique has limitations: STR is unable to mitigate low CT number artifacts, the median filter blurs the image which challenges the preservation of tissue heterogeneities, and both sinogram approaches introduce new streaks. Large local dose differences are generally due to differences in voxel tissue-type rather than mass density. The largest differences in target dose metrics (D90, V100, V150), over 50% lower compared to the other models, are when uncorrected CT images are used with TAS that consider calcifications. Metrics found using models which include calcifications are generally a few percent lower than prostate-only models. Generally, metrics from any MAR method and any TAS which considers calcifications agree within 6%. Overall, the studied MAR methods and TAS show promise for further retrospective MC dose

  7. Monte Carlo investigation of I-125 interseed attenuation for standard and thinner seeds in prostate brachytherapy with phantom validation using a MOSFET.

    Science.gov (United States)

    Mason, J; Al-Qaisieh, B; Bownes, P; Henry, A; Thwaites, D

    2013-03-01

    In permanent seed implant prostate brachytherapy the actual dose delivered to the patient may be less than that calculated by TG-43U1 due to interseed attenuation (ISA) and differences between prostate tissue composition and water. In this study the magnitude of the ISA effect is assessed in a phantom and in clinical prostate postimplant cases. Results are compared for seed models 6711 and 9011 with 0.8 and 0.5 mm diameters, respectively. A polymethyl methacrylate (PMMA) phantom was designed to perform ISA measurements in a simple eight-seed arrangement and at the center of an implant of 36 seeds. Monte Carlo (MC) simulation and experimental measurements using a MOSFET dosimeter were used to measure dose rate and the ISA effect. MC simulations of 15 CT-based postimplant prostate treatment plans were performed to compare the clinical impact of ISA on dose to prostate, urethra, rectum, and the volume enclosed by the 100% isodose, for 6711 and 9011 seed models. In the phantom, ISA reduced the dose rate at the MOSFET position by 8.6%-18.3% (6711) and 7.8%-16.7% (9011) depending on the measurement configuration. MOSFET measured dose rates agreed with MC simulation predictions within the MOSFET measurement uncertainty, which ranged from 5.5% to 7.2% depending on the measurement configuration (k = 1, for the mean of four measurements). For 15 clinical implants, the mean ISA effect for 6711 was to reduce prostate D90 by 4.2 Gy (3%), prostate V100 by 0.5 cc (1.4%), urethra D10 by 11.3 Gy (4.4%), rectal D2cc by 5.5 Gy (4.6%), and the 100% isodose volume by 2.3 cc. For the 9011 seed the mean ISA effect reduced prostate D90 by 2.2 Gy (1.6%), prostate V100 by 0.3 cc (0.7%), urethra D10 by 8.0 Gy (3.2%), rectal D2cc by 3.1 Gy (2.7%), and the 100% isodose volume by 1.2 cc. Differences between the MC simulation and TG-43U1 consensus data for the 6711 seed model had a similar impact, reducing mean prostate D90 by 6 Gy (4.2%) and V100 by 0.6 cc (1.8%). ISA causes the delivered dose

  8. Studies on the preparation of 103Pd inner core of seed sources for brachytherapy applications

    International Nuclear Information System (INIS)

    Saha, Sujata; Manolkar, R.B.; Vimalnath, K.V.; Dash, A.; Venkatesh, Meera

    2007-01-01

    103 Pd seed sources are used widely world over for brachytherapy applications. 103 Pd available in-house was used to study its deposition on silver wire using electro-deposition and electroless deposition techniques with an aim to developing the inner core preparation of sealed radiation sources for treatment of prostate and ocular melanoma. Various parameters such as radioactive concentration of the feed solution, current density, time, temperature and pH of the solution were optimized to achieve maximum 103 Pd deposition on Ag wire. In electroless technique, the deposited amount of Pd was found to be nearly triple compared to electro-deposition in two hours time period. Both the methods gave nonleachable and well adherent sources. (author)

  9. COMP report: CPQR technical quality control guidelines for low-dose-rate permanent seed brachytherapy.

    Science.gov (United States)

    Beaulieu, Luc; Radford, Dee-Ann; Eduardo Villarreal-Barajas, J

    2018-03-14

    The Canadian Organization of Medical Physicists (COMP), in close partnership with the Canadian Partnership for Quality Radiotherapy (CPQR) has developed a series of Technical Quality Control (TQC) guidelines for radiation treatment equipment. These guidelines outline the performance objectives that equipment should meet in order to ensure an acceptable level of radiation treatment quality. The TQC guidelines have been rigorously reviewed and field tested in a variety of Canadian radiation treatment facilities. The development process enables rapid review and update to keep the guidelines current with changes in technology. This article contains detailed performance objectives and safety criteria for low-dose-rate (LDR) permanent seed brachytherapy. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  10. Development and characterisation of iridium-192 seeds for brachytherapy treatment of ocular tumors

    International Nuclear Information System (INIS)

    Peleias Jr, F.S.; Zeituni, C.A.; Souza, C.D.; Rostelato, M.E.CM.; Mattos, F.R.; Banega, M.A.G.; Rodrigues, B.T.; Tiezzi, R.; Oliveira, T.B.; Feher, A.; Moura, J.A.; Costa, O.L.

    2014-01-01

    Even ocular tumors are not amongst the cases with a high incidence, they affect the population, particularly children. The Institute of Energy and Nuclear Research (IPEN-CNEN/SP) in partnership with Escola Paulista de Medicina (UNIFESP), created a project to develop an alternative treatment for ophthalmic cancer that uses iridium-192 seeds in brachytherapy. This work aims to study and develop a seed of iridium-192 from a platinum-iridium alloy The prototype seed has a 3.0 mm long core sealed by a titanium capsule of 0.8 mm of outer diameter, 0.05 mm of wall thickness and 4.5 mm long. We developed a methodology that covered: characterisation of the material used in the core, creation of a device for neutron activation of the cores and leakage tests. The results show that this methodology is feasible. As a suggestion for future work, studies regarding metrology and dosimetry of these sources should be carried out. (authors)

  11. Effect of geometrical optimization on the treatment volumes and the dose homogeneity of biplane interstitial brachytherapy implants

    International Nuclear Information System (INIS)

    Anacak, Yavuz; Esassolak, Mustafa; Aydin, Ayhan; Aras, Arif; Olacak, Ibrahim; Haydaroglu, Ayfer

    1997-01-01

    Background and purpose: The isodose distributions of HDR stepping source brachytherapy implants can be modified by changing dwell times and this procedure is called optimization. The purpose of this study is to evaluate the effect of geometrical optimization on the brachytherapy volumes and the dose homogeneity inside the implant and to compare them with non-optimized counterparts. Material and methods: A set of biplane breast implants consisting of 84 different configurations have been digitized by the planning computer and volumetric analysis was performed for both non-optimized and geometrically optimized implants. Treated length (T L ), treated volume (V 100 ), irradiated volume (V 50 ), overdose volume (V 200 ) and quality index (QI) have been calculated for every non-optimized implant and compared to its corresponding geometrically optimized implant having a similar configuration and covering the same target length. Results: The mean T L was 74.48% of the active length (A L ) for non-optimized implants and was 91.87% for optimized implants (P 50 /V 100 value was 2.71 for non-optimized implants and 2.65 for optimized implants (P 200 /V 100 value was 0.09 for non-optimized implants and 0.10 for optimized implants (P < 0.001). Conclusions: By performing geometrical optimization it is possible to implant shorter needles for a given tumour to adequately cover the target volume with the reference isodose and thus surgical damage is reduced. The amount of healthy tissues outside the target receiving considerable radiation is significantly reduced due to the decrease in irradiated volume. Dose homogeneity inside the implant is significantly improved. Although there is a slight increase of overdose volume inside the implant, this increase is considered to be negligible in clinical applications

  12. The effectiveness of 125I seed interstitial brachytherapy for transplantation tumor of human pancreatic carcinoma in nude mice: an experiment in vivo

    International Nuclear Information System (INIS)

    Song Qi; Liu Yu; Wang Zhongmin; Huang Wei; Lu Jian; Chen Kemin

    2010-01-01

    Objective: To discuss the effectiveness and therapeutic mechanism of 125 I interstitial brachytherapy for transplantation tumor of human pancreatic carcinoma in nude mice. Methods: The human pancreatic cell line Sw1990 was subcutaneously injected into the right lower limb partially dorsal area next to the groin of the immunodeficient BABL /c nude mice. The tumor was removed and cut into small pieces after it was formed,then the tumor pieces were inoculated in nude mice. The tumor developed to 8-10 mm in size after six weeks. A total of 16 nude mice with the suitable tumor size were used in this study. The 16 experimental mice were randomly and equally divided into two groups. The mice in study group (n = 8) were implanted with 125 I seeds, while the mice in control group (n = 8) were implanted with ghost seeds. After the implantation both the long and short diameter of the tumors as well as the mouse body weight were measured every 4 days. The tumor weight was measured when the mouse was sacrificed. The paraffin-embedded samples were sent for histopathological examination. Apoptotic cells were checked with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. Expression of proliferating cell nuclear antigen (PCNA) was detected with immuno-histochemical staining. Results: The tumor grew slowly in the study group, but rapidly in the control group. The tumor weight in the study group and the control group was (2.68 ± 0.70)g and (4.68 ± 1.45)g, respectively, the difference between two groups was statistically significant (P = 0.021). The tumor inhibition rate was about 42.66%. No significant difference in body weight of nude mice existed between two groups both before and after the treatment (P > 0.05). Marked tumor necrosis was seen in study group, but no obvious, or only a little, tumor necrosis could be observed in the control group. The apoptotic index checked with the TUENL method in the study group and control group was (23.2 ± 1.9)% and

  13. Efficacy and safety of iodine-125 radioactive seeds brachytherapy for advanced non-small cell lung cancer-A meta-analysis.

    Science.gov (United States)

    Zhang, Wenchao; Li, Jiawei; Li, Ran; Zhang, Ying; Han, Mingyong; Ma, Wei

    This meta-analysis was conducted to investigate the efficacy and safety of 125 I brachytherapy for locally advanced non-small cell lung cancer (NSCLC). Trials comparing 125 I brachytherapy with chemotherapy in NSCLC were identified. Meta-analysis was performed to obtain pooled risk ratios for an overall response rate (ORR), disease control rate (DCR) and complications, and pooled hazard ratio for overall survival (OS). Fifteen studies including 1188 cases were included. The pooled result indicated that there were significant differences in ORR, DCR, and OS between 125 I brachytherapy combined with chemotherapy and chemotherapy alone, but no statistic differences in gastrointestinal symptoms, leukopenia, myelosuppression, and hemoglobin reduction. Patients treated with 125 I brachytherapy combined with chemotherapy have a higher relative risk of pneumothorax, bloody sputum, and pneumorrhagia compared with chemotherapy alone. Seeds migration only occurred in the group treated with 125 I brachytherapy. There were significant differences in ORR, DCR, and myelosuppression between 125 I brachytherapy alone and chemotherapy. 125 I brachytherapy combined with chemotherapy can significantly enhance the clinical efficacy and improve the OS of patients with advanced NSCLC without increasing the incidence of complications of chemotherapy. 125 I brachytherapy alone can significantly enhance the clinical efficacy and reduce the incidence of myelosuppression compared with chemotherapy. However, 125 I brachytherapy may cause lung injury. Large sample and higher-quality randomized controlled trials are needed to confirm the pooled results of complications. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  14. Experimental evaluation of an online gamma-camera imaging of permanent seed implantation (OGIPSI) prototype for partial breast irradiation

    International Nuclear Information System (INIS)

    Ravi, Ananth; Caldwell, Curtis B.; Pignol, Jean-Philippe

    2008-01-01

    Previously, our team used Monte Carlo simulation to demonstrate that a gamma camera could potentially be used as an online image guidance device to visualize seeds during permanent breast seed implant procedures. This could allow for intraoperative correction if seeds have been misplaced. The objective of this study is to describe an experimental evaluation of an online gamma-camera imaging of permanent seed implantation (OGIPSI) prototype. The OGIPSI device is intended to be able to detect a seed misplacement of 5 mm or more within an imaging time of 2 min or less. The device was constructed by fitting a custom built brass collimator (16 mm height, 0.65 mm hole pitch, 0.15 mm septal thickness) on a 64 pixel linear array CZT detector (eValuator-2000, eV Products, Saxonburg, PA). Two-dimensional projection images of seed distributions were acquired by the use of a digitally controlled translation stage. Spatial resolution and noise characteristics of the detector were measured. The ability and time needed for the OGIPSI device to image the seeds and to detect cold spots was tested using an anthropomorphic breast phantom. Mimicking a real treatment plan, a total of 52 103 Pd seeds of 65.8 MBq each were placed on three different layers at appropriate depths within the phantom. The seeds were reliably detected within 30 s with a median error in localization of 1 mm. In conclusion, an OGIPSI device can potentially be used for image guidance of permanent brachytherapy applications in the breast and, possibly, other sites

  15. Rectourethral fistula following LDR brachytherapy.

    Science.gov (United States)

    Borchers, Holger; Pinkawa, Michael; Donner, Andreas; Wolter, Timm P; Pallua, Norbert; Eble, Michael J; Jakse, Gerhard

    2009-01-01

    Modern LDR brachytherapy has drastically reduced rectal toxicity and decreased the occurrence of rectourethral fistulas to <0.5% of patients. Therefore, symptoms of late-onset sequelae are often ignored initially. These fistulas cause severe patient morbidity and require interdisciplinary treatment. We report on the occurrence and management of a rectourethral fistula which occurred 4 years after (125)I seed implantation. Copyright 2009 S. Karger AG, Basel.

  16. Dosimetric studies, spectrometric, radiographic, metallographic of a new argentinean seed of 125 I used in brachytherapy

    International Nuclear Information System (INIS)

    Pirchio, R.; Saravi, M.; Banchik, D.; Munoz, C.

    2006-01-01

    A new source of 125 I model Braquibac TM has been developed in Argentina for applications in interstitial brachytherapy. The AAPM Task Group 43 (TG-43) recommends that dosimetric characteristics of new sources of brachytherapy of Iodine-125 have been theoretically and experimentally determined before its clinical use. The objectives outlined in this work were the study of the design of the new seed, the calculation of dosimetric parameters and the photons spectra analysis. Its were carried out radiographic and metallographic studies to determine the physical characteristics of the source. For the realization of the dosimetric calculations it was used the Monte Carlo code MCNP5. Values of the radial dose function, g(r), of the constant of dose rate, Λ, of the function of anisotropy of two dimensions, F(r, θ), of the factor and constant of anisotropy its were obtained simulating the source in water according to the recommended methodology in TG-43. The constant of dose rate is similar to 0,880 ± 0,080 c Gy h -1 U -1 . The kerma in air rate of reference, S K , was calculated as 1,036 c Gy cm 2 h -1 mCi -1 simulating the seed in dry air. Its were carried out spectrometric studies using a semiconductor planar detector of HPGe (high purity germanium). Photons spectra showed characteristic x-rays of 125 I with energies of 27,20 keV, 27,47 keV, 31 keV and 31,70 keV gamma photons of 35,5 keV, and x-ray fluorescent coming from the silver nucleus of 22,10 keV, 24,94 keV and 25,45 keV. The angular dependence of the intensity of photons around the seed and in air it was analyzed with the planar detector. This was carried out to study the anisotropy in the photons flow due to variation in the thickness of the titanium wall and of the welding, movements of the silver tube inside the source and deposition of the radioactive material on the silver tube. (Author)

  17. Radiochromic film calibration for low-energy seed brachytherapy dose measurement

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, Hali, E-mail: hamorris@ualberta.ca; Menon, Geetha; 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)

    2014-07-15

    Purpose: Radiochromic film dosimetry is typically performed for high energy photons and moderate doses characterizing external beam radiotherapy (XRT). The purpose of this study was to investigate the accuracy of previously established film calibration procedures used in XRT when applied to low-energy, seed-based brachytherapy at higher doses, and to determine necessary modifications to achieve similar accuracy in absolute dose measurements. Methods: Gafchromic EBT3 film was used to measure radiation doses upwards of 35 Gy from 75 kVp, 200 kVp, 6 MV, and (∼28 keV) I-125 photon sources. For the latter irradiations a custom phantom was built to hold a single I-125 seed. Film pieces were scanned with an Epson 10000XL flatbed scanner and the resulting 48-bit RGB TIFF images were analyzed using both FilmQA Pro software andMATLAB. Calibration curves relating dose and optical density via a rational functional form for all three color channels at each irradiation energy were determined with and without the inclusion of uncertainties in the measured optical densities and dose values. The accuracy of calibration curve variations obtained using piecewise fitting, a reduced film measurement area for I-125 irradiation, and a reduced number of dose levels was also investigated. The energy dependence of the film lot used was also analyzed by calculating normalized optical density values. Results: Slight differences were found in the resulting calibration curves for the various fitting methods used. The accuracy of the calibration curves was found to improve at low doses and worsen at high doses when including uncertainties in optical densities and doses, which may better represent the variability that could be seen in film optical density measurements. When exposing the films to doses > 8 Gy, two-segment piecewise fitting was found to be necessary to achieve similar accuracies in absolute dose measurements as when using smaller dose ranges. When reducing the film measurement

  18. Poster — Thur Eve — 77: Implanted Brachythearpy Seed Movement due to Transrectal Ultrasound Probe-Induced Prostate Deformation

    International Nuclear Information System (INIS)

    Liu, D; Usmani, N; Sloboda, R; Meyer, T; Husain, S; Angyalfi, S; Kay, I

    2014-01-01

    The study investigated the movement of implanted brachytherapy seeds upon transrectal US probe removal, providing insight into the underlying prostate deformation and an estimate of the impact on prostate dosimetry. Implanted seed distributions, one obtained with the prostate under probe compression and another with the probe removed, were reconstructed using C-arm fluoroscopy imaging. The prostate, delineated on ultrasound images, was registered to the fluoroscopy images using seeds and needle tracks identified on ultrasound. A deformation tensor and shearing model was developed to correlate probe-induced seed movement with position. Changes in prostate TG-43 dosimetry were calculated. The model was used to infer the underlying prostate deformation and to estimate the location of the prostate surface in the absence of probe compression. Seed movement patterns upon probe removal reflected elastic decompression, lateral shearing, and rectal bending. Elastic decompression was characterized by expansion in the anterior-posterior direction and contraction in the superior-inferior and lateral directions. Lateral shearing resulted in large anterior movement for extra-prostatic seeds in the lateral peripheral region. Whole prostate D90 increased up to 8 Gy, mainly due to the small but systematic seed movement associated with elastic decompression. For selected patients, lateral shearing movement increased prostate D90 by 4 Gy, due to increased dose coverage in the anterior-lateral region at the expense of the posterior-lateral region. The effect of shearing movement on whole prostate D90 was small compared to elastic decompression due to the subset of peripheral seeds involved, but is expected to have greater consequences for local dose coverage

  19. Determination of dosimetric characteristics of OptiSeedTM a plastic brachytherapy 103Pd source

    International Nuclear Information System (INIS)

    Wang Zhonglu; Hertel, Nolan E.

    2005-01-01

    A new 103 Pd plastic brachytherapy source, OptiSeed TM Model 1032P, is being introduced by International Brachytherapy sa (IBt). Measurements of the dose distributions about the source were performed using LiF thermoluminescent dosimeters (TLD-100) in Virtual Water TM . MCNP5 calculations were performed to determine the dose distributions in Virtual Water TM and liquid water. The source dose rate constant, radial dose function, anisotropy function and anisotropy factor have been determined following the updated AAPM TG-43 recommendations. The measured dose rate constant in the Virtual Water TM phantom was determined to be 0.727±6.9% cGy h -1 U -1 , and the computed value is 0.716±2.1% cGy h -1 U -1 . The Monte-Carlo simulation yielded a dose rate constant of 0.665±2.1% cGy h -1 U -1 in water. The measured dose rate constant in water is 0.675±7.5% cGy h -1 U -1 . It is determined by multiplying the dose rate constant measured in the Virtual Water TM phantom with the ratio of the value calculated in water to that in Virtual Water TM . The average of the measured and calculated dose rate constant is 0.670±5.5% cGy h -1 U -1 . The radial dose functions of the new source were measured for distances ranging from 1 to 7 cm in a Virtual Water TM phantom. The anisotropy functions in Virtual Water TM phantom were measured for distances of 2, 3, 5, and 7 cm. The Monte-Carlo computed radial dose functions, anisotropy functions, and anisotropy factors in both Virtual Water TM phantom and water are reported

  20. Comparison of Combined X-Ray Radiography and Magnetic Resonance (XMR) Imaging-Versus Computed Tomography-Based Dosimetry for the Evaluation of Permanent Prostate Brachytherapy Implants

    International Nuclear Information System (INIS)

    Acher, Peter; Rhode, Kawal; Morris, Stephen; Gaya, Andrew; Miquel, Marc; Popert, Rick; Tham, Ivan; Nichol, Janette; McLeish, Kate; Deehan, Charles; Dasgupta, Prokar; Beaney, Ronald; Keevil, Stephen F.

    2008-01-01

    Purpose: To present a method for the dosimetric analysis of permanent prostate brachytherapy implants using a combination of stereoscopic X-ray radiography and magnetic resonance (MR) imaging (XMR) in an XMR facility, and to compare the clinical results between XMR- and computed tomography (CT)-based dosimetry. Methods and Materials: Patients who had received nonstranded iodine-125 permanent prostate brachytherapy implants underwent XMR and CT imaging 4 weeks later. Four observers outlined the prostate gland on both sets of images. Dose-volume histograms (DVHs) were derived, and agreement was compared among the observers and between the modalities. Results: A total of 30 patients were evaluated. Inherent XMR registration based on prior calibration and optical tracking required a further automatic seed registration step that revealed a median root mean square registration error of 4.2 mm (range, 1.6-11.4). The observers agreed significantly more closely on prostate base and apex positions as well as outlining contours on the MR images than on those from CT. Coefficients of variation were significantly higher for observed prostate volumes, D90, and V100 parameters on CT-based dosimetry as opposed to XMR. The XMR-based dosimetry showed little agreement with that from CT for all observers, with D90 95% limits of agreement ranges of 65, 118, 79, and 73 Gy for Observers 1, 2, 3, and 4, respectively. Conclusions: The study results showed that XMR-based dosimetry offers an alternative to other imaging modalities and registration methods with the advantages of MR-based prostate delineation and confident three-dimensional reconstruction of the implant. The XMR-derived dose-volume histograms differ from the CT-derived values and demonstrate less interobserver variability

  1. Iodine-125 seed brachytherapy for early stage prostate cancer: a single-institution review

    International Nuclear Information System (INIS)

    Zuber, Simon; Weiß, Susan; Baaske, Dieter; Schöpe, Michael; Stevens, Simon; Bodis, Stephan; Zwahlen, Daniel R

    2015-01-01

    We are reporting the five-year biochemical control, toxicity profile and dosimetric parameters using iodine-125 low dose rate brachytherapy (BT) as monotherapy for early stage prostate cancer at a single institution. Between April 2006 and December 2010, 169 men with early stage prostate cancer were treated with BT. Biochemical failure was defined using the Phoenix definition (nadir + 2 ng/mL). Treatment-related morbidities, including urinary, rectal and sexual function, were measured, applying the International Prostate Symptom Score (IPSS), the 7-grade Quality of Life Scale (QoL) and medical status, the International Consultation on Incontinence Modular Questionnaire (ICIQ), the International Index of Erectile Function (IIEF-5) and the Common Terminology Criteria for Adverse Events (CTCAE v4.03). Seed migration and loss, dosimetric parameters and learning effects were also analyzed. Medium follow-up time was 50 months (range, 1–85 months). The five-year biochemical failure rate was 7%. Acute proctitis rates were 19% (grade 1) and 1% (grade 2), respectively. The overall incidence of incontinence was 19% (mild), 16% (moderate) and < 1% (severe). An increase in IPSS ≥ 5 points was detected in 59% of patients, with 38% regaining their baseline. Seed dislocation was found in 24% of patients and correlated with D90 and V100. A learning curve was found for seed migration, D90 and V100. QoL correlated with the general health condition of patient, incontinence symptoms and IPSS. BT for early stage prostate cancer offers excellent five-year biochemical control with low toxicities. QoL aspects are favorable. A learning curve was detected for procedural aspects but its impact on patient relevant endpoints remains inconclusive

  2. Urinary morbidity following ultrasound-guided transperineal prostate seed implantation

    International Nuclear Information System (INIS)

    Gelblum, Daphna Y.; Potters, Louis; Ashley, Richard; Waldbaum, Robert; Wang Xiaohong; Leibel, Steven

    1999-01-01

    Purpose: To assess the urinary morbidity experienced by patients undergoing ultrasound-guided, permanent transperineal seed implantation for adenocarcinoma of the prostate. Methods and Materials: Between September 1992 and September 1997, 693 consecutive patients presented with a diagnosis of clinically localized adenocarcinoma of the prostate, and were treated with ultrasound-guided transperineal interstitial permanent brachytherapy (TPIPB). Ninety-three patients are excluded from this review, having received neoadjuvant antiandrogen therapy. TPIPB was performed with 125 I in 165 patients and with 103 Pd in 435 patients. Patients treated with implant alone received 160 Gy with 125 I (pre TG43) or 120 Gy with 103 Pd. One hundred two patients received preimplant, pelvic external beam radiation (XRT) to a dose of either 41.4 or 45 Gy because of high-risk features including PSA ≥ 10 and/or Gleason score ≥ 7. Combined modality patients received 120 Gy and 90 Gy, respectively for 125 I or 103 Pd. All patients underwent postimplant cystoscopy and placement of an indwelling Foley catheter for 24-48 h. Follow-up was at 5 weeks after implant, every 3 months for the first 2 years, and then every 6 months for subsequent years. Patients completed AUA urinary symptom scoring questionnaires at initial consultation and at each follow-up visit. Urinary toxicity was classified by the RTOG toxicity scale with the following adaptations; grade 1 urinary toxicity was symptomatic nocturia or frequency requiring none or minimal medical intervention such as phenazopyridine; grade 2 urinary toxicity was early obstructive symptomatology requiring alpha-blocker therapy; and grade 3 toxicity was considered that requiring indwelling catheters or posttreatment transurethral resection of the prostate for symptom relief. Log-rank analysis and Chi-square testing was performed to assess AUA score, prostate size, isotope selection, and the addition of XRT as possible prognosticators of

  3. Radiation protection procedures and dose to the staff in brachytherapy with permanent implant of the sources

    International Nuclear Information System (INIS)

    Tosi, G.; Cattani, F.

    2002-01-01

    The treatment of intra capsular prostate cancers with the permanent implantation of low energy sealed radioactive sources (''103 Pd-''125I) offers the same probability of curing the tumours as surgery and external-beam radiotherapy with a minimum incidence of unwanted side-effects. The first attempts of using sealed sources for treating prostate cancers go back to 1917, when Barringer reported the results obtained with the implant of ''236Ra needles. Beginning from that period the interest for prostate brachytherapy has shown a fluctuating trend, due especially to the technological possibilities and to the status of the alternative treatment modalities (surgery, external radiotherapy). The main reason of the substantial failure of brachytherapy as compared to the two other treatment modalities had two main causes: the energy, too high ( E≅ 840 keV), of γ-radiation emitted by ''226 Ra in equilibrium with its decay products and the lack of imaging techniques able to visualize with sufficient accuracy both the prostate and the arrangement, inside it, of the radioactive sources. The employ of low energy γ-emitting radionuclides began in 1974, when Whitmore et al. working at the Sloan Kettering Memorial Cancer Hospital of New York suggested the use of ''125 I sealed sources for the realisation of interstitial permanent implants. Also this attempt, though reducing the side effects typical of the surgical intervention (incontinence, impotence), did non give the expected results in terms of local control of the disease and, as a consequence, of the survival's length. This partial failure was attributed to the fact that, in most cases the dose distribution inside the target volume was not homogeneous, due to the inadequacy of the available imaging techniques used for checking the real position of the sources, during their manual insertion in the tissues. In the last ten years,however, great progresses have been made in the US i maging techniques, in the manufacture of

  4. Brachytherapy needle deflection evaluation and correction

    International Nuclear Information System (INIS)

    Wan Gang; Wei Zhouping; Gardi, Lori; Downey, Donal B.; Fenster, Aaron

    2005-01-01

    In prostate brachytherapy, an 18-gauge needle is used to implant radioactive seeds. This thin needle can be deflected from the preplanned trajectory in the prostate, potentially resulting in a suboptimum dose pattern and at times requiring repeated needle insertion to achieve optimal dosimetry. In this paper, we report on the evaluation of brachytherapy needle deflection and bending in test phantoms and two approaches to overcome the problem. First we tested the relationship between needle deflection and insertion depth as well as whether needle bending occurred. Targeting accuracy was tested by inserting a brachytherapy needle to target 16 points in chicken tissue phantoms. By implanting dummy seeds into chicken tissue phantoms under 3D ultrasound guidance, the overall accuracy of seed implantation was determined. We evaluated methods to overcome brachytherapy needle deflection with three different insertion methods: constant orientation, constant rotation, and orientation reversal at half of the insertion depth. Our results showed that needle deflection is linear with needle insertion depth, and that no noticeable bending occurs with needle insertion into the tissue and agar phantoms. A 3D principal component analysis was performed to obtain the population distribution of needle tip and seed position relative to the target positions. Our results showed that with the constant orientation insertion method, the mean needle targeting error was 2.8 mm and the mean seed implantation error was 2.9 mm. Using the constant rotation and orientation reversal at half insertion depth methods, the deflection error was reduced. The mean needle targeting errors were 0.8 and 1.2 mm for the constant rotation and orientation reversal methods, respectively, and the seed implantation errors were 0.9 and 1.5 mm for constant rotation insertion and orientation reversal methods, respectively

  5. SU-E-T-12: A Comparative Dosimetric Study of Pre and Post Prostate Iodine-125 Permanent Seed Implants

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X; Rahimian, J; Goy, B; Cosmatos, H; Qian, Y [Kaiser Permanente, Los Angeles, CA (United States)

    2015-06-15

    Purpose: Post-implant dosimetry has become the gold standard for prostate implant evaluation. The goal of this research is to compare the dosimetry between pre-plan and post-plan in permanent prostate seed implant brachytherapy. Methods: A retrospective study of 91 patients treated with Iodine-125 prostate seed implant between year 2012∼2014 were performed. All plans were created using a VariSeed 8.0 planning system. Pre-plan ultrasound images were acquired using 0.5 cm slice thickness. Post-plan CT images acquired about 1–4 weeks after implant, fused with the preplan ultrasound images. The prostate and urethra contours were generated using the fusion of ultrasound and CT images. Iodine-125 seed source activities varied between 0.382 to 0.414 mCi per seed. The loading patterns varied slightly between patients depending on the prostate size. Statistical analysis of pre and post plans for prostate and urethra volumes, V100%, V150% and D90, and urethra D10 were performed and reported. Results: The pre and post implant average prostate size was 36.90cc vs. 38.58cc; V100% was 98.33% vs. 96.89%; V150% was 47.09% vs. 56.95%; D90 was 116.35Gy vs. 116.12Gy, urethra volume was 1.72cc vs. 1.85cc, urethra D10% was 122.0% vs. 135.35%, respectively. There was no statistically significant difference between the pre and post-plan values for D90(p-value=0.43). However, there are significant differences between other parameters most likely due to post surgical edema; prostate size (p-value= 0.00015); V100% (p-value=3.7803E-07); V150% (p-value=1.49E-09); urethra volume (p-value= 2.77E-06); Urethra D10 (p-value=7.37E-11). Conclusion: The post-plan dosimetry using CT image set showed similar D90 dose coverage to the pre-plan using the ultrasound image dataset. The study showed that our prostate seed implants have consistently delivered adequate therapeutic dose to the prostate while sparing urethra. Future studies to correlate dose versus biochemical response using patients’ PSA

  6. Suggestions on technical guide of implantation of radioactive seeds

    International Nuclear Information System (INIS)

    Wang Zhongmin; Huang Gang; Lv Zhongwei; Liu Jianjun; Chen Kemin; Chen Yongde

    2009-01-01

    Implantation of radioactive seeds is an effective therapeutic option for the treatment of malignant tumors. With the development of imaging technique and the use of treatment planning system (TPS) it has been more and more employed in clinical settings. The technique has been widely practiced in various malignant tumors, such as prostate cancer, lung caner, pancreatic cancer, hepatocarcinoma, etc. In order to standardize the clinical application of this technology, the authors propose some suggestions concerning the management of radioactive seeds, the indications and contraindications as well as the method of operation as a technical guidance. (authors)

  7. Suggestions on technical guide of implantation of radioactive seeds

    Energy Technology Data Exchange (ETDEWEB)

    Zhongmin, Wang; Gang, Huang; Zhongwei, Lv; Jianjun, Liu [Department of Radiology, Luwan Branch of Ruijin Hospital, School of Medicine, Shanghai Jiaotong Univ., Shanghai (China); Kemin, Chen; Yongde, Chen

    2009-09-15

    Implantation of radioactive seeds is an effective therapeutic option for the treatment of malignant tumors. With the development of imaging technique and the use of treatment planning system (TPS) it has been more and more employed in clinical settings. The technique has been widely practiced in various malignant tumors, such as prostate cancer, lung caner, pancreatic cancer, hepatocarcinoma, etc. In order to standardize the clinical application of this technology, the authors propose some suggestions concerning the management of radioactive seeds, the indications and contraindications as well as the method of operation as a technical guidance. (authors)

  8. Evaluation of radiation dose on people adjacent to implant patients during brachytherapy for prostate cancer using {sup 192}Ir

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hoon; Ko, Seong Jin; Kang, Se Sik; Kim, Chang Soo [Catholic University, Busan (Korea, Republic of)

    2009-10-15

    The incidence of prostate cancer is rapidly increasing due to aging of the population and westernization of dietary habits, etc. As a result, the frequency of prostate cancer has become the fifth highest among all male cancers and the first among urological cancers. Brachytherapy is commonly used for locally progressing prostate cancers. Since the mid 1980s, therapies using radio-isotopes, such as low-invasive {sup 125}I, {sup 103}Pd and {sup 192}Ir, have been widely performed in the U.S. and Europe. However, brachytherapy involves implanting radio-isotopes into the human body which is of concern because it may expose the health care professionals administering the therapy to unnecessary radiation. Accordingly, this study intends to predict the radiation dose that people adjacent to patients implanted with a radio-isotope are exposed to during prostate cancer radiation therapy by using a mathematical anthropomorphic phantom and {sup 192}Ir.

  9. Brazilian demand for Iodine-125 seeds in cancer treatment after a decade of medical procedures

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Osvaldo L. da; Souza, Daiane C.B. de; Feher, Anselmo; Moura, João A.; Souza, Carla D.; Oliveira, Henrique B. de; Peleiras Junior, Fernando S.; Zeituni, CArlos A.; Rostelaro, Maria E.C.M., E-mail: olcosta@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-07-01

    Iodine-125 and palladium-103 are radionuclides employed to made medical devices used in cancer treatment known as brachytherapy seeds. These radioactive sealed sources are applied in brain and ophthalmic cancer as a temporary implant to irradiate the tumor and in permanent implants to prostatic cancer. Brazilian Nuclear Energy Commission (CNEN) has the monopoly in Brazil of iodine-125 brachytherapy seeds distribution which is executed for Nuclear and Energy Research Institute (IPEN-CNEN/SP). Along a decade of use in Brazil more than 240 thousand seeds were implanted in patients or used to treat cancer tumors. In this article the Brazilian demand for iodine-125 brachytherapy seeds is analyzed. The demand behavior along a decade of using loose, strand, ophthalmic and brain brachytherapy seeds are shown. The annual quantity of seeds demanded by Brazil has dropped since 2012. The loose seeds which represented until 30% from total brachytherapy seeds used in Brazil decreased to less than 3%. The brain brachytherapy seeds had low demand along the decade and presented zero demand in several years. Concurrent treatment techniques are listed and main trends are discussed. The influence of Brazilian economic crisis and the demand behavior of the main hospitals and clinics that use Iodine-125 brachytherapy are shown. (author)

  10. Brazilian demand for Iodine-125 seeds in cancer treatment after a decade of medical procedures

    International Nuclear Information System (INIS)

    Costa, Osvaldo L. da; Souza, Daiane C.B. de; Feher, Anselmo; Moura, João A.; Souza, Carla D.; Oliveira, Henrique B. de; Peleiras Junior, Fernando S.; Zeituni, CArlos A.; Rostelaro, Maria E.C.M.

    2017-01-01

    Iodine-125 and palladium-103 are radionuclides employed to made medical devices used in cancer treatment known as brachytherapy seeds. These radioactive sealed sources are applied in brain and ophthalmic cancer as a temporary implant to irradiate the tumor and in permanent implants to prostatic cancer. Brazilian Nuclear Energy Commission (CNEN) has the monopoly in Brazil of iodine-125 brachytherapy seeds distribution which is executed for Nuclear and Energy Research Institute (IPEN-CNEN/SP). Along a decade of use in Brazil more than 240 thousand seeds were implanted in patients or used to treat cancer tumors. In this article the Brazilian demand for iodine-125 brachytherapy seeds is analyzed. The demand behavior along a decade of using loose, strand, ophthalmic and brain brachytherapy seeds are shown. The annual quantity of seeds demanded by Brazil has dropped since 2012. The loose seeds which represented until 30% from total brachytherapy seeds used in Brazil decreased to less than 3%. The brain brachytherapy seeds had low demand along the decade and presented zero demand in several years. Concurrent treatment techniques are listed and main trends are discussed. The influence of Brazilian economic crisis and the demand behavior of the main hospitals and clinics that use Iodine-125 brachytherapy are shown. (author)

  11. Prostate brachytherapy

    Science.gov (United States)

    Implant therapy - prostate cancer; Radioactive seed placement; Internal radiation therapy - prostate; High dose radiation (HDR) ... place the seeds that deliver radiation into your prostate. The seeds are placed with needles or special ...

  12. Bypassing the learning curve in permanent seed implants using state-of-the-art technology

    International Nuclear Information System (INIS)

    Beaulieu, Luc; Evans, Dee-Ann Radford; Aubin, Sylviane; Angyalfi, Steven; Husain, Siraj; Kay, Ian; Martin, Andre-Guy; Varfalvy, Nicolas; Vigneault, Eric; Dunscombe, Peter

    2007-01-01

    Purpose: The aim of this study was to demonstrate, based on clinical postplan dose distributions, that technology can be used efficiently to eliminate the learning curve associated with permanent seed implant planning and delivery. Methods and Materials: Dose distributions evaluated 30 days after the implant of the initial 22 consecutive patients treated with permanent seed implants at two institutions were studied. Institution 1 (I1) consisted of a new team, whereas institution 2 (I2) had performed more than 740 preplanned implantations over a 9-year period before the study. Both teams had adopted similar integrated systems based on three-dimensional (3D) transrectal ultrasonography, intraoperative dosimetry, and an automated seed delivery and needle retraction system (FIRST, Nucletron). Procedure time and dose volume histogram parameters such as D90, V100, V150, V200, and others were collected in the operating room and at 30 days postplan. Results: The average target coverage from the intraoperative plan (V100) was 99.4% for I1 and 99.9% for I2. D90, V150, and V200 were 191.4 Gy (196.3 Gy), 75.3% (73.0%), and 37.5% (34.1%) for I1 (I2) respectively. None of these parameters shows a significant difference between institutions. The postplan D90 was 151.2 Gy for I1 and 167.3 Gy for I2, well above the 140 Gy from the Stock et al. analysis, taking into account differences at planning, results in a p value of 0.0676. The procedure time required on average 174.4 min for I1 and 89 min for I2. The time was found to decrease with the increasing number of patients. Conclusion: State-of-the-art technology enables a new brachytherapy team to obtain excellent postplan dose distributions, similar to those achieved by an experienced team with proven long-term clinical results. The cost for bypassing the usual dosimetry learning curve is time, with increasing team experience resulting in shorter treatment times

  13. Evaluation of dose-volume histograms after prostate seed implantation. 4-year experience

    International Nuclear Information System (INIS)

    Hoinkis, C.; Lehmann, D.; Winkler, C.; Herrmann, T.; Hakenberg, O.W.; Wirth, M.P.

    2004-01-01

    Background and purpose: permanent interstitial brachytherapy by seed implantation is a treatment alternative for low-volume low-risk prostate cancer and a complex interdisciplinary treatment with a learning curve. Dose-volume histograms are used to assess postimplant quality. The authors evaluated their learning curve based on dose-volume histograms and analyzed factors influencing implantation quality. Patients and methods: since 1999, 38 patients with a minimum follow-up of 6 months were treated at the authors' institution with seed implantation using palladium-103 or iodine-125, initially using the preplan method and later real-time planning. Postimplant CT was performed after 4 weeks. The dose-volume indices D90, V100, V150, the D max of pre- and postplans, and the size and position of the volume receiving the prescribed dose (high-dose volume) of the postplans were evaluated. In six patients, postplan imaging both by CT and MRI was used and prostate volumes were compared with preimplant transrectal ultrasound volumes. The first five patients were treated under external supervision. Results: patients were divided into three consecutive groups for analysis of the learning curve (group 1: n = 5 patients treated under external supervision; group 2: n = 13 patients; group 3: n = 20 patients). D90 post for the three groups were 79.3%, 74.2%, and 99.9%, the V100 post were 78.6%, 73.5%, and 88.2%, respectively. The relationship between high-dose volume and prostate volume showed a similar increase as the D90, while the relationship between high-dose volume lying outside the prostate and prostate volume remained constant. The ratio between prostate volumes from transrectal ultrasound and CT imaging decreased with increasing D90 post , while the preplanning D90 and V100 remained constant. The different isotopes used, the method of planning, and the implanted activity per prostate volume did not influence results. Conclusion: a learning curve characterized by an increase

  14. Implants with {sup 32}P-foils for LDR-brachytherapy of benign stenosis in urology and gastroenterology; {sup 32}P-haltige Folien als Implantate fuer die LDR-Brachytherapie gutartiger Stenosen in der Urologie und Gastroenterologie

    Energy Technology Data Exchange (ETDEWEB)

    Assmann, Walter [Ludwig-Maximilians-Univ., Muenchen (Germany). Fakultaet fuer Physik; Becker, Ricarda; Otto, Henrike [Klinikum der Universitaet Muenchen, Campus Grosshadern (Germany). Laser-Forschungslabor] [and others

    2013-03-01

    For LDR-brachytherapy, a limited number of implant geometries and materials are available. To avoid wound healing related hyper-proliferation (stenosis, keloids) a novel radioactive foil system was developed based on beta emitting {sup 32}P, which can be easily integrated in existing implants such as urethral catheters or bile duct stents. As substrate material for these foils PEEK (polyetherethercetone) was chosen because of its radiation hardness during neutron activation of {sup 32}P. The activity was determined by liquid scintillation counting and gamma spectroscopy, dose distributions were measured with scintillation detectors and radiochromic films. The correlation between activity and dose was checked by Monte-Carlo-simulations (Geant4). Prototypes of the {sup 32}P-implants have shown in wash-out tests the required tightness for sealed radioactive sources. In animal tests on urethra and bile duct, the uncomplicated and save application of {sup 32}P-foils mounted on standard implants has been demonstrated, which is almost unchanged due to the simple radiation protection with plexiglass. This concept of radioactive implants with integrated {sup 32}P-foils could extend essentially the application possibilities of LDR-brachytherapy. (orig.)

  15. A proteomics analysis for certain signature proteins of rabbit lacrimal passages after 125I seeds brachytherapy

    International Nuclear Information System (INIS)

    Li Dandan; Liu Lin; Gao Shi; Qi Liangchen; Ma Qingjie; Jin Longyun

    2010-01-01

    To search for certain signature proteins and the expression profiles in lacrimal passage stenosis, rabbit models of lacrimal passage stenosis were treated by 125 I seed brachytherapy. All the signature proteins were separated by two-dimensional electrophoresis, and identified by mass spectrometry. The results show that the up-regulated proteins are peptidyl-prolyl cis-trans isomerase A (PPIase A), and epidermal fatty acid-binding protein (E-FABP), while the down-regulated proteins are myosin light chain 1 (isomer of skeletal muscle), myosin light polypeptide 6 (isomer 1 of smooth muscle and non-muscle), myosin light chain 1 (isomer of slow-twitch muscle A), isomer 2 of ERC protein 2, and α-crystalline family protein. The proteins may play a role in healing the wound and regulating synaptic active zone of neurons due to correlation to cell apoptosis, proliferation and migration of smooth muscle cell. These provide molecular mechanism for preventing stenosis and restenosis of lacrimal passage. (authors)

  16. Impact of pre-implant lower urinary tract symptoms on postoperative urinary morbidity after permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    Teishima, Jun; Iwamoto, Hideo; Miyamoto, Katsutoshi; Shoji, Koichi; Masumoto, Hiroshi; Inoue, Shogo; Kobayashi, Kanao; Kajiwara, Mitsuru; Matsubara, Akio

    2012-01-01

    prolongation. The present findings suggest that the presence of lower urinary tract symptoms before implantation does not prolong urinary morbidity after permanent prostate brachytherapy. (author)

  17. Applicability and dosimetric impact of ultrasound-based preplanning in high-dose-rate brachytherapy of prostate cancer

    International Nuclear Information System (INIS)

    Aebersold, D.M.; Isaak, B.; Behrensmeier, F.; Kolotas, C.; Mini, R.; Greiner, R.H.; Thalmann, G.; Kranzbuehler, H.

    2004-01-01

    Background and purpose: analyses of permanent brachytherapy seed implants of the prostate have demonstrated that the use of a preplan may lead to a considerable decrease of dosimetric implant quality. The authors aimed to determine whether the same drawbacks of preplanning also apply to high-dose-rate (HDR) brachytherapy. Patients and methods: 15 patients who underwent two separate HDR brachytherapy implants in addition to external-beam radiation therapy for advanced prostate cancer were analyzed. A pretherapeutic transrectal ultrasound was performed in all patients to generate a preplan for the first brachytherapy implant. For the second brachytherapy, a subset of patients were treated by preplans based on the ultrasound from the first brachytherapy implant. Preplans were compared with the respective postplans assessing the following parameters: coverage index, minimum target dose, homogeneity index, and dose exposure of organs at risk. The prostate geometries (volume, width, height, length) were compared as well. Results: at the first brachytherapy, the matching between the preplan and actual implant geometry was sufficient in 47% of the patients, and the preplan could be applied. The dosimetric implant quality decreased considerably: the mean coverage differed by -0.11, the mean minimum target dose by -0.15, the mean homogeneity index by -0.09. The exposure of organs at risk was not substantially altered. At the second brachytherapy, all patients could be treated by the preplan; the differences between the implant quality parameters were less pronounced. The changes of prostate geometry between preplans and postplans were considerable, the differences in volume ranging from -8.0 to 13.8 cm 3 and in dimensions (width, height, length) from -1.1 to 1.0 cm. Conclusion: preplanning in HDR brachytherapy of the prostate is associated with a substantial decrease of dosimetric implant quality, when the preplan is based on a pretherapeutic ultrasound. The implant quality

  18. Optimization of permanent breast seed implant dosimetry incorporating tissue heterogeneity

    Science.gov (United States)

    Mashouf, Shahram

    Seed brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose around brachytherapy sources is based on the AAPM TG43 formalism, which generates the dose in homogeneous water medium. Recently, AAPM task group no. 186 (TG186) emphasized the importance of accounting for heterogeneities. In this work we introduce an analytical dose calculation algorithm in heterogeneous media using CT images. The advantages over other methods are computational efficiency and the ease of integration into clinical use. An Inhomogeneity Correction Factor (ICF) is introduced as the ratio of absorbed dose in tissue to that in water medium. ICF is a function of tissue properties and independent of the source structure. The ICF is extracted using CT images and the absorbed dose in tissue can then be calculated by multiplying the dose as calculated by the TG43 formalism times ICF. To evaluate the methodology, we compared our results with Monte Carlo simulations as well as experiments in phantoms with known density and atomic compositions. The dose distributions obtained through applying ICF to TG43 protocol agreed very well with those of Monte Carlo simulations and experiments in all phantoms. In all cases, the mean relative error was reduced by at least a factor of two when ICF correction factor was applied to the TG43 protocol. In conclusion we have developed a new analytical dose calculation method, which enables personalized dose calculations in heterogeneous media using CT images. The methodology offers several advantages including the use of standard TG43 formalism, fast calculation time and extraction of the ICF parameters directly from Hounsfield Units. The methodology was implemented into our clinical treatment planning system where a cohort of 140 patients were processed to study the clinical benefits of a heterogeneity corrected dose.

  19. Implants with 32P-foils for LDR-brachytherapy of benign stenosis in urology and gastroenterology

    International Nuclear Information System (INIS)

    Assmann, Walter; Becker, Ricarda; Otto, Henrike

    2013-01-01

    For LDR-brachytherapy, a limited number of implant geometries and materials are available. To avoid wound healing related hyper-proliferation (stenosis, keloids) a novel radioactive foil system was developed based on beta emitting 32 P, which can be easily integrated in existing implants such as urethral catheters or bile duct stents. As substrate material for these foils PEEK (polyetherethercetone) was chosen because of its radiation hardness during neutron activation of 32 P. The activity was determined by liquid scintillation counting and gamma spectroscopy, dose distributions were measured with scintillation detectors and radiochromic films. The correlation between activity and dose was checked by Monte-Carlo-simulations (Geant4). Prototypes of the 32 P-implants have shown in wash-out tests the required tightness for sealed radioactive sources. In animal tests on urethra and bile duct, the uncomplicated and save application of 32 P-foils mounted on standard implants has been demonstrated, which is almost unchanged due to the simple radiation protection with plexiglass. This concept of radioactive implants with integrated 32 P-foils could extend essentially the application possibilities of LDR-brachytherapy. (orig.)

  20. [Implants with 32P-foils for LDR-brachytherapy of benign stenosis in urology and gastroenterology].

    Science.gov (United States)

    Assmann, Walter; Becker, Ricarda; Otto, Henrike; Bader, Markus; Clemente, Lucas; Reinhardt, Sabine; Schäfer, Claus; Schirra, Jörg; Uschold, Stephanie; Welzmüller, Andreas; Sroka, Ronald

    2013-02-01

    For LDR-brachytherapy, a limited number of implant geometries and materials are available. To avoid wound healing related hyper-proliferation (stenosis, keloids) a novel radioactive foil system was developed based on beta emitting (32)P, which can be easily integrated in existing implants such as urethral catheters or bile duct stents. As substrate material for these foils PEEK (polyetherethercetone) was chosen because of its radiation hardness during neutron activation of (32)P. The activity was determined by liquid scintillation counting and gamma spectroscopy, dose distributions were measured with scintillation detectors and radiochromic films. The correlation between activity and dose was checked by Monte-Carlo-simulations (Geant4). Prototypes of the (32)P-implants have shown in wash-out tests the required tightness for sealed radioactive sources. In animal tests on urethra and bile duct, the uncomplicated and save application of (32)P-foils mounted on standard implants has been demonstrated, which is almost unchanged due to the simple radiation protection with plexiglass. This concept of radioactive implants with integrated (32)P-foils could extend essentially the application possibilities of LDR-brachytherapy. Copyright © 2012. Published by Elsevier GmbH.

  1. Does prostate brachytherapy treat the seminal vesicles? A dose-volume histogram analysis of seminal vesicles in patients undergoing combined PD-103 prostate implantation and external beam irradiation

    International Nuclear Information System (INIS)

    Stock, Richard G.; Lo, Yeh-Chi; Gaildon, Mohamoud; Stone, Nelson N.

    1999-01-01

    Purpose: Combined brachytherapy of the prostate and external beam irradiation (EBRT) of the prostate and seminal vesicles (SV) is becoming a popular treatment for high-risk prostate cancer. Dose-volume histogram (DVH) analysis of the SV in patients undergoing this treatment was performed to determine the dose distribution to the SV and the adequacy of this treatment in patients with potential SV involvement. Methods and Materials: Twenty-five consecutive patients were treated with a Pd-103 implant of the prostate alone and 45 Gy of EBRT to the prostate and SV. Attempts were not made to implant the SV but seeds were routinely placed at the junction of the prostate and SV. All patients underwent CT-based post implant dosimetric analysis 1 month after implantation. As part of this analysis, DVH were generated for the prostate and total SV volume (SVT). In addition, the SV was divided into 6-mm-thick volumes identified as SV1, SV2, SV3, SV4, and SV5 starting from the junction of the prostate and SV and extending distally. DVH were also generated for these structures. Delivered dose was defined as the D90 (dose delivered to 90% of the organ on DVH). Results: The median volumes in cc of the prostate, SVT, SV1, SV2, SV3, SV4, and SV5 were 34.33, 9.75, 2.7, 3.48, 2.92, 3.18, and 1.96 respectively. The SVT contained from 0-9 seeds (median 2). There was little dose delivered to the SVT and SV volumes from the implanted prostate. The median D90 values for the prostate, SVT, SV1, SV2, SV3, SV4, and SV5 were 8615 cGy, 675 cGy, 3100 cGy, 1329 cGy, 553 cGy, 246 cGy, and 67 cGy, respectively. The dose delivered to the prostate covered small percentages of SV. The percents of SV volumes covered by the prostate D90 were 11, 35, 3.3, 0, 0, and 0 for SVT, SV1, SV2, SV3, SV4, and SV5, respectively. Conclusions: DVH analysis of the SV reveals that dose generated from an implanted prostate contributes little to the SV. Those patients at high risk for SV involvement may be under treated

  2. Development of computational models for the simulation of isodose curves on dosimetry films generated by iodine-125 brachytherapy seeds

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Adriano M.; Meira-Belo, Luiz C.; Reis, Sergio C.; Grynberg, Suely E., E-mail: amsantos@cdtn.b [Center for Development of Nuclear Technology (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The interstitial brachytherapy is one modality of radiotherapy in which radioactive sources are placed directly in the region to be treated or close to it. The seeds that are used in the treatment of prostate cancer are generally cylindrical radioactive sources, consisting of a ceramic or metal matrix, which acts as the carrier of the radionuclide and as the X-ray marker, encapsulated in a sealed titanium tube. This study aimed to develop a computational model to reproduce the film-seed geometry, in order to obtain the spatial regions of the isodose curves produced by the seed when it is put over the film surface. The seed modeled in this work was the OncoSeed 6711, a sealed source of iodine-125, which its isodose curves were obtained experimentally in previous work with the use of dosimetric films. For the films modeling, compositions and densities of the two types of dosimetric films were used: Agfa Personal Monitoring photographic film 2/10, manufactured by Agfa-Geavaert; and the model EBT radiochromic film, by International Specialty Products. The film-seed models were coupled to the Monte Carlo code MCNP5. The results obtained by simulations showed to be in good agreement with experimental results performed in a previous work. This indicates that the computational model can be used in future studies for other seeds models. (author)

  3. Development of computational models for the simulation of isodose curves on dosimetry films generated by iodine-125 brachytherapy seeds

    International Nuclear Information System (INIS)

    Santos, Adriano M.; Meira-Belo, Luiz C.; Reis, Sergio C.; Grynberg, Suely E.

    2011-01-01

    The interstitial brachytherapy is one modality of radiotherapy in which radioactive sources are placed directly in the region to be treated or close to it. The seeds that are used in the treatment of prostate cancer are generally cylindrical radioactive sources, consisting of a ceramic or metal matrix, which acts as the carrier of the radionuclide and as the X-ray marker, encapsulated in a sealed titanium tube. This study aimed to develop a computational model to reproduce the film-seed geometry, in order to obtain the spatial regions of the isodose curves produced by the seed when it is put over the film surface. The seed modeled in this work was the OncoSeed 6711, a sealed source of iodine-125, which its isodose curves were obtained experimentally in previous work with the use of dosimetric films. For the films modeling, compositions and densities of the two types of dosimetric films were used: Agfa Personal Monitoring photographic film 2/10, manufactured by Agfa-Geavaert; and the model EBT radiochromic film, by International Specialty Products. The film-seed models were coupled to the Monte Carlo code MCNP5. The results obtained by simulations showed to be in good agreement with experimental results performed in a previous work. This indicates that the computational model can be used in future studies for other seeds models. (author)

  4. Dosimetric effectiveness in implants with distinct HO166-seed distribution in prostate

    International Nuclear Information System (INIS)

    Braga, Viviane V. B.; Campos, Tarcísio P. R.

    2017-01-01

    Currently, there is a need to produce new therapeutic techniques for the treatment of prostate tumors, considering the high incidence of the disease and significant morbidity rates associated with surgery and radiotherapy. Simulations in brachytherapy produce essential information about the efficiency and dosimetric efficacy compared to other techniques. Computational simulation by Monte Carlo method has been used to evaluate the absorbed dose and effective dose in radiotherapy and radiology. Virtual, analytical or voxelized phantoms are useful in the internal assessment of the spatial distribution of absorbed dose. This study estimated the efficiency of dosimetry by parameters of merit generated from volumetric distributions of absorbed doses simulating various spatial distributions of Ho-166 seeds in a prostate model. A computer model of voxels was developed, using the code SISCODES (Computational System for Dosimetry by Neutrons and Photons by Stochastic Methods applied to radiology and radiotherapy), representative of a real physical simulator predefined as a calibration method. The virtual model reproduced a cubic box, filled with muscle equivalent tissue (TE), where a 5-cm diameter ball with TE-prostate was positioned 2-cm from the air interface. A Ho-166 seed distribution, produced by 16 filet-implants distributed regularly (10-mm pitch) containing 04 separate 8-mm seeds, was employed. Two pitch were considered: 9 and 10 mm, with same distance between seed in a fillet. Based on SISCODE database of chemical composition of tissues and nuclear data, The code allowed the association of nuclear and chemical data to the voxels of the model, by the selection of the tissue of each voxel, as well as the positioning of the sources and their spatial distribution and spectra. The code MCNP5 simulated the transport of photons and electrons in the model, generating the energy deposited per unit mass in each voxel for photons in MeV.g-1 and energy absorbed in MeV for beta

  5. Dosimetric effectiveness in implants with distinct HO166-seed distribution in prostate

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Viviane V. B.; Campos, Tarcísio P. R., E-mail: Vitoriabraga06@gmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-07-01

    Currently, there is a need to produce new therapeutic techniques for the treatment of prostate tumors, considering the high incidence of the disease and significant morbidity rates associated with surgery and radiotherapy. Simulations in brachytherapy produce essential information about the efficiency and dosimetric efficacy compared to other techniques. Computational simulation by Monte Carlo method has been used to evaluate the absorbed dose and effective dose in radiotherapy and radiology. Virtual, analytical or voxelized phantoms are useful in the internal assessment of the spatial distribution of absorbed dose. This study estimated the efficiency of dosimetry by parameters of merit generated from volumetric distributions of absorbed doses simulating various spatial distributions of Ho-166 seeds in a prostate model. A computer model of voxels was developed, using the code SISCODES (Computational System for Dosimetry by Neutrons and Photons by Stochastic Methods applied to radiology and radiotherapy), representative of a real physical simulator predefined as a calibration method. The virtual model reproduced a cubic box, filled with muscle equivalent tissue (TE), where a 5-cm diameter ball with TE-prostate was positioned 2-cm from the air interface. A Ho-166 seed distribution, produced by 16 filet-implants distributed regularly (10-mm pitch) containing 04 separate 8-mm seeds, was employed. Two pitch were considered: 9 and 10 mm, with same distance between seed in a fillet. Based on SISCODE database of chemical composition of tissues and nuclear data, The code allowed the association of nuclear and chemical data to the voxels of the model, by the selection of the tissue of each voxel, as well as the positioning of the sources and their spatial distribution and spectra. The code MCNP5 simulated the transport of photons and electrons in the model, generating the energy deposited per unit mass in each voxel for photons in MeV.g-1 and energy absorbed in MeV for beta

  6. Therapeutic value of 3-D printing template-assisted 125I-seed implantation in the treatment of malignant liver tumors

    Directory of Open Access Journals (Sweden)

    Han T

    2017-07-01

    Full Text Available Tao Han,1,* Xiaodan Yang,1,* Ying Xu,2,* Zhendong Zheng,1,* Ying Yan,2 Ning Wang2 1Department of Oncology, 2Department of Radiotherapy, General Hospital of Shenyang Military Region, Shenyang, China *These authors contributed equally to this work Objective: To explore the therapeutic value of 3-D printing template-assisted 125I-seed implantation in the treatment of malignant liver tumors.Materials and methods: Fifteen liver cancer patients with 47 total lesions were treated with 3-D printing template-assisted radioactive seed implantation (group A, and 25 liver-tumor patients with 66 total lesions were treated with 125I-seed implantation without a template auxiliary (group B. Operation time, in-hospital time, operation complications, dose distribution, and response rate (number were compared between the two groups. Results: Shorter operation times and better dose distribution were observed in group A than in group B, and the differences were statistically significant. The response rate after 2 months was 86.7% (13 of 15 in group A and 84% (21 of 25 in group B; differences between the two groups were not significant.Conclusion: Application of 3-D printing template-assisted radioactive seed implantation in the treatment of malignant liver tumors can help shorten operation time and optimize radiation-dose distribution, is worthy of further study, and has clinical significance. Keywords: brachytherapy, stereotactic techniques, iodine isotopes, liver, carcinoma 

  7. TU-AB-201-11: A Novel Theoretical Framework for MRI-Only Image Guided LDR Prostate and Breast Brachytherapy Implant Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, A; Elzibak, A; Fatemi, A; Safigholi, H; Ravi, A; Morton, G; Song, W [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Han, D [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); University of California, San Diego, La Jolla, CA (United States)

    2015-06-15

    Purpose: To propose a novel framework for accurate model-based dose calculations using only MR images for LDR prostate and breast seed implant brachytherapy. Methods: Model-based dose calculation methodologies recommended by TG-186 require further knowledge about specific tissue composition, which is challenging with MRI. However, relying on MRI-only for implant dosimetry would reduce the soft tissue delineation uncertainty, costs, and uncertainties associated with multi-modality registration and fusion processes. We propose a novel framework to address this problem using quantitative MRI acquisitions and reconstruction techniques. The framework includes three steps: (1) Identify the locations of seeds(2) Identify the presence (or absence) of calcification(s)(3) Quantify the water and fat content in the underlying tissueSteps (1) and (2) consider the sources that limit patient dosimetry, particularly the inter-seed attenuation and the calcified regions; while step (3) targets the quantification of the tissue composition to consider the heterogeneities in the medium. Our preliminary work has shown that the seeds and the calcifications can be identified with MRI using both the magnitude and the phase images. By employing susceptibility-weighted imaging with specific post-processing techniques, the phase images can be further explored to distinguish the seeds from the calcifications. Absolute quantification of tissue, water, and fat content is feasible and was previously demonstrated in phantoms and in-vivo applications, particularly for brain diseases. The approach relies on the proportionality of the MR signal to the number of protons in an image volume. By employing appropriate correction algorithms for T1 - and T2*-related biases, B1 transmit and receive field inhomogeneities, absolute water/fat content can be determined. Results: By considering calcification and interseed attenuation, and through the knowledge of water and fat mass density, accurate patient

  8. Development of measurement method using TLD for workers occupation personally exposed to 125I seed source in the implant

    International Nuclear Information System (INIS)

    Luo Suming; He Zhijian; Yuan Jilong; Yue Baorong; Wei Kedao

    2011-01-01

    I seeds, the worker received the absorbed dose 0.09-14.29 μGy and effective dose 2.40-4.50 μSv outside lead aprons and the highest absorbed dose 7.77 μGy and effective 0.12 μSv inside lead aprons, respectively, with more than 34% of rays shielded. For one case of eye cancer with implantation of 125 I seeds, the workers received the absorbed dose 2.2-39.84 μGy and effective dose 4.48-10.06 μSv outside aprons and the highest absorbed dose 5.19 μGy and effective 0.16 μSv inside aprons, respectively, with more than 54.6 % of rays shielded. Conclusions: The method of using TLDs to measure the doses to the occupational workers in the course of the implantation of 125 I seed sources is simple and easy to operate. It would be an effective approach to protecting medical workers in the case of brachytherapy. (authors)

  9. 3D-CT implanted interstitial brachytherapy for T2b nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Ren, Yu-Feng; Gao, Yuan-Hong; Cao, Xin-Ping; Ye, Wei-Jun; Teh, Bin S

    2010-01-01

    To compare the results of external beam radiotherapy in combination with 3D- computed tomography (CT)-implanted interstitial high dose rate brachytherapy (ERT/3D-HDR-BT) versus conventional external beam radiotherapy (ERT) for the treatment of stage T2b nasopharyngeal carcinoma (NPC). Forty NPC patients diagnosed with stage T2b NPC were treated with ERT/3D-HDR-BT under local anesthesia. These patients received a mean dose of 60 Gy, followed by 12-20 Gy administered by 3D-HDR-BT. Another 101 patients diagnosed with non-metastatic T2b NPC received a mean dose of 68 Gy by ERT alone during the same period. Patients treated with ERT/3D-HDR-BT versus ERT alone exhibited an improvement in their 5-y local failure-free survival rate (97.5% vs. 80.2%, P = 0.012) and disease-free survival rate (92.5% vs. 73.3%, P = 0.014). Using multivariate analysis, administration of 3D-HDR-BT was found to be favorable for local control (P = 0.046) and was statistically significant for disease-free survival (P = 0.021). The incidence rate of acute and chronic complications between the two groups was also compared. It is possible that the treatment modality enhances local control due to improved conformal dose distributions and the escalated radiation dose applied

  10. The Quadrella: A novel approach to analyzing optimal outcomes after permanent seed prostate brachytherapy

    International Nuclear Information System (INIS)

    Tétreault-Laflamme, Audrey; Zilli, Thomas; Meissner, Aliza; Larrivée, Sandra; Sylvestre, Marie-Pierre; Delouya, Guila

    2014-01-01

    Background and purpose: To study a four-point combined analysis (Quadrella) of optimal outcome among patients treated with exclusive permanent seed prostate brachytherapy (PB), as defined by the likelihood of achieving disease control and preserving normal urinary, gastro-intestinal (GI) and sexual function. Materials and methods: 384 patients with localized prostate cancer underwent PB at our institution with 125 I at a dose level of 144 Gy. Subjects with erectile dysfunction who did not respond to medication were excluded. 281 patients with minimum 3-year follow-up were evaluated. Patients with concurrent biochemical progression-free survival (bPFS), absent urinary and GI toxicities (grade 0 toxicities according to CTCAE v 3.0) and preserved sexual potency (with our without medication) were classified as the Quadrella group. Results: Among the 281 patients analyzed, the Quadrella was achieved in 49.1%, 48.0%, 50.4%, 41.7% and 65.2% in years 3–7, respectively. bPFS rates were 82.6–96.1%, corresponding potency rates were 63.6–82.3%, and normal urinary and GI function rates were 64.8–82.6% and 95–100%, respectively. By multivariate analysis, significant predictors of Quadrella were age (p = 0.015), baseline IPSS (p = 0.03) and time since PB (p = 0.02). Conclusion: Urinary and sexual toxicity remained the most common reasons for excluding patients from a perfect outcome (Quadrella), defined by strict criteria. This analysis can be useful for subsequent comparison between treatment modalities

  11. SU-E-T-301: Dosimetric Comparison Between Adaptive and Rectilinear Template-Based Prostate Seed Implants

    Energy Technology Data Exchange (ETDEWEB)

    Sugar, E Neubauer; Buzurovic, I; O’Farrell, D; Hansen, J; Devlin, P; Cormack, R; Nguyen, P [Brigham and Women’s Hospital, Boston, MA (United States)

    2015-06-15

    Purpose: To compare the dosimetry of a standard rectilinear and an adaptive technique used in I125 prostate seed implants. Methods: To achieve favorable dosimetry in prostate implants we used adaptive needle updates to match actual positions in real-time. The seed locations were optimized based on actual needle locations. The seeds were delivered automatically with a robotic device seedSelectron™ (Elekta Brachytherapy). In this study, we evaluated the former approach against the standard rectilinear technique in which the needles have a parallel distribution. The treatment plans for 10 patients were analyzed. For comparison, the actual treatment plans were revised so each needle was repositioned to its original parallel location through the template. The analysis was performed by comparing the target coverage and dose to the organs at risk. The comparison was done using the following planning goals: the target D90> 90%, V100% > 90%, V50% <70% and V200% <30%; the urethra V125% < 1cm3 and V150%= 0cm3; and the Rectum V100%<1cm3 and V69% < 8cm3. The prescription dose to the target was 145Gy. Results: The average target volume and number of seeds were 44.39cm3(SD=11.14) and 74(SD=12), respectively. The D90 for adaptive and rectilinear plans was 159.9Gy(SD=2.99) and 155.53Gy(SD=4.04) resulting in a 2.74% difference for the average target coverage. A similar difference (1.75%) was noticed in the target V100[%]. No significant difference was noticed in the dose to the urethra and rectum. All planning goals were met with both the adaptive and rectilinear approach for each plan. Conclusion: The study reveals enhanced coverage of the target when using the adaptive needle adjustments as compared to the rectilinear approach for the analyzed cases. However, the differences in dosimetry did not translate to meaningful clinical outcomes.

  12. Dosimetry consequences of the accuracy at the position of the seeds in a seeds implant of I-125 in prostate

    International Nuclear Information System (INIS)

    Luquero Llopis, N.; Ferrer Gracia, C.; Huertas Martinez, C.; Huerga Cabrerizo, C.; Corredoira Silva, E.; Serrada Hierro, A.

    2013-01-01

    The quality control of equipment used to carry out implants of seeds of low rate in prostate, van destined to watch, the activity of seeds and the calculation of planning both positioning them on the inside of the patient. The objective of this work is, using the Nucletron Spot Pro and SeedSelectron, rating dosimetry possible consequences related to the position of the seeds. (Author)

  13. Effect of improved TLD dosimetry on the determination of dose rate constants for 125I and 103Pd brachytherapy seeds

    International Nuclear Information System (INIS)

    Rodriguez, M.; Rogers, D. W. O.

    2014-01-01

    Purpose: To more accurately account for the relative intrinsic energy dependence and relative absorbed-dose energy dependence of TLDs when used to measure dose rate constants (DRCs) for 125 I and 103 Pd brachytherapy seeds, to thereby establish revised “measured values” for all seeds and compare the revised values with Monte Carlo and consensus values. Methods: The relative absorbed-dose energy dependence, f rel , for TLDs and the phantom correction, P phant , are calculated for 125 I and 103 Pd seeds using the EGSnrc BrachyDose and DOSXYZnrc codes. The original energy dependence and phantom corrections applied to DRC measurements are replaced by calculated (f rel ) −1 and P phant values for 24 different seed models. By comparing the modified measured DRCs to the MC values, an appropriate relative intrinsic energy dependence, k bq rel , is determined. The new P phant values and relative absorbed-dose sensitivities, S AD rel , calculated as the product of (f rel ) −1 and (k bq rel ) −1 , are used to individually revise the measured DRCs for comparison with Monte Carlo calculated values and TG-43U1 or TG-43U1S1 consensus values. Results: In general, f rel is sensitive to the energy spectra and models of the brachytherapy seeds. Values may vary up to 8.4% among 125 I and 103 Pd seed models and common TLD shapes. P phant values depend primarily on the isotope used. Deduced (k bq rel ) −1 values are 1.074 ± 0.015 and 1.084 ± 0.026 for 125 I and 103 Pd seeds, respectively. For (1 mm) 3 chips, this implies an overall absorbed-dose sensitivity relative to 60 Co or 6 MV calibrations of 1.51 ± 1% and 1.47 ± 2% for 125 I and 103 Pd seeds, respectively, as opposed to the widely used value of 1.41. Values of P phant calculated here have much lower statistical uncertainties than literature values, but systematic uncertainties from density and composition uncertainties are significant. Using these revised values with the literature’s DRC measurements, the

  14. Urethra-Sparing, Intraoperative, Real-Time Planned, Permanent-Seed Prostate Brachytherapy: Toxicity Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zilli, Thomas [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal-Hopital Notre-Dame, Montreal, QC (Canada); Taussky, Daniel, E-mail: daniel.taussky.chum@ssss.gouv.qc.ca [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal-Hopital Notre-Dame, Montreal, QC (Canada); Donath, David; Le, Hoa Phong; Larouche, Renee-Xaviere; Beliveau-Nadeau, Dominique; Hervieux, Yannick; Delouya, Guila [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal-Hopital Notre-Dame, Montreal, QC (Canada)

    2011-11-15

    Purpose: To report the toxicity outcome in patients with localized prostate cancer undergoing {sup 125}I permanent-seed brachytherapy (BT) according to a urethra-sparing, intraoperative (IO), real-time planned conformal technique. Methods and Materials: Data were analyzed on 250 patients treated consecutively for low- or intermediate-risk prostate cancer between 2005 and 2009. The planned goal was urethral V{sub 150} = 0. Acute and late genitourinary (GU), gastrointestinal (GI), and erectile toxicities were scored with the International Prostate Symptom Score (IPSS) questionnaire and Common Terminology Criteria for Adverse Events (version 3.0). Median follow-up time for patients with at least 2 years of follow-up (n = 130) was 34.4 months (range, 24-56.9 months). Results: Mean IO urethra V{sub 150} was 0.018% {+-} 0.08%. Mean prostate D{sub 90} and V{sub 100} on day-30 computed tomography scan were 158.0 {+-} 27.0 Gy and 92.1% {+-} 7.2%, respectively. Mean IPSS peak was 9.5 {+-} 6.3 1 month after BT (mean difference from baseline IPSS, 5.3). No acute GI toxicity was observed in 86.8% of patients. The 3-year probability of Grade {>=}2 late GU toxicity-free survival was 77.4% {+-} 4.0%, with Grade 3 late GU toxicity encountered in only 3 patients. Three-year Grade 1 late GI toxicity-free survival was 86.1% {+-} 3.2%. No patient presented Grade {>=}2 late GI toxicity. Of patients with normal sexual status at baseline, 20.7% manifested Grade {>=}2 erectile dysfunction after BT. On multivariate analysis, elevated baseline IPSS (p = 0.016) and high-activity sources (median 0.61 mCi) (p = 0.033) predicted increased Grade {>=}2 late GU toxicity. Conclusions: Urethra-sparing IO BT results in low acute and late GU toxicity compared with the literature. High seed activity and elevated IPSS at baseline increased long-term GU toxicity.

  15. Methods for prostate stabilization during transperineal LDR brachytherapy

    International Nuclear Information System (INIS)

    Podder, Tarun; Yu Yan; Sherman, Jason; Rubens, Deborah; Strang, John; Messing, Edward; Ng, Wan-Sing

    2008-01-01

    In traditional prostate brachytherapy procedures for a low-dose-rate (LDR) radiation seed implant, stabilizing needles are first inserted to provide some rigidity and support to the prostate. Ideally this will provide better seed placement and an overall improved treatment. However, there is much speculation regarding the effectiveness of using regular brachytherapy needles as stabilizers. In this study, we explored the efficacy of two types of needle geometries (regular brachytherapy needle and hooked needle) and several clinically feasible configurations of the stabilization needles. To understand and assess the prostate movement during seed implantation, we collected in vivo data from patients during actual brachytherapy procedures. In vitro experimentation with tissue-equivalent phantoms allowed us to further understand the mechanics behind prostate stabilization. We observed superior stabilization with the hooked needles compared to the regular brachytherapy needles (more than 40% in bilateral parallel needle configuration). Prostate movement was also reduced significantly when regular brachytherapy needles were in an angulated configuration as compared to the parallel configuration (more than 60%). When the hooked needles were angulated for stabilization, further reduction in prostate displacement was observed. In general, for convenience of dosimetric planning and to avoid needle collision, all needles are desired to be in a parallel configuration. In this configuration, hooked needles provide improved stabilization of the prostate. On the other hand, both regular and hooked needles appear to be equally effective in reducing prostate movement when they are in angulated configurations, which will be useful in seed implantation using a robotic system. We have developed nonlinear spring-damper model for the prostate movement which can be used for adapting dosimetric planning during brachytherapy as well as for developing more realistic haptic devices and

  16. Methods for prostate stabilization during transperineal LDR brachytherapy.

    Science.gov (United States)

    Podder, Tarun; Sherman, Jason; Rubens, Deborah; Messing, Edward; Strang, John; Ng, Wan-Sing; Yu, Yan

    2008-03-21

    In traditional prostate brachytherapy procedures for a low-dose-rate (LDR) radiation seed implant, stabilizing needles are first inserted to provide some rigidity and support to the prostate. Ideally this will provide better seed placement and an overall improved treatment. However, there is much speculation regarding the effectiveness of using regular brachytherapy needles as stabilizers. In this study, we explored the efficacy of two types of needle geometries (regular brachytherapy needle and hooked needle) and several clinically feasible configurations of the stabilization needles. To understand and assess the prostate movement during seed implantation, we collected in vivo data from patients during actual brachytherapy procedures. In vitro experimentation with tissue-equivalent phantoms allowed us to further understand the mechanics behind prostate stabilization. We observed superior stabilization with the hooked needles compared to the regular brachytherapy needles (more than 40% in bilateral parallel needle configuration). Prostate movement was also reduced significantly when regular brachytherapy needles were in an angulated configuration as compared to the parallel configuration (more than 60%). When the hooked needles were angulated for stabilization, further reduction in prostate displacement was observed. In general, for convenience of dosimetric planning and to avoid needle collision, all needles are desired to be in a parallel configuration. In this configuration, hooked needles provide improved stabilization of the prostate. On the other hand, both regular and hooked needles appear to be equally effective in reducing prostate movement when they are in angulated configurations, which will be useful in seed implantation using a robotic system. We have developed nonlinear spring-damper model for the prostate movement which can be used for adapting dosimetric planning during brachytherapy as well as for developing more realistic haptic devices and

  17. ALGEBRA: ALgorithm for the heterogeneous dosimetry based on GEANT4 for BRAchytherapy.

    Science.gov (United States)

    Afsharpour, H; Landry, G; D'Amours, M; Enger, S; Reniers, B; Poon, E; Carrier, J-F; Verhaegen, F; Beaulieu, L

    2012-06-07

    Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry platforms. The scientific community has expressed the need for an accurate dosimetry platform in brachytherapy. The purpose of this paper is to present ALGEBRA, a Monte Carlo platform for dosimetry in brachytherapy which is sufficiently fast and accurate for clinical and research purposes. ALGEBRA is based on the GEANT4 Monte Carlo code and is capable of handling the DICOM RT standard to recreate a virtual model of the treated site. Here, the performance of ALGEBRA is presented for the special case of LDR brachytherapy in permanent prostate and breast seed implants. However, the algorithm is also capable of handling other treatments such as HDR brachytherapy.

  18. Exposure of treating physician to radiation during prostate brachytherapy using iodine-125 seeds. Dose measurements on both hands with thermoluminescence dosimeters

    International Nuclear Information System (INIS)

    Schiefer, Hans; Seelentag, Wolf; Plasswilm, Ludwig; Ries, Gerhard; Toggenburg, Friedrich von; Lenggenhager, Cornelius; Schmid, Hans-Peter; Leippold, Thomas; Engeler, Daniel; Prikler, Ladislav; Krusche, Bernd; Roth, Jakob

    2009-01-01

    Background and purpose: only sparse reports have been made about radiation exposure of the treating physician during prostate seed implantation. Therefore, thermoluminescence dosimeter (TLD) measurements on the index fingers and the backs of both hands were conducted. Material and methods: stranded iodine-125 seeds with a mean apparent activity of 27.4 MBq per seed were used. During application, the treating physician manipulated the loaded needle with the index fingers, partially under fluoroscopic control. Four physicians with varying experience treated 24 patients. The radiation exposure was determined with TLD-100 chips attached to the index fingertips and the backs of hands. Radiation exposure was correlated with the physician's experience. Results: the average brachytherapy duration by the most experienced physician was 19.2 min (standard deviation σ = 1.2 min; novices: 34.8 min [σ = 10.2 min]). The mean activity was 1,703 MBq (σ = 123 MBq), applied with 16.3 needles (σ = 2.5 needles; novices: 1,469 MBq [σ = 229 MBq]; 16.8 needles [σ = 2.3 needles ]). The exposure of the finger of the ''active hand'' and the back of the hand amounted to 1.31 mSv (σ = 0.54 mSv) and 0.61 mSv (σ = 0.23 mSv), respectively (novices: 2.07 mSv [σ = 0.86 mSv] and 1.05 mSv [σ = 0.53 mSv]). Conclusion: if no other radiation exposure needs to be considered, an experienced physician can perform about 400 applications per year without exceeding the limit of 500 mSv/year; for novices, the corresponding figure is about 200. (orig.)

  19. Radiobiology for eye plaque brachytherapy and evaluation of implant duration and radionuclide choice using an objective function

    International Nuclear Information System (INIS)

    Gagne, Nolan L.; Leonard, Kara L.; Rivard, Mark J.

    2012-01-01

    Purpose: Clinical optimization of Collaborative Ocular Melanoma Study (COMS) eye plaque brachytherapy is currently limited to tumor coverage, consensus prescription dosage, and dose calculations to ocular structures. The biologically effective dose (BED) of temporary brachytherapy treatments is a function of both chosen radionuclide R and implant duration T. This study endeavored to evaluate BED delivered to the tumor volume and surrounding ocular structures as a function of plaque position P, prescription dose, R, and T. Methods: Plaque-heterogeneity-corrected dose distributions were generated with MCNP5 for the range of currently available COMS plaques loaded with sources using three available low-energy radionuclides. These physical dose distributions were imported into the PINNACLE 3 treatment planning system using the TG-43 hybrid technique and used to generate dose volume histograms for a T = 7 day implant within a reference eye geometry including the ciliary body, cornea, eyelid, foveola, lacrimal gland, lens, optic disc, optic nerve, retina, and tumor at eight standard treatment positions. The equation of Dale and Jones was employed to create biologically effective dose volume histograms (BEDVHs), allowing for BED volumetric analysis of all ROIs. Isobiologically effective prescription doses were calculated for T = 5 days down to 0.01 days, with BEDVHs subsequently generated for all ROIs using correspondingly reduced prescription doses. Objective functions were created to evaluate the BEDVHs as a function of R and T. These objective functions are mathematically accessible and sufficiently general to be applied to temporary or permanent brachytherapy implants for a variety of disease sites. Results: Reducing T from 7 to 0.01 days for a 10 mm plaque produced an average BED benefit of 26%, 20%, and 17% for 103 Pd, 125 I, and 131 Cs, respectively, for all P; 16 and 22 mm plaque results were more position-dependent. 103 Pd produced a 16%–35% BED benefit over

  20. Novel prostate brachytherapy technique: Improved dosimetric and clinical outcome

    International Nuclear Information System (INIS)

    Nobes, Jenny P.; Khaksar, Sara J.; Hawkins, Maria A.; Cunningham, Melanie J.; Langley, Stephen E.M.; Laing, Robert W.

    2008-01-01

    Purpose: Erectile dysfunction following prostate brachytherapy is reported to be related to dose received by the penile bulb. To minimise this, whilst preserving prostate dosimetry, we have developed a technique for I-125 seed brachytherapy using both stranded seeds and loose seeds delivered with a Mick applicator, and implanted via the sagittal plane on trans-rectal ultrasound. Materials and methods: Post-implant dosimetry and potency rates were compared in 120 potent patients. In Group 1, 60 patients were treated using a conventional technique of seeds implanted in a modified-uniform distribution. From January 2005, a novel technique was developed using stranded seeds peripherally and centrally distributed loose seeds implanted via a Mick applicator (Group 2). The latter technique allows greater flexibility when implanting the seeds at the apex. Each patient was prescribed a minimum peripheral dose of 145 Gy. No patients received external beam radiotherapy or hormone treatment. There was no significant difference in age or pre-implant potency score (mean IIEF-5 score 22.4 vs. 22.6, p = 0.074) between the two groups. Results: The new technique delivers lower penile bulb doses (D 25 as %mPD - Group 1: 61.2 ± 35.7, Group 2: 29.7 ± 16.0, p 50 as %mPD - Group 1: 45.8 ± 26.9, Group 2: 21.4 ± 11.7, p 90 - Group 1: 147 Gy ± 21.1, Group 2: 155 Gy ± 16.7, p = 0.03). At 2 years, the potency rate was also improved: Group 1: 61.7%; Group 2: 83.3% (p = 0.008). Conclusions: In this study, the novel brachytherapy technique using both peripheral stranded seeds and central loose seeds delivered via a Mick applicator results in a lower penile bulb dose whilst improving prostate dosimetry, and may achieve higher potency rates

  1. Obtention of brachytherapy seeds by sealing process using polymer; Obtencao de sementes de braquiterapia pelo processo de selagem com polimero

    Energy Technology Data Exchange (ETDEWEB)

    Lana, Diogo Alberto P.D.; Ferraz, Wilmar B.; Santos, Ana Maria M., E-mail: amms@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Carvalho, Luiz Claudio F.M. Garcia [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2012-08-15

    Brachytherapy is an advanced cancer treatment where radioactive seeds or sources are placed near or directly into the tumor thus reducing the radiation exposure in the surrounding healthy tissues. Several kinds of seeds have been developed in order to obtain a better dose distribution around them and with a lower cost manufacturing. These seeds consist of an encapsulation (titanium or stainless steel tube), a radionuclide carrier, and X-ray marker. The usual sealing process of the seeds is done with laser welding, but this process can promote radionuclide volatilization. In this paper, we present a new sealing process using epoxy resin and characterizations of two epoxy resins. These resins were characterized by Fourier transform infrared spectroscopic (FTIR), ultraviolet-visible spectroscopy (UV-vis) and differential scanning calorimetry (DSC). Interactions of the resins and of the sealed seeds in a simulated body fluid (SBF) were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and by a counting gamma-rays. (author)

  2. Intraoperative real-time planned conformal prostate brachytherapy: Post-implantation dosimetric outcome and clinical implications

    International Nuclear Information System (INIS)

    Zelefsky, Michael J.; Yamada, Yoshiya; Cohen, Gil'ad N.; Sharma, Neha; Shippy, Alison M.; Fridman, David; Zaider, Marco

    2007-01-01

    Purpose: To report the dosimetric outcome of patients with clinically localized prostate cancer treated with I-125 permanent implantation using an intraoperative real-time conformal planning technique. Methods and materials: Five hundred and sixty-two patients with prostate cancer were treated with I-125 permanent interstitial implantation using a transrectal ultrasound-guided approach. Real-time intraoperative treatment planning software that incorporates inverse planning optimization was used. Dose-volume constraints for this inverse-planning system included: prostate V100 ≥95%, maximal urethral dose ≤120%, and average rectal dose 3 of the rectum was exposed to the prescription dose, the incidence of late grade 2 toxicity rectal toxicity was 9% compared to 4% for smaller volumes of the rectum exposed to similar doses (p = 0.003). No dosimetric parameter in these patients with tight dose confines for the urethra influenced acute or late urinary toxicity. Conclusion: Real-time intraoperative planning was associated with a 90% consistency of achieving the planned intraoperative dose constraints for target coverage and maintaining planned urethral and rectal constraints in a high percentage of implants. Rectal volumes of ≥2.5 cm 3 exposed to the prescription doses were associated with an increased incidence of grade 2 rectal bleeding. Further enhancements in imaging guidance for optimal seed deposition are needed to guarantee optimal dose distribution for all patients. Whether such improvements lead to further reduction in acute and late morbidities associated with therapy requires further study

  3. Evaluation of failure modes of computerized planning phase of interstitial implants with high dose rate brachytherapy using HFMEA

    International Nuclear Information System (INIS)

    Biazotto, Bruna; Tokarski, Marcio

    2014-01-01

    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)

  4. Dosimetry study of three-dimensional print template-guided precision 125I seed implantation

    Directory of Open Access Journals (Sweden)

    Zhang Hongtao

    2016-01-01

    Conclusions: The postplan and preplan dose parameters of 3D print template-guided seed implantation were nearly consistent. The dose parameters of template group superior to the traditional group. The seeds can be implanted accurately with 3D print template.

  5. BEDVH--A method for evaluating biologically effective dose volume histograms: Application to eye plaque brachytherapy implants

    International Nuclear Information System (INIS)

    Gagne, Nolan L.; Leonard, Kara L.; Huber, Kathryn E.; Mignano, John E.; Duker, Jay S.; Laver, Nora V.; Rivard, Mark J.

    2012-01-01

    Purpose: A method is introduced to examine the influence of implant duration T, radionuclide, and radiobiological parameters on the biologically effective dose (BED) throughout the entire volume of regions of interest for episcleral brachytherapy using available radionuclides. This method is employed to evaluate a particular eye plaque brachytherapy implant in a radiobiological context. Methods: A reference eye geometry and 16 mm COMS eye plaque loaded with 103 Pd, 125 I, or 131 Cs sources were examined with dose distributions accounting for plaque heterogeneities. For a standardized 7 day implant, doses to 90% of the tumor volume ( TUMOR D 90 ) and 10% of the organ at risk volumes ( OAR D 10 ) were calculated. The BED equation from Dale and Jones and published α/β and μ parameters were incorporated with dose volume histograms (DVHs) for various T values such as T = 7 days (i.e., TUMOR 7 BED 10 and OAR 7 BED 10 ). By calculating BED throughout the volumes, biologically effective dose volume histograms (BEDVHs) were developed for tumor and OARs. Influence of T, radionuclide choice, and radiobiological parameters on TUMOR BEDVH and OAR BEDVH were examined. The nominal dose was scaled for shorter implants to achieve biological equivalence. Results: TUMOR D 90 values were 102, 112, and 110 Gy for 103 Pd, 125 I, and 131 Cs, respectively. Corresponding TUMOR 7 BED 10 values were 124, 140, and 138 Gy, respectively. As T decreased from 7 to 0.01 days, the isobiologically effective prescription dose decreased by a factor of three. As expected, TUMOR 7 BEDVH did not significantly change as a function of radionuclide half-life but varied by 10% due to radionuclide dose distribution. Variations in reported radiobiological parameters caused TUMOR 7 BED 10 to deviate by up to 46%. Over the range of OAR α/β values, OAR 7 BED 10 varied by up to 41%, 3.1%, and 1.4% for the lens, optic nerve, and lacrimal gland, respectively. Conclusions: BEDVH permits evaluation of the

  6. Description and features of a technique of seeds implantation with 3D real time planning connected to an automatic afterloading and quality control device

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz Seidal, M.; Cantera de Frutos, C.

    2002-07-01

    According to statistics, 9% of males older than 50 years will develop prostate cancer and 33% of them will finally die of their disease. Detection can be based on digital rectal examination, tumoral markers measurements as PSA (Prostate Specific Antigen). CT/MR or Ultra sound imaging. Treatments may be radical prostatectomy (usually combined with chemotherapy), external radiation therapy, brachytherapy, or a combination of the former two techniques. In the last years permanent seed implantation is becoming an attractive alternative for treatment of prostate cancer at early stages, either as monotherapy (total prescribed dose of 145 Gy) or as an additional boost after external beam irradiation (95-100Gy after external beam delivery of 50Gy). But not all cases are suitable for seed treatment. Tumors must be at an early state and not very active (low tumoral markers values), without extra-capsular spreading and no metastasis in surrounding area. There must be no trans-urethral resection, no calcifications nor public arc interference and, finally, the volume should not be bigger than 50 cm''3. The technique consists on the permanent implantation of radioactive seeds into the prostate that, while decaying, will deliver the prescribed dose to the tumor. Isotopes mostly used are I-125 and Pd-103. Procedures for seed implantation vary but traditional ones generally imply two stages. The first one is the manual pre-loading of needles which can be performed either by composing loose seeds and spacers, either by cutting off strands of seeds and re absorbable spacers. This process can be done according to a previously approved pre plan or based on the accumulated experience about the number of needles and loading usually needed. Second stage consist on the implantation of these preloaded needles on the operation room. (Author)

  7. Loss of I-125 seeds after perineal implantation of the prostate

    International Nuclear Information System (INIS)

    Wopereis, A.J.M.; Moerland, M.A.; Koning, J.H.A.G. de; Battermann, J.J.

    1996-01-01

    Introduction: One of the treatment modalities of early stage prostate cancer is the permanent implantation of I-125 seeds. The aim of this study was to obtain insight in the loss of seeds after implantation. Methods and Materials: During the past 6 years, 100 patients were treated and examined. Radiographs of the prostate area were taken at discharge (after 2 or 3 days) and combined with a follow-up appointment, successively after 1, 3, 6, 12 and 24 months. 10 patients were excluded from this study because of a later performed prostatectomy or TURP. During the hospitalisation period the patient's excrements were examined for lost seeds. Furthermore patients were instructed to urinate through a tea-strainer in the first month following implantation in order to prevent seeds from entering the sewage system. Results: We observed an overall loss of 5% during the entire follow-up period of 2 years. Further analysis of the obtained data showed that most of the seeds (3% of the implanted seeds) were lost in the first 2 days after implantation. Due to special attention paid to safety measures, 94% of the lost seeds were retrieved during the admission period. Because of adequate instructions given to the patients, 70% of the seeds lost during the first month after discharge (0.5% of the total number of remaining implanted seeds) were also retrieved. Losing seeds during the first month after implantation did not increase the chance of further loss later on. A total of 13 seeds (in all patients) was lost after 1 month (of which 6 were lost after more then one year and are for radiation safety reasons not of importance). Conclusions: Most seeds are lost during the first days after implantation. Therefore, radiographs are indicated at discharge, after 1 month (for evaluation of safety precautions) and after 1 year as a conclusion to the treatment

  8. Implant strategies for endocervical and interstitial ultrasound hyperthermia adjunct to HDR brachytherapy for the treatment of cervical cancer

    International Nuclear Information System (INIS)

    Wootton, Jeffery H; Prakash, Punit; Hsu, I-Chow Joe; Diederich, Chris J

    2011-01-01

    Catheter-based ultrasound devices provide a method to deliver 3D conformable heating integrated with HDR brachytherapy delivery. Theoretical characterization of heating patterns was performed to identify implant strategies for these devices which can best be used to apply hyperthermia to cervical cancer. A constrained optimization-based hyperthermia treatment planning platform was used for the analysis. The proportion of tissue ≥41 deg. C in a hyperthermia treatment volume was maximized with constraints T max ≤ 47 deg. C, T rectum ≤ 41.5 deg. C, and T bladder ≤ 42.5 deg. C. Hyperthermia treatment was modeled for generalized implant configurations and complex configurations from a database of patients (n = 14) treated with HDR brachytherapy. Various combinations of endocervical (360 0 or 2 x 180 0 output; 6 mm OD) and interstitial (180 0 , 270 0 , or 360 0 output; 2.4 mm OD) applicators within catheter locations from brachytherapy implants were modeled, with perfusion constant (1 or 3 kg m -3 s -1 ) or varying with location or temperature. Device positioning, sectoring, active length and aiming were empirically optimized to maximize thermal coverage. Conformable heating of appreciable volumes (>200 cm 3 ) is possible using multiple sectored interstitial and endocervical ultrasound devices. The endocervical device can heat >41 deg. C to 4.6 cm diameter compared to 3.6 cm for the interstitial. Sectored applicators afford tight control of heating that is robust to perfusion changes in most regularly spaced configurations. T 90 in example patient cases was 40.5-42.7 deg. C (1.9-39.6 EM 43deg.C ) at 1 kg m -3 s -1 with 10/14 patients ≥41 deg. C. Guidelines are presented for positioning of implant catheters during the initial surgery, selection of ultrasound applicator configurations, and tailored power schemes for achieving T 90 ≥ 41 deg. C in clinically practical implant configurations. Catheter-based ultrasound devices, when adhering to the guidelines, show

  9. Postoperative [{sup 125}I] seed brachytherapy in the treatment of acinic cell carcinoma of the parotid gland. With associated risk factors

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Ming-hui; Zhang, Jian-Guo; Zhang, Jie; Zheng, Lei; Liu, Shu-ming; Huang, Ming-wei; Shi, Yan [Peking Univ. School and Hospital of Stomatology, Beijing (China). Dept. of Oral and Maxillofacial Surgery

    2014-11-15

    This retrospective study was undertaken to analyze data from patients receiving iodine-125 ([{sup 125}I]) seed brachytherapy postoperatively for the treatment of acinic cell carcinoma (ACC) of the parotid gland along with the following risk factors: residual tumor, recurrent tumor, facial nerve invasion, positive resection margins, advanced tumor stage, or tumor spillage. Twenty-nine patients with ACC (17 females, 12 males; age range, 13-73 years; median age, 37.3 years) were included. Median follow-up was 58.2 months (range, 14-122 months). Patients received [{sup 125}I] seed brachytherapy (median actuarial D90, 177 Gy) 3-41 days (median, 14 days) following surgery. Radioactivity was 18.5-33.3 MBq per seed, and the prescription dose was 80-120 Gy. The 3-, 5-, and 10-year rates of local control were 93.1, 88.7, and 88.7 %, respectively; overall survival was 96.6, 92, and 92 %; disease-free survival was 93.1, 88.4, and 88.4 %; and freedom from distant metastasis was 96.6, 91.2, and 91.2 %. Lymph node metastases were absent in all patients, although two patients died with distant metastases. Facial nerve recovery was quick, and no severe radiotherapy-related complications were noted. Recurrence history, local recurrence, and distant metastasis significantly affected overall survival. Postoperative [{sup 125}I] seed brachytherapy is effective in treating ACC and has minor complications. Patients with a history of recurrence showed poor prognosis and were more likely to experience disease recurrence and develop metastases. (orig.) [German] Diese retrospektive Studie wurde durchgefuehrt, um die Daten von Patienten zu analysieren, die postoperativ eine Seed-Brachytherapie mit Iod-125 ([{sup 125}I]) zur Behandlung von Azinuszellkarzinomen der Ohrspeicheldruese mit begleitenden Risikofaktoren, wie Residualtumor, Rezidivtumor, Invasion in den N. facialis, positive (= nicht tumorfreie) Resektionsraender, fortgeschrittenes Tumorstadium oder lokale Verbreitung von Tumorzellen

  10. SU-F-T-39: Comparing Nomograms for Ordering of Palladium-103 Seeds for Dynamic Intraoperative Prostate Seed Implantation

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P; Wang, L; Riegel, A [Northwell Health, Lake Success, NY (United States)

    2016-06-15

    Purpose: Several nomograms exist for the purpose of ordering palladium- 103 seeds for permanent prostate seed implants. Excess seeds pose additional radiation safety risks and increase the cost of care. This study compared three seed ordering nomograms with seed counts from dynamic intra-operative PSI to determine (1) the cause of excess seeds and (2) the optimal nomogram for our institution. Methods: Pre-operative and intra-operative clinical data were collected for 100 Gy (n=151) and 125 Gy (n=224) prostate seed implants. The number of implanted seeds which would have given D90=100% was normalized to that criteria and seed strength of 2U. This was plotted against intra-operative prostate volume and compared to two previously published nomograms and an in-house nomogram. A linear fit was produced and confidence intervals were calculated. The causes of excess seeds were assessed by comparing pre- and intra-operative prostate volumes, variability of D90 around 100%, and variance of seed strength from 2U. Results: Of the 375 total cases, 97.6% had excess seeds. On average, 27.17±12.91% of ordered seeds were wasted. Of this percentage, 6.98±5.47% of excess seeds were due to overestimation of pre-operative prostate volume, 1.10±0.88% were due to D90<100%, 1.17±0.67% were due to seed strength over 2U, and 17.36±7.79% could not be directly attributed to a specific reason. The latter percentage may be due to overestimation of the in-house nomogram. Two of three nomograms substantially overestimated the number of seeds required. The third nomogram underestimated the required seed number for smaller prostate treatment volume. A linear fit to the clinical data was derived and 99.9% confidence intervals were calculated. Conclusion: Over 85% of clinical cases wasted over 15% of ordered seeds. Two of three nomograms overestimated the required number of seeds. The upper 99.9% C.I. of the clinical data may provide a more reasonable nomogram for Pd-103 seed ordering.

  11. SU-F-T-39: Comparing Nomograms for Ordering of Palladium-103 Seeds for Dynamic Intraoperative Prostate Seed Implantation

    International Nuclear Information System (INIS)

    Taylor, P; Wang, L; Riegel, A

    2016-01-01

    Purpose: Several nomograms exist for the purpose of ordering palladium- 103 seeds for permanent prostate seed implants. Excess seeds pose additional radiation safety risks and increase the cost of care. This study compared three seed ordering nomograms with seed counts from dynamic intra-operative PSI to determine (1) the cause of excess seeds and (2) the optimal nomogram for our institution. Methods: Pre-operative and intra-operative clinical data were collected for 100 Gy (n=151) and 125 Gy (n=224) prostate seed implants. The number of implanted seeds which would have given D90=100% was normalized to that criteria and seed strength of 2U. This was plotted against intra-operative prostate volume and compared to two previously published nomograms and an in-house nomogram. A linear fit was produced and confidence intervals were calculated. The causes of excess seeds were assessed by comparing pre- and intra-operative prostate volumes, variability of D90 around 100%, and variance of seed strength from 2U. Results: Of the 375 total cases, 97.6% had excess seeds. On average, 27.17±12.91% of ordered seeds were wasted. Of this percentage, 6.98±5.47% of excess seeds were due to overestimation of pre-operative prostate volume, 1.10±0.88% were due to D90<100%, 1.17±0.67% were due to seed strength over 2U, and 17.36±7.79% could not be directly attributed to a specific reason. The latter percentage may be due to overestimation of the in-house nomogram. Two of three nomograms substantially overestimated the number of seeds required. The third nomogram underestimated the required seed number for smaller prostate treatment volume. A linear fit to the clinical data was derived and 99.9% confidence intervals were calculated. Conclusion: Over 85% of clinical cases wasted over 15% of ordered seeds. Two of three nomograms overestimated the required number of seeds. The upper 99.9% C.I. of the clinical data may provide a more reasonable nomogram for Pd-103 seed ordering.

  12. Clinical Study on Using 125I Seeds Articles Combined with Biliary Stent Implantation in the Treatment of Malignant Obstructive Jaundice.

    Science.gov (United States)

    Wang, Tao; Liu, Sheng; Zheng, Yan-Bo; Song, Xue-Peng; Sun, Bo-Lin; Jiang, Wen-Jin; Wang, Li-Gang

    2017-08-01

    Aim: To study the feasibility and curative effect of 125 I seeds articles combined with biliary stent implantation in the treatment of malignant obstructive jaundice. Patients and Methods: Fifty patients with malignant obstructive jaundice were included. Twenty-four were treated by biliary stent implantation combined with intraluminal brachytherapy by 125 I seeds articles as the experimental group, while the remaining 26 were treated by biliary stent implantation only as the control group. The goal of this study was to evaluate total bilirubin, direct bilirubin and tumor markers (cancer antigen (CA)-199, CA-242 and carcinoembryonic antigen (CEA)), as well as biliary stent patency status and survival time before and after surgery. Results: Jaundice improved greatly in both groups. The decreases of CA-199 and CA-242 had statistical significance (p=0.003 and p=0.004) in the experimental group. The ratio of biliary stent patency was 83.3% (20/24) in the experimental group and 57.7% (15/26) in the control group (p=0.048). The biliary stent patency time in the experimental group was 1~15.5 (mean=9.84) months. The biliary stent patency time in the control group was 0.8~9 (mean=5.57) months, which was statistically significant (p=0.018). The median survival time was 10.2 months in the experimental group, while 5.4 months in control group (pjaundice possibly by inhibiting the proliferation of vascular endothelial cells and the growth of tumor. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  13. Optimum timing for image-based dose evaluation of 125I and 103Pd prostate seed implants

    International Nuclear Information System (INIS)

    Yue Ning; Chen Zhe; Peschel, Richard; Dicker, Adam P.; Waterman, Frank M.; Nath, Ravinder

    1999-01-01

    Purpose/Objective: Image-based dose evaluation of permanent brachytherapy implants for prostate cancer is important for optimal patient management after implantation. Because of edema caused by the surgical procedure in the implantation, if the dose evaluation is based on the images obtained too early after implantation, dose coverage will usually be underestimated. Conversely, if the images are obtained too late, the dose coverage will be overestimated. This study uses a biomathematical model to simulate edema and its resolution on 29 patients, so that the optimum time to obtain image scans and perform dose evaluation can be investigated and estimated. Methods and Materials: Edema of a prostate and its resolution has been shown to follow an exponential function V(t) = V(0)(1 + ΔV[e -0.693t/Te - 1]) where ΔV is the initial relative increase in the prostate volume due to edema (and is related to edema magnitude), and T e (edema half-life) is the time for the edema to decrease by half in volume. In this study, edema was simulated by increasing the volume of preimplant prostate (obtained from ultrasound volume study) to a given magnitude of edema. Similarly, the locations of planned seeds were changed to their corresponding locations in the edematous prostate proportionally. The edema was then allowed to resolve according to the exponential function. The correct dose distribution was calculated by taking into account the dynamic variations of the prostate volume, seed locations, and source strengths with respect to time. Dose volume histograms (DVHs) were then generated from this dose distribution. The conventional postimplant DVHs, which assume the prostate volume and seed locations are as in the image scans and constant in time, were also calculated based on the simulated image scans for various days postimplantation. The conventional DVHs of prostate on various days after implantation were compared to the DVH calculated assuming dynamic conditions. The optimum

  14. Urethral toxicity after LDR brachytherapy: experience in Japan.

    Science.gov (United States)

    Tanaka, Nobumichi; Asakawa, Isao; Hasegawa, Masatoshi; Fujimoto, Kiyohide

    2015-01-01

    Urinary toxicity is common after low-dose-rate (LDR) brachytherapy, and the resolution of urinary toxicity is a concern. In particular, urinary frequency is the most common adverse event among the urinary toxicities. We have previously reported that approximately 70% of patients experience urinary frequency during the first 6 months after seed implantation. Most urinary adverse events were classified as Grade 1, and Grade 2 or higher adverse events were rare. The incidence of urinary retention was approximately 2-4%. A high International Prostate Symptom Score before seed implantation was an independent predictor of acute urinary toxicity of Grade 2 or higher. Several previous reports from the United States also supported this trend. In Japan, LDR brachytherapy was legally approved in 2003. A nationwide prospective cohort study entitled Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation was initiated in July 2005. It is an important issue to limit urinary toxicities in patients who undergo LDR brachytherapy. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  15. Randomized comparison between intracoronary β-radiation brachytherapy and implantation of paclitaxel-eluting stents for the treatment of diffuse in-stent restenosis

    International Nuclear Information System (INIS)

    Schukro, Christoph; Syeda, Bonni; Kirisits, Christian; Schmid, Rainer; Pichler, Philipp; Pokrajac, Boris; Lang, Irene; Poetter, Richard; Glogar, Dietmar

    2007-01-01

    Background and purpose: Intracoronary brachytherapy was the primary therapeutic option for the treatment of in-stent restenosis (ISR) during the last years. Especially for the treatment of diffuse ISR (lesions >10 mm), β-source brachytherapy was significantly superior to singular balloon angioplasty. Despite lacking clinical database, the implantation of drug eluting stents recently became a common procedure for the treatment of ISR. This randomized trial aimed to compare the efficacy of β-brachytherapy with β-radioisotopes 90 Sr/ 90 Y and paclitaxel-eluting stent implantation for the treatment of diffuse ISR. Material and methods: Thirty-seven patients with diffuse ISR were randomly assigned to β-brachytherapy after balloon angioplasty (Beta-Cath TM in 17 patients) or paclitaxel-eluting stent implantation (Taxus-Express2 TM in 20 patients). Six-month clinical follow-up was obtained for all patients, while angiographic follow-up was available for 30 patients. Results: Binary ISR (restenosis >50%) within target segment was observed in three patients treated with Beta-Cath TM , of which one needed target segment revascularisation for recurrent ISR, whereas no significant restenosis occurred in the patients treated with Taxus-Express2 TM (P = 0.037). No further major adverse cardiac (target segment revascularisation, myocardial infarction, death) was found in either group (P = NS). Stent implantation was the more time-saving (31 ± 11 min versus 60 ± 23 min, P TM arm, we found no difference in clinical outcome after implantation of paclitaxel-eluting stents for the treatment of diffuse ISR when compared to β-brachytherapy

  16. Development of an automation system for iodine-125 brachytherapy seed production by (Nd:YAG) laser welding; Automacao do processo de soldagem a laser (Nd:YAG) para confeccao das sementes de iodo-125 utilizadas em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Somessari, Samir Luiz

    2010-07-01

    The aim of this work is to develop an automation system for iodine-125 radioactive seed production by (Nd:YAG) laser welding, which has been used successfully in Low Dose Rate (LDR) brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8mm in diameter and 4.5mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at IPEN-CNEN/SP imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources becomes a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a largest number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with Good Manufacturing Practices (GMP). The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing Programmable Logic Controller (PLC), stepper motors, drivers, (Nd:YAG) laser welding machine, photoelectric sensors and supervisory. (author)

  17. Surface coating for prevention of metallic seed migration in tissues

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyunseok; Park, Jong In [Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, Won Seok; Park, Min [Interdisciplinary Program in Bioengineering, Seoul National University College of Engineering, Seoul 151-742 (Korea, Republic of); Son, Kwang-Jae [Hanaro Applications Research, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Bang, Young-bong [Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Choy, Young Bin, E-mail: ybchoy@snu.ac.kr, E-mail: sye@snu.ac.kr [Interdisciplinary Program in Bioengineering, Seoul National University College of Engineering, Seoul 110-744 (Korea, Republic of); Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University, Seoul 110-744 (Korea, Republic of); Ye, Sung-Joon, E-mail: ybchoy@snu.ac.kr, E-mail: sye@snu.ac.kr [Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 151-742 (Korea, Republic of); Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of)

    2015-06-15

    Purpose: In radiotherapy, metallic implants often detach from their deposited sites and migrate to other locations. This undesirable migration could cause inadequate dose coverage for permanent brachytherapy and difficulties in image-guided radiation delivery for patients. To prevent migration of implanted seeds, the authors propose a potential strategy to use a biocompatible and tissue-adhesive material called polydopamine. Methods: In this study, nonradioactive dummy seeds that have the same geometry and composition as commercial I-125 seeds were coated in polydopamine. Using scanning electron microscopy and x-ray photoelectron spectroscopy, the surface of the polydopamine-coated and noncoated seeds was characterized. The detachment stress between the two types of seeds and the tissue was measured. The efficacy of polydopamine-coated seed was investigated through in vitro migration tests by tracing the seed location after tissue implantation and shaking for given times. The cytotoxicity of the polydopamine coating was also evaluated. Results: The results of the coating characterization have shown that polydopamine was successfully coated on the surface of the seeds. In the adhesion test, the polydopamine-coated seeds had 2.1-fold greater detachment stress than noncoated seeds. From the in vitro test, it was determined that the polydopamine-coated seed migrated shorter distances than the noncoated seed. This difference was increased with a greater length of time after implantation. Conclusions: The authors suggest that polydopamine coating is an effective technique to prevent migration of implanted seeds, especially for permanent prostate brachytherapy.

  18. Efficacies of 125I seed implantation in advanced stage central lung cancer via fibrobronchoscope

    International Nuclear Information System (INIS)

    Liu Jianguo; An Liqing; Cheng Jinguang; Zhang Yufen; Guo Xiaokui

    2009-01-01

    Objective: To explore the temporal curative effect of 125 I seed implantation in advanced stage central type lung cancer. Methods: 125 I seed was implanted in 56 patients confirmed advanced stage central type lung cancer via fibrobronchoscope and all cases were fellow up in certain duration to explore their efficacies and the adverse reaction. Results: Total efficient rate was 76.78% in 56 patients. Lung reexpanded rate was 90.90%. Conclusion: The therapy of 125 I seed implantation in advanced stage central type lung cancer is safe and available. (authors)

  19. Preliminary results of interstitial [sup 192]Ir brachytherapy for malignant gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Kengo; Nakagawa, Minoru; Higashi, Hisato [Okayama Univ. (Japan). School of Medicine; and others

    1992-09-01

    Twenty-six patients with recurrent or unremovable malignant gliomas were treated by interstitial brachytherapy with iridium-192 seeds. Stereotactic implantation of the afterloading catheters using the Brown-Roberts-Wells computed tomography (CT)-guided stereotactic system was performed in 24 patients and surgical CT, magnetic resonance imaging, and clinical examination. Tumor regression was seen in 17 patients 1-3 months after implantation. Tumor progression was seen in only three patients. After interstitial brachytherapy, the most commonly observed CT finding was central low density. Median survival time was 18 months after implantation. Autopsies in five patients revealed the delayed effects of radiation injury such as typical vascular changes, microcalcification, and coagulative necrosis in the implant area and tumor recurrence at the periphery. The results suggest that brachytherapy is not curative but prolonged the median survival time by 6 months. (author).

  20. Long term conservation of sexual functions after prostate brachytherapy by permanents implants

    International Nuclear Information System (INIS)

    Pena, P.C.; Hijal, T.; Pierrat, N.; Pontvert, D.; Cosset, J.M.; Thiounn, N.; Flam, T.; Chauveinc, L.

    2009-01-01

    These series suggest that the preservation of sexual abilities after prostate brachytherapy would be in relation with the previous performances and age. So, in patients aged over seventy years and with an satisfying initial IIEF5 score, the conservation rate at long term appears to go over the 50%. (N.C.)

  1. Electroless Sliver-Plating Process in the Preparation of 103Pd-125I Hybrid Brachytherapy Seed Cores

    Directory of Open Access Journals (Sweden)

    LI Zhong-yong1,2;CHEN Bin-da1;Lv Xiao-zhou1;LU Jin-hui1;CUI Hai-ping1,2

    2014-02-01

    Full Text Available Electroless 103Pd plating and electroless Ag plating and chemical 125I depositing were took place on the surface of carbon rods in turn, which was a reliable method for the preparation of 103Pd-125I hybrid brachytherapy seed cores. 103Pd and 125I were deposited on the same substrate effectively through silver coating as a bridge. The process of electroless Ag plating was a novel and important step in the preparation of 103Pd-125I hybrid seed. In this work, the process of electroless Ag plating was studied using 0.5×3.0 mm carbon rods with palladium coating as substrate, silver-ammino complex as precursor, 110mAg as radioactive tracer, and hydrazine as reductant. The optimum conditions were AgNO3 2g/L,Na2EDTA 40 g/L,NH3•H2O 16.25%,H4N2•H2O 5‰,pH=10,t=60 min,and T=35 ℃. Sliver deposited on each carbon rod was uniform, and sliver-coating was white and smooth.

  2. Towards a determination of the absorbed dose to water in water for low-energy photon-emitting brachytherapy seeds

    International Nuclear Information System (INIS)

    Schneider, T.; Lange, B.; Selbach, H.J.

    2007-01-01

    An accurate determination of the dose produced by brachytherapy seeds emitting low-energy photons is an important component of the radiotherapeutic process. As yet, the output of these seeds has usually been specified in terms of the air kerma rate. The desired quantity in radiation therapy is, however, the absorbed dose to water inside a water phantom, for which primary standards are not available. For this reason, developments are under way in the Physikalisch - Technische Bundesanstalt to establish a primary standard to determine the absorbed dose to water within a phantom. As a fundamental step towards this aim, a method will be introduced in this publication to determine the water kerma inside a graphite phantom housing an extrapolation chamber. Experimental results will be presented and compared with water kerma values obtained from air kerma measurements in free air and applying a conversion factor to water kerma for the conditions of the experiment. First estimates indicate that the relative uncertainty is of the order of 1% (k 1). (authors)

  3. SU-G-IeP1-01: A Novel MRI Post-Processing Algorithm for Visualization of the Prostate LDR Brachytherapy Seeds and Calcifications Based On B0 Field Inhomogeneity Correction and Hough Transform

    Energy Technology Data Exchange (ETDEWEB)

    Nosrati, R [Reyrson University, Toronto, Ontario (Canada); Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Soliman, A; Owrangi, A [Sunnybrook Research Institute, Toronto, Ontario (Canada); Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Ghugre, N [Sunnybrook Research Institute, Toronto, Ontario (Canada); University of Toronto, Toronto, ON (Canada); Morton, G [Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); University of Toronto, Toronto, ON (Canada); Pejovic-Milic, A [Reyrson University, Toronto, Ontario (Canada); Song, W [Reyrson University, Toronto, Ontario (Canada); Sunnybrook Research Institute, Toronto, Ontario (Canada); Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); University of Toronto, Toronto, ON (Canada)

    2016-06-15

    Purpose: This study aims at developing an MRI-only workflow for post-implant dosimetry of the prostate LDR brachytherapy seeds. The specific goal here is to develop a post-processing algorithm to produce positive contrast for the seeds and prostatic calcifications and differentiate between them on MR images. Methods: An agar-based phantom incorporating four dummy seeds (I-125) and five calcifications of different sizes (from sheep cortical bone) was constructed. Seeds were placed arbitrarily in the coronal plane. The phantom was scanned with 3T Philips Achieva MR scanner using an 8-channel head coil array. Multi-echo turbo spin echo (ME-TSE) and multi-echo gradient recalled echo (ME-GRE) sequences were acquired. Due to minimal susceptibility artifacts around seeds, ME-GRE sequence (flip angle=15; TR/TE=20/2.3/2.3; resolution=0.7×0.7×2mm3) was further processed.The induced field inhomogeneity due to the presence of titaniumencapsulated seeds was corrected using a B0 field map. B0 map was calculated using the ME-GRE sequence by calculating the phase difference at two different echo times. Initially, the product of the first echo and B0 map was calculated. The features corresponding to the seeds were then extracted in three steps: 1) the edge pixels were isolated using “Prewitt” operator; 2) the Hough transform was employed to detect ellipses approximately matching the dimensions of the seeds and 3) at the position and orientation of the detected ellipses an ellipse was drawn on the B0-corrected image. Results: The proposed B0-correction process produced positive contrast for the seeds and calcifications. The Hough transform based on Prewitt edge operator successfully identified all the seeds according to their ellipsoidal shape and dimensions in the edge image. Conclusion: The proposed post-processing algorithm successfully visualized the seeds and calcifications with positive contrast and differentiates between them according to their shapes. Further

  4. Permanent LDR implants in treatment of prostate cancer

    International Nuclear Information System (INIS)

    Skowronek, J.; Kanikowski, M.; Chichel, A.; Zwierzchowski, G.

    2009-01-01

    Low-dose rate brachytherapy (LDR-BT) is a radiation method known for several years in the treatment of localized prostate cancer. The main idea of this method is to implant small radioactive seeds directly into the prostate gland. LDR brachytherapy is applied as a monotherapy and also used along with external beam radiation therapy (EBRT) as a boost. In most cases it is used as a sole radical treatment modality, but not as a palliative treatment. The application of permanent seed implants is a curative treatment alternative in patients with organ- confined cancer, without extracapsular extension of the tumour. This technique is particularly popular in the United States. In Europe, however, high-dose rate brachytherapy (HDR-BT) is more popular in early-stage prostate cancer treatment (as a boost). The aim of this publication is to describe methods, indications, complications and selected results of prostate cancer LDR brachytherapy. (authors)

  5. Computational system to create an entry file for replicating I-125 seeds simulating brachytherapy case studies using the MCNPX code

    Directory of Open Access Journals (Sweden)

    Leonardo da Silva Boia

    2014-03-01

    decline for short distances.------------------------------Cite this article as: Boia LS, Junior J, Menezes AF, Silva AX. Computational system to create an entry file for replicating I-125 seeds simulating brachytherapy case studies using the MCNPX code. Int J Cancer Ther Oncol 2014; 2(2:02023.DOI: http://dx.doi.org/10.14319/ijcto.0202.3

  6. Clinical application of permanent implantation of iodine 125 seeds for osseous metastases

    International Nuclear Information System (INIS)

    Li Jinxin; Zhang Qizhou; Li Guoliang

    2010-01-01

    Objective: To evaluate the clinical efficacy of permanent implantation of iodine 125 seeds in the treatment of osseous metastases. Methods: Radioactive iodine 125 seeds were implanted permanently in 32 lesions of 25 patients with osseous metastases of different origins. The ostalgia-relieving degree and the imaging alterations of the osseous metastasis lesions were observed. Results: The effective pain-relieving rate was 92% caused by permanent implantation of iodine 125 seeds. Of al 1 the patients, 15 patients achieved complete response, 8 patients obtained partial response (PR), and 2 patients had no change. The pain grade was decreased significantly after the treatment (P 125 I seeds has a definite effect on tumor metastasis and caused minimal damage and few complications. It is worthy of popularization in clinic. (authors)

  7. Ten cases of metastatic cervical cancer with the treatment of permanent 125I seeds interstitial implants

    International Nuclear Information System (INIS)

    Zhang Hongwei; Li Naibin; Li Qingxin; Liu Huiping; Meng Hui; Chao Dong

    2011-01-01

    Objective: To investigate the clinical effect of permanent 125 I seeds interstitial implants for metastatic cervical cancer. Methods: Under the guidance of the B-sonography, 125 I seeds were implanted into the eleven cervical lymph nodes of ten patients who had been given tumor resection. The pain relief and tumor size were observed in regular follow-up after one-month treatment. Results: All the patients were followed up for 6-14 months,and the postoperative recovery was good with no complication. One month after the implantation, the pain symptom was alleviated entirely in two nodes and partly in nine nodes. The tumor size shrank in ten nodes while there was no change in one node after one month. Conclusion: Permanent 125 I seeds interstitial implants for metastatic cervical cancer is a safe, minimally invasive and effective treatment. (authors)

  8. SU-F-T-46: The Effect of Inter-Seed Attenuation and Tissue Composition in Prostate 125I Brachytherapy Dose Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, K; Araki, F; Ohno, T [Kumamoto University, Kumamoto, Kumamoto (Japan)

    2016-06-15

    Purpose: To investigate the difference of dose distributions with/without the effect of inter-seed attenuation and tissue compositions in prostate {sup 125}I brachytherapy dose calculations, using Monte Carlo simulations of Particle and Heavy Ion Transport code System (PHITS). Methods: The dose distributions in {sup 125}I prostate brachytherapy were calculated using PHITS for non-simultaneous and simultaneous alignments of STM1251 sources in water or prostate phantom for six patients. The PHITS input file was created from DICOM-RT file which includes source coordinates and structures for clinical target volume (CTV) and organs at risk (OARs) of urethra and rectum, using in-house Matlab software. Photon and electron cutoff energies were set to 1 keV and 100 MeV, respectively. The dose distributions were calculated with the kerma approximation and the voxel size of 1 × 1 × 1 mm{sup 3}. The number of incident photon was set to be the statistical uncertainty (1σ) of less than 1%. The effect of inter-seed attenuation and prostate tissue compositions was evaluated from dose volume histograms (DVHs) for each structure, by comparing to results of the AAPM TG-43 dose calculation (without the effect of inter-seed attenuation and prostate tissue compositions). Results: The dose reduction due to the inter-seed attenuation by source capsules was approximately 2% for CTV and OARs compared to those of TG-43. In additions, by considering prostate tissue composition, the D{sub 90} and V{sub 100} of CTV reduced by 6% and 1%, respectively. Conclusion: It needs to consider the dose reduction due to the inter-seed attenuation and tissue composition in prostate {sup 125}I brachytherapy dose calculations.

  9. Enhanced ULtrasound Visualization of Brachytherapy Seeds by a Novel Magnetically Induced Motion Image Method

    National Research Council Canada - National Science Library

    McAleavey, Stephen A

    2006-01-01

    ... to determine the sensitivity of torque to geometry. We have created a finite element model of a prototype coil configuration for seed vibration and demonstrated the ability of this coil configuration to steer the magnetic field in a manner suitable...

  10. Iodine-125 seed implantation for unresectable pancreatic carcinoma guided by intraoperative ultrasound

    International Nuclear Information System (INIS)

    Wang Junjie; Xiu Dianrong; Ran Weiqiang; Bai Jing; Zhu Lihong; Liu Jiangping

    2005-01-01

    Objective: To investigate the surgical technique, efficacy and side effects of 125 I seed interstitial implantation for pancreatic carcinoma. Methods: A total of 22 patients with biopsy proven unresectable adenocarcinoma of pancreas were treated with 125 I implants during laparotomy. Of them 11 patients were treated previously by a combination of bypass surgery. The stent was implanted in 2 cases 2 weeks before and 4 weeks after seed implantation. Seed needles were implanted parallelly to each other, with 1-1.5 cm apart. Mick applicator was being connected to each needle to implant seed. The radioactive activity ranged 0.40-0.70 mCi, the matched peripheral doses were 65-145 Gy. The mean number of 125 I seed was 11-78. Five cases received external beam irradiation with 3D-CRT, the doses were 39-70 Gy and 5 patients received 2 cycle of gemcitabine chemotherapy at 1000 mg/m 2 on dl and d8. Results: Pain was completely relieved in 12 cases, partially relieved in 2 cases, and no response was noted in one case, so the response rate was 93.33%. The median time was 2-3 d. Altogethe 27.27% of the cases died from local recurrence of pancreatic carcinoma and 50% from metastasis. The median survival time in these patients was 6 months, with a 2-year survival rate of 9.09%. The seed immigrated to liver in 3 cases. There were no serious side effects such as infection, pancreatitis, pancreatic fistula, etc. Conclusion: Radioactive seed implantation was safe, high local control, minidamage, satisfactory palliation of pain and without significant complications. (authors)

  11. SU-F-I-19: MRI Positive Contrast Visualization of Prostate Brachytherapy Seeds Using An Integrated Laplacian-Based Phase Processing

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, A; Safigholi, H [Sunnybrook Research Institute, Toronto, ON (Canada); Sunnybrook Health Sciences Center, Toronto, ON (Canada); Nosrati, R [Sunnybrook Health Sciences Center, Toronto, ON (Canada); Ryerson University, Toronto, ON (Canada); Owrangi, A; Morton, G [Sunnybrook Health Sciences Center, Toronto, ON (Canada); University of Toronto, Toronto, ON (Canada); Song, W [Sunnybrook Research Institute, Toronto, ON (Canada); Sunnybrook Health Sciences Center, Toronto, ON (Canada); Ryerson University, Toronto, ON (Canada); University of Toronto, Toronto, ON (Canada)

    2016-06-15

    Purpose: To propose a new method that provides a positive contrast visualization of the prostate brachytherapy seeds using the phase information from MR images. Additionally, the feasibility of using the processed phase information to distinguish seeds from calcifications is explored. Methods: A gel phantom was constructed using 2% agar dissolved in 1 L of distilled water. Contrast agents were added to adjust the relaxation times. Four iodine-125 (Eckert & Ziegler SML86999) dummy seeds were placed at different orientations with respect to the main magnetic field (B0). Calcifications were obtained from a sheep femur cortical bone due to its close similarity to human bone tissue composition. Five samples of calcifications were shaped into different dimensions with lengths ranging between 1.2 – 6.1 mm.MR imaging was performed on a 3T Philips Achieva using an 8-channel head coil. Eight images were acquired at eight echo-times using a multi-gradient echo sequence. Spatial resolution was 0.7 × 0.7 × 2 mm, TR/TE/dTE = 20.0/2.3/2.3 ms and BW = 541 Hz/pixel. Complex images were acquired and fed into a two-step processing pipeline: the first includes phase unwrapping and background phase removal using Laplacian operator (Wei et al. 2013). The second step applies a specific phase mask on the resulting tissue phase from the first step to provide the desired positive contrast of the seeds and to, potentially, differentiate them from the calcifications. Results: The phase-processing was performed in less than 30 seconds. The proposed method has successfully resulted in a positive contrast of the brachytherapy seeds. Additionally, the final processed phase image showed difference between the appearance of seeds and calcifications. However, the shape of the seeds was slightly distorted compared to the original dimensions. Conclusion: It is feasible to provide a positive contrast of the seeds from MR images using Laplacian operator-based phase processing.

  12. Early therapy monitoring of 125I seed interstitial implant in a pancreatic cancer xenograft by 18F-FDG Micro-PET/CT

    International Nuclear Information System (INIS)

    Wang Zhongmin; Liu Yu; Chen Kemin; Lu Jian; Gong Ju; Zheng Yunfeng; Zhang Liyun; Liu Fenju

    2011-01-01

    Objective: To investigate the application value of early evaluation and monitoring of 125 I interstitial implantation in a pancreatic cancer xenograft. Methods: Xenograft models were created by subcutaneous injection of Sw 1990 human pancreatic cancer cell suspensions into the right hind limbs of the immunodeficient BABL/c nude mice. The tumors size were about 8-10 mm after two weeks. The mice were randomly divided into 3 groups,including control group (n=4), empty seed implantation group (n=4) and 125 I implantation group (n=4). Before treatment and one week after treatment, 18 F-FDG Micro-PET/CT scan was performed and then maximum standardized uptake values (SUV max ), mean standardized uptake values (SUV mean ), tumor size and necrosis rate were measured. HE staining and TK1 immunohistochemistry examination were carried out in the paraffin-embedded sample. Results: Before treatment the SUV max and SUV mean values of three groups did not reach statistical significance. One week after treatment the SUV max and SUV mean values of three groups were 3.53±1.20 and 0.57±0.26 vs. 3.83±2.13 and 0.59 ±0.24 vs. 0.29±0.23 and 0.016±0.001, respectively, with a significant difference (F=7.62, P=0.01; F=10.34, P=0.005). The SUV max and SUV mean values of 125 I implant group were significantly lower than empty seed implant group and control group and were significantly lower than before treatment. Before treatment, tumor necrosis rate of three groups were not significantly different. Immunohistochemical staining found the TK1 positive staining index of three groups were respectively (64.25±1.71)%, (62.25±2.22)% and (38.25±1.71)% with statistically significant difference (F=233.67, P<0.001). The TK1 positive staining index of 125 I implant group was significantly lower than empty seed implant group and control group. The SUV max values had some positive correlation with TK1 positive staining index (r=0.85, P=0.001). Conclusions: 18 F-FDG Micro-PET/CT may be useful as a

  13. 1251 seed calibration using afterloading equipment SeedSelectron. Practical solution to meet the recommendations of the AAPM

    International Nuclear Information System (INIS)

    Perez-Calatayud, J.; Richart, J.; Perez-Garcia, J.; Guirado, D.; Ballester, F.; Rodriguez, S.; Santos, M.; Depiaggio, M.; Carmona, V.; Lliso, F.; Camacho, C.; Pujades, M. C.

    2011-01-01

    SeedSelectron is a system used in the afterloader permanent implant brachytherapy seeds 1-125 interstitial prostate. Two aspects are critical when you can meet the recommendations of the AAPM: a practical difficulty to check the quantity of seed required, and the great uncertainty of all measured diodes. The purpose of this paper is to present a practical solution that has been adopted to implement the recommendations of the AAPM

  14. The temperature effect of low-energy ion beam implantation on seed

    International Nuclear Information System (INIS)

    Chang Shenghe; Su Mingjie; Qin Guangyong; Wu Yuping; Zhao Haizhen

    2005-01-01

    The temperature effects of low-energy ion beam implantation on the seed germination were studied. Maize dry seeds were covered with copy paper, aluminum foil and without cover, respectively. Results showed that the germination rate of the seeds covered with paper which was the bad heat transmitter was the highest among three treatments, while that covered with aluminum foil which can transmit heat energy well was the least. The germination rate of the seeds covered with nothing was the second. Temperature affected seeds germination markedly. Generally the temperature of the target room inhibited the seeds' germination. After minus the effects of the temperature in the target room, the germination rates of the seeds were modified in this paper. The modified germination rate curve was also provided. (authors)

  15. Method of localization and implantation of the lumpectomy site for high dose rate brachytherapy after conservative surgery for T1 and T2 breast cancer

    International Nuclear Information System (INIS)

    Perera, F.; Chisela, F.; Engel, J.; Venkatesan, V.

    1995-01-01

    Purpose: This article describes our technique of localization and implantation of the lumpectomy site of patients with T1 and T2 breast cancer. Our method was developed as part of our Phase I/II pilot study of high dose rate (HDR) brachytherapy alone after conservative surgery for early breast cancer. Methods and Materials: In March 1992, we started a pilot study of HDR brachytherapy to the lumpectomy site as the sole radiotherapy after conservative surgery for clinical T1 or T2 invasive breast cancer. Initially, the protocol required intraoperative placement of the interstitial needles at the time of definitive surgery to the breast. The protocol was then generalized to allow the implantation of the lumpectomy site after definitive surgery to the breast, either at the time of subsequent axillary nodal dissection or postoperatively. To date, five patients have been implanted intraoperatively at the time of definitive breast surgery. Twelve patients were implanted after definitive breast surgery, with 7 patients being done at the time of axillary nodal dissection and 5 patients postoperatively. We devised a method of accurately localizing and implanting the lumpectomy site after definitive breast surgery. The method relies on the previous placement of surgical clips by the referring surgeon to mark the lumpectomy site. For each patient, a breast mold is made with radio-opaque angiocatheters taped onto the mold in the supero-inferior direction. A planning CT scan is then obtained through the lumpectomy site. The volume of the lumpectomy site, the number of implant planes necessary, and the orientation of the implants are then determined from the CT scan. The angiocatheters provide a reference grid on the CT films to locate the entry and exit points of the interstitial needles on the plastic mold. The entry and exit points for reference needles are then transferred onto the patient's skin enabling implantation of the lumpectomy site. Needle positions with respect to

  16. Monte carlo simulation of penetration range distribution of ion beam with low energy implanted in plant seeds

    International Nuclear Information System (INIS)

    Huang Xuchu; Hou Juan; Liu Xiaoyong

    2009-01-01

    The depth and density distribution of V + ion beam implanted into peanut seed is simulated by the Monte Carlo method. The action of ions implanted in plant seeds is studied by the classical collision theory of two objects, the electronic energy loss is calculated by Lindhard-Scharff formulation. The result indicates that the depth of 200keV V + implanted into peanut seed is 5.57μm, which agrees with experimental results, and the model is appropriate to describe this interaction. This paper provides a computational method for the depth and density distribution of ions with low energy implanted in plant seeds. (authors)

  17. The Effect of Scattering from Leg Region on Organ Doses in Prostate Brachytherapy for 103Pd, 125I and 131Cs Seeds

    Directory of Open Access Journals (Sweden)

    Seyed Milad Vahabi

    2016-09-01

    Full Text Available Introduction Dose calculation of tumor and surrounding tissues is essential during prostate brachytherapy. Three radioisotopes, namely, 125I, 103Pd, and 131Cs, are extensively used in this method. In this study, we aimed to calculate the received doses by the prostate and critical organs using the aforementioned radioactive seeds and to investigate the effect of scattering contribution for the legs on dose calculations. Materials and Methods The doses to organs of interest were calculated using MCNPX code and ORNL (Oak Ridge National Laboratory phantom. Results Doses to the prostate as a source of radiation for 125I, 103Pd, and 131Cs were approximately 108.9, 97.7, and 81.5 Gy, respectively. Bladder, sigmoid colon, and testes received higher doses than other organs due to proximity to the prostate. Differences between the doses when tallying with the legs intact and with the legs voided were significant for testes, sigmoid colon contents, and sigmoid colon wall because of their proximity to the prostate. There was also a good consistency between our results and the data published by Montefiore Medical Center and Albert Einstein College of Medicine for the prostate. Conclusion Scattering from leg region had a significant effect on doses to testes, sigmoid colon contents, and sigmoid colon wall in the pelvic region, and prostate and the other organs were unaffected. Brachytherapy treatment plans using 131Cs seeds allow for better sparing of critical tissues, with a comparable number of, or fewer, seeds required, compared to 125I seeds.

  18. SU-F-T-40: Can CBCT Images Be Used for Volume Studies of Prostate Seed Implants for Boost Treatment?

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H; Lee, S; Diwanji, T; Amin, P; Krudys, K; Guerrero, M [University of Maryland School of Medicine, Baltimore, MD (United States)

    2016-06-15

    Purpose: In our clinic, the planning CT is used for definitive and boost low-dose-rate (LDR) brachytherapy treatments to determine the ultrasound volume in the operating room (OR) at the time of the implant. While the CT overestimation of OR volume is known, a larger estimation discrepancy has been observed for boost treatments. A possible reason is the prostate size reduction during EBRT for boost patients. Since cone-beam CT (CBCT) is often used as routine imaging guidance of EBRT, this prostate volume change may be captured. This study investigates if CBCT taken during EBRT includes the volume change information and therefore beats CT in estimating the prostate OR volumes. Methods: 9 prostate patients treated with EBRT (45Gy in 1.8Gy per fractions to the whole pelvis) and I-125 seed implants (108Gy) were involved in this study. During EBRT, CBCT image guidance was performed on a weekly basis. For each patient, the prostate volumes on the first and the last available CBCT images were manually contoured by a physician. These volumes were then compared to each other and with the contoured volumes from the planning CT and from the ultrasound images in the OR. Results: The first and the last CBCT images did not show significant prostate volume change. Their average +/− standard deviation of prostate volumes were 24.4cc+/−14.6cc and 29.9cc+/−16.1cc, respectively (T-test p=0.68). The ratio of the OR volume to the last CBCT (0.71+/−0.21) was not significantly different from the ratio of OR volumes to the planning CT (0.61+/−0.13) (p=0.25). Conclusion: In this study, CBCT does not show significant prostate volume changes during EBRT. CBCT and CT volumes are quite consistent and no improvement of volume estimation using CBCT is observed. The advantage of CBCT as a replacement of CT for volume study of boost LDR brachytherapy is limited.

  19. Implant strategies for endocervical and interstitial ultrasound hyperthermia adjunct to HDR brachytherapy for the treatment of cervical cancer

    Science.gov (United States)

    Wootton, Jeffery H.; Prakash, Punit; Hsu, I.-Chow Joe; Diederich, Chris J.

    2011-07-01

    Catheter-based ultrasound devices provide a method to deliver 3D conformable heating integrated with HDR brachytherapy delivery. Theoretical characterization of heating patterns was performed to identify implant strategies for these devices which can best be used to apply hyperthermia to cervical cancer. A constrained optimization-based hyperthermia treatment planning platform was used for the analysis. The proportion of tissue >=41 °C in a hyperthermia treatment volume was maximized with constraints Tmax 200 cm3) is possible using multiple sectored interstitial and endocervical ultrasound devices. The endocervical device can heat >41 °C to 4.6 cm diameter compared to 3.6 cm for the interstitial. Sectored applicators afford tight control of heating that is robust to perfusion changes in most regularly spaced configurations. T90 in example patient cases was 40.5-42.7 °C (1.9-39.6 EM43 °C) at 1 kg m-3 s-1 with 10/14 patients >=41 °C. Guidelines are presented for positioning of implant catheters during the initial surgery, selection of ultrasound applicator configurations, and tailored power schemes for achieving T90 >= 41 °C in clinically practical implant configurations. Catheter-based ultrasound devices, when adhering to the guidelines, show potential to generate conformal therapeutic heating ranging from a single endocervical device targeting small volumes local to the cervix (directional interstitial applicators in the lateral periphery to target much larger volumes (6 cm radial), while preferentially limiting heating of the bladder and rectum.

  20. Role of TPS in 125I brachytherapy for orbital tumors

    International Nuclear Information System (INIS)

    Ren Ling; Dai Haojie; Li Quan

    2012-01-01

    Objective: To investigate the role of TPS in 125 I brachytherapy for orbital tumors. Methods: Sixty-six patients with orbital tumor treated with 125 I seeds from 2005 to 2009 were retrospectively analyzed. Forty-three patients were treated using TPS guided brachytherapy and the prescribed dose was 140 Gy. Other 23 patients were treated without TPS but simply implanted with 125 I seeds at 1 cm intervals in parallel with each other intraoperatively. CT and TPS quality verification were performed postoperatively in all patients. Also, CT and (or) MRI examination were performed at 3, 6, 12 and 24 months after brachytherapy for follow-up. χ 2 test and Kaplan-Meier survival analysis with log-rank significance test were used with SPSS 17.0. Results: A total of 1070 125 I seeds were implanted in 66 cases, on average, (16.2 ± 7.3) seeds for each patient. The satisfaction rates of postoperative quality verification in patients with and without TPS pre-plans were 79.07% (34/43) and 43.48% (10/23) respectively (χ 2 =8.542, P=0.003). Ten patients were lost in follow-up. Local recurrence rates in patients with favorable postoperative quality verification were 0 (0/37) in 3 months, 6.25% (2/32) in 6 months, 13.64% (3/22) in 12 months and 3/9 in 24 months respectively, which were significantly different from those (5.26% (1/19), 16.67% (3/18), 30.77% (4/13), 6/6) in the patients with inferior postoperative quality verification (χ 2 =9.017, P=0.0003). Conclusions: TPS plays an important role in 125 I brachytherapy for orbital tumors. Also, postoperative quality verification by TPS may help predict the local recurrence after brachytherapy. (authors)

  1. DuraSeal® as a spacer to reduce rectal doses in low-dose rate brachytherapy for prostate cancer

    International Nuclear Information System (INIS)

    Heikkilä, Vesa-Pekka; Kärnä, Aarno; Vaarala, Markku H.

    2014-01-01

    The purpose of this study was to evaluate the utility of off-label use of DuraSeal® polyethylene glycol (PEG) gel in low-dose rate (LDR) prostate brachytherapy seed implantation to reduce rectal doses. Diluted DuraSeal® was easy to use and, in spite of a clearance effect, useful in decreasing D 2cc rectal doses

  2. Spectral CT with monochromatic imaging and metal artifacts reduction software for artifacts reduction of ¹²⁵I radioactive seeds in liver brachytherapy.

    Science.gov (United States)

    Yang, Qiuxia; Peng, Sheng; Wu, Jing; Ban, Xiaohua; He, Mingyan; Xie, Chuanmiao; Zhang, Rong

    2015-11-01

    To investigate the optimal monochromatic energy for artifacts reduction from (125)I seeds as well as image improvement in the vicinity of seeds on monochromatic images with and without metal artifacts reduction software (MARS) and to compare this with traditional 120-kVp images, so as to evaluate the application value of gemstone spectral imaging for reducing artifacts from (125)I seeds in liver brachytherapy. A total of 45 tumors from 25 patients treated with (125)I seed brachytherapy in the liver were enrolled in this study. Multiphasic spectral computed tomography (CT) scanning was performed for each patient. After a delay time of 15 s of portal vein phase, a traditional 120-kVp scan was performed, focusing on several planes of (125)I seeds only. The artifact index (AI) in the vicinity of seeds and the standard deviation (SD) of the CT density of region of interest in the outside liver parenchyma were calculated. Artifact appearance was evaluated and classified on reconstructed monochromatic S and 120-kVp images. Image quality in the vicinity of seeds of three data sets were evaluated using a 1-5 scale scoring method. The Friedman rank-sum test was used to estimate the scoring results of image quality. The greatest noise in monochromatic images was found at 40 keV (SD = 27.38, AI = 206.40). The optimal monochromatic energy was found at 75 keV, which provided almost the least image noise (SD = 10.01) and good performance in artifact reduction (AI = 102.73). Image noise and AI reduction at 75 keV was decreased by 63.44 and 50.23%, compared with at 40 keV. Near-field thick artifacts were obvious in all 45 lesions, in 120-kVp images, and 75-keV images, but basically reduced in 75 keV MARS images and artifacts completely invisible in 7 lesions. The number of diagnosable images (score ≥3) was significantly more in the 75-keV MARS group (28/45), and the 75-keV group (22/45) than in the 120-kVp group (11/45) (p improve image quality, even to a state of being

  3. Correlations of post-implant regional dosimetric parameters at 24 hours and one month, with clinical results of low-dose-rate brachytherapy for localized prostate cancer

    Directory of Open Access Journals (Sweden)

    Eiichiro Okazaki

    2017-12-01

    Full Text Available Purpose : To evaluate the correlations of post-implant regional dosimetrics at 24 hours (24 h and 1 month after implant procedures, with clinical outcomes of low-dose-rate (LDR brachytherapy for localized prostate cancer. Material and methods : Between January 2008 and December 2014, 130 consecutive patients treated for localized prostate cancer, receiving definitive iodine-125 ( 125 I brachytherapy treatment were retrospectively analyzed. All patients underwent post-implant CT imaging for dosimetric analysis at 24 h and 1 month after implantation procedure. Prostate contours were divided into quadrants: anterior-superior (ASQ, posterior-superior (PSQ, anterior-inferior (AIQ, and posterior-inferior (PIQ. Predictive factors and cut-off values of biochemical failure-free survival (BFFS and toxicities of LDR brachytherapy were analyzed. Results : The median follow-up time was 69.5 months. Seven patients (5.4% had biochemical failure. The 3-year and 5-year BFFS rates were 96.7% and 93.1%, respectively. On multivariate analysis, prostate-specific antigen and Gleason score were significant prognostic factors for biochemical failure. D 90 (the minimal dose received by 90% of the volume of PSQ and PIQ at 24 h, and D 90 of PSQ at 1 month were also significant factors. The cut-off values of PSQ D 90 were 145 Gy at 24 h and 160 Gy at 1 month. D 90 of the whole prostate was not significant at 24 h and at 1 month. D 90 of PSQ at 1 month was a significant factor for rectal hemorrhage. Conclusions : Post-implant D 90 of PSQ is significantly associated with BFFS for localized prostate cancer not only at 1 month, but also at 24 hours. D 90 of PSQ at 1 month is also a significant factor for rectal hemorrhage.

  4. Analysis of the radiobiology of ytterbium-169 and iodine-125 permanent brachytherapy implants

    Energy Technology Data Exchange (ETDEWEB)

    Lazarescu, G.R. [Windsor Regional Cancer Center, Ontario Cancer Treatment and Research Foundation, Windsor, Canada N8W 2X3 (Canada); Battista, J.J. [London Regional Cancer Center, Ontario Cancer Treatment and Research Foundation, Dept. of Oncology and Dept. of Medical Biophysics, University of Western Ontario, London, Canada N6A 4L6 (Canada)

    1997-09-01

    Recently, Yb-169 has been considered as a potential replacement for I-125 and Pd-103 in permanent implants. In spite of the uncertainties in the parameters necessary for an accurate radiobiological modelling, the linear quadratic model can be useful in the comparative evaluation of the radiotherapeutic merit of similar implants. In order to find out if a Yb-169 permanent implant can be made biologically 'equivalent' to an I-125 implant, we studied the dependence of local control on the tumour cell radiosensitivity and on the balance between the rate of tumour cell killing and tumour cell proliferation, for rapidly and slowly proliferating tumours. The extrapolated response dose (ERD) has been calculated for tumour and late reacting normal tissue for both types of implants and the possible biological restrictions due to the normal tissue tolerance have been discussed. Our theoretical analysis is consistent with the clinical results published for I-125 permanent implants in prostate tumours and meningiomas. It predicts that Yb-169, which has only recently been used in human tumours, can provide comparable tumour control for permanent implants in slowly proliferating tumours with an initial dose rate of 13 cGy h{sup -1}. Control might be extended to rapidly proliferating tumours by increasing the initial dose rate within a range consistent with an acceptable level of normal tissue late reaction. (author)

  5. Monte Carlo study of a new I‐125 brachytherapy prototype seed with a ceramic radionuclide carrier and radiographic marker

    Science.gov (United States)

    Paixão, Lucas; Santos, Ana Maria M.; dos Santos, Adriano Márcio; Grynberg, Suely Epsztein

    2012-01-01

    In prostate cancer treatment, there is an increasing interest in the permanent radioactive seeds implant technique. Currently, in Brazil, the seeds are imported with high prices, which prohibit their use in public hospitals. A ceramic matrix that can be used as a radioisotope carrier and radiographic marker was developed at our institution. The ceramic matrix is distinguished by the characteristic of maintaining the radioactive material uniformly distributed in its surface. In this work, Monte Carlo simulations were performed in order to assess the dose distributions generated by this prototype seed model, with the ceramic matrix encapsulated in titanium, in the same way as the commercial 6711 seed. The obtained data was assessed, as described in the TG‐43U1 report by the American Association of Physicists in Medicine, for two seed models: (1) the most used model 6711 source — for validation and comparison, and (2) for the prototype model with the ceramic matrix. The dosimetric parameters dose rate constant, Λ, radial dose function, gL(r), and anisotropy function, F(r,θ), were derived from simulations by the Monte Carlo method using the MCNP5 code. A Λ 0.992 (±2.33%) cGyh−1U−1 was found for the prototype model. In comparison with the 6711 model, a lower dose fall‐off on transverse axis was found, as well as a lower dose anisotropy for the radius r= 0.25 cm. In general, for all distances, the prototype seed model presents a slightly larger anisotropy between 0° ≤ Θ < 50° and anisotropy similar to the 6711 model for Θ ≥ 50°. The dosimetric characteristics of the prototype model presented in this study suggest that its use is feasible. Because of the model's characteristics, seeds of lower specific activity iodine might be necessary which, on the other hand, would help to reduce costs. However, it has to be emphasized that the proposed source is a prototype, and the required (AAPM prerequisites) experimental study and tolerance

  6. A magazine for the implantation of I-125 seeds in interstitial therapy of cerebral tumors

    International Nuclear Information System (INIS)

    Bockermann, V.; Dieckmann, G.; Lott, H.

    1988-01-01

    A compact magazine has been developed allowing a quick and easy implantation of I-125 seeds in interstitial therapy of intracranial tumors. The magazine is made of steel and has the shape of a right parallelepiped. One seed can be put each time into a movable insert. The magazine is connected to a normal application canula. It is easy to handle and contributes much to radioprotection. (orig.) [de

  7. Monte Carlo calculation of dosimetric parameters of a {sup 125}I brachytherapy seed encapsulation with biocompatible polymer and a ceramic matrix as radiographic marker

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Lucas P.; Santos, Adriano M.; Grynberg, Suely E., E-mail: lpr@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Dosimetria e Simulacao Computacional; Facure, Alessandro, E-mail: facure@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    For prostate cancer treatments, there is an increasing interest in the permanent radioactive seeds implant technique. Currently, in Brazil, the seeds are imported at high prices, which prohibit their use in public hospitals. One of the seed models that have been developed at CDTN has a ceramic matrix as a radioisotope carrier and a radiographic marker; the seed is encapsulated with biocompatible polymer. In this work, Monte Carlo simulations were performed in order to assess the dose distributions generated by the prototype seed model. The obtained data was assessed as described in the TG-43U1 report by the AAPM. The dosimetric parameters dose rate constant, {Lambda}, radial dose function, g{sub L}(r), and anisotropy function, F(r,{theta}), were derived from simulations using the MCNP5 code. The function g(r) shows that the seed has a lower decrease in dose rate on its transverse axis when compared to the 6711 model (one of the most used seeds in permanent prostate implants). F(r,{theta}) shows that CDTN's seed anisotropy curves are smoother than the 6711 model curves for {theta}{<=}20 deg and 0.25{<=}r{<=}1 cm. As well, the {Lambda} value is 15% lower than the {Lambda} value of 6711. The results show that CDTN's seed model can deposit a more isotropic dose. Because of the model's characteristics, the seeds can be impregnated with iodine of lower specific activity which would help reducing costs. (author)

  8. Role of hormonal therapy in the management of intermediate- to high-risk prostate cancer treated with permanent radioactive seed implantation

    International Nuclear Information System (INIS)

    Lee, Lucille N.; Stock, Richard G.; Stone, Nelson N.

    2002-01-01

    Purpose: To study the impact of hormonal therapy (HTx) on intermediate- to high-risk prostate cancer treated with permanent radioactive seed implantation. Methods and Materials: Patients with Stage T1b-T3bN0 prostate cancer, and Gleason score ≥7 or prostate-specific antigen (PSA) level >10 ng/mL were treated with seed implantation with or without HTx. Their disease was defined as intermediate risk (PSA 10-20, Gleason score 7, or Stage T2b) or high risk (two or more intermediate criteria, or PSA >20 ng/mL, Gleason score 8-10, or Stage T2c-T3). The median follow-up for 201 eligible patients was 42 months (range 18-110). Biochemical failure was defined as a rising PSA >1.0 ng/mL. Pretreatment disease characteristics, implant dose, and HTx were evaluated using univariate and multivariate analyses. Results: HTx significantly improved 5-year actuarial freedom from biochemical failure rate, 79% vs. 54% without HTx. In addition, high-dose, PSA ≤15 ng/mL, intermediate risk, and Stage T2a or lower significantly improved outcome in the univariate analyses. HTx was the most significant predictor of 5-year actuarial freedom from biochemical failure (p <0.0001) in a multivariate analysis. The best outcome was in the intermediate-risk patients treated with a high implant dose and HTx, resulting in a 4-year actuarial freedom from biochemical failure rate of 94%. Conclusion: In this retrospective review, HTx improved outcome in intermediate- to high-risk prostate cancer patients treated with brachytherapy. HTx was the most important prognostic factor in the univariate and multivariate analyses

  9. Poster — Thur Eve — 42: Radiochromic film calibration for low-energy seed brachytherapy dose measurement

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, H; Menon, G; Sloboda, R [Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2 (Canada); Department of Oncology, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada)

    2014-08-15

    The purpose of this study was to investigate the accuracy of radiochromic film calibration procedures used in external beam radiotherapy when applied to I-125 brachytherapy sources delivering higher doses, and to determine any necessary modifications to achieve similar accuracy in absolute dose measurements. GafChromic EBT3 film was used to measure radiation doses upwards of 35 Gy from 6 MV, 75 kVp and (∼28 keV) I-125 photon sources. A custom phantom was used for the I-125 irradiations to obtain a larger film area with nearly constant dose to reduce the effects of film heterogeneities on the optical density (OD) measurements. RGB transmission images were obtained with an Epson 10000XL flatbed scanner, and calibration curves relating OD and dose using a rational function were determined for each colour channel and at each energy using a non-linear least square minimization method. Differences found between the 6 MV calibration curve and those for the lower energy sources are large enough that 6 MV beams should not be used to calibrate film for low-energy sources. However, differences between the 75 kVp and I-125 calibration curves were quite small; indicating that 75 kVp is a good choice. Compared with I-125 irradiation, this gives the advantages of lower type B uncertainties and markedly reduced irradiation time. To obtain high accuracy calibration for the dose range up to 35 Gy, two-segment piece-wise fitting was required. This yielded absolute dose measurement accuracy above 1 Gy of ∼2% for 75 kVp and ∼5% for I-125 seed exposures.

  10. Fully automated MRI-guided robotics for prostate brachytherapy

    International Nuclear Information System (INIS)

    Stoianovici, D.; Vigaru, B.; Petrisor, D.; Muntener, M.; Patriciu, A.; Song, D.

    2008-01-01

    The uncertainties encountered in the deployment of brachytherapy seeds are related to the commonly used ultrasound imager and the basic instrumentation used for the implant. An alternative solution is under development in which a fully automated robot is used to place the seeds according to the dosimetry plan under direct MRI-guidance. Incorporation of MRI-guidance creates potential for physiological and molecular image-guided therapies. Moreover, MRI-guided brachytherapy is also enabling for re-estimating dosimetry during the procedure, because with the MRI the seeds already implanted can be localised. An MRI compatible robot (MrBot) was developed. The robot is designed for transperineal percutaneous prostate interventions, and customised for fully automated MRI-guided brachytherapy. With different end-effectors, the robot applies to other image-guided interventions of the prostate. The robot is constructed of non-magnetic and dielectric materials and is electricity free using pneumatic actuation and optic sensing. A new motor (PneuStep) was purposely developed to set this robot in motion. The robot fits alongside the patient in closed-bore MRI scanners. It is able to stay fully operational during MR imaging without deteriorating the quality of the scan. In vitro, cadaver, and animal tests showed millimetre needle targeting accuracy, and very precise seed placement. The robot tested without any interference up to 7T. The robot is the first fully automated robot to function in MRI scanners. Its first application is MRI-guided seed brachytherapy. It is capable of automated, highly accurate needle placement. Extensive testing is in progress prior to clinical trials. Preliminary results show that the robot may become a useful image-guided intervention instrument. (author)

  11. Intraoperative ultrasound quided iodine-125 seed implantation for unresectable pancreatic carcinoma

    International Nuclear Information System (INIS)

    Wang Junjie; Liu Jiangping; Jiang Yuliang; Jiang Weijuan; Li Jinna; Xiu Dianrong; Ran Weiqiang

    2007-01-01

    Objective: To investigate the surgical technique, efficacy and side effects of intraoperative ultrasound quided 125 I seed interstitial implantation for pancreatic carcinoma. Methods: Twenty-seven patients with biopsy proven unresectable adenocarcinoma of pancreas were treated with 125 I implants during laparotomy. Eleven patients were treated by a combination of bypass surgery. Seed needles were implanted parallel to each other, at 1.0-1.5 cm apart and guided by ultrasound. Mick applicator was applied to each needle to implant seed at 1.0-1.5 cm apart. The radioactive activity ranged 0.40-0.70 mCi; the D 90 were 110-160 Gy. The mean number of 125 I seed were 11-78. Six patients also received external beam radiation at doses of 39-50 Gy. Five patients received 2-4 cycle DDP + gemCitabine chemotherapy also. Results: The incidence of perioperative mortality was 0%. Pain was complete relieved in 15 patients, partial relieved in two, but in the rest three patients there was no response. The response rate was 85%. The starting time of pain relief was 1-30 d, with a median of 5 days. The overall local control rate was 74%. Four patients have died of recurrence, 20 patients died of metastasis, 3 patients died of recurrence and metastasis. The median survival of II + III[ stage patients was 8 months, with a 1- and 2-year survival of 25% and 15%, respectively. The median survival time of IV stage patients was 5 months, with 1-year survival of 8%. The seeds immigrated into the liver in 3 patients. There are no serious side effects such as infection or pancreatic fistula. Conclusions: Intraoperative ultrasound quided 125 I seed implantation is safe, giving high local control, but minimal damage. It is a satisfactorily palliative for pain and causing little noticeable complications. (authors)

  12. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    International Nuclear Information System (INIS)

    Xu Gang; Wang Xiaoteng; Gan Cailing; Fang Yanqiong; Zhang Meng

    2012-01-01

    Highlights: ► We analyzed biological effects of N + implantation on dry Jatropha curcas seed. ► N + implantation greatly decreased seedling survival rate. ► At doses beyond 15 × 10 16 ion cm −2 , biological repair took place. ► CAT was essential for H 2 O 2 removal. POD mainly functioned as seed was severely hurt. ► HAsA–GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N + with energy of 25 keV was applied to treat the dry seed at six different doses. N + beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 10 16 to 15 × 10 16 ions cm −2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 10 16 ion cm −2 , biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 10 16 ions cm −2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA–GSH cycle appeared to be for regeneration of HAsA.

  13. Design and optimization of a brachytherapy robot

    Science.gov (United States)

    Meltsner, Michael A.

    Trans-rectal ultrasound guided (TRUS) low dose rate (LDR) interstitial brachytherapy has become a popular procedure for the treatment of prostate cancer, the most common type of non-skin cancer among men. The current TRUS technique of LDR implantation may result in less than ideal coverage of the tumor with increased risk of negative response such as rectal toxicity and urinary retention. This technique is limited by the skill of the physician performing the implant, the accuracy of needle localization, and the inherent weaknesses of the procedure itself. The treatment may require 100 or more sources and 25 needles, compounding the inaccuracy of the needle localization procedure. A robot designed for prostate brachytherapy may increase the accuracy of needle placement while minimizing the effect of physician technique in the TRUS procedure. Furthermore, a robot may improve associated toxicities by utilizing angled insertions and freeing implantations from constraints applied by the 0.5 cm-spaced template used in the TRUS method. Within our group, Lin et al. have designed a new type of LDR source. The "directional" source is a seed designed to be partially shielded. Thus, a directional, or anisotropic, source does not emit radiation in all directions. The source can be oriented to irradiate cancerous tissues while sparing normal ones. This type of source necessitates a new, highly accurate method for localization in 6 degrees of freedom. A robot is the best way to accomplish this task accurately. The following presentation of work describes the invention and optimization of a new prostate brachytherapy robot that fulfills these goals. Furthermore, some research has been dedicated to the use of the robot to perform needle insertion tasks (brachytherapy, biopsy, RF ablation, etc.) in nearly any other soft tissue in the body. This can be accomplished with the robot combined with automatic, magnetic tracking.

  14. Quality control of system of imaging for rectal ultrasound for implants seed prostate low rate

    International Nuclear Information System (INIS)

    Luquero Llopis, N.; Ferrer Gracia, C.; Huertas Martinez, C.; Huerga Cabrerizo, C.; Corredoira Silva, E.; Serrada Hierro, A.

    2013-01-01

    In this work, the objective is the evaluation of the image system used in implants of prostate of low rate held at our hospital, for maximum control on the placement of the seeds in the patient and therefore carried out dosimetry. (Author)

  15. Technical aspects of the integration of three-dimensional treatment planning dose parameters (GEC-ESTRO Working Group) into pre-implant planning for LDR gynecological interstitial brachytherapy.

    Science.gov (United States)

    Chi, A; Gao, M; Nguyen, N P; Albuquerque, K

    2009-06-01

    This study investigates the technical feasibility of pre-implant image-based treatment planning for LDR GYN interstitial brachytherapy(IB) based on the GEC-ESTRO guidelines. Initially, a virtual plan is generated based on the prescription dose and GEC-ESTRO defined OAR dose constraints with a pre-implant CT. After the actual implant, a regular diagnostic CT was obtained and fused with our pre-implant scan/initial treatment plan in our planning software. The Flexi-needle position changes, and treatment plan modifications were made if needed. Dose values were normalized to equivalent doses in 2 Gy fractions (LQED 2 Gy) derived from the linear-quadratic model with alpha/beta of 3 for late responding tissues and alpha/beta of 10 for early responding tissues. D(90) to the CTV, which was gross tumor (GTV) at the time of brachytherapy with a margin to count for microscopic disease, was 84.7 +/- 4.9% of the prescribed dose. The OAR doses were evaluated by D(2cc) (EBRT+IB). Mean D(2cc) values (LQED(2Gy)) for the rectum, bladder, sigmoid, and small bowel were the following: 63.7 +/- 8.4 Gy, 61.2 +/- 6.9 Gy, 48.0 +/- 3.5 Gy, and 49.9 +/- 4.2 Gy. This study confirms the feasibility of applying the GEC-ESTRO recommended dose parameters in pre-implant CT-based treatment planning in GYN IB. In the process, this pre-implant technique also demonstrates a good approximation of the target volume dose coverage, and doses to the OARs.

  16. CT-guided iodine-125 seed permanent implantation for recurrent head and neck cancers

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yu L; Meng, Na; Wang, Jun J; Jiang, Ping [Department of Radiation Oncology, Peking University Third Hospital, Beijing 100191 (China); Yuan, Hui SH; Liu, Chen [Department of Radiology, Peking University Third Hospital, Beijing, 100191 (China); Qu, Ang; Yang, Rui J [Department of Radiation Oncology, Peking University Third Hospital, Beijing 100191 (China)

    2010-07-30

    To investigate the feasibility, and safety of {sup 125}I seed permanent implantation for recurrent head and neck carcinoma under CT-guidance. A retrospective study on 14 patients with recurrent head and neck cancers undergone {sup 125}I seed implantation with different seed activities. The post-plan showed that the actuarial D90 of {sup 125}I seeds ranged from 90 to 218 Gy (median, 157.5 Gy). The follow-up was 3 to 60 months (median, 13 months). The median local control was 18 months (95% CI, 6.1-29.9 months), and the 1-, 2-, 3-, and 5- year local controls were 52%, 39%, 39%, and 39%, respectively. The 1-, 2-, 3-, and 5- survival rates were 65%, 39%, 39% and 39%, respectively, with a median survival time of 20 months (95% CI, 8.7-31.3 months). Of all patients, 28.6% (4/14) died of local recurrence, 7.1% (1/14) died of metastases, one patient died of hepatocirrhosis, and 8 patients are still alive to the date of data analysis. CT-guided {sup 125}I seed implantation is feasible and safe as a salvage or palliative treatment for patients with recurrent head and neck cancers.

  17. Biologically effective dose (BED) for interstitial seed implants containing a mixture of radionuclides with different half-lives

    International Nuclear Information System (INIS)

    Chen Zhe; Nath, Ravinder

    2003-01-01

    Purpose: To develop a tool for evaluating interstitial seed implants that contain a mixture of radionuclides with different half-lives and to demonstrate its utility by examining the clinical implications of prescribing to an isodose surface for such an implant. Methods and Materials: A linear-quadratic model for continuous low dose rate irradiation was developed for permanent implants containing a mixture of radionuclides. Using a generalized equation for the biologically effective dose (BED), the effects of cell proliferation and sublethal damage repair were examined systematically for implants containing a mixture of radionuclides. A head-and-neck permanent seed implant that contained a mixture of 125 I and 103 Pd seeds was used to demonstrate the utility of the generalized BED. Results: An equation of BED for implants containing a mixture of radionuclides with different half-lives was obtained. In such an implant, the effective cell kill was shown to depend strongly on the relative dose contributions from each radionuclide type; dose delivered by radionuclides with shorter half-life always resulted in more cell kill for any given sublethal damage repair and cell proliferation rates. Application of the BED formula to an implant containing a mixture of 125 I and 103 Pd seeds demonstrates that the conventional dose prescription to an isodose surface is not unique for such an implant. When the prescription dose was based on existing clinical experience of using 125 I seeds alone, mixing 103 Pd seeds with 125 I seeds would increase the cell kill. On the other hand, if the prescription dose were based on existing clinical experience of using 103 Pd seeds alone, mixing 125 I seeds with 103 Pd seeds in the same implant would create radiobiologically 'cold' spots (i.e., an increase in cell survival) at locations where a major portion of the prescription dose is contributed by the 125 I seeds. For fast-growing tumors, these 'cold' spots can become significant

  18. An analysis of intraoperative versus post-operative dosimetry with CT, CT-MRI fusion and XMR for the evaluation of permanent prostate brachytherapy implants

    International Nuclear Information System (INIS)

    Acher, Peter; Puttagunta, Srikanth; Rhode, Kawal; Morris, Stephen; Kinsella, Janette; Gaya, Andrew; Dasgupta, Prokar; Deehan, Charles; Beaney, Ronald; Popert, Rick; Keevil, Stephen

    2010-01-01

    Background and purpose: To assess the agreement between intraoperative and post-operative dosimetry and to identify factors that influence dose calculations of prostate brachytherapy implants. Materials and methods: Patients treated with prostate brachytherapy implants underwent post-operative CT and XMR (combined X-ray and MR) imaging. Dose-volume histograms were calculated from CT, XMR and CT-MR fusion data and compared with intraoperative values for two observers. Multiple linear regression models assessed the influences of intraoperative D90, gland oedema, gland volume, source loss and migration, and implanted activity/volume prostate on post-operative D90. Results: Forty-nine patients were studied. The mean D90 differences (95% confidence limits) between intraoperative and post-operative CT, XMR and CT-MR fusion assessments were: 11 Gy (-22, 45), 18 Gy (-13, 49) and 20 Gy (-17, 58) for Observer 1; and 15 Gy (-34, 63), 13 Gy (-29, 55) and 14 Gy (-27, 54) for Observer 2. Multiple linear regression modelling showed that the observed oedema and intraoperative D90 were significant independent variables for the prediction of post-operative D90 values for both observers using all modalities. Conclusion: This is the first study to report Bland-Altman agreement analysis between intraoperative and post-operative dosimetry. Agreement is poor. Post-operative dosimetry is dependent on the intraoperative D90 and the subjectively outlined gland volume.

  19. SU-E-J-166: Sensitivity of Clinically Relevant Dosimetric Parameters to Contouring Uncertainty During Post Implant Dosimetry of Prostate Permanent Seed Implants

    Energy Technology Data Exchange (ETDEWEB)

    Mashouf, S [Sunnybrook Odette Cancer Centre, Toronto, ON (Canada); University of Toronto, Dept. of Radiation Oncology, Toronto, ON (Canada); Ravi, A; Morton, G; Song, W [Sunnybrook Odette Cancer Centre, Toronto, ON (Canada); University of Toronto, Dept. of Radiation Oncology, Toronto, ON (Canada); Sunnybrook Research Institute, Toronto, ON (Canada)

    2015-06-15

    Purpose: There is a strong evidence relating post-implant dosimetry for permanent seed prostate brachytherpy to local control rates. The delineation of the prostate on CT images, however, represents a challenge as it is difficult to confidently identify the prostate borders from soft tissue surrounding it. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to prostate contouring uncertainty. Methods: The post-implant CT images and plans for a cohort of 43 patients, who have received I–125 permanent prostate seed implant in our centre, were exported to MIM Symphony LDR brachytherapy treatment planning system (MIM Software Inc., Cleveland, OH). The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00mm, ±2.00mm, ±3.00mm, ±4.00mm and ±5.00mm (±0.01mm). The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: The mean value of V100 and D90 was obtained as 92.3±8.4% and 108.4±12.3% respectively (Rx=145Gy). V100 was reduced by −3.2±1.5%, −7.2±3.0%, −12.8±4.0%, −19.0±4.8%, − 25.5±5.4% for expanded contours of prostate with margins of +1mm, +2mm, +3mm, +4mm, and +5mm, respectively, while it was increased by 1.6±1.2%, 2.4±2.4%, 2.7±3.2%, 2.9±4.2%, 2.9±5.1% for the contracted contours. D90 was reduced by −6.9±3.5%, −14.5±6.1%, −23.8±7.1%, − 33.6±8.5%, −40.6±8.7% and increased by 4.1±2.6%, 6.1±5.0%, 7.2±5.7%, 8.1±7.3% and 8.1±7.3% for the same set of contours. Conclusion: Systematic expansion errors of more than 1mm may likely render a plan sub-optimal. Conversely contraction errors may Result in labeling a plan likely as optimal. The use of MRI images to contour the prostate should results in better delineation of prostate organ which increases the predictive value of post-op plans. Since observers tend to overestimate the prostate volume on CT, compared with MRI, the impact of the

  20. Implant volume as a prognostic variable in brachytherapy decision-making for malignant gliomas stratified by the RTOG recursive partitioning analysis

    International Nuclear Information System (INIS)

    Videtic, Gregory M.M.; Gaspar, Laurie E.; Zamorano, Lucia; Stitt, Larry W.; Fontanesi, James; Levin, Kenneth J.

    2001-01-01

    Purpose: When an initial retrospective review of malignant glioma patients (MG) undergoing brachytherapy was carried out using the Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) criteria, it revealed that glioblastoma multiforme (GBM) cases benefit the most from implant. In the present study, we focused exclusively on these GBM patients stratified by RPA survival class and looked at the relationship between survival and implanted target volume, to distinguish the prognostic value of volume in general and for a given GBM class. Methods and Materials: Between 1991 and 1998, 75 MG patients were treated with surgery, external beam radiation, and stereotactic iodine-125 (I-125) implant. Of these, 53 patients (70.7%) had GBMs, with 52 (98%) having target volume (TV) data for analysis. Stratification by RPA criteria showed 12, 26, 13, and 1 patients in classes III to VI, respectively. For analysis purposes, classes V and VI were merged. There were 27 (51.9%) male and 25 (48.1%) female patients. Mean age was 57.5 years (range 14-79). Median Karnofsky performance status (KPS) was 90 (range 50-100). Median follow-up time was 11 months (range 2-79). Results: At analysis, 18 GBM patients (34.6%) were alive and 34 (65.4%) were dead. Two-year and 5-year survivals were 42% and 17.5%, respectively, with a median survival time (MST) of 16 months. Two-year survivals and MSTs for the implanted GBM patients compared to the RTOG database were as follows: 74% vs. 35% and 28 months vs. 17.9 months for class III; 32% vs. 15% and 16 months vs. 11.1 months for class IV; 29% vs. 6% and 11 months vs. 8.9 months for class V/VI. Mean implanted TV was 15.5 cc (range 0.8-78), which corresponds to a spherical implant diameter of 3.1 cm. Plotting survival as a function of 5-cc TV increments suggested a trend toward poorer survival as the implanted volume increases. The impact of incremental changes in TV on survival within a given RPA class of GBMs was compared to the

  1. The american brachytherapy society recommendations for permanent prostate brachytherapy postimplant dosimetric analysis

    International Nuclear Information System (INIS)

    Nag, Subir; Bice, William; Wyngaert, Keith de; Prestidge, Bradley; Stock, Richard; Yu Yan

    2000-01-01

    Purpose: The purpose of this report is to establish guidelines for postimplant dosimetric analysis of permanent prostate brachytherapy. Methods: Members of the American Brachytherapy Society (ABS) with expertise in prostate dosimetry evaluation performed a literature review and supplemented with their clinical experience formulated guidelines for performing and analyzing postimplant dosimetry of permanent prostate brachytherapy. Results: The ABS recommends that postimplant dosimetry should be performed on all patients undergoing permanent prostate brachytherapy for optimal patient care. At present, computed tomography (CT)-based dosimetry is recommended, based on availability cost and the ability to image the prostate as well as the seeds. Additional plane radiographs should be obtained to verify the seed count. Until the ideal postoperative interval for CT scanning has been determined, each center should perform dosimetric evaluation of prostate implants at a consistent postoperative interval. This interval should be reported. Isodose displays should be obtained at 50%, 80%, 90%, 100%, 150%, and 200% of the prescription dose and displayed on multiple cross-sectional images of the prostate. A dose-volume histogram (DVH) of the prostate should be performed and the D 90 (dose to 90% of the prostate gland) reported by all centers. Additionally, the D 80, D 100, the fractional V 80, V 90, V 100, V 150, and V 200, (i.e., the percentage of prostate volume receiving 80%, 90%, 100%, 150%, and 200% of the prescribed dose, respectively), the rectal, and urethral doses should be reported and ultimately correlated with clinical outcome in the research environment. On-line real-time dosimetry, the effects of dose heterogeneity, and the effects of tissue heterogeneity need further investigation. Conclusion: It is essential that postimplant dosimetry should be performed on all patients undergoing permanent prostate brachytherapy. Guidelines were established for the performance

  2. Dosimetric effects of edema in permanent prostate seed implants: a rigorous solution

    International Nuclear Information System (INIS)

    Chen Zhe; Yue Ning; Wang Xiaohong; Roberts, Kenneth B.; Peschel, Richard; Nath, Ravinder

    2000-01-01

    Purpose: To derive a rigorous analytic solution to the dosimetric effects of prostate edema so that its impact on the conventional pre-implant and post-implant dosimetry can be studied for any given radioactive isotope and edema characteristics. Methods and Materials: The edema characteristics observed by Waterman et al (Int. J. Rad. Onc. Biol. Phys, 41:1069-1077; 1998) was used to model the time evolution of the prostate and the seed locations. The total dose to any part of prostate tissue from a seed implant was calculated analytically by parameterizing the dose fall-off from a radioactive seed as a single inverse power function of distance, with proper account of the edema-induced time evolution. The dosimetric impact of prostate edema was determined by comparing the dose calculated with full consideration of prostate edema to that calculated with the conventional dosimetry approach where the seed locations and the target volume are assumed to be stationary. Results: A rigorous analytic solution on the relative dosimetric effects of prostate edema was obtained. This solution proved explicitly that the relative dosimetric effects of edema, as found in the previous numerical studies by Yue et. al. (Int. J. Radiat. Oncol. Biol. Phys. 43, 447-454, 1999), are independent of the size and the shape of the implant target volume and are independent of the number and the locations of the seeds implanted. It also showed that the magnitude of relative dosimetric effects is independent of the location of dose evaluation point within the edematous target volume. It implies that the relative dosimetric effects of prostate edema are universal with respect to a given isotope and edema characteristic. A set of master tables for the relative dosimetric effects of edema were obtained for a wide range of edema characteristics for both 125 I and 103 Pd prostate seed implants. Conclusions: A rigorous analytic solution of the relative dosimetric effects of prostate edema has been

  3. SU-F-T-61: Treatment Planning Observations for the CivaSheet Directional Brachytherapy Device Using VariSeed 9.0

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, MJ [Tufts University School of Medicine, Boston, MA (United States); Rothley, DJ [Cancer Treatment Centers of America, Newnan, GA (United States)

    2016-06-15

    Purpose: The VariSeed 9.0 brachytherapy TPS is recently available and has new features such as ability to rotate a brachytherapy source away from normal to the imaging plane. Consequently, a dosimetric analysis was performed for a directional brachytherapy source (CivaSheet) with tests of this functionality and experiences from clinical treatment planning were documented. These observations contribute to safe, practical, and accurate use of such new software features. Methods: Several tests were established to evaluate the new rotational feature, specific to the CivaSheet for the first patients treated using this new brachytherapy device. These included suitability of imaging slice-thickness and in-plane resolution, window/level adjustments for brachytherapy source visualization, commissioning the source physical length for performing rotations, and using different planar and 3D window views to identify source orientation. Additional CivaSheet-specific tests were performed to determine the dosimetric influence on target coverage: changing the source tilt angle, source positioning in the treatment plan based on the CivaSheet rectangular array of CivaDots, and influence of prescription depth on the necessary treatment margin for adequate target coverage. Results: Higher imaging-resolution produced better accuracy for source orientation and positioning, with sub-millimeter CT slice-thickness and in-plane resolution preferred. Source rotation was possible only in sagittal or coronal views. The process for validating source orientation required iteratively altering rotations then checking them in the 3D view, which was cumbersome given the absence of quantitative plan documentation to indicate orientation. Given the small Pd-103 source size, influence of source tilt within 30° was negligible for <1.0 cm. Influence of source position was important when the source was positioned in/out of the adjacent source plane, causing changes of 15%, 7%, and 3% at depths of 0.5, 0

  4. Volume study pre and post-implant brachytherapy prostate for establishment of PTV margins; Estudio de volumenes pre y post-implante en braquiterapia de prostata para establecimiento de margenes del PTV

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Dominguez, M.; Carrasco Herrera, M.; Baeza Trujillo, M.; Herrador Cordoba, M.

    2011-07-01

    Treatment of prostate cancer by permanent implantation of radioactive seeds is now a good alternative to radical surgery or radiotherapy, as it provides a good tumor control while the risk is reduced by a lower complication irradiation of adjacent healthy organs. The large volume change during seed implantation occurs in the prostate of the patient, makes it important to consider margins around the organs of interest both to ensure optimal coverage and minimal tumor irradiation of healthy tissue. Analyze how the volume varies during and after implantation and establish a margin around the prostate to the practice of our hospital are the two objectives of this work.

  5. Sci-Sat AM(2): Brachy-05: Dosimetry effects of the TG-43 approximations for two iodine seeds in LDR brachytherapy.

    Science.gov (United States)

    Furstoss, C; Bertrand, M J; Poon, E; Reniers, B; Pignol, J P; Carrier, J F; Beaulieu, L; Verhaegen, F

    2008-07-01

    This work consists of studying the interseed and tissue composition effects for two model iodine seeds: the IBt Interseed-125 and the 6711 model seed. Three seeds were modeled with the MCNP MC code in a water sphere to evaluate the interseed effect. The dose calculated at different distances from the centre was compared to the dose summed when the seeds were simulated separately. The tissue composition effect was studied calculating the radial dose function for different tissues. Before carrying out post-implant studies, the absolute dose calculated by MC was compared to experiment results: with LiF TLDs in an acrylic breast phantom and with an EBT Gafchromic film placed in a water tank. Afterwards, the TG-43 approximation effects were studied for a prostate and breast post-implant. The interseed effect study shows that this effect is more important for model 6711 (15%) than for IBt (10%) due to the silver rod in 6711. For both seed models the variations of the radial dose function as a function of the tissue composition are quasi similar. The absolute dose comparisons between MC calculations and experiments give good agreement (inferior to 3% in general). For the prostate and breast post-implant studies, a 10% difference between MC calculations and the TG-43 is found for both models of seeds. This study shows that the differences in dose distributions between TG43 and MC are quite similar for the two models of seeds and are about 10% for the studied post-implant treatments. © 2008 American Association of Physicists in Medicine.

  6. Prostate brachytherapy in Ghana: our initial experience

    Directory of Open Access Journals (Sweden)

    James Edward Mensah

    2016-10-01

    Full Text Available Purpose: This study presents the experience of a brachytherapy team in Ghana with a focus on technology transfer and outcome. The team was initially proctored by experienced physicians from Europe and South Africa. Material and methods : A total of 90 consecutive patients underwent either brachytherapy alone or brachytherapy in combination with external beam radiotherapy for prostate carcinoma between July 2008 and February 2014 at Korle Bu Teaching Hospital, Accra, Ghana. Patients were classified as low-risk, intermediate, and high-risk according to the National Comprehensive Cancer Network (NCCN criteria. All low-risk and some intermediate risk group patients were treated with seed implantation alone. Some intermediate and all high-risk group patients received brachytherapy combined with external beam radiotherapy. Results: The median patient age was 64.0 years (range 46-78 years. The median follow-up was 58 months (range 18-74 months. Twelve patients experienced biochemical failure including one patient who had evidence of metastatic disease and died of prostate cancer. Freedom from biochemical failure rates for low, intermediate, and high-risk cases were 95.4%, 90.9%, and 70.8%, respectively. Clinical parameters predictive of biochemical outcome included: clinical stage, Gleason score, and risk group. Pre-treatment prostate specific antigen (PSA was not a statistically significant predictor of biochemical failure. Sixty-nine patients (76.6% experienced grade 1 urinary symptoms in the form of frequency, urgency, and poor stream. These symptoms were mostly self-limiting. Four patients needed catheterization for urinary retention (grade 2. One patient developed a recto urethral fistula (grade 3 following banding for hemorrhoids. Conclusions : Our results compare favorably with those reported by other institutions with more extensive experience. We believe therefore that, interstitial permanent brachytherapy can be safely and effectively

  7. Imaging of implant needles for real-time HDR-brachytherapy prostate treatment using biplane ultrasound transducers.

    Science.gov (United States)

    Siebert, Frank-André; Hirt, Markus; Niehoff, Peter; Kovács, György

    2009-08-01

    Ultrasound imaging is becoming increasingly important in prostate brachytherapy. In high-dose-rate (HDR) real-time planning procedures the definition of the implant needles is often performed by transrectal ultrasound. This article describes absolute measurements of the visibility and accuracy of manual detection of implant needle tips and compares measurement results of different biplane ultrasound systems in transversal and longitudinal (i.e., sagittal) ultrasound modes. To obtain a fixed coordinate system and stable conditions the measurements were carried out in a water tank using a dedicated marker system. Needles were manually placed in the phantom until the observer decided by the real-time ultrasound image that the zero position was reached. A comparison of three different ultrasound systems yielded an offset between 0.8 and 3.1 mm for manual detection of the needle tip in ultrasound images by one observer. The direction of the offset was discovered to be in the proximal direction, i.e., the actual needle position was located more distally compared to the ultrasound-based definition. In the second part of the study, the ultrasound anisotropy of trocar implant needles is reported. It was shown that the integrated optical density in a region of interest around the needle tip changes with needle rotation. Three peaks were observed with a phase angle of 120 degrees. Peaks appear not only in transversal but also in longitudinal ultrasound images, with a phase shift of 60 degrees. The third section of this study shows results of observer dependent influences on needle tip detection in sagittal ultrasound images considering needle rotation. These experiments were carried out using the marker system in a water tank. The needle tip was placed exactly at the position z=0 mm. It was found that different users tend to differently interpret the same ultrasound images. The needle tip was manually detected five times in the ultrasound images by three experienced observers

  8. AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: Report of Task Group 192

    Energy Technology Data Exchange (ETDEWEB)

    Podder, Tarun K., E-mail: tarun.podder@uhhospitals.org [Department of Radiation Oncology, University Hospitals, Case Western Reserve University, Cleveland, Ohio 44122 (United States); Beaulieu, Luc [Department of Radiation Oncology, Centre Hospitalier Univ de Quebec, Quebec G1R 2J6 (Canada); Caldwell, Barrett [Schools of Industrial Engineering and Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907 (United States); Cormack, Robert A. [Department of Radiation Oncology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Crass, Jostin B. [Department of Radiation Oncology, Vanderbilt University, Nashville, Tennessee 37232 (United States); Dicker, Adam P.; Yu, Yan [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Fenster, Aaron [Department of Imaging Research, Robarts Research Institute, London, Ontario N6A 5K8 (Canada); Fichtinger, Gabor [School of Computer Science, Queen’s University, Kingston, Ontario K7L 3N6 (Canada); Meltsner, Michael A. [Philips Radiation Oncology Systems, Fitchburg, Wisconsin 53711 (United States); Moerland, Marinus A. [Department of Radiotherapy, University Medical Center Utrecht, Utrecht, 3508 GA (Netherlands); Nath, Ravinder [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520 (United States); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Salcudean, Tim [Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada); Song, Danny Y. [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 (United States); Thomadsen, Bruce R. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705 (United States)

    2014-10-15

    In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3–6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests

  9. AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: Report of Task Group 192

    International Nuclear Information System (INIS)

    Podder, Tarun K.; Beaulieu, Luc; Caldwell, Barrett; Cormack, Robert A.; Crass, Jostin B.; Dicker, Adam P.; Yu, Yan; Fenster, Aaron; Fichtinger, Gabor; Meltsner, Michael A.; Moerland, Marinus A.; Nath, Ravinder; Rivard, Mark J.; Salcudean, Tim; Song, Danny Y.; Thomadsen, Bruce R.

    2014-01-01

    In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3–6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests

  10. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    Science.gov (United States)

    Xu, Gang; Wang, Xiao-teng; Gan, Cai-ling; Fang, Yan-qiong; Zhang, Meng

    2012-09-01

    To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N+ with energy of 25 keV was applied to treat the dry seed at six different doses. N+ beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 1016 to 15 × 1016 ions cm-2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 1016 ion cm-2, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 1016 ions cm-2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  11. Accelerated Partial Breast Irradiation With Low-Dose-Rate Interstitial Implant Brachytherapy After Wide Local Excision: 12-Year Outcomes From a Prospective Trial

    Energy Technology Data Exchange (ETDEWEB)

    Hattangadi, Jona A. [Harvard Radiation Oncology Program, Boston, MA (United States); Powell, Simon N. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); MacDonald, Shannon M.; Mauceri, Thomas; Ancukiewicz, Marek [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Freer, Phoebe [Department of Radiology, Massachusetts General Hospital, Boston, MA (United States); Lawenda, Brian [21st Century Oncology, Las Vegas, NV (United States); Alm El-Din, Mohamed A. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Clinical Oncology, Tanta University Hospital, Tanta (Egypt); Gadd, Michele A.; Smith, Barbara L. [Department of Surgical Oncology, Massachusetts General Hospital, Boston, MA (United States); Taghian, Alphonse G., E-mail: ataghian@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States)

    2012-07-01

    Purpose: To evaluate the long-term toxicity, cosmesis, and local control of accelerated partial breast irradiation with implant brachytherapy after wide local excision for Stage T1N0 breast cancer (BCa). Materials and Methods: Between 1997 and 2001, 50 patients with Stage T1N0M0 BCa were treated in a Phase I-II protocol using low-dose-rate accelerated partial breast irradiation with implant brachytherapy after wide local excision and lymph node surgery. The total dose was escalated in three groups: 50 Gy (n = 20), 55 Gy (n = 17), and 60 Gy (n = 13). Patient- and physician-assessed breast cosmesis, patient satisfaction, toxicity, mammographic abnormalities, repeat biopsies, and disease status were prospectively evaluated at each visit. Kendall's tau ({tau}{sub {beta}}) and logistic regression analyses were used to correlate outcomes with dose, implant volume, patient age, and systemic therapy. Results: The median follow-up period was 11.2 years (range, 4-14). The patient satisfaction rate was 67%, 67% reported good-excellent cosmesis, and 54% had moderate-severe fibrosis. Higher dose was correlated with worse cosmetic outcome ({tau}{sub {beta}} 0.6, p < .0001), lower patient satisfaction ({tau}{sub {beta}} 0.5, p < .001), and worse fibrosis ({tau}{sub {beta}} 0.4, p = .0024). Of the 50 patients, 35% had fat necrosis and 34% developed telangiectasias {>=}1 cm{sup 2}. Grade 3-4 late skin and subcutaneous toxicities were seen in 4 patients (9%) and 6 patients (13%), respectively, and both correlated with higher dose ({tau}{sub {beta}} 0.3-0.5, p {<=} .01). One patient had Grade 4 skin ulceration and fat necrosis requiring surgery. Mammographic abnormalities were seen in 32% of the patients, and 30% underwent repeat biopsy, of which 73% were benign. Six patients had ipsilateral breast recurrence: five elsewhere in the breast, and one at the implant site. One patient died of metastatic BCa after recurrence. The 12-year actuarial local control, recurrence

  12. Accelerated Partial Breast Irradiation With Low-Dose-Rate Interstitial Implant Brachytherapy After Wide Local Excision: 12-Year Outcomes From a Prospective Trial

    International Nuclear Information System (INIS)

    Hattangadi, Jona A.; Powell, Simon N.; MacDonald, Shannon M.; Mauceri, Thomas; Ancukiewicz, Marek; Freer, Phoebe; Lawenda, Brian; Alm El-Din, Mohamed A.; Gadd, Michele A.; Smith, Barbara L.; Taghian, Alphonse G.

    2012-01-01

    Purpose: To evaluate the long-term toxicity, cosmesis, and local control of accelerated partial breast irradiation with implant brachytherapy after wide local excision for Stage T1N0 breast cancer (BCa). Materials and Methods: Between 1997 and 2001, 50 patients with Stage T1N0M0 BCa were treated in a Phase I-II protocol using low-dose-rate accelerated partial breast irradiation with implant brachytherapy after wide local excision and lymph node surgery. The total dose was escalated in three groups: 50 Gy (n = 20), 55 Gy (n = 17), and 60 Gy (n = 13). Patient- and physician-assessed breast cosmesis, patient satisfaction, toxicity, mammographic abnormalities, repeat biopsies, and disease status were prospectively evaluated at each visit. Kendall’s tau (τ β ) and logistic regression analyses were used to correlate outcomes with dose, implant volume, patient age, and systemic therapy. Results: The median follow-up period was 11.2 years (range, 4–14). The patient satisfaction rate was 67%, 67% reported good-excellent cosmesis, and 54% had moderate-severe fibrosis. Higher dose was correlated with worse cosmetic outcome (τ β 0.6, p β 0.5, p β 0.4, p = .0024). Of the 50 patients, 35% had fat necrosis and 34% developed telangiectasias ≥1 cm 2 . Grade 3–4 late skin and subcutaneous toxicities were seen in 4 patients (9%) and 6 patients (13%), respectively, and both correlated with higher dose (τ β 0.3–0.5, p ≤ .01). One patient had Grade 4 skin ulceration and fat necrosis requiring surgery. Mammographic abnormalities were seen in 32% of the patients, and 30% underwent repeat biopsy, of which 73% were benign. Six patients had ipsilateral breast recurrence: five elsewhere in the breast, and one at the implant site. One patient died of metastatic BCa after recurrence. The 12-year actuarial local control, recurrence-free survival, and overall survival rate was 85% (95% confidence interval, 70–97%), 72% (95% confidence interval, 54–86%), and 87% (95

  13. High-Dose-Rate Brachytherapy of a Single Implant With Two Fractions Combined With External Beam Radiotherapy for Hormone-Naive Prostate Cancer

    International Nuclear Information System (INIS)

    Sato, Morio; Mori, Takashi; Shirai, Shintaro; Kishi, Kazushi; Inagaki, Takeshi; Hara, Isao

    2008-01-01

    Purpose: To evaluate the preliminary outcomes of high-dose-rate (HDR) brachytherapy of a single implant with two fractions and external beam radiotherapy (EBRT) for hormone-naive prostate cancer. Methods and Materials: Between March 2000 and Sept 2003, a total of 53 patients with tumor Stage T1c-T3b N0 M0 prostate cancer were treated with HDR brachytherapy boost doses (7.5 Gy/fraction) and 50-Gy EBRT during a 5.5-week period. Median follow-up was 61 months. Patients were divided into groups with localized (T1c-T2b) and advanced disease (T3a-T3b). We used the American Society for Therapeutic Radiology and Oncology (ASTRO) definition for biochemical failure. According to recommendations of the Radiation Therapy Oncology Group-ASTRO Phoenix Consensus Conference, biochemical failure-free control rates (BF-FCRs) at 3 years were investigated as 2 years short of the median follow-up. Results: Between April 2000 and Sept 2007, Common Terminology Criteria for Adverse Events Version 2.0 late Grade 2 genitourinary and gastrointestinal toxicity rates were 0% and 3.8%, respectively. Erectile preservation was 25% at 5 years. Overall survival was 88.1% and cause-specific survival was 100%. At 3 years, ASTRO BF-FCRs of the localized and advanced groups were 100% and 42%, respectively (p = 0.001). Conclusions: The HDR brachytherapy of a single implant with two fractions plus EBRT is effective in treating patients with localized hormone-naive prostate cancer, with the least genitourinary and gastrointestinal toxicities; however, longer median BF-FCR follow-up is required to assess these findings

  14. Implantation of the maxillary antrum for delivery of iridium brachytherapy and microwave induced hyperthermia

    International Nuclear Information System (INIS)

    Coughlin, C.T.; Wong, T.Z.; Geurkink, N.

    1985-01-01

    A 63 year-old male was referred tp Dartmouth in March 1984 for a locally advanced recurrent squamous cell carcinoma of the left maxillary antrum. This had been initially diagnosed in January 1983 by a Caldwell-Luc procedure and had failed partial resection, external radiation therapy, and multiagent chemotherapy. Our initial evaluation revealed disease replacing the left maxillary antrum, extending into the pterygomaxillary fossa, the lateral aspect of the superior alveloar ridge, and into the soft palate. He was taken to the operating room and under general anesthesia was implanted the 7 catheters through this tumor volume. Two days later a therapeutic (>42 0 C for 1 hour) hyperthermia treatment was administered followed by iridium placement. A second heating was performed upon removal of the iridium and was accomplished without major side effects. Thermometry data and follow-up are presented

  15. The effect of the radial function on I-125 seeds used for permanent prostate implantation

    International Nuclear Information System (INIS)

    Pickett, Barby; Pouliot, Jean

    2004-01-01

    The purpose of this study was to evaluate the integrity of eight commercially-available low-activity Iodine-125 ( 125 I) seeds for their radial function g(r) and its effect on the dose delivered to the adjacent critical structures when used in permanent prostate implants (PPI). Ten previously treated patients were retrospectively used in this comparison. The Amersham Health Oncura seed was used to peripherally design an isodose distribution with urethral and anterior rectal wall sparing. Plan criteria included minimum coverage of 144 Gy to the planning target volume (PTV), ≤ 70% dose to 150% of the PTV volume (V150-PTV), and the quantity of needles ≤ 70% of the size of the PTV, in cc. Upon completion of the Oncura plan, the seed type was changed and the activity was adjusted until the V100-PTV for each of the other 7 seed types matched the V100-PTV defined by the Oncura seed. Computed tomography (CT)-based postimplant dosimetry was used to determine the dose to 40% (D40) of the bulb of the penis (in Gy). Dose-volume histograms (DVH) were used to evaluate the differences to V100 (in %) and D40 (in Gy) of the anterior rectal wall and bulb of the penis, and V100 (in %) of the urethra. The data was tabulated. Radioactive 125 I sources included in this study were 125 I Source 2301 (Best); I-Plant (MedTech), IoGold (Mentor), Oncura (Amersham Health), ProstaSeed (UroCor), SelectSeed (Nucletron), SourceTech (Bard), and Symmetra (UroMed). The sizes of the PTV for the 10 patients ranged from 18.82 cc to 48.99 cc. The Oncura seed was used as the reference seed and all other seed types were normalized to it for data comparison. It was determined that the dose rate constant (xwedge) and anisotropy factor (phi) contribute to the activity needed to achieve comparable V100-PTV doses, but a strong dependence on the radial function g(r) was found to effect the doses to the critical structures studied. Values of g(r) at 4 cm were calculated and the IoGold and SourceTech seeds

  16. Carcinological results at five years of the prostate brachytherapy by iodine 125 implants. About 327 cases; Resultats carcinologiques a cinq ans de la curietherapie de prostate par implants d'iode 125. A propos de 327 cas

    Energy Technology Data Exchange (ETDEWEB)

    Peiffert, D.; Bernier, V.; Aletti, P.; Noela, A.; Marchesi, V. [Centre Alexis-Vautrin, 54 - Vandoeuvre-les-Nancy (France); Cormier, L.; Moreau, J.L. [CHU, Service d' Urologie, 54 - Nancy (France)

    2006-11-15

    The prostate brachytherapy by iodine 125 implants is reserved to patients damaged by a favourable prognosis cancer. The objective of this study is to present the carcinological results at five years in these indications with a technique keeping urethra. The achieving of a P.S.A. nadir inferior to 0.5 ng/ml is long. the technique used in this study keeping urethra and respecting the inclusion criteria recommended allows to get results as less equivalent as these ones of big series previously published with a low failure rate. (N.C.)

  17. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Xu Gang, E-mail: xg335300@yahoo.com.cn [Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang 550025 (China); Institute of Entomology, Guizhou University, Guiyang 550025 (China); Wang Xiaoteng [Department of Agricultural Resources and Environment, College of Agricultural, Guizhou University, Guiyang 550025 (China); Gan Cailing; Fang Yanqiong; Zhang Meng [College of Life Sciences, Guizhou University, Guiyang 550025 (China)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We analyzed biological effects of N{sup +} implantation on dry Jatropha curcas seed. Black-Right-Pointing-Pointer N{sup +} implantation greatly decreased seedling survival rate. Black-Right-Pointing-Pointer At doses beyond 15 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place. Black-Right-Pointing-Pointer CAT was essential for H{sub 2}O{sub 2} removal. POD mainly functioned as seed was severely hurt. Black-Right-Pointing-Pointer HAsA-GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N{sup +} with energy of 25 keV was applied to treat the dry seed at six different doses. N{sup +} beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 Multiplication-Sign 10{sup 16} to 15 Multiplication-Sign 10{sup 16} ions cm{sup -2} severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 Multiplication-Sign 10{sup 16} ions cm{sup -2} may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  18. Use of brachytherapy with permanent implants of iodine-125 in localized prostate cancer; La curietherapie par implants permanents d'I-125 dans le cancer localise de la prostate

    Energy Technology Data Exchange (ETDEWEB)

    Bladou, F.; Serment, G. [Hopital Salvador, Service d' Urologie, 13 - Marseille (France); Salem, N.; Simonian, M. [Hopital Salvador, Dept. de Radiotherapie, 13 - Marseille (France); Rosello, R.; Ternier, F. [Institut Paoli-Calmettes, Dept. de Radiologie, 13 - Marseille (France)

    2002-07-01

    Approximately 15,000 cases of early stage prostate cancer T1 and T2 are diagnosed every year in France by testing for PSA and performing prostatic biopsies. The treatment of these localized forms is based in most cases on radical prostatectomy or nn external beam radiotherapy. Although the ontological results obtained by these two therapeutic methods are satisfactory and equivalent in the long term, the side effects can be important. For a number of years, trans-perineal brachytherapy using permanent implants of iodine -125 or palladium-103 has proved itself as an alternative therapy with equivalent medium to long-term results. The low urinary, digestive and sexual side effects of prostate brachytherapy are important reasons for the enthusiasm among patients and the medical community for this therapy and the growing number of applications and centres which practice it. In September 1998 we started the prostate brachytherapy programmes- in Marseilles with close collaboration between the department of urology of the Hopital Salvator, and the departments of radiotherapy, medical imaging and medical physics of the Institut Paoli-Calmettes. To date, around 250 patients with localized adenocarcinoma of the prostate have benefited from this alternative therapy in our centre. Preliminary results, with a 3 year-follow-up, are comparable to results published in the literature by pioneer teams. (authors)

  19. 1251 seed calibration using afterloading equipment Seed Selectron. Practical solution to meet the recommendations of the AAPM; Calibracion de semillas de {sup 1}25I usando el equipo de carga difereida SeedSelectron. Solucion practica para cumplir las recomendaciones de la AAPM

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Calatayud, J.; Richart, J.; Perez-Garcia, J.; Guirado, D.; Ballester, F.; Rodriguez, S.; Santos, M.; Depiaggio, M.; Carmona, V.; Lliso, F.; Camacho, C.; Pujades, M. C.

    2011-07-01

    Seed Selectron is a system used in the after loader permanent implant brachytherapy seeds 1-125 interstitial prostate. Two aspects are critical when you can meet the recommendations of the AAPM: a practical difficulty to check the quantity of seed required, and the great uncertainty of all measured diodes. The purpose of this paper is to present a practical solution that has been adopted to implement the recommendations of the AAPM.

  20. SLM Produced Porous Titanium Implant Improvements for Enhanced Vascularization and Osteoblast Seeding

    Science.gov (United States)

    Matena, Julia; Petersen, Svea; Gieseke, Matthias; Kampmann, Andreas; Teske, Michael; Beyerbach, Martin; Murua Escobar, Hugo; Haferkamp, Heinz; Gellrich, Nils-Claudius; Nolte, Ingo

    2015-01-01

    To improve well-known titanium implants, pores can be used for increasing bone formation and close bone-implant interface. Selective Laser Melting (SLM) enables the production of any geometry and was used for implant production with 250-µm pore size. The used pore size supports vessel ingrowth, as bone formation is strongly dependent on fast vascularization. Additionally, proangiogenic factors promote implant vascularization. To functionalize the titanium with proangiogenic factors, polycaprolactone (PCL) coating can be used. The following proangiogenic factors were examined: vascular endothelial growth factor (VEGF), high mobility group box 1 (HMGB1) and chemokine (C-X-C motif) ligand 12 (CXCL12). As different surfaces lead to different cell reactions, titanium and PCL coating were compared. The growing into the porous titanium structure of primary osteoblasts was examined by cross sections. Primary osteoblasts seeded on the different surfaces were compared using Live Cell Imaging (LCI). Cross sections showed cells had proliferated, but not migrated after seven days. Although the cell count was lower on titanium PCL implants in LCI, the cell count and cell spreading area development showed promising results for titanium PCL implants. HMGB1 showed the highest migration capacity for stimulating the endothelial cell line. Future perspective would be the incorporation of HMGB1 into PCL polymer for the realization of a slow factor release. PMID:25849656

  1. SLM Produced Porous Titanium Implant Improvements for Enhanced Vascularization and Osteoblast Seeding

    Directory of Open Access Journals (Sweden)

    Julia Matena

    2015-04-01

    Full Text Available To improve well-known titanium implants, pores can be used for increasing bone formation and close bone-implant interface. Selective Laser Melting (SLM enables the production of any geometry and was used for implant production with 250-µm pore size. The used pore size supports vessel ingrowth, as bone formation is strongly dependent on fast vascularization. Additionally, proangiogenic factors promote implant vascularization. To functionalize the titanium with proangiogenic factors, polycaprolactone (PCL coating can be used. The following proangiogenic factors were examined: vascular endothelial growth factor (VEGF, high mobility group box 1 (HMGB1 and chemokine (C-X-C motif ligand 12 (CXCL12. As different surfaces lead to different cell reactions, titanium and PCL coating were compared. The growing into the porous titanium structure of primary osteoblasts was examined by cross sections. Primary osteoblasts seeded on the different surfaces were compared using Live Cell Imaging (LCI. Cross sections showed cells had proliferated, but not migrated after seven days. Although the cell count was lower on titanium PCL implants in LCI, the cell count and cell spreading area development showed promising results for titanium PCL implants. HMGB1 showed the highest migration capacity for stimulating the endothelial cell line. Future perspective would be the incorporation of HMGB1 into PCL polymer for the realization of a slow factor release.

  2. Distribution of implanted ions in seeds and roots of mung bean

    International Nuclear Information System (INIS)

    Liu Donghua; Wang Wei; Jiang Wusheng; Zhang Zhixiang; Hou Wenqiang; Guo Ximing; Li Yi

    1998-01-01

    Doses of 1 x 10 16 , and 2 x 10 16 cm -2 and 1 x 10 16 , 2 x 10 16 , 3 x 10 16 and 3.6 x 10 16 cm -2 for iron and copper ions are implanted in dry seeds of mung bean, respectively. The results show that the accumulated-copper and -iron ion amounts in the seeds and roots vary with different doses of ion beam, and the fresh and dry weights of the roots decrease progressively with increasing iron and copper doses, except the treatment of 1 x 10 16 Cu + ions/cm 2 , and the accumulated-copper and -iron ion amounts in the seeds of the different test groups can be correlated with the ion distribution in the roots

  3. Biological effects of ion implantation on processing tomato and eggplant seed

    International Nuclear Information System (INIS)

    Mao Peihong; Zeng Xianxian; Jin Xiang

    2004-01-01

    The seed of processing tomato '87-5' (Lycopersicon esculentum Mill) were implanted by the low energy nitrogen ion (N + ) with 6 different doses. The rate of emergence was little reduced in M1 generation, but the fruiting number per plant was increased and it's maturing earlier 20 days than the control. The precocity, disease resistance and stronger growth vigor were shown in M2 generation. Experimental results of two years showed that, according to synthetic analysis in factors such as precocity, disease resistance, high yield and quality, the N + dose of 6 x 10 16 cm -2 (60 times of pulse) for tomato seed '87-5' had been proved to have notable biological effects on M1 and M2 generation. The seed of eggplant 'Wuyeqie' (Solanum melongena L.) was also implanted by the low energy nitrogen ion (N + ) with 2 different doses. Multi-vertical channel fruits were obtained in variable M1 generation, which liked the pomelo without peel. The seed of these variable eggplants was taken and planted in the next year. The meaningful variable fruits, the characters of disease-resistance, purple-peel, small-navel, lantern-form, large-scale, etc. were obtained in beneficial M2 generation. The biggest single-fruit weight reached 1.53 kg, providing valuable germplasm resource for breeding. (authors)

  4. Comparison of seed brachytherapy or external beam radiotherapy (70 Gy or 74 Gy) in 919 low-risk prostate cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, G.; Poetter, R.; Schmid, M.P.; Kirisits, C. [University Hospital of Vienna (Austria). Dept. of Radiotherapy and Radiobiology; Battermann, J.J.; Sljivic, S.; Vulpen, M. van [University Medical Center Utrecht (Netherlands). Dept. of Radiation Oncology

    2012-04-15

    The aim of this analysis was to compare the biochemical no evidence of disease (bNED) rates in low-risk prostate cancer patients treated at two centers of excellence using different approaches: seed brachytherapy (BT) and external beam radiotherapy (EBRT). Materials and methods: A total of 919 low-risk prostate cancer patients, treated from 1998-2008, were identified in the two databases. In Utrecht, 667 patients received I-125 BT applying a dose of 144 Gy. In Vienna, 252 patients were treated with EBRT, applying a local dose of 70 Gy in 82 patients and 74 Gy in 170 patients. bNED rates (Phoenix definition) were assessed. Results: The median follow-up was 46 months (range 1-148 months). The 5-year actuarial bNED rates were 94% for BT patients and 88% for EBRT patients (p = 0.002) - 84% for patients receiving 70 Gy and 91% for patients receiving 74 Gy, respectively. In the univariate analysis, patients receiving 70 Gy showed significantly worse outcome compared to BT (p = 0.001) and a difference close to significance compared to 74 Gy (p = 0.06). In the multivariate analysis including tumor stage, Gleason score, initial PSA, hormonal therapy, and dose, patients receiving 70 Gy EBRT showed significantly worse bNED rates compared to BT patients. Conclusion: Low-risk prostate cancer patients receiving 74 Gy by EBRT show comparable biochemical control rates to patients receiving seed brachytherapy, whereas patients receiving 70 Gy show significantly worse outcome. (orig.)

  5. The role of long half-life isotopes for use in LDR brachytherapy. Report of the advisory group meeting (325-E3-AG-1086)

    International Nuclear Information System (INIS)

    2000-08-01

    Brachytherapy is a growing activity in the management of cancer. Where indications exist for brachytherapy, LDR still retains a significant but decreasingly important role in the overall management. It remains the preferred form of brachytherapy in a few sites such as the nose, lip, vagina and penis. It is well tested in the paediatric population where long-term sequelae are highly significant and have not yet been evaluated for mHDR. Prostatic cancer permanent seed implant boosts is currently the only application where LDR is receiving increasing clinical support. LDR still can play an equally effective role when brachytherapy is required in gynaecological, breast and head and neck cancer and soft tissue sarcomas. The meeting recognised the growing role of mHDR as the major modality in brachytherapy administration. It is further noted that changing circumstances and opinions regarding mHDR may exert a major influence on the continued future of LDR as a treatment modality. LDR brachytherapy special techniques are becoming less widely distributed and less frequently performed. Only a few centres remain where sufficient procedures are performed to give adequate training in a period of a few months. The meeting recommended that the Agency should promote the creation of regional training centres of excellence where the practice of LDR brachytherapy should be available. The meeting recommended that the Member States should continue support for LDR brachytherapy techniques beyond gynaecological techniques until such time as clear evidence is presented for discontinuation

  6. Impact of target area selection in 125 Iodine seed brachytherapy on locoregional recurrence in patients with non-small cell lung cancer.

    Science.gov (United States)

    Yan, Wei-Liang; Lv, Jin-Shuang; Guan, Zhi-Yu; Wang, Li-Yang; Yang, Jing-Kui; Liang, Ji-Xiang

    2017-05-01

    Computed tomography (CT)-guided percutaneous implantation of 125 Iodine radioactive seeds requires the precise arrangement of seeds by tumor shape. We tested whether selecting target areas, including subclinical areas around tumors, can influence locoregional recurrence in patients with non-small cell lung cancer (NSCLC). We divided 82 patients with NSCLC into two groups. Target areas in group 1 (n = 40) were defined along tumor margins based on lung-window CT. Target areas in group 2 (n = 42) were extended by 0.5 cm in all dimensions outside tumor margins. Preoperative plans for both groups were based on a treatment plan system, which guided 125 I seed implantation. Six months later, patients underwent chest CT to evaluate treatment efficacy (per Response Evaluation Criteria in Solid Tumors version 1). We compared locoregional recurrences between the groups after a year of follow-up. We then used the treatment plan system to extend target areas for group 1 patients by 0.5 cm (defined as group 3 data) and compared these hypothetical group 3 planned seeds with the actual seed numbers used in group 1 patients. All patients successfully underwent implantation; none died during the follow-up period. Recurrence was significantly lower in group 2 than in group 1 ( P  area for 125 I seeds can decrease recurrence risk by eradicating cancerous lymph-duct blockades within the extended areas. © 2017 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

  7. Polyethylene glycol hydrogel rectal spacer implantation in patients with prostate cancer undergoing combination high-dose-rate brachytherapy and external beam radiotherapy.

    Science.gov (United States)

    Yeh, Jekwon; Lehrich, Brandon; Tran, Carolyn; Mesa, Albert; Baghdassarian, Ruben; Yoshida, Jeffrey; Torrey, Robert; Gazzaniga, Michael; Weinberg, Alan; Chalfin, Stuart; Ravera, John; Tokita, Kenneth

    2016-01-01

    To present rectal toxicity rates in patients administered a polyethylene glycol (PEG) hydrogel rectal spacer in conjunction with combination high-dose-rate brachytherapy and external beam radiotherapy. Between February 2010 and April 2015, 326 prostate carcinoma patients underwent combination high-dose-rate brachytherapy of 16 Gy (average dose 15.5 Gy; standard deviation [SD] = 1.6 Gy) and external beam radiotherapy of 59.4 Gy (average dose 60.2 Gy; SD = 2.9 Gy). In conjunction with the radiation therapy regimen, each patient was injected with 10 mL of a PEG hydrogel in the anterior perirectal fat space. The injectable spacer (rectal spacer) creates a gap between the prostate and the rectum. The rectum is displaced from the radiation field, and rectal dose is substantially reduced. The goal is a reduction in rectal radiation toxicity. Clinical efficacy was determined by measuring acute and chronic rectal toxicity using the National Cancer Center Institute Common Terminology Criteria for Adverse Events v4.0 grading scheme. Median followup was 16 months. The mean anterior-posterior separation achieved was 1.6 cm (SD = 0.4 cm). Rates of acute Grade 1 and 2 rectal toxicity were 37.4% and 2.8%, respectively. There were no acute Grade 3/4 toxicities. Rates of late Grade 1, 2, and 3 rectal toxicity were 12.7%, 1.4%, and 0.7%, respectively. There were no late Grade 4 toxicities. PEG rectal spacer implantation is safe and well tolerated. Acute and chronic rectal toxicities are low despite aggressive dose escalation. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  8. On the question of 3D seed reconstruction in prostate brachytherapy: the determination of x-ray source and film locations

    International Nuclear Information System (INIS)

    Zhang Mutian; Zaider, Marco; Worman, Michael; Cohen, Gilad

    2004-01-01

    Inaccuracy in seed placement during permanent prostate implants may lead to significant dosimetric deviations from the intended plan. In two recent publications (Todor et al 2002 Phys. Med. Biol. 47 2031-48, Todor et al 2003 Phys. Med. Biol. 48 1153-71), methodology was described for identifying intraoperatively the positions of seeds already implanted, thus allowing re-optimization of the treatment plan and correcting for such seed misplacement. Seed reconstruction is performed using fluoroscopic images and an important (and non-trivial) component of this approach is the ability to accurately determine the position of the gantry relative to the treatment volume. We describe the methodology for acquiring this information, based on the known geometry of six markers attached to the ultrasound probe. This method does not require the C-arm unit to be isocentric and films can be taken with the gantry set at any arbitrary position. This is significant because the patient positioning on the operating table (in the lithotomy position) restricts the range of angles at which films can be taken to a quite narrow (typically ±10 0 ) interval and, as a general rule, the closer the angles the larger the uncertainty in the seed location reconstruction along the direction from the x-ray source to the film. (note)

  9. Long-Term Results of Brachytherapy With Temporary Iodine-125 Seeds in Children With Low-Grade Gliomas

    International Nuclear Information System (INIS)

    Korinthenberg, Rudolf; Neuburger, Daniela; Trippel, Michael; Ostertag, Christoph; Nikkhah, Guido

    2011-01-01

    Purpose: To retrospectively review the results of temporary I-125 brachytherapy in 94 children and adolescents with low-grade glioma. Methods and Materials: Treatment was performed in progressive tumors roughly spherical in shape with a diameter of up to 5 cm, including 79 astrocytomas, 5 oligodendrogliomas, 4 oligoastrocytomas, 1 ependymoma, and 5 other tumors. Location was suprasellar/chiasmal in 44, thalamic/basal ganglia in 18, hemispheric in 15, midbrain/pineal region in 13, and lower brainstem in 3. Initially, 8% of patients were free of symptoms, 47% were symptomatic but not disabled, and 30% were slightly, 6% moderately, and 3% severely disabled. Results: 5- and 10-year survival was 97% and 92%. The response to I-125 brachytherapy over the long term was estimated after a median observation period of 38.4 (range, 6.4-171.0) months. At that time, 4 patients were in complete, 27 in partial, and 18 in objective remission; 15 showed stable and 30 progressive tumors. Treatment results did not correlate with age, sex, histology, tumor size, location, or demarcation of the tumor. Secondary treatment became necessary in 36 patients, including 19 who underwent repeated I-125 brachytherapy. At final follow-up, the number of symptom-free patients had risen to 21%. Thirty-eight percent showed symptoms without functional impairment, 19% were slightly and 11% moderately disabled, and only 4% were severely disabled. Conclusions: Response rates similar to those of conventional radiotherapy or chemotherapy can be anticipated with I-125 brachytherapy in tumors of the appropriate size and shape. We believe it to be a useful contribution to the treatment of low-grade gliomas in children.

  10. Edema associated with I-125 or Pd-103 prostate brachytherapy and its effect on post-implant dosimetry: an analysis based on serial CT acquisition

    International Nuclear Information System (INIS)

    Waterman, Frank M.; Yue Ning; Corn, Benjamin W.; Dicker, Adam P.

    1997-01-01

    Purpose/Objective: The dosimetric evaluation of prostate implants is based on analyses of post-implant CT scans. However, if the prostate is edematous as a consequence of needle insertion at the time of imaging, parameters such as dose coverage and the minimum prostatic dose may be underestimated. The purpose of this study is to characterize the magnitude and duration of post-implant edema, and its effect on dosimetry. Materials and Methods: Serial CT scans were obtained at 0, 1, 3, 7, and 15 weeks post-implant on 10 patients who received either I-125 or Pd-103 seed implants. Pre-implant CT scans of each prostate were also obtained. None of the patients received hormone therapy. The magnitude and duration of edema were evaluated by two different methods. In the first, the relative change in the prostate dimensions was determined from the change in the spatial distribution of the implanted seeds, which contract as edema decreases. The radial distance of each seed from the geometric center of the seed cluster was first calculated and then the mean value was computed. The relative change in the mean radial distance in the serial CT scans reflects the relative change in the prostate dimensions. In the second, the prostate in each CT scan was contoured by the same individual, and the prostate volume was computed. A dose-volume histogram of each contoured volume was compiled, from which the minimum prostatic dose and the percentage of the prostate volume which received the prescribed dose were determined. Results: Edema was present in all of the implanted prostates. The magnitude of the edema, expressed as the ratio of the post- to pre-implant volume, ranged from 1.25 to 1.70 (mean 1.47) immediately after implantation. Both methodologies revealed that the edema decreased exponentially with time; however, the edema half-life (time for the edema to decrease by (1(2))) varied considerably, ranging from 3 to 23 days (mean 8.5 days). As edema regressed, the minimum prostatic

  11. The clinical application of TACE together with RFA and 125I seed implantation in treating hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Xie Xiaoxi; Lu Yinxiang; Zhang Hongxin; Zhang Shengchu; Zhou Jianwei; Zhang Guodong; Wang Xiaowei; Yang Liping

    2011-01-01

    Objective: to assess the clinical value of the combined treatment of transcatheter arterial chemoembolization (TACE), CT-guided radiofrequency ablation (RFA) and radioactive 125 I seed implantation for hepatocellular carcinoma (HCC). Methods: During the period from March 2008 to Dec. 2010, 15 patients with HCC were admitted to the hospital. A total of 25 hepatic lesions were detected with the size of 1-8 cm. TACE was carried out first, which was followed by CT-guided RFA and radioactive 125 I seed implantation. With the help of treat plan system (TPS), the radioactive 125 I seed implantation was conducted to make additional management for the same lesion when RFA was finished, or the radioactive 125 I seeds were directly implanted into the areas where RFA could not reach. The radioactive dose was 60-100 Gy. All the patients were followed up and were kept under observation for the signs of related complications. The therapeutic results were evaluated. Results: The combined treatment was successfully accomplished in all patients. All patients were followed up for 3-28 months (mean of 10.6 months). The complete necrosis rate of the tumor was 96%. No serious complications occurred except the immigration of 125 I seeds in 1 case. Conclusion: The combined treatment of TACE and CT-guided RFA together with 125 I seed implantation is a safe, reliable and effective therapy for HCC with excellent short-term result. (authors)

  12. Low-dose-rate brachytherapy for patients with transurethral resection before implantation in prostate cancer: long-term results

    International Nuclear Information System (INIS)

    Prada, Pedro J.; Anchuelo, Javier; Blanco, Ana Garcia; Paya, Gema; Cardenal, Juan; Acuña, Enrique; Ferri, Maria; Vazquez, Andres; Pacheco, Maite; Sanchez, Jesica

    2016-01-01

    Objectives: We analyzed the long-term oncologic outcome for patients with prostate cancer and transurethral resection who were treated using low-dose-rate (LDR) prostate brachytherapy. Methods and Materials: From January 2001 to December 2005, 57 consecutive patients were treated with clinically localized prostate cancer. No patients received external beam radiation. All of them underwent LDR prostate brachytherapy. Biochemical failure was defined according to the 'Phoenix consensus'. Patients were stratified as low and intermediate risk based on The Memorial Sloan Kettering group definition. Results: The median follow-up time for these 57 patients was 104 months. The overall survival according to Kaplan-Meier estimates was 88% (±6%) at 5 years and 77% (±6%) at 12 years. The 5 and 10 years for failure in tumour-free survival (TFS) was 96% and respectively (±2%), whereas for biochemical control was 94% and respectively (±3%) at 5 and 10 years, 98% (±1%) of patients being free of local recurrence. A patient reported incontinence after treatment (1.7%). The chronic genitourinary complains grade I were 7% and grade II, 10%. At six months 94% of patients reported no change in bowel function. Conclusions: The excellent long-term results and low morbidity presented, as well as the many advantages of prostate brachytherapy over other treatments, demonstrates that brachytherapy is an effective treatment for patients with transurethral resection and clinical organ-confined prostate cancer. (author)

  13. Low-dose-rate brachytherapy for patients with transurethral resection before implantation in prostate cancer: long-term results

    Energy Technology Data Exchange (ETDEWEB)

    Prada, Pedro J.; Anchuelo, Javier; Blanco, Ana Garcia; Paya, Gema; Cardenal, Juan; Acuña, Enrique; Ferri, Maria [Department of Radiation Oncology, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria (Spain); Vazquez, Andres; Pacheco, Maite; Sanchez, Jesica [Department of Radiation Physics, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria (Spain)

    2016-01-15

    Objectives: We analyzed the long-term oncologic outcome for patients with prostate cancer and transurethral resection who were treated using low-dose-rate (LDR) prostate brachytherapy. Methods and Materials: From January 2001 to December 2005, 57 consecutive patients were treated with clinically localized prostate cancer. No patients received external beam radiation. All of them underwent LDR prostate brachytherapy. Biochemical failure was defined according to the 'Phoenix consensus'. Patients were stratified as low and intermediate risk based on The Memorial Sloan Kettering group definition. Results: The median follow-up time for these 57 patients was 104 months. The overall survival according to Kaplan-Meier estimates was 88% (±6%) at 5 years and 77% (±6%) at 12 years. The 5 and 10 years for failure in tumour-free survival (TFS) was 96% and respectively (±2%), whereas for biochemical control was 94% and respectively (±3%) at 5 and 10 years, 98% (±1%) of patients being free of local recurrence. A patient reported incontinence after treatment (1.7%). The chronic genitourinary complains grade I were 7% and grade II, 10%. At six months 94% of patients reported no change in bowel function. Conclusions: The excellent long-term results and low morbidity presented, as well as the many advantages of prostate brachytherapy over other treatments, demonstrates that brachytherapy is an effective treatment for patients with transurethral resection and clinical organ-confined prostate cancer. (author)

  14. Gamma spectrometry and chemical characterization of bioactive glass seeds with Holmium-166 for oncological implants

    International Nuclear Information System (INIS)

    Valente, Eduardo S.

    2009-01-01

    Bioactive glass seeds synthesized by the sol-gel technique with Si:Ho:Ca composition with natural holmium incorporated were irradiated in the TRIGA type nuclear reactor IPR-R1 at 100kW, in the central thimble where the thermal neutron flux is 2.8x10 12 n/cm 2 .s and the epithermal neutron flux is 2.6 X 10 11 n/cm 2 .s . After an 8 hour irradiation time, with an induced activity close to 110MBq/seed, a set of seeds was submitted to Gamma Spectrometry Analysis in a counting system with an HPGe detector, ORTEC electronic instrumentation and a Camberra Multichannel Analyser, to determine all radionuclides present on the sample as well as its individual activities. Special attention was paid on the discrimination of Si, 40 Ca, 44 Ca, C and Ho as the other expected elements like 48 Ca, 2 H and 18 O were present in traces or have very short half-lives. The second sample was submitted to Plasma spectrometry to determine the 166 Ho concentration in weight. The third sample was submitted to an X-ray spectrometry in a JEOL-JXA-8900RL equipment to determine its qualitative chemical composition, in order to evaluate impurities and nominal composition. It was determined that most of the activity, after decaying of short half-life elements, was due to 166 Ho present on the sample, with a well characterized β and gamma spectra. The homogeneity of the seeds was tested on the X-ray spectrometry, and verified that there is no discrepancy in composition from distinct seeds or in a same seed. The results are relevant on the investigation of the viability of producing 166 Ho radioactive seeds for oncological implants. (author)

  15. SU-F-T-653: Radiation Exposure from Cs-131 Permanent Seed Implants

    Energy Technology Data Exchange (ETDEWEB)

    Giaddui, T; Hardin, M; To, D; Kremmel, E; Peng, C; Hann, P; Richardson, S; Yu, Y; Harrison, A; Doyle, L [Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States)

    2016-06-15

    Purpose: Permanent seed implants have traditionally been used to treat prostate, lung and head or neck cancers using I-125 and Pd-103. Cs-131, which has higher dose rate is being used to treat brain, head and/or neck cancers in our clinic, therefore, we chose to monitor the dose received by surgeons during the extensive procedure. The aims of this work are to assess the level of radiation exposure to surgeons and the instantaneous exposure at bedside and 1 m from patients. Methods: Ten patients received Cs-131 implants for recurrent brain,head and/or neck cancer; the median implanted activity, number of implanted seeds and prescription dose at 0.5 cm from the perpendicular plane of the implant were: 54.3 mCi (14.52 – 77); 19 (4 – 24) and 60 Gy (range 42 – 60) respectively. Radiation exposure was recorded at bedside and 1 m from the patient using Victoreen ion chamber (Fluke Biomedical, Cleveland, OH). Exposure to surgeons was measured using TLD (Mirion Technologies (GDS), Inc., USA). Results: The median equivalent dose rate at 1 m and bedside immediately following implantation were 1.49×10-2 mSv/h (8.77×10-3–2.63×10-2) and 7.76×10-2 mSv/h (3.1×10-2– 1.53×10-1) respectively. Median equivalent dose to surgeons’ hands was 0.60 mSv (0.33 – 1.48) and no doses were detected for whole-body. Surgical reconstruction for one patient was performed 71 days post-implant and resulted in zero exposure to surgeons. Conclusion: The recorded exposure rates were low when compared with the literature. Post procedure surveys at bed site and 1 m indicated that all patients were within safe limits for discharge (< 0.05 mSv/h at 1 m). However, as a precautionary measure, patients were advised to avoid direct contact with children and pregnant women within four weeks of the implant and stay at least at 3 ft from other people. Surgeons doses were well within occupational dose limits.

  16. High-resolution 3D dose distribution measured for two low-energy x-ray brachytherapy seeds: 125I and 103Pd

    International Nuclear Information System (INIS)

    Massillon-JL, G.; Minniti, R.; Mitch, M.G.; Soares, C.G.; Hearn, R.A.

    2011-01-01

    In this work, we have investigated the 3D absorbed dose distribution around 125 I and 103 Pd low-energy photon brachytherapy seeds using a high-spatial-resolution gel scanning system to address the current difficulty in measuring absorbed dose at close distances to these sources as a consequence of high dose rate gradient. A new version of BANG-gel coupled with a small format laser CT scanner has been used. Measurements were performed with 100 μm resolution in all dimensions. In particular, radial dose function and absorbed dose rate in the plane parallel to the sources longitudinal-axis were derived at radial distances smaller than or equal to 1 cm. In addition, the energy dependence was evaluated, finding that, within measurement uncertainties, the gel response is independent of the energy for energy photon values between 20 keV and 1250 keV. We have observed that at distances larger than 1.4 mm from the source, the delivered dose is similar to predictions from published Monte Carlo calculations (MC) for the 125 I seed. For distances between 1 mm and 3 mm, differences in magnitude and shape are significant for the 103 Pd seed, where an enhancement is observed. In the enhancement region, a difference of up to 70% in the radial dose function was obtained. Such observation suggests a contribution from other radionuclides emitting beta-particles or electrons, and not considered by MC. To understand the effect, spectrometry measurements were performed. A small contribution of 102 Rh/ 102m Rh radionuclide relative to 103 Pd was observed and its importance on the absorbed dose measured at close distances to the seed is time dependent and consequently, avoids reproducible measurements. Finally, the results obtained in this work underscore the importance of using high-spatial-resolution and water-equivalent detectors for measuring absorbed dose in low-energy photon radiation fields.

  17. Seeding of silicon by copper ion implantation for selective electroless copper plating

    Energy Technology Data Exchange (ETDEWEB)

    Bhansali, S; Sood, D K; Zmood, R B [Microelectronic and Materials Technology Centre, Royal Melbourne Institute of Technolgy, Melbourne, VIC (Australia)

    1994-12-31

    We report on the successful use of copper(self) ion implantation into silicon to seed the electroless plating of copper on silicon (100) surfaces. Copper ions have been implanted to doses of 5E14-6.4E16 ions/cm{sup 2} using a MEEVA ion implanter at extraction voltage of 40kV. Dose was varied in fine steps to determine the threshold dose of 2E15 Cu ions/cm{sup 2} for `seed` formation of copper films on silicon using a commercial electroless plating solution. Plated films were studied with Rutherford backscattering spectrometry, scanning electron microscopy, EDX and profilometry . The adhesion of films was measured by `scotch tape test`. The adhesion was found to improve with increasing dose. However thicker films exhibited rather poor adhesion and high internal stress. SEM results show that the films grow first as isolated islands which become larger and eventually impinge into a continuous film as the plating time is increased. (authors). 5 refs., 1 tab., 3 figs.

  18. Seeding of silicon by copper ion implantation for selective electroless copper plating

    Energy Technology Data Exchange (ETDEWEB)

    Bhansali, S.; Sood, D.K.; Zmood, R.B. [Microelectronic and Materials Technology Centre, Royal Melbourne Institute of Technolgy, Melbourne, VIC (Australia)

    1993-12-31

    We report on the successful use of copper(self) ion implantation into silicon to seed the electroless plating of copper on silicon (100) surfaces. Copper ions have been implanted to doses of 5E14-6.4E16 ions/cm{sup 2} using a MEEVA ion implanter at extraction voltage of 40kV. Dose was varied in fine steps to determine the threshold dose of 2E15 Cu ions/cm{sup 2} for `seed` formation of copper films on silicon using a commercial electroless plating solution. Plated films were studied with Rutherford backscattering spectrometry, scanning electron microscopy, EDX and profilometry . The adhesion of films was measured by `scotch tape test`. The adhesion was found to improve with increasing dose. However thicker films exhibited rather poor adhesion and high internal stress. SEM results show that the films grow first as isolated islands which become larger and eventually impinge into a continuous film as the plating time is increased. (authors). 5 refs., 1 tab., 3 figs.

  19. Seeding of silicon by copper ion implantation for selective electroless copper plating

    International Nuclear Information System (INIS)

    Bhansali, S.; Sood, D.K.; Zmood, R.B.

    1993-01-01

    We report on the successful use of copper(self) ion implantation into silicon to seed the electroless plating of copper on silicon (100) surfaces. Copper ions have been implanted to doses of 5E14-6.4E16 ions/cm 2 using a MEEVA ion implanter at extraction voltage of 40kV. Dose was varied in fine steps to determine the threshold dose of 2E15 Cu ions/cm 2 for 'seed' formation of copper films on silicon using a commercial electroless plating solution. Plated films were studied with Rutherford backscattering spectrometry, scanning electron microscopy, EDX and profilometry . The adhesion of films was measured by 'scotch tape test'. The adhesion was found to improve with increasing dose. However thicker films exhibited rather poor adhesion and high internal stress. SEM results show that the films grow first as isolated islands which become larger and eventually impinge into a continuous film as the plating time is increased. (authors). 5 refs., 1 tab., 3 figs

  20. Dosimetric response of radioactive bio glass seeds implants on rabbit brain; Resposta radiodosimetrica de implantes de sementes de biovidros radioativos no cerebro de coelhos

    Energy Technology Data Exchange (ETDEWEB)

    Costa, I.T.; Campos, T.P.R., E-mail: itemponi@yahoo.com.br, E-mail: campos@nuclear.ufmg.br [Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares - Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil)

    2007-07-01

    Interstitial implants of radioactive seeds are used as an efficient way of treating brain tumors. Bio glasses is an interesting alternative to the metallic implanted materials, because they can be absorbed by the organism, reducing the possibilities of side effects. The present paper investigates the dosimetry by the implants performed on rabbit's brain on the NRI/UFMG research group. The spatial distribution of the specific ionizing energy deposited per unit of mass generated by Sm-153 seeds were evaluated. A computational model of the brain's region was built using the software SISCODES produced by the research group. The sections of the computer tomography of a rabbit, which was included on the experiment, were digitalized. Those were converted in a three dimensional voxel model, including the tissues, its chemical composition and density. A simulation of the particles transport is performed by the stochastic code MCNP5. The implants consist of 15 ceramic Ca-Si-Sm seeds enriched with Sm-153, with 1.1.6 mm of length and 0.3 mm diameter, implanted on the rabbit's brain. It was predicted on the model three ribbons of 5 seeds each, spaced by 1.1.2 mm, since the ribbons were in a triangular topology whose vertices were spaced by 8 mm. The activities were 120 MBq/seed. The results show isodose regions superposed over the rabbits' model, reproducing the spatial energy deposition on the brain region. The absorbed dose predicted was 3.2 Gy per 15 seed; however it was not enough to tumor control. The authors suggest to increase the number of seeds and activity, reduction of the space to 5-6 mm among ribbons, improving dose with the beta emitting. (author)

  1. GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

    International Nuclear Information System (INIS)

    Lemaréchal, Yannick; Bert, Julien; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris; Falconnet, Claire; Després, Philippe; Valeri, Antoine

    2015-01-01

    In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125 I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10 −6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications. (paper)

  2. GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

    Science.gov (United States)

    Lemaréchal, Yannick; Bert, Julien; Falconnet, Claire; Després, Philippe; Valeri, Antoine; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris

    2015-07-01

    In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10-6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications.

  3. Edema associated with I-125 or Pd-103 prostate brachytherapy and its impact on post-implant dosimetry: an analysis based on serial CT acquisition

    International Nuclear Information System (INIS)

    Waterman, Frank M.; Yue, Ning; Corn, Benjamin W.; Dicker, Adam P.

    1998-01-01

    Purpose: To characterize the magnitude and duration of post-implant edema following the implantation of I-125 or Pd-103 seeds into the prostate and to investigate its effect on the CT-based calculation of the total dose delivered by the implant. Materials and Methods: A pre-implant CT scan and 3 to 5 serial post-implant CT scans were obtained on 10 patients who received either I-125 or Pd-103 seed implants. None of the patients received hormone therapy. The magnitude and duration of edema were determined from the change in the spatial distribution of the implanted seeds as the edema resolves. Dose volume histograms were compiled to determine the percentage of the prostate volume that received a dose equal to, or greater than, the prescribed dose. Results: The magnitude of the edema, expressed as the ratio of the post- to pre-implant volume on the day of the procedure, ranged from 1.33 to 1.96 (mean 1.52). The edema decreased exponentially with time; however, the edema half-life (time for the edema to decrease by 1/2) varied from 4 to 25 days (mean 9.3 days). As the edema resolved, the percentage of the prostate that received a dose equal to or greater than the prescribed dose increased by at least 7% in 7 of the 10 patients and increased by more than 15% in 2. In those patients in whom dose coverage was unaffected by the resolution of edema, more than 90% of the prostate was covered by the prescribed dose in the initial CT scan. Conclusion: Post-implant edema increased the prostate volume by factors which ranged from 1.33 to 1.96 (mean: 1.52). The edema resolved exponentially with an edema half-life which varied from 4 to 25 days (mean: 9.3 days). Edema had a significant effect on the post-implant dosimetry in 7 of 10 cases. Factors that affect the impact of edema on the dosimetry are the magnitude of the edema and the planned margin between the prescribed isodose line and the periphery of the prostate

  4. CT-guided interstitial 125I seed implantation for intractable pelvic recurrence of rectal carcinomas

    International Nuclear Information System (INIS)

    Lin Zhenwen; Chu Hong; Kong Jian; Dou Yongchong

    2011-01-01

    Objective: To evaluate the therapeutic effect and safety of CT-guided interstitial 125 I seed implantation in treating intractable pelvic recurrence of rectal carcinomas. Methods: During the period from April 2010 to September 2010 CT-guided interstitial 125 I seed implantation was carried out in 11 patients with pelvic recurrence of rectal carcinoma which developed after the patients had received comprehensive treatments such as surgical resection, chemotherapy and/or radiotherapy. The clinical data were retrospectively analyzed. The clinical symptoms, the tumor size and the quality of life (QOL) before the treatment and at two and six months after the treatment were recorded, and the complications were observed. The results were compared. All the patients were followed up for six months. Results: At two and six months after the treatment, the improvement rate of the clinical symptoms was 100.0% (11/11) and 90.9% (10/11) respectively, while the effective reduction of the tumor size was 90.9% (10/11) and 81.8% (9/11) respectively. At two and six months after the treatment the QOL score was (56.0±3.66) and (54.4±5.41) respectively, both of which were higher than the QOL score determined before the treatment (42.5±6.93), the difference between them was statistically significant (P 125 I seed implantation has satisfactory short-term effect. This treatment is also quite safe and effective for patients who are unbearable to external radiation therapy due to the tissue dose restriction. (authors)

  5. Dosimetry verification of radioactive seed implantation for malignant tumors assisted by 3D printing individual templates and CT guidance

    International Nuclear Information System (INIS)

    Ji, Zhe; Jiang, Yuliang; Guo, Fuxin; Sun, Haitao; Fan, Jinghong; Zhang, Lujing; Wang, Junjie

    2017-01-01

    Objective: We compared the dose distributions of postoperative plans with preoperative plans for 3D printing template-assisted radioactive seed implantations. Methods: A total of 14 patients with malignant tumors enrolled in the study. The dose parameters included D90, minimum peripheral dose, V100, V150, and V200. The statistical method was the paired t-test. Results: There was no significant difference in P values between the two groups for all parameters except for V100. Conclusions: The 3D printing guide template can provide good accuracy for radioactive seed implantation. - Highlights: • It is the first study we as for as we know to compare the preoperative and postoperative dosimetry results of 3D printing templates-assisted radioactive seeds implantation for malignant tumor. • 3D printing guide template can provide good accuracy for radioactive seeds implantation. • The actual dose distributions in postoperative validations were closed to the expectations of preoperative plans. • 3D printing template providing us an effective tool for the standardization and normalization of seed implantation, and having a good application prospect and worthy of further development and popularization.

  6. Simplified quality control of radioactive seeds in sterile cartridge for prostate brachytherapy using an imaging plate and a collimator

    International Nuclear Information System (INIS)

    Saze, T.; Miyoshi, H.; Maezawa, H.; Kubota, M.; Furutani, S.; Nishitani, H.; Kawaguchi, Y.; Nakayama, S.; Ito, S.; Nishizawa, K.

    2008-01-01

    Image analyzer system and collimator has been successfully applied to calibrate simultaneously multiple 125 I seeds in a sterile cartridge. Seeds within the cartridge were placed on an imaging plate, and the imaging plate irradiated. To remove scatter radiation, and improve spatial resolution of seed images, this study used a specially designed collimator. The irradiated imaging plate was scanned using an image analyzer system, and radioactivity intensities of seed images were given in counts. Counts could be translated to profiles, and each seed within the cartridge was analyzed. It is observed that a good correlation between counts and total radioactivity of the seeds within the cartridge. Thus, using a least-squares line, it was possible to calibrate a seed with unknown apparent activity. By analyzing the profiles, it was possible not only to detect a mis calibrated seed in the cartridge from its relative difference in counts, but also to identify its position in the cartridge. Using an imaging analyzer system, all seeds in a cartridge could be calibrated in a sterile environment. (author)

  7. Cell Seeding Densities in Autologous Chondrocyte Implantation Techniques for Cartilage Repair.

    Science.gov (United States)

    Foldager, Casper Bindzus; Gomoll, Andreas H; Lind, Martin; Spector, Myron

    2012-04-01

    Cartilage repair techniques have been among the most intensively investigated treatments in orthopedics for the past decade, and several different treatment modalities are currently available. Despite the extensive research effort within this field, the generation of hyaline cartilage remains a considerable challenge. There are many parameters attendant to each of the cartilage repair techniques that can affect the amount and types of reparative tissue generated in the cartilage defect, and some of the most fundamental of these parameters have yet to be fully investigated. For procedures in which in vitro-cultured autologous chondrocytes are implanted under a periosteal or synthetic membrane cover, or seeded onto a porous membrane or scaffold, little is known about how the number of cells affects the clinical outcome. Few published clinical studies address the cell seeding density that was employed. The principal objective of this review is to provide an overview of the cell seeding densities used in cell-based treatments currently available in the clinic for cartilage repair. Select preclinical studies that have informed the use of specific cell seeding densities in the clinic are also discussed.

  8. 10 CFR 35.2406 - Records of brachytherapy source accountability.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of brachytherapy source accountability. 35.2406... Records of brachytherapy source accountability. (a) A licensee shall maintain a record of brachytherapy source accountability required by § 35.406 for 3 years. (b) For temporary implants, the record must...

  9. Ultrasonically guided 125iodine seed implantation with external radiation in management of localized prostatic carcinoma

    DEFF Research Database (Denmark)

    Iversen, P; Bak, M; Juul, N

    1989-01-01

    Thirty-three patients with localized prostatic carcinoma (16 poorly differentiated) were treated with transperineal 125Iodine seed implantation (160 Gy) guided by transrectal ultrasonography and subsequent external beam irradiation (47.4 Gy). The observation time was six to sixty-eight months...... with a median follow-up of thirty-five months. Median change in prostatic volume was a reduction of 35 percent. Re-biopsy or transurethral resection of the prostate was performed in 25 patients after one to two years, revealing still malignant histology in 12 (48%). Development of distant metastases occurred...

  10. Patterns of failure after iodine-125 seed implantation for prostate cancer

    International Nuclear Information System (INIS)

    Lamb, David S.; Greig, Lynne; Russell, Grant L.; Nacey, John N.; Broome, Kim; Studd, Rod; Delahunt, Brett; Iupati, Douglas; Jain, Mohua; Rooney, Colin; Murray, Judy; Lamb, Peter J.; Bethwaite, Peter B.

    2014-01-01

    Purpose: To determine the site of relapse when biochemical failure (BF) occurs after iodine-125 seed implantation for prostate cancer. Materials and methods: From 2001–2009, 500 men underwent implantation in Wellington, New Zealand. Men who sustained BF were placed on relapse guidelines that delayed restaging and intervention until the prostate-specific antigen (PSA) was ⩾20 ng/mL. Results: Most implants (86%) had a prostate D90 of ⩾90%, and multivariate analysis showed that this parameter was not a variable that affected the risk of BF. Of 21 BFs that occurred, the site of failure was discovered to be local in one case and distant in nine cases. Restaging failed to identify the site of relapse in two cases. In nine cases the trigger for restaging had not been reached. Conclusions: If post-implant dosimetry is generally within the optimal range, distant rather than local failure appears to be the main cause of BF. Hormone treatment is therefore the most commonly indicated secondary treatment intervention (STI). Delaying the start of STI prevents the unnecessary treatment of men who undergo PSA ‘bounce’ and have PSA dynamics initially mimicking those of BF

  11. Penile brachytherapy: Results for 49 patients

    International Nuclear Information System (INIS)

    Crook, Juanita M.; Jezioranski, John; Grimard, Laval; Esche, Bernd; Pond, G.

    2005-01-01

    Purpose: To report results for 49 men with squamous cell carcinoma (SCC) of the penis treated with primary penile interstitial brachytherapy at one of two institutions: the Ottawa Regional Cancer Center, Ottawa, and the Princess Margaret Hospital, Toronto, Ontario, Canada. Methods and Materials: From September 1989 to September 2003, 49 men (mean age, 58 years; range, 22-93 years) had brachytherapy for penile SCC. Fifty-one percent of tumors were T1, 33% T2, and 8% T3; 4% were in situ and 4% Tx. Grade was well differentiated in 31%, moderate in 45%, and poor in 2%; grade was unspecified for 20%. One tumor was verrucous. All tumors in Toronto had pulsed dose rate (PDR) brachytherapy (n = 23), whereas those in Ottawa had either Iridium wire (n 22) or seeds (n = 4). Four patients had a single plane implant with a plastic tube technique, and all others had a volume implant with predrilled acrylic templates and two or three parallel planes of needles (median, six needles). Mean needle spacing was 13.5 mm (range, 10-18 mm), mean dose rate was 65 cGy/h (range, 33-160 cGy/h), and mean duration was 98.8 h (range, 36-188 h). Dose rates for PDR brachytherapy were 50-61.2 cGy/h, with no correction in total dose, which was 60 Gy in all cases. Results: Median follow-up was 33.4 months (range, 4-140 months). At 5 years, actuarial overall survival was 78.3% and cause-specific survival 90.0%. Four men died of penile cancer, and 6 died of other causes with no evidence of recurrence. The cumulative incidence rate for never having experienced any type of failure at 5 years was 64.4% and for local failure was 85.3%. All 5 patients with local failure were successfully salvaged by surgery; 2 other men required penectomy for necrosis. The soft tissue necrosis rate was 16% and the urethral stenosis rate 12%. Of 8 men with regional failure, 5 were salvaged by lymph node dissection with or without external radiation. All 4 men with distant failure died of disease. Of 49 men, 42 had an intact

  12. Radiological response of ceramic and polymeric devices for breast brachytherapy

    International Nuclear Information System (INIS)

    Batista Nogueira, Luciana; Passos Ribeiro de Campos, Tarcisio

    2012-01-01

    In the present study, the radiological visibility of ceramic and polymeric devices implanted in breast phantom was investigated for future applications in brachytherapy. The main goal was to determine the radiological viability of ceramic and polymeric devices in vitro by performing simple radiological diagnostic methods such as conventional X-ray analysis and mammography due to its easy access to the population. The radiological response of ceramic and polymeric devices implanted in breast phantom was determined using conventional X-ray, mammography and CT analysis. - Highlights: ► Radiological visibility of ceramic and polymeric devices implanted in breast phantom. ► The barium incorporation in the seed improves the radiological contrast. ► Radiological monitoring shows the position, orientation and degradation of devices. ► Simple radiological methods such as X-ray and mammography were used for radiological monitoring.

  13. Clinical analysis of 125I seed implants in worst-casts of the malignant tumors after radiography and chemotherapy

    International Nuclear Information System (INIS)

    Chen Zhijun; Tu Xinhua; Zhou Aiqing; Wang Xueqin

    2006-01-01

    Objective: To investigate the curative effect and side reaction after 125 I seed implanted among tissue were treated the malignant neoplasm by radiography and chemotherapy. Methods: Retrospective analysis the cancerous sufferer after the failure of radiography and chemotherapy, percutaneous puncture or intraoperative under gaze forward 125 I seed were implanted the bed of the tumour forever. Follow-up blood routine examination, symptom, sign, using USG or CT observe the change of the tumour and the distribution of the particles etc. Results: In 3 cases, treat 2 cases, tumour reduced obviously, symptoms improved obviously, the face of the ulcer cured, the particles did not shift, hemogram did not decline obviously. Conclusion: 125 I seed among the tissue implanted forever for the unsuccessful case after radiography and chemotherapy supply a new therapeutic methods. In the neat future curative effect is exactly, toxic reaction is small, which can remedy the deficiency of the treatment for radiography and chemotherapy. (authors)

  14. Nursing care for patients with local recurrent rectal cancer after CT-guided 125I seed implantation therapy

    International Nuclear Information System (INIS)

    Yuan Li; Wei Fan; Ren Caifeng; Tu Mingmei; Qian Guixiang

    2010-01-01

    Objective: To discuss the nursing care strategy for patients with local recurrent rectal cancer who has been treated with CT-guided 125 I seed implantation therapy. Methods: Twenty patients with local recurrent rectal cancer received a series of nursing interventions, including comfort care and pain care. The clinical results were observed and analyzed. Results: The therapy was smoothly accomplished in all patients. The pain was remarkably relived and the anxiety was alleviated. No displacement of implanted 125 I seed occurred. Conclusion: For patients with local recurrent rectal cancer occurred after CT-guided 125 I seed implantation therapy, careful nursing can effectively relieve the pain and anxiety feeling,and the living quality can also be markedly improved. (authors)

  15. SU-E-J-214: MR Protocol Development to Visualize Sirius MRI Markers in Prostate Brachytherapy Patients for MR-Based Post-Implant Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Lim, T; Wang, J; Frank, S; Stafford, R; Bruno, T; Bathala, T; Mahmood, U; Pugh, T; Ibbott, G; Kudchadker, R [UT MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: The current CT-based post-implant dosimetry allows precise seed localization but limited anatomical delineation. Switching to MR-based post-implant dosimetry is confounded by imprecise seed localization. One approach is to place positive-contrast markers (Sirius) adjacent to the negative-contrast seeds. This patient study aims to assess the utility of a 3D fast spoiled gradient-recalled echo (FSPGR) sequence to visualize Sirius markers for post-implant dosimetry. Methods: MRI images were acquired in prostate implant patients (n=10) on Day 0 (day-of-implant) and Day 30. The post-implant MR protocol consisted of 3D T2-weighted fast-spin-echo (FSE), T2-weighted 2D-FSE (axial) and T1-weighted 2D-FSE (axial/sagittal/coronal). We incorporated a 3D-FSPGR sequence into the post-implant MR protocol to visualize the Sirius markers. Patients were scanned with different number-of-excitations (6, 8, 10), field-of-view (10cm, 14cm, 18cm), slice thickness (1mm, 0.8mm), flip angle (14 degrees, 20 degrees), bandwidth (122.070 Hz/pixel, 325.508 Hz/pixel, 390.625 Hz/pixel), phase encoding steps (160, 192, 224, 256), frequency-encoding direction (right/left, anterior/posterior), echo-time type (minimum-full, out-of-phase), field strength (1.5T, 3T), contrast (with, without), scanner vendor (Siemens, GE), coil (endorectal-coil only, endorectal-and-torso-coil, torsocoil only), endorectal-coil filling (30cc, 50cc) and endorectal-coil filling type (air, perfluorocarbon [PFC]). For post-implant dosimetric evaluation with greater anatomical detail, 3D-FSE images were fused with 3D-FSPGR images. For comparison with CT-based post-implant dosimetry, CT images were fused with 3D-FSPGR images. Results: The 3D-FSPGR sequence facilitated visualization of markers in patients. Marker visualization helped distinguish signal voids as seeds versus needle tracks for more definitive MR-based post-implant dosimetry. On the CT-MR fused images, the distance between the seed on CT to MR images was 3

  16. SU-E-J-214: MR Protocol Development to Visualize Sirius MRI Markers in Prostate Brachytherapy Patients for MR-Based Post-Implant Dosimetry

    International Nuclear Information System (INIS)

    Lim, T; Wang, J; Frank, S; Stafford, R; Bruno, T; Bathala, T; Mahmood, U; Pugh, T; Ibbott, G; Kudchadker, R

    2015-01-01

    Purpose: The current CT-based post-implant dosimetry allows precise seed localization but limited anatomical delineation. Switching to MR-based post-implant dosimetry is confounded by imprecise seed localization. One approach is to place positive-contrast markers (Sirius) adjacent to the negative-contrast seeds. This patient study aims to assess the utility of a 3D fast spoiled gradient-recalled echo (FSPGR) sequence to visualize Sirius markers for post-implant dosimetry. Methods: MRI images were acquired in prostate implant patients (n=10) on Day 0 (day-of-implant) and Day 30. The post-implant MR protocol consisted of 3D T2-weighted fast-spin-echo (FSE), T2-weighted 2D-FSE (axial) and T1-weighted 2D-FSE (axial/sagittal/coronal). We incorporated a 3D-FSPGR sequence into the post-implant MR protocol to visualize the Sirius markers. Patients were scanned with different number-of-excitations (6, 8, 10), field-of-view (10cm, 14cm, 18cm), slice thickness (1mm, 0.8mm), flip angle (14 degrees, 20 degrees), bandwidth (122.070 Hz/pixel, 325.508 Hz/pixel, 390.625 Hz/pixel), phase encoding steps (160, 192, 224, 256), frequency-encoding direction (right/left, anterior/posterior), echo-time type (minimum-full, out-of-phase), field strength (1.5T, 3T), contrast (with, without), scanner vendor (Siemens, GE), coil (endorectal-coil only, endorectal-and-torso-coil, torsocoil only), endorectal-coil filling (30cc, 50cc) and endorectal-coil filling type (air, perfluorocarbon [PFC]). For post-implant dosimetric evaluation with greater anatomical detail, 3D-FSE images were fused with 3D-FSPGR images. For comparison with CT-based post-implant dosimetry, CT images were fused with 3D-FSPGR images. Results: The 3D-FSPGR sequence facilitated visualization of markers in patients. Marker visualization helped distinguish signal voids as seeds versus needle tracks for more definitive MR-based post-implant dosimetry. On the CT-MR fused images, the distance between the seed on CT to MR images was 3

  17. Definition of medical event is to be based on the total source strength for evaluation of permanent prostate brachytherapy: A report from the American Society for Radiation Oncology.

    Science.gov (United States)

    Nag, Subir; Demanes, D Jeffrey; Hagan, Michael; Rivard, Mark J; Thomadsen, Bruce R; Welsh, James S; Williamson, Jeffrey F

    2011-10-01

    The Nuclear Regulatory Commission deems it to be a medical event (ME) if the total dose delivered differs from the prescribed dose by 20% or more. A dose-based definition of ME is not appropriate for permanent prostate brachytherapy as it generates too many spurious MEs and thereby creates unnecessary apprehension in patients, and ties up regulatory bodies and the licensees in unnecessary and burdensome investigations. A more suitable definition of ME is required for permanent prostate brachytherapy. The American Society for Radiation Oncology (ASTRO) formed a working group of experienced clinicians to review the literature, assess the validity of current regulations, and make specific recommendations about the definition of an ME in permanent prostate brachytherapy. The working group found that the current definition of ME in §35.3045 as "the total dose delivered differs from the prescribed dose by 20 percent or more" was not suitable for permanent prostate brachytherapy since the prostate volume (and hence the resultant calculated prostate dose) is dependent on the timing of the imaging, the imaging modality used, the observer variability in prostate contouring, the planning margins used, inadequacies of brachytherapy treatment planning systems to calculate tissue doses, and seed migration within and outside the prostate. If a dose-based definition for permanent implants is applied strictly, many properly executed implants would be improperly classified as an ME leading to a detrimental effect on brachytherapy. The working group found that a source strength-based criterion, of >20% of source strength prescribed in the post-procedure written directive being implanted outside the planning target volume is more appropriate for defining ME in permanent prostate brachytherapy. ASTRO recommends that the definition of ME for permanent prostate brachytherapy should not be dose based but should be based upon the source strength (air-kerma strength) administered.

  18. Dosimetric characterization of the GammaClip™{sup 169}Yb low dose rate permanent implant brachytherapy source for the treatment of nonsmall cell lung cancer postwedge resection

    Energy Technology Data Exchange (ETDEWEB)

    Currier, Blake [Medical Physics, University of Massachusetts Lowell, 1 University Avenue, Lowell, Massachusetts 01854 (United States); Munro, John J. III [Source Production and Equipment Co., Inc., 113 Teal Street, St. Rose, Louisiana 70087 (United States); Medich, David C. [Department of Physics, Worcester Polytechnic Institute, 100 Institute Road, Worcester, Massachusetts 01609 (United States)

    2013-08-15

    Purpose: A novel {sup 169}Yb low dose rate permanent implant brachytherapy source, the GammaClip™, was developed by Source Production and Equipment Co. (New Orleans, LA) which is designed similar to a surgical staple while delivering therapeutic radiation. In this report, the brachytherapy source was characterized in terms of “Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO” by Perez-Calatayud et al. [Med. Phys. 39, 2904–2929 (2012)] using the updated AAPM Task Group Report No. 43 formalism.Methods: Monte Carlo calculations were performed using Monte Carlo N-Particle 5, version 1.6 in water and air, the in-air photon spectrum filtered to remove photon energies below 10 keV in accordance with TG-43U1 recommendations and previously reviewed {sup 169}Yb energy cutoff levels [D. C. Medich, M. A. Tries, and J. M. Munro, “Monte Carlo characterization of an Ytterbium-169 high dose rate brachytherapy source with analysis of statistical uncertainty,” Med. Phys. 33, 163–172 (2006)]. TG-43U1 dosimetric data, including S{sub K}, D-dot (r,θ), Λ, g{sub L}(r), F(r, θ), φ{sub an}(r), and φ{sub an} were calculated along with their statistical uncertainties. Since the source is not axially symmetric, an additional set of calculations were performed to assess the resulting axial anisotropy.Results: The brachytherapy source's dose rate constant was calculated to be (1.22 ± 0.03) cGy h{sup −1} U{sup −1}. The uncertainty in the dose to water calculations, D-dot (r,θ), was determined to be 2.5%, dominated by the uncertainties in the cross sections. The anisotropy constant, φ{sub an}, was calculated to be 0.960 ± 0.011 and was obtained by integrating the anisotropy factor between 1 and 10 cm using a weighting factor proportional to r{sup −2}. The radial dose function was calculated at distances between 0.5 and 12 cm, with a maximum value of 1.20 at 5.15 ± 0.03 cm. Radial dose

  19. Iodine-125 seeds for cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Rostelato, Maria E.C.M.; Zeituni, Carlos A.; Feher, Anselmo; Moura, Joao A.; Moura, Eduardo S.; Nagatomi, Helio R.; Manzoli, Jose E.; Souza, Carla D., E-mail: elisaros@ipen.b, E-mail: czeituni@pobox.co, E-mail: afeher@ipen.b, E-mail: jmoura31@yahoo.com.b, E-mail: esmoura@ipen.b, E-mail: hrnagato@ipen.b, E-mail: jemanzoli@ipen.b, E-mail: cdsouza@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Karam, Dib, E-mail: dib.karan@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Escola de Artes, Ciencias e Humanidades

    2009-07-01

    In Brazil, cancer has become one of the major public health problems. An estimate by the Health Ministry showed that 466,430 people had the disease in the country in 2008. The prostate cancer is the second largest death cause among men. The National Institute of Cancer estimated the occurrence of 50,000 new cases for 2009. Some of these patients are treated with Brachytherapy, using Iodine-125 seeds. By this technique, small seeds with Iodine-125, a radioactive material, are implanted in the prostate. The advantages of radioactive seed implants are the preservation of healthy tissues and organs near the prostate, besides the low rate of impotence and urinary incontinence. The Energy and Nuclear Research Institute - IPEN, which belongs to the Nuclear Energy National Commission - CNEN, established a program for the development of the technique and production of Iodine-125 seeds in Brazil. The estimate for the 125-Iodine seeds demand is of 8,000 seeds/month and the laboratory to be implanted will need this production capacity. The purpose of this paper is to explain the project status and show some data about the seeds used in the country. The project will be divided in two phases: technological development of a prototype and a laboratory implementation for the seeds production. (author)

  20. Radiation safety and protection of close contacts from radiators after implantation of radioactive 125I seeds

    International Nuclear Information System (INIS)

    Sui Aixia; Li Jianmin; Tang Fulong; Zhang Hongtao; Ren Ju'na; Pang Linbin; Xia Haishui; Gao Zhen; Wu Lili; Wang Juan

    2012-01-01

    Objective: To study the effective dose and precaution time of the irradiation of the close contact from the radiators who underwent implantation of radioactive 125 I seeds so as to guide scientifically people how to avoid radiation damage. Methods: Twenty patients with different types of cancer underwent implantation of radioactive 125 I seeds with the median value of implantation depth of 2.16 cm. Within 24 h after the operations the dose rates 30 cm and 100 cm from the skin were measured with pocket-size radiometer so as to imitate the situations of the close contacts. The effective doses and precaution times of different persons were calculated according to relevant formula. Results: The dose rate a person received at the same time points (1, 54, 78, and 109 d, respectively) decreased along with the increase of the distance from the skin (t=5.962, 5.961, 5.961, 5.962, P<0.05), and the dose rate a person received at the same distance from the skin decreased along with the extension of time (30 cm: t=6.236, 6.236, 6.235, P<0.05; 100 cm: t=7.310, 7.315, 7.314, P<0.05). At different time points, the dose rates at 30 cm distance point were all significant higher than those at the 100 cm point (P <0.05). The adult living together, minors and pregnant women sharing the room, colleagues,adults who slept together with the patients began to reach the 50% dose constraint values 0, 54, 78 and 109 days after the operation. Conclusions: After their precaution time, it's safe to contact with the patients for the groups; otherwise, it's necessary to take some protect works within the precaution time. (authors)

  1. SU-G-TeP1-01: A Simulation Study to Investigate Maximum Allowable Deformations of Implant Geometry Before Plan Objectives Are Violated in Prostate HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Babier, A [Department of Physics, Engineering Physics and Astronomy, Queens University, Kingston, Ontario (Canada); Joshi, C [Department of Physics, Engineering Physics and Astronomy, Queens University, Kingston, Ontario (Canada); Cancer Center of Southeastern Ontario, Kingston General Hospital, Kingston, Ontario (Canada)

    2016-06-15

    Purpose: In prostate HDR brachytherapy dose distributions are highly sensitive to changes in prostate volume and catheter displacements. We investigate the maximum deformations in implant geometry before planning objectives are violated. Methods: A typical prostate Ir-192 HDR brachytherapy reference plan was calculated on the Oncentra planning system, which used CT images from a tissue equivalent prostate phantom (CIRS Model 053S) embedded inside a pelvis wax phantom. The prostate was deformed and catheters were displaced in simulations using a code written in MATLAB. For each deformation dose distributions were calculated, based on TG43 methods, using the MATLAB code. The calculations were validated through comparison with Oncentra calculations for the reference plan, and agreed within 0.12%SD and 0.3%SD for dose and volume, respectively. Isotropic prostate volume deformations of up to +34% to −27% relative to its original volume, and longitudinal catheter displacements of 7.5 mm in superior and inferior directions were simulated. Planning objectives were based on American Brachytherapy Society guidelines for prostate and urethra volumes. A plan violated the planning objectives when less than 90% of the prostate volume received the prescribed dose or higher (V{sub 100}), or the urethral volume receiving 125% of prescribed dose or higher was more than 1 cc (U{sub 125}). Lastly, the dose homogeneity index (DHI=1-V{sub 150}/V{sub 100}) was evaluated; a plan was considered sub-optimal when the DHI fell below 0.62. Results and Conclusion: Planning objectives were violated when the prostate expanded by 10.7±0.5% or contracted by 11.0±0.2%; objectives were also violated when catheters were displaced by 4.15±0.15 mm and 3.70±0.15 mm in the superior and inferior directions, respectively. The DHI changes did not affect the plan optimality, except in the case of prostate compression. In general, catheter displacements have a significantly larger impact on plan

  2. An overview of interstitial brachytherapy and hyperthermia

    International Nuclear Information System (INIS)

    Brandt, B.B.; Harney, J.

    1989-01-01

    Interstitial thermoradiotherapy, an experimental cancer treatment that combines interstitial radiation implants (brachytherapy) and interstitial hyperthermia, is in the early stages of investigation. In accordance with the procedure used in a current national trial protocol, a 60-minute hyperthermia treatment is administered after catheters are placed into the tumor area while the patient is under general anesthesia. This is immediately followed by loading of radioactive Iridium-192 seeds into the catheters for a defined period of time. Once the prescribed radiation dose is delivered, the radioactive sources are removed and a second, 60-minute hyperthermia treatment is administered. Clinical trials with hyperthermia in combination with radiation have increased in recent years. Nurses caring for these patients need to become more knowledgeable about this investigational therapy. This paper provides an overview of the biologic rationale for this therapy, as well as a description of the delivery method and clinical application. Specific related nursing interventions are defined in a nursing protocol.23 references

  3. The effect of interstitial 125I seeds implantation on intestinal wall: a pathological observation in experimental dogs

    International Nuclear Information System (INIS)

    Ning Houfa; Zhang Fenglian; Shen An; Cao Guiwen; Cui Xinjiang

    2010-01-01

    Objective: To observe the radiation injury of the bowel wall due to the implantation of interstitial 125 I seeds in experimental dogs. Methods: A total of 12 healthy male dogs were randomly and equally divided into 3 experimental groups and 1 control group, with 3 dogs in each group.In the experimental groups, two 125 I seeds with the active radiation dose of 0.8mCi were symmetrically implanted under the serous membrane of the dog's small intestinal wall. The dogs were fed for 14 days (group A), for one month (group B) and for two months (group C) respectively when the animals were scheduled to be sacrificed. The dogs' general condition was observed till they were sacrificed. The seed-implanting intestinal segments were then removed and dyed with HE staining method for electronic microscopic exam. The histopathologic findings were recorded and the results were compared between four groups. Results: No obvious histopathological changes were found in the dog's bowel wall 14 days after the implantation. One month after the procedure cellular injury was observed under electronic microscope, and two months after the operation partial fibrosis of the intestinal wall appeared but no ulceration or perforation occurred. Conclusion: The implantation of 125 I seeds can cause reversible cellular injuries of the intestinal wall in experimental dogs, the degree of the damage reaches its peak at one month after the implant when the partial fibrosis of bowel wall becomes evident. However, the seeds do not cause any serious complications, such as ulceration or perforation. (authors)

  4. The use of nomograms in LDR-HDR prostate brachytherapy.

    Science.gov (United States)

    Pujades, Ma Carmen; Camacho, Cristina; Perez-Calatayud, Jose; Richart, José; Gimeno, Jose; Lliso, Françoise; Carmona, Vicente; Ballester, Facundo; Crispín, Vicente; Rodríguez, Silvia; Tormo, Alejandro

    2011-09-01

    The common use of nomograms in Low Dose Rate (LDR) permanent prostate brachytherapy (BT) allows to estimate the number of seeds required for an implant. Independent dosimetry verification is recommended for each clinical dosimetry in BT. Also, nomograms can be useful for dose calculation quality assurance and they could be adapted to High Dose Rate (HDR). This work sets nomograms for LDR and HDR prostate-BT implants, which are applied to three different institutions that use different implant techniques. Patients treated throughout 2010 till April 2011 were considered for this study. This example was chosen to be the representative of the latest implant techniques and to ensure consistency in the planning. A sufficient number of cases for both BT modalities, prescription dose and different work methodology (depending on the institution) were taken into account. The specific nomograms were built using the correlation between the prostate volume and some characteristic parameters of each BT modality, such as the source Air Kerma Strength, number of implanted seeds in LDR or total radiation time in HDR. For each institution and BT modality, nomograms normalized to the prescribed dose were obtained and fitted to a linear function. The parameters of the adjustment show a good agreement between data and the fitting. It should be noted that for each institution these linear function parameters are different, indicating that each centre should construct its own nomograms. Nomograms for LDR and HDR prostate brachytherapy are simple quality assurance tools, specific for each institution. Nevertheless, their use should be complementary to the necessary independent verification.

  5. The use of nomograms in LDR-HDR prostate brachytherapy

    Directory of Open Access Journals (Sweden)

    Ma Carmen Pujades

    2011-09-01

    Full Text Available Purpose: The common use of nomograms in Low Dose Rate (LDR permanent prostate brachytherapy (BT allowsto estimate the number of seeds required for an implant. Independent dosimetry verification is recommended for eachclinical dosimetry in BT. Also, nomograms can be useful for dose calculation quality assurance and they could be adaptedto High Dose Rate (HDR. This work sets nomograms for LDR and HDR prostate-BT implants, which are applied tothree different institutions that use different implant techniques. Material and methods: Patients treated throughout 2010 till April 2011 were considered for this study. This examplewas chosen to be the representative of the latest implant techniques and to ensure consistency in the planning. A sufficientnumber of cases for both BT modalities, prescription dose and different work methodology (depending on theinstitution were taken into account. The specific nomograms were built using the correlation between the prostatevo lume and some characteristic parameters of each BT modality, such as the source Air Kerma Strength, numberof implanted seeds in LDR or total radiation time in HDR. Results: For each institution and BT modality, nomograms normalized to the prescribed dose were obtained andfitted to a linear function. The parameters of the adjustment show a good agreement between data and the fitting.It should be noted that for each institution these linear function parameters are different, indicating that each centreshould construct its own nomograms. Conclusions: Nomograms for LDR and HDR prostate brachytherapy are simple quality assurance tools, specific foreach institution. Nevertheless, their use should be complementary to the necessary independent verification.

  6. I-125 seed dose estimates in heterogeneous phantom

    International Nuclear Information System (INIS)

    Branco, Isabela S.L.; Antunes, Paula C.G.; Cavalieri, Tassio A.; Moura, Eduardo S.; Zeituni, Carlos A.; Yoriyaz, Helio

    2015-01-01

    Brachytherapy plays an important role in the healing process involving tumors in a variety of diseases. Several studies are currently conducted to examine the heterogeneity effects of different tissues and organs in brachytherapy clinical situations and a great effort has been made to incorporate new methodologies to estimate doses with greater accuracy. The objective of this study is to contribute to the assessment of heterogeneous effects on dose due to I-125 brachytherapy source in the presence of different materials with different densities and chemical compositions. The study was performed in heterogeneous phantoms using materials that simulate human tissues. Among these is quoted: breast, fat, muscle, lungs (exhaled and inhaled) and bones with different densities. Monte Carlo simulations for dose calculation in these phantoms were held and subsequently validated. The model 6711 I-125 seed was considered because it is widely used as a brachytherapy permanent implant and the one used in clinics and hospitals in Brazil. Thermoluminescent dosimeters TLD-700 (LiF: Mg, Ti) were simulated for dose assess. Several tissue configurations and positioning of I-125 sources were studied by simulations for future dose measurements. The methodology of this study so far shall be suitable for accurate dosimetric evaluation for different types of brachytherapy treatments, contributing to brachytherapy planning systems complementation allowing a better assessment of the dose actually delivered to the patient. (author)

  7. I-125 seed dose estimates in heterogeneous phantom

    Energy Technology Data Exchange (ETDEWEB)

    Branco, Isabela S.L.; Antunes, Paula C.G.; Cavalieri, Tassio A.; Moura, Eduardo S.; Zeituni, Carlos A.; Yoriyaz, Helio, E-mail: isabela.slbranco@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Brachytherapy plays an important role in the healing process involving tumors in a variety of diseases. Several studies are currently conducted to examine the heterogeneity effects of different tissues and organs in brachytherapy clinical situations and a great effort has been made to incorporate new methodologies to estimate doses with greater accuracy. The objective of this study is to contribute to the assessment of heterogeneous effects on dose due to I-125 brachytherapy source in the presence of different materials with different densities and chemical compositions. The study was performed in heterogeneous phantoms using materials that simulate human tissues. Among these is quoted: breast, fat, muscle, lungs (exhaled and inhaled) and bones with different densities. Monte Carlo simulations for dose calculation in these phantoms were held and subsequently validated. The model 6711 I-125 seed was considered because it is widely used as a brachytherapy permanent implant and the one used in clinics and hospitals in Brazil. Thermoluminescent dosimeters TLD-700 (LiF: Mg, Ti) were simulated for dose assess. Several tissue configurations and positioning of I-125 sources were studied by simulations for future dose measurements. The methodology of this study so far shall be suitable for accurate dosimetric evaluation for different types of brachytherapy treatments, contributing to brachytherapy planning systems complementation allowing a better assessment of the dose actually delivered to the patient. (author)

  8. Results of a dummy run of postimplant dosimetry between multi-institutional centers in prostate brachytherapy with 125I seeds

    International Nuclear Information System (INIS)

    Aoki, Manabu; Yorozu, Atsunori; Dokiya, Takushi

    2009-01-01

    The purpose of this study was to determine the reproducibility and precision of postimplant dosimetry following 125 I prostate brachytherapy (PB) and to evaluate the effects of learning and experience in CT-based postimplant dosimetry. One-month postimplant CT data from two patients who underwent PB alone or combined therapy (PB+external beam radiation therapy (EBRT)) were sent to 28 institutions for postimplant dosimetry and analyzed in 2006 (study 1). Similarly, 1-month postimplant CT data from two other patients were also analyzed in 2008 (study 2; 23 institutions). For both modalities in studies 1 and 2, the variance of the difference between CT-based D90 at each institution and CT/MRI fusion-based D90 was estimated. In monotherapy, F test and Mann-Whitney U test revealed no significant difference in the variance in studies 1 and 2 (P=0.72, 0.46). In combined therapy, the variance significantly converged in study 2 compared with study 1 (P<0.05). Even in the two studies, however, the difference between the median CT-based D90 and fusion-based D90 was at least 20-30 Gy. Marked interobserver variability was seen in the prostate volume and D90 with CT alone. The precision of postimplant dosimetry based on CT alone was revealed to be limited. (author)

  9. Evaluation of the dose distribution for prostate implants using various 125I and 103Pd sources

    International Nuclear Information System (INIS)

    Meigooni, Ali S.; Luerman, Christine M.; Sowards, Keith T.

    2009-01-01

    Recently, several different models of 125 I and 103 Pd brachytherapy sources have been introduced in order to meet the increasing demand for prostate seed implants. These sources have different internal structures; hence, their TG-43 dosimetric parameters are not the same. In this study, the effects of the dosimetric differences among the sources on their clinical applications were evaluated. The quantitative and qualitative evaluations were performed by comparisons of dose distributions and dose volume histograms of prostate implants calculated for various designs of 125 I and 103 Pd sources. These comparisons were made for an identical implant scheme with the same number of seeds for each source. The results were compared with the Amersham model 6711 seed for 125 I and the Theragenics model 200 seed for 103 Pd using the same implant scheme.

  10. Establishing High-Quality Prostate Brachytherapy Using a Phantom Simulator Training Program

    Energy Technology Data Exchange (ETDEWEB)

    Thaker, Nikhil G. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kudchadker, Rajat J. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Swanson, David A. [Department of Urology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Albert, Jeffrey M. [Department of Radiation Oncology, Banner Health, Loveland/Greeley, Colorado (United States); Mahmood, Usama; Pugh, Thomas J.; Boehling, Nicholas S. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Bruno, Teresa L. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Prestidge, Bradley R. [Department of Radiation Oncology, Bon Secours Health System, Norfolk, Virginia (United States); Crook, Juanita M. [Department of Radiation Oncology, Cancer Center for the Southern Interior, Kelowna, British Columbia (Canada); Cox, Brett W.; Potters, Louis [Department of Radiation Medicine, North Shore-LIJ Health System, New Hyde Park, New York (United States); Moran, Brian J. [Chicago Prostate Center, Westmont, Illinois (United States); Keyes, Mira [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver Center, Vancouver, British Columbia (Canada); Kuban, Deborah A. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Frank, Steven J., E-mail: sjfrank@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-11-01

    Purpose: To design and implement a unique training program that uses a phantom-based simulator to teach the process of prostate brachytherapy (PB) quality assurance and improve the quality of education. Methods and Materials: Trainees in our simulator program were practicing radiation oncologists, radiation oncology residents, and fellows of the American Brachytherapy Society. The program emphasized 6 core areas of quality assurance: patient selection, simulation, treatment planning, implant technique, treatment evaluation, and outcome assessment. Using the Iodine 125 ({sup 125}I) preoperative treatment planning technique, trainees implanted their ultrasound phantoms with dummy seeds (ie, seeds with no activity). Pre- and postimplant dosimetric parameters were compared and correlated using regression analysis. Results: Thirty-one trainees successfully completed the simulator program during the period under study. The mean phantom prostate size, number of seeds used, and total activity were generally consistent between trainees. All trainees met the V100 >95% objective both before and after implantation. Regardless of the initial volume of the prostate phantom, trainees' ability to cover the target volume with at least 100% of the dose (V100) was not compromised (R=0.99 pre- and postimplant). However, the V150 had lower concordance (R=0.37) and may better reflect heterogeneity control of the implant process. Conclusions: Analysis of implants from this phantom-based simulator shows a high degree of consistency between trainees and uniformly high-quality implants with respect to parameters used in clinical practice. This training program provides a valuable educational opportunity that improves the quality of PB training and likely accelerates the learning curve inherent in PB. Prostate phantom implantation can be a valuable first step in the acquisition of the required skills to safely perform PB.

  11. Establishing High-Quality Prostate Brachytherapy Using a Phantom Simulator Training Program

    International Nuclear Information System (INIS)

    Thaker, Nikhil G.; Kudchadker, Rajat J.; Swanson, David A.; Albert, Jeffrey M.; Mahmood, Usama; Pugh, Thomas J.; Boehling, Nicholas S.; Bruno, Teresa L.; Prestidge, Bradley R.; Crook, Juanita M.; Cox, Brett W.; Potters, Louis; Moran, Brian J.; Keyes, Mira; Kuban, Deborah A.; Frank, Steven J.

    2014-01-01

    Purpose: To design and implement a unique training program that uses a phantom-based simulator to teach the process of prostate brachytherapy (PB) quality assurance and improve the quality of education. Methods and Materials: Trainees in our simulator program were practicing radiation oncologists, radiation oncology residents, and fellows of the American Brachytherapy Society. The program emphasized 6 core areas of quality assurance: patient selection, simulation, treatment planning, implant technique, treatment evaluation, and outcome assessment. Using the Iodine 125 ( 125 I) preoperative treatment planning technique, trainees implanted their ultrasound phantoms with dummy seeds (ie, seeds with no activity). Pre- and postimplant dosimetric parameters were compared and correlated using regression analysis. Results: Thirty-one trainees successfully completed the simulator program during the period under study. The mean phantom prostate size, number of seeds used, and total activity were generally consistent between trainees. All trainees met the V100 >95% objective both before and after implantation. Regardless of the initial volume of the prostate phantom, trainees' ability to cover the target volume with at least 100% of the dose (V100) was not compromised (R=0.99 pre- and postimplant). However, the V150 had lower concordance (R=0.37) and may better reflect heterogeneity control of the implant process. Conclusions: Analysis of implants from this phantom-based simulator shows a high degree of consistency between trainees and uniformly high-quality implants with respect to parameters used in clinical practice. This training program provides a valuable educational opportunity that improves the quality of PB training and likely accelerates the learning curve inherent in PB. Prostate phantom implantation can be a valuable first step in the acquisition of the required skills to safely perform PB

  12. Statistical differences and systematic effect on measurement procedure in thermoluminescent dosimetry of the Iodine-125 brachytherapy seed

    International Nuclear Information System (INIS)

    Zeituni, Carlos A.; Moura, Eduardo S.; Rostelato, Maria Elisa C.M.; Manzoli, Jose E.; Moura, Joao Augusto; Feher, Anselmo; Karam, Dib

    2009-01-01

    In order to provide the dosimetry for Iodine-125 seed production in Brazil, Harshaw thermoluminescent dosimeters (TLD-100) will be used. Even if measurements with TLD-100 of the same batch of fabrication are performed, the response will not be the same. As a consequence, they must be measured one by one. These dosimeters are LiF type with a micro-cube (1 mm x 1 mm x 1 mm) shape. Irradiations were performed using Iodine-125 seeds to guarantee the same absorbed dose of 5 Gy in each dosimeter. It has been used a Solid Water Phantom with three concentrically circle with 20 mm, 50 mm and 70 mm diameters. The angle of positions used was 0 deg, 30 deg, 60 deg and 90 deg. Of course there are 2 positions in 0 deg and 90 deg and 4 positions in 30 deg and 60 deg. These complete procedures were carried out five times in order to compare the data and minimize the systematic error. The iodine-125 seed used in the experiment was take off in each measure and put again turning his position 180 deg to guarantee the systematic error was minimized. This paper presents also a little discussion about the statistical difference in the measurement and the calculation procedure to determine the systematic error in these measurements. (author)

  13. Statistical differences and systematic effect on measurement procedure in thermoluminescent dosimetry of the Iodine-125 brachytherapy seed

    Energy Technology Data Exchange (ETDEWEB)

    Zeituni, Carlos A.; Moura, Eduardo S.; Rostelato, Maria Elisa C.M.; Manzoli, Jose E.; Moura, Joao Augusto; Feher, Anselmo, E-mail: czeituni@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil); Karam, Dib [Universidade de Sao Paulo (USP Leste), Sao Paulo, SP (Brazil). Escola de Artes, Ciencias e Humanidades

    2009-07-01

    In order to provide the dosimetry for Iodine-125 seed production in Brazil, Harshaw thermoluminescent dosimeters (TLD-100) will be used. Even if measurements with TLD-100 of the same batch of fabrication are performed, the response will not be the same. As a consequence, they must be measured one by one. These dosimeters are LiF type with a micro-cube (1 mm x 1 mm x 1 mm) shape. Irradiations were performed using Iodine-125 seeds to guarantee the same absorbed dose of 5 Gy in each dosimeter. It has been used a Solid Water Phantom with three concentrically circle with 20 mm, 50 mm and 70 mm diameters. The angle of positions used was 0 deg, 30 deg, 60 deg and 90 deg. Of course there are 2 positions in 0 deg and 90 deg and 4 positions in 30 deg and 60 deg. These complete procedures were carried out five times in order to compare the data and minimize the systematic error. The iodine-125 seed used in the experiment was take off in each measure and put again turning his position 180 deg to guarantee the systematic error was minimized. This paper presents also a little discussion about the statistical difference in the measurement and the calculation procedure to determine the systematic error in these measurements. (author)

  14. Effect of edema, relative biological effectiveness, and dose heterogeneity on prostate brachytherapy

    International Nuclear Information System (INIS)

    Wang, Jian Z.; Mayr, Nina A.; Nag, Subir; Montebello, Joseph; Gupta, Nilendu; Samsami, Nina; Kanellitsas, Christos

    2006-01-01

    Many factors influence response in low-dose-rate (LDR) brachytherapy of prostate cancer. Among them, edema, relative biological effectiveness (RBE), and dose heterogeneity have not been fully modeled previously. In this work, the generalized linear-quadratic (LQ) model, extended to account for the effects of edema, RBE, and dose heterogeneity, was used to assess these factors and their combination effect. Published clinical data have shown that prostate edema after seed implant has a magnitude (ratio of post- to preimplant volume) of 1.3-2.0 and resolves exponentially with a half-life of 4-25 days over the duration of the implant dose delivery. Based on these parameters and a representative dose-volume histogram (DVH), we investigated the influence of edema on the implant dose distribution. The LQ parameters (α=0.15 Gy -1 and α/β=3.1 Gy) determined in earlier studies were used to calculate the equivalent uniform dose in 2 Gy fractions (EUD 2 ) with respect to three effects: edema, RBE, and dose heterogeneity for 125 I and 103 Pd implants. The EUD 2 analysis shows a negative effect of edema and dose heterogeneity on tumor cell killing because the prostate edema degrades the dose coverage to tumor target. For the representative DVH, the V 100 (volume covered by 100% of prescription dose) decreases from 93% to 91% and 86%, and the D 90 (dose covering 90% of target volume) decrease from 107% to 102% and 94% of prescription dose for 125 I and 103 Pd implants, respectively. Conversely, the RBE effect of LDR brachytherapy [versus external-beam radiotherapy (EBRT) and high-dose-rate (HDR) brachytherapy] enhances dose effect on tumor cell kill. In order to balance the negative effects of edema and dose heterogeneity, the RBE of prostate brachytherapy was determined to be approximately 1.2-1.4 for 125 I and 1.3-1.6 for 103 Pd implants. These RBE values are consistent with the RBE data published in the literature. These results may explain why in earlier modeling studies

  15. Intraoperative dynamic dosimetry for prostate implants

    Energy Technology Data Exchange (ETDEWEB)

    Todor, D A [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States); Zaider, M [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States); Cohen, G N [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States); Worman, M F [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States); Zelefsky, M J [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States)

    2003-05-07

    This paper describes analytic tools in support of a paradigm shift in brachytherapy treatment planning for prostate cancer - a shift from standard pre-planning to intraoperative planning using dosimetric feedback based on the actual deposited seed positions within the prostate. The method proposed is guided by several desiderata: (a) bringing both planning and evaluation in the operating room (i.e. make post-implant evaluation superfluous) therefore making rectifications - if necessary - still achievable; (b) making planning and implant evaluation consistent by using the same imaging system (ultrasound); and (c) using only equipment commonly found in a hospital operating room. The intraoperative dosimetric evaluation is based on the fusion between ultrasound images and 3D seed coordinates reconstructed from fluoroscopic projections. Automatic seed detection and registration of the fluoroscopic and ultrasound information, two of the three key ingredients needed for the intraoperative dynamic dosimetry optimization (IDDO), are explained in detail. The third one, the reconstruction of 3D coordinates from projections, was reported in a previous article. The algorithms were validated using a custom-designed phantom with non-radioactive (dummy) seeds. Also, fluoroscopic images were taken at the conclusion of an actual permanent prostate implant and compared with data on the same patient obtained from radiographic-based post-implant evaluation. To offset the effect of organ motion the comparison was performed in terms of the proximity function of the two seed distributions. The agreement between the intra- and post-operative seed distributions was excellent.

  16. Development of prostate voxel models for brachytherapy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Adriano M.; Reis, Lucas P.; Grynberg, Suely E., E-mail: amsantos@cdtn.b [Center for Development of Nuclear Technology (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The tools developed recently in the areas of computer graphics and animation movies to computer games allow the creation of new voxel anthropomorphic phantoms with better resolution and thus, more anatomical details. These phantoms can be used in nuclear applications, especially in radiation protection for estimating doses in cases of occupational or accidental radioactive incidents, and in medical and biological applications. For dose estimates, the phantoms are coupled to a Monte Carlo code, which will be responsible for the transport of radiation in this environment. This study aimed to develop a computational tool to estimate the isodose curves in the prostate after brachytherapy seed implants. For this, we have created a model called FANTPROST in the shape of a 48 mm side cube, with a standard prostate inserted in the center of this cube with different distributions of brachytherapy seeds in this volume. The prostate, according to this model, was obtained from the phantom voxels MASH2 developed by Numerical Dosimetry Group, Department of Nuclear Energy - Federal University of Pernambuco. The modeling of the seeds, added to FANTPROST, was done through the use of geometric information of Iodine-125 Amersham 6711 commercial seed. The simulations were performed by the code MCNP5 for spatial distributions containing different amounts of seeds within the FANTPROST. The obtained curves allowed an estimation of the behavior of the maximum dose that decreases with distance, showing that this tool can be used for a more accurate analysis of the effects produced by the presence of such seeds in the prostate and its vicinity. (author)

  17. Computed tomography in brachytherapy

    International Nuclear Information System (INIS)

    Mansfield, C.M.; Lee, K.R.; Dwyer, S.; Zellmer, D.; Cook, P.

    1983-01-01

    CT scanning adds to the ability to evaluate brachytherapy techniques. It provides an additional method in the assessment of patients who are candidates for or who are being treated by brachytherapy. The CT scan can give information regarding the position of the sources and their relation to the tumor and normal structures with greater ease than do orthogonal views. This makes it possible to accurately calculate areas of high or low dose. Potential areas of overdose can be recognized, thereby decreasing the chances of postbrachytherapy complications. CT scanning can be used at various levels of complexity in dosimetry evaluation. Adequate brachytherapy dosimetry information is obtainable from CT slices through one or more levels of the implanted volume. In some instances it is possible to obtain additional information by reconstructing the scans in other planes, e.g., coronal or sagittal. Three-dimensional viewing of the implant is desirable, but it should be pointed out that this approach is time-consuming and beyond the capabilities of most institutions at present. It will be necessary to continue work on three-dimensional treatment planning to make it readily available

  18. Intra-operative pubic arch interference during prostate seed brachytherapy in patients with CT-based pubic arch interference of ≤1 cm

    International Nuclear Information System (INIS)

    Sejpal, Samir V.; Sathiaseelan, Vythialingam; Helenowski, Irene B.; Kozlowski, James M.; Carter, Michael F.; Nadler, Robert B.; Dalton, Daniel P.; McVary, Kevin T.; Lin, William W.; Garnett, John E.; Kalapurakal, John A.

    2009-01-01

    Purpose: There are only a few reports on the frequency of intra-operative pubic arch interference (I-PAI) during prostate seed brachytherapy (PB). Materials and methods: Two hundred and forty-three patients with a CT-based pubic arch interference (PAI) of ≤1 cm and a prostate volume of ≤50-60 cc underwent PB. Those patients requiring needle repositioning by ≥0.5 cm on the template were scored as having I-PAI. The incidence of I-PAI and its impact on biochemical control were analyzed. Results: Intra-operative PAI was encountered in 47 (19.3%) patients. Forty two patients (17.3%) had I-PAI in 1-2 needles, two (0.8%) had I-PAI in four needles and three patients (1.2%) had I-PAI in six needles. Overall, 1.4% of needles required repositioning due to I-PAI. BMI > 27 kg/m 2 and wider (>75 mm) pubic bone separation at mid ramus (PS-ML) were associated with a lower incidence of I-PAI. At a median follow-up of 50.1 months, the 3- and 5-year bPFS was 97.3% and 95.2%, respectively. The 5-year bPFS rates for patients with and without I-PAI were 95.6% and 95%, respectively (p = 0.28). Conclusions: The use of CT-based PAI of ≤1 cm as a selection criterion for PB is a simple and reliable method for minimizing the incidence of I-PAI and maintaining excellent biochemical control rates.

  19. Intracavitary mould brachytherapy in malignant tumors of the maxilla

    International Nuclear Information System (INIS)

    Rosenblatt, Edward; Blumenfeld, Israel; Cederbaum, Martin; Kuten, Abraham

    1996-01-01

    Purpose: To integrate brachytherapy in the combined modality management of malignant tumors of the maxilla, as a means of increasing the radiotherapy dose to the tumor bed while avoiding high doses to the orbital contents. Materials and methods: Following a partial or total maxillectomy, a duplication of the interim surgical obturator was created using a wash of vinyl polysiloxane. This mould was used as a carrier for afterloading nylon catheters through which 192-Iridium seed-ribbons were inserted. Following brachytherapy, selected patients also received external beam irradiation. Results and discussion: After a median follow-up of 36 months, 9 out of 11 patients are alive and disease-free; 1 developed a local recurrence and another relapsed at another site in the oral cavity. Transient grade 1 - 2 mucositis at the implant site was observed in all patients. The review of computer isodose distributions showed that the average dose received by the homolateral eyeball was 10% (range 9,2 - 10.0) of the prescribed surface dose to the surgical cavity. Conclusions: Brachytherapy can be integrated in the management of patients with malignant tumors of the maxilla in the form of a custom-made intracavitary mould carrying 192-Iridium sources. We found this technique particularly useful in cases with close or positive surgical margins

  20. EchoSeed Model 6733 Iodine-125 brachytherapy source: Improved dosimetric characterization using the MCNP5 Monte Carlo code

    Energy Technology Data Exchange (ETDEWEB)

    Mosleh-Shirazi, M. A.; Hadad, K.; Faghihi, R.; Baradaran-Ghahfarokhi, M.; Naghshnezhad, Z.; Meigooni, A. S. [Center for Research in Medical Physics and Biomedical Engineering and Physics Unit, Radiotherapy Department, Shiraz University of Medical Sciences, Shiraz 71936-13311 (Iran, Islamic Republic of); Radiation Research Center and Medical Radiation Department, School of Engineering, Shiraz University, Shiraz 71936-13311 (Iran, Islamic Republic of); Comprehensive Cancer Center of Nevada, Las Vegas, Nevada 89169 (United States)

    2012-08-15

    This study primarily aimed to obtain the dosimetric characteristics of the Model 6733 {sup 125}I seed (EchoSeed) with improved precision and accuracy using a more up-to-date Monte-Carlo code and data (MCNP5) compared to previously published results, including an uncertainty analysis. Its secondary aim was to compare the results obtained using the MCNP5, MCNP4c2, and PTRAN codes for simulation of this low-energy photon-emitting source. The EchoSeed geometry and chemical compositions together with a published {sup 125}I spectrum were used to perform dosimetric characterization of this source as per the updated AAPM TG-43 protocol. These simulations were performed in liquid water material in order to obtain the clinically applicable dosimetric parameters for this source model. Dose rate constants in liquid water, derived from MCNP4c2 and MCNP5 simulations, were found to be 0.993 cGyh{sup -1} U{sup -1} ({+-}1.73%) and 0.965 cGyh{sup -1} U{sup -1} ({+-}1.68%), respectively. Overall, the MCNP5 derived radial dose and 2D anisotropy functions results were generally closer to the measured data (within {+-}4%) than MCNP4c and the published data for PTRAN code (Version 7.43), while the opposite was seen for dose rate constant. The generally improved MCNP5 Monte Carlo simulation may be attributed to a more recent and accurate cross-section library. However, some of the data points in the results obtained from the above-mentioned Monte Carlo codes showed no statistically significant differences. Derived dosimetric characteristics in liquid water are provided for clinical applications of this source model.

  1. Postimplantation Analysis Enables Improvement of Dose-Volume Histograms and Reduction of Toxicity for Permanent Seed Implantation

    International Nuclear Information System (INIS)

    Wust, Peter; Postrach, Johanna; Kahmann, Frank; Henkel, Thomas; Graf, Reinhold; Cho, Chie Hee; Budach, Volker; Boehmer, Dirk

    2008-01-01

    Purpose: To demonstrate how postimplantation analysis is useful for improving permanent seed implantation and reducing toxicity. Patients and Methods: We evaluated 197 questionnaires completed by patients after permanent seed implantation (monotherapy between 1999 and 2003). For 70% of these patients, a computed tomography was available to perform postimplantation analysis. The index doses and volumes of the dose-volume histograms (DVHs) were determined and categorized with respect to the date of implantation. Differences in symptom scores relative to pretherapeutic status were analyzed with regard to follow-up times and DVH descriptors. Acute and subacute toxicities in a control group of 117 patients from an earlier study (June 1999 to September 2001) by Wust et al. (2004) were compared with a matched subgroup from this study equaling 110 patients treated between October 2001 and August 2003. Results: Improved performance, identifying a characteristic time dependency of DVH parameters (after implantation) and toxicity scores, was demonstrated. Although coverage (volume covered by 100% of the prescription dose of the prostate) increased slightly, high-dose regions decreased with the growing experience of the users. Improvement in the DVH and a reduction of toxicities were found in the patient group implanted in the later period. A decline in symptoms with follow-up time counteracts this gain of experience and must be considered. Urinary and sexual discomfort was enhanced by dose heterogeneities (e.g., dose covering 10% of the prostate volume, volume covered by 200% of prescription dose). In contrast, rectal toxicities correlated with exposed rectal volumes, especially the rectal volume covered by 100% of the prescription dose. Conclusion: The typical side effects occurring after permanent seed implantation can be reduced by improving the dose distributions. An improvement in dose distributions and a reduction of toxicities were identified with elapsed time between

  2. CT-guided radioactive 125I-seed implantation for the treatment of pancreatic carcinoma: a clinical observation of 19 cases

    International Nuclear Information System (INIS)

    Lu Jian; Zheng Yunfeng; Zhang Huan; Wang Zhongmin; Chen Kemin

    2010-01-01

    Objective: To explore the dynamic changes of serum tumor markers after CT-guided radioactive 125 I-seed implantation treatment in patients with pancreatic carcinoma and to assess the therapeutic effectiveness of 125 I-seed implantation. Methods: CT-guided radioactive 125 I-seed implantation was performed in 19 patients with unresectable advanced pancreatic cancer. Treatment planning system was used to reconstruct 3-dimentional images of the tumor, and the quantity and distribution of 125 I-seeds to be implanted were thus determined. Under CT guidance 125 I-seeds were embedded into pancreatic cancer. Before and after the 125 I-seed implantation the levels of serum tumor markers, including CEA, CA19-9 and CA50, were determined by using radioimmunoassay method. The clinical effects were observed and the therapeutic results were statistically analyzed. Results: The pain stared to be relieved 2 to 5 days after implantation. The total effective rate (CR + PR) at one and three months after treatment was 68.42% (13 /19) and 63.16% (12 /19) respectively. One month after 125 I-seed implantation, the levels of serum CEA, CA19-9 and CA50 were significantly different to that determined before implantation in all cases (P 125 I-seed implantation is a safe and effective interventional treatment for advanced pancreatic cancer with reliable short-term result and remarkable pain-relieving effect. Moreover, this therapy can significantly lower the levels of many serum tumor markers, which play some suggestive roles in evaluating the clinical curativeness. (authors)

  3. Brachytherapy in early prostate cancer--early experience.

    Science.gov (United States)

    Jose, B O; Bailen, J L; Albrink, F H; Steinbock, G S; Cornett, M S; Benson, D C; Schmied, W K; Medley, R N; Spanos, W J; Paris, K J; Koerner, P D; Gatenby, R A; Wilson, D L; Meyer, R

    1999-01-01

    Use of brachytherapy with radioactive seeds in the management of early prostate cancer is commonly used in the United States. The early experience has been reported from the prostate treatment centers in Seattle for the last 10 years. In this manuscript we are reporting our early experience of 150 radioactive seed implantations in early stage prostate cancer using either Iodine 125 or Palladium 103 seeds. The average age of the patient is 66 years and the median Gleason score is 5.4 with a median PSA of 6. A brief description of the evolution of the treatment of prostate cancer as well as the preparation for the seed implantation using the volume study with ultrasound of the prostate, pubic arch study using CT scan of the pelvis and the complete planning using the treatment planning computers are discussed. We also have described the current technique which is used in our experience based on the Seattle guidelines. We plan a follow-up report with the results of the studies with longer follow-up.

  4. Radiation exposure after permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    Cattani, Federica; Vavassori, Andrea; Polo, Alfredo; Rondi, Elena; Cambria, Raffaella; Orecchia, Roberto; Tosi, Giampiero

    2006-01-01

    Background and purpose: Limited information is available on the true radiation exposure and associated risks for the relatives of the patients submitted to prostate brachytherapy with permanent implant of radioactive sources and for any other people coming into contact with them. In order to provide appropriate information, we analyzed the radiation exposure data from 216 prostate cancer patients who underwent 125 I or 103 Pd implants at the European Institute of Oncology of Milan, Italy. Patients and methods: Between October 1999 and October 2004, 216 patients with low risk prostate carcinoma were treated with 125 I (200 patients) or 103 Pd (16 patients) permanent seed implantation. One day after the procedure, radiation exposure measurements around the patients were performed using an ionization chamber survey meter (Victoreen RPO-50) calibrated in dose rate at an accredited calibration center (calibration Centre SIT 104). Results: The mean dose rate at the posterior skin surface (gluteal region) following 125 I implants was 41.3 μSv/h (range: 6.2-99.4 μSv/h) and following 103 Pd implants was 18.9 μSv/h (range 5.0-37.3 μSv/h). The dose rate at 50 cm from the skin decreased to the mean value of 6.4 μSv/h for the 125 I implants and to the mean value of 1.7 μSv/h for the 103 Pd implants. Total times required to reach the annual dose limit (1 mSv/year) recommended for the general population by the European Directive 96/29/Euratom and by the Italian law (Decreto Legislativo 241/2000) at a distance of 50 cm from the posterior skin surface of the implanted patient would be 7.7 and 21.6 days for 125 I and for 103 Pd. Good correlation between the measured dose rates and both the total implanted activity and the distance between the most posteriorly implanted seed and the skin surface of the patients was found. Conclusions: Our data show that the dose rates at 50 cm away from the prostate brachytherapy patients are very low and that the doses possibly absorbed by the

  5. Effect of Foley catheters on seed positions and urethral dose in 125I and 103Pd prostate implants

    International Nuclear Information System (INIS)

    Brezovich, Ivan A.; Pareek, Prem N.; Duan, Jun; Fiveash, John

    2001-01-01

    Purpose: To estimate the perturbation of seed position and urethral dose, subsequent to withdrawal of urethral catheters. Methods and Materials: A mathematical model based on the volume incompressibility of tissues was used to compute seed positions and doses following removal of the Foley. The model assumed that the central axis of the urethra remains stationary, and that prostate tissue and seeds move radially toward the center of the urethra to fill the void left by the catheter. Seed motion has also been measured using transrectal ultrasound. Results: Based on the computations, seeds located originally close to the urethra travel relatively large distances toward the urethra upon Foley removal, whereas seeds located further away move substantially less. This seed motion leads to higher urethral doses than shown in a standard treatment plan. Dose enhancements increase with catheter size, decrease with increasing prostate volume, are more pronounced for 103 Pd than for 125 I, and range between 3.5% and 32.4%. Postimplant dosimetry is equally affected if images are taken with urethral catheters in place, showing lower urethral doses than actually delivered. Preliminary ultrasound based measurements of seed motion agree with the theory. Conclusion: During the implantation procedure, 12 fr or smaller urethral catheters are preferable to larger diameter catheters if urine drainage is sufficient. Treatment planners should avoid planning seeds at 5 mm or closer from the urethra. Special caution is indicated in prostates having about 20 cm 3 or smaller volumes, and when 103 Pd is used. Postimplant dosimetry is susceptible to the same errors

  6. Evaluation of radioactive seeds implantation under PET-CT guidance for the treatment of central lung cancer with obstructive atelectasis

    International Nuclear Information System (INIS)

    Zhou Yi; Jiang Zhongpu; Wang Haiting; Zhang Yanjun; Jiang Qiang; Wang Jun; Ren Lijun; Xie Bin

    2010-01-01

    Objective: To evaluate percutaneous puncturing 125 I seed implantation by using PET-CT guided target localization technique in treating central lung cancer complicated by obstructive pulmonary atelectasis. Methods: A total of 30 patients with suspected central lung cancer complicated by obstructive pulmonary atelectasis on preoperative chest films were enrolled in this study. As no clear distinction existed between the tumor and the atelectatic consolidation shadow on plain chest films, CT scanning was carried out in all patients. If CT scan was still not able to determine the margin of the tumor, an additional PET-CT scanning was adopted. After ascertaining the location of the lung cancer, percutaneous puncturing implantation of 125 I seeds under PET-CT guidance was performed. The clinical data and the therapeutic results were evaluated. Results: A sharp distinction between the tumor and the atelectatic consolidation shadow was demonstrated on PET-CT scans in 21 cases. The mean volume of the targeted lesion reckoned from PET-CT scans was 26 cm 3 , and the 125 I seeds were implanted. The mean volume of the targeted lesion calculated on CT scans was 37 cm 3 . Six months after the treatment, the follow-up CT exam showed that the effective rate was 93% (28/30). The one-year survival rate was 100% . The complications included pneumothorax (n = 8), small amount of hemoptysis (n = 12) and fever (n = 2). No displacement or immigration of the implanted seeds occurred. Conclusion: PET-CT scanning is far superior to conventional CT scanning in determining the target area of the tumor in patients with central lung cancer complicated by obstructive pulmonary atelectasis. (authors)

  7. Automated matching of corresponding seed images of three simulator radiographs to allow 3D triangulation of implanted seeds

    Science.gov (United States)

    Altschuler, Martin D.; Kassaee, Alireza

    1997-02-01

    To match corresponding seed images in different radiographs so that the 3D seed locations can be triangulated automatically and without ambiguity requires (at least) three radiographs taken from different perspectives, and an algorithm that finds the proper permutations of the seed-image indices. Matching corresponding images in only two radiographs introduces inherent ambiguities which can be resolved only with the use of non-positional information obtained with intensive human effort. Matching images in three or more radiographs is an `NP (Non-determinant in Polynomial time)-complete' problem. Although the matching problem is fundamental, current methods for three-radiograph seed-image matching use `local' (seed-by-seed) methods that may lead to incorrect matchings. We describe a permutation-sampling method which not only gives good `global' (full permutation) matches for the NP-complete three-radiograph seed-matching problem, but also determines the reliability of the radiographic data themselves, namely, whether the patient moved in the interval between radiographic perspectives.

  8. On the feasibility of polyurethane based 3D dosimeters with optical CT for dosimetric verification of low energy photon brachytherapy seeds

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, Justus, E-mail: justus.adamson@duke.edu; Yang, Yun; Juang, Titania; Chisholm, Kelsey; Rankine, Leith; Yin, Fang Fang; Oldham, Mark [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Adamovics, John [Department of Chemistry, Rider University, Lawrenceville, New Jersey 08648 (United States)

    2014-07-15

    Purpose: To investigate the feasibility of and challenges yet to be addressed to measure dose from low energy (effective energy <50 keV) brachytherapy sources (Pd-103, Cs-131, and I-125) using polyurethane based 3D dosimeters with optical CT. Methods: The authors' evaluation used the following sources: models 200 (Pd-103), CS-1 Rev2 (Cs-131), and 6711 (I-125). The authors used the Monte Carlo radiation transport code MCNP5, simulations with the ScanSim optical tomography simulation software, and experimental measurements with PRESAGE{sup ®} dosimeters/optical CT to investigate the following: (1) the water equivalency of conventional (density = 1.065 g/cm{sup 3}) and deformable (density = 1.02 g/cm{sup 3}) formulations of polyurethane dosimeters, (2) the scatter conditions necessary to achieve accurate dosimetry for low energy photon seeds, (3) the change in photon energy spectrum within the dosimeter as a function of distance from the source in order to determine potential energy sensitivity effects, (4) the optimal delivered dose to balance optical transmission (per projection) with signal to noise ratio in the reconstructed dose distribution, and (5) the magnitude and characteristics of artifacts due to the presence of a channel in the dosimeter. Monte Carlo simulations were performed using both conventional and deformable dosimeter formulations. For verification, 2.8 Gy at 1 cm was delivered in 92 h using an I-125 source to a PRESAGE{sup ®} dosimeter with conventional formulation and a central channel with 0.0425 cm radius for source placement. The dose distribution was reconstructed with 0.02 and 0.04 cm{sup 3} voxel size using the Duke midsized optical CT scanner (DMOS). Results: While the conventional formulation overattenuates dose from all three sources compared to water, the current deformable formulation has nearly water equivalent attenuation properties for Cs-131 and I-125, while underattenuating for Pd-103. The energy spectrum of each source is

  9. Dosimetry on ocular brachytherapy with ROPES plaque with Iodine-125 and Palladium-103 seeds; Dosimetria em braquiterapia ocular com placa ROPES contendo sementes de iodo-125 e paladium-103

    Energy Technology Data Exchange (ETDEWEB)

    Mourao, Arnaldo P. [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET/MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar], e-mail: aprata@des.cefetmg.br; Campos, Tarcisio P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares

    2010-03-15

    Radiotherapy is an alternative to ocular enucleation. However, the irradiation of ocular region can bring deleterious effects due to the high doses, mainly in the lens, retina and in the bone structures in growth phase. Brachytherapy instead of teletherapy looks for departuring absorbed doses in tumor minimizing doses in the lens and the adjacent tissues of the eyeball (orbital region), avoiding deleterious effects. Thus, a three-dimensional computational model of ocular area was developed to simulate orbital irradiation with ROPES ophthalmologic plaque placed on the sclera surface filled to ten iodine-125 seeds, and palladium-103 seeds. Simulations are performed on the MCNP5 code. The computational simulation allows evaluating how the dose rates are spatially distributed in the orbital volume. The results are normalized to 100% at the maximum dose on the tumor base, and by the applied source activity. The maximum dose is found onto the eyeball, in the vitreous. The present model represents an advance in simulating and predicting absorbed dose on ocular brachytherapy. (author)

  10. SU-F-BRA-04: Prostate HDR Brachytherapy with Multichannel Robotic System

    International Nuclear Information System (INIS)

    Joseph, F Maria; Podder, T; Yu, Y

    2015-01-01

    Purpose: High-dose-rate (HDR) brachytherapy is gradually becoming popular in treating patients with prostate cancers. However, placement of the HDR needles at desired locations into the patient is challenging. Application of robotic system may improve the accuracy of the clinical procedure. This experimental study is to evaluate the feasibility of using a multichannel robotic system for prostate HDR brachytherapy. Methods: In this experimental study, the robotic system employed was a 6-DOF Multichannel Image-guided Robotic Assistant for Brachytherapy (MIRAB), which was designed and fabricated for prostate seed implantation. The MIRAB has the provision of rotating 16 needles while inserting them. Ten prostate HDR brachytherapy needles were simultaneously inserted using MIRAB into a commercially available prostate phantom. After inserting the needles into the prostate phantom at desired locations, 2mm thick CT slices were obtained for dosimetric planning. HDR plan was generated using Oncetra planning system with a total prescription dose of 34Gy in 4 fractions. Plan quality was evaluated considering dose coverage to prostate and planning target volume (PTV), with 3mm margin around prostate, as well as the dose limit to the organs at risk (OARs) following the American Brachytherapy Society (ABS) guidelines. Results: From the CT scan, it is observed that the needles were inserted straight into the desired locations and they were adequately spaced and distributed for a clinically acceptable HDR plan. Coverage to PTV and prostate were about 91% (V100= 91%) and 96% (V100=96%), respectively. Dose to 1cc of urethra, rectum, and bladder were within the ABS specified limits. Conclusion: The MIRAB was able to insert multiple needles simultaneously into the prostate precisely. By controlling the MIRAB to insert all the ten utilized needles into the prostate phantom, we could achieve the robotic HDR brachytherapy successfully. Further study for assessing the system

  11. Can the prostate brachytherapy by permanent implants represent an alternative to external radiotherapy for the localised prostate cancers with intermediary risk?

    International Nuclear Information System (INIS)

    Farnault, B.; Duberge, T.; Salem, N.; Boher, J.M.; Gravis, G.; Bladou, F.; Jochen, W.; Resbeut, M.

    2009-01-01

    Purpose: the prostate brachytherapy stands out as treatment of low risk prostate cancers, but the data concerning its use as exclusive treatment of intermediary risk prostate cancer are rare. We present a retrospective analysis of intermediary risk prostate cancers which treatment was either an external conformal radiotherapy or an exclusive brachytherapy. conclusion: In this mono centric series, the brachytherapy brings excellent results in comparison with external conformal radiotherapy with dose escalation and could be proposed as alternative to patients suffering of intermediary risk prostate cancer. (N.C.)

  12. Spectroscopic characterization of low dose rate brachytherapy sources

    Science.gov (United States)

    Beach, Stephen M.

    The low dose rate (LDR) brachytherapy seeds employed in permanent radioactive-source implant treatments usually use one of two radionuclides, 125I or 103Pd. The theoretically expected source spectroscopic output from these sources can be obtained via Monte Carlo calculation based upon seed dimensions and materials as well as the bare-source photon emissions for that specific radionuclide. However the discrepancies resulting from inconsistent manufacturing of sources in comparison to each other within model groups and simplified Monte Carlo calculational geometries ultimately result in undesirably large uncertainties in the Monte Carlo calculated values. This dissertation describes experimentally attained spectroscopic outputs of the clinically used brachytherapy sources in air and in liquid water. Such knowledge can then be applied to characterize these sources by a more fundamental and metro logically-pure classification, that of energy-based dosimetry. The spectroscopic results contained within this dissertation can be utilized in the verification and benchmarking of Monte Carlo calculational models of these brachytherapy sources. This body of work was undertaken to establish a usable spectroscopy system and analysis methods for the meaningful study of LDR brachytherapy seeds. The development of a correction algorithm and the analysis of the resultant spectroscopic measurements are presented. The characterization of the spectrometer and the subsequent deconvolution of the measured spectrum to obtain the true spectrum free of any perturbations caused by the spectrometer itself is an important contribution of this work. The approach of spectroscopic deconvolution that was applied in this work is derived in detail and it is applied to the physical measurements. In addition, the spectroscopically based analogs to the LDR dosimetry parameters that are currently employed are detailed, as well as the development of the theory and measurement methods to arrive at these

  13. Analysis of prostate-specific antigen bounce after I125 permanent seed implant for localised prostate cancer

    International Nuclear Information System (INIS)

    Mitchell, Darren M.; Swindell, Ric; Elliott, Tony; Wylie, James P.; Taylor, Cathy M.; Logue, John P.

    2008-01-01

    Background and purpose: To report on the incidence of benign prostate-specific antigen bounce following permanent I 125 prostate brachytherapy, to describe the associations in our population and review the relationship of bounce to subsequent biochemical failure. Materials and methods: From February 2000 to May 2005, 374 patients with localised prostate cancer were treated with I 125 permanent prostate brachytherapy at a single institution. A prospectively collected database was used to identify cases of prostate-specific antigen (PSA) bounce, defined as a rise of ≥0.2 ng/ml above an initial PSA nadir with subsequent decline to or below that nadir without treatment. The patients who received neo-adjuvant or adjuvant hormone manipulation were excluded. Biochemical failure was determined using the both the ASTRO consensus definition and Phoenix (nadir +2 ng/mL) definition. Results: Two hundred and five patients were identified with a median follow-up of 45 months (24-85). PSA bounce was noted in 79 (37%) men, occurring at a median of 14.8 months (1.7-40.6) following implant. The median peak PSA was 1.8 ng/ml (0.4-7.4) with a bounce magnitude of 0.91 ng/ml (0.2-5.8). When pre- and post-implant factors were assessed for association to bounce, only younger age was statistically significant (p = 0.002). The threshold for biochemical failure as defined by the ASTRO consensus definition (1997) was met in 4 (5%) patients after experiencing bounce as opposed to 19 (15%) non-bounce patients (p = 0.01). The threshold for Phoenix (nadir +2 ng/mL) was met in 6 (7.5%) patients following bounce versus 22 (17%) of non-bounce patients (p = 0.003). Both definitions are prone to false positive calls during bounce. Median PSA velocity during the bounce was 0.08 ng/mL/month (0.02-0.98) and was statistically significantly lower than the median velocity prior to the Phoenix biochemical failure at 0.28 ng/mL/month (0.07-2.04) (p = 0.0005). Conclusion: PSA bounce is a common finding in

  14. Comparison of Dosimetric and Biologic Effective Dose Parameters for Prostate and Urethra Using 131Cs and 125I for Prostate Permanent Implant Brachytherapy

    International Nuclear Information System (INIS)

    Sahgal, Arjun; Jabbari, Siavash; Chen, Josephine; Pickett, Barbie; Roach, Mack; Weinberg, Vivian; Hsu, I-C.; Pouliot, Jean

    2008-01-01

    Purpose: To compare the urethral and prostate absolute and biologic effective doses (BEDs) for 131 Cs and 125 I prostate permanent implant brachytherapy (PPI). Methods and Materials: Eight previously implanted manually planned 125 I PPI patients were replanned manually with 131 Cs, and re-planned using Inverse Planning Simulated Annealing. 131 Cs activity and the prescribed dose (115 Gy) were determined from that recommended by IsoRay. The BED was calculated for the prostate and urethra using an α/β ratio of 2 and was also calculated for the prostate using an α/β ratio of 6 and a urethral α/β ratio of 2. The primary endpoints of this study were the prostate D 90 BED (pD 90 BED) and urethral D 30 BED normalized to the maximal potential prostate D 90 BED (nuD 30 BED). Results: The manual plan comparison (α/β = 2) yielded no significant difference in the prostate D 90 BED (median, 192 Gy 2 for both isotopes). No significant difference was observed for the nuD 30 BED (median, 199 Gy 2 and 202 Gy 2 for 125 I and 131 Cs, respectively). For the inverse planning simulated annealing plan comparisons (α/β 2), the prostate D 90 BED was significantly lower with 131 Cs than with 125 I (median, 177 Gy 2 vs. 187 Gy 2 , respectively; p = 0.01). However, the nuD 30 BED was significantly greater with 131 Cs than with 125 I (median, 192 Gy 2 vs. 189 Gy 2 , respectively; p = 0.01). Both the manual and the inverse planning simulated annealing plans resulted in a significantly lower prostate D 90 BED (p = 0.01) and significantly greater nuD 30 BED for 131 Cs (p = 0.01), compared with 125 I, when the prostate α/β ratio was 6 and the urethral α/β ratio was 2. Conclusion: This report highlights the controversy in comparing the dose to both the prostate and the organs at risk with different radionuclides

  15. Dose heterogeneity correction for low-energy brachytherapy sources using dual-energy CT images

    Science.gov (United States)

    Mashouf, S.; Lechtman, E.; Lai, P.; Keller, B. M.; Karotki, A.; Beachey, D. J.; Pignol, J. P.

    2014-09-01

    Permanent seed implant brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose around brachytherapy sources is based on the AAPM TG-43 formalism, which generates the dose in a homogeneous water medium. Recently, AAPM TG-186 emphasized the importance of accounting for tissue heterogeneities. We have previously reported on a methodology where the absorbed dose in tissue can be obtained by multiplying the dose, calculated by the TG-43 formalism, by an inhomogeneity correction factor (ICF). In this work we make use of dual energy CT (DECT) images to extract ICF parameters. The advantage of DECT over conventional CT is that it eliminates the need for tissue segmentation as well as assignment of population based atomic compositions. DECT images of a heterogeneous phantom were acquired and the dose was calculated using both TG-43 and TG-43 × \\text{ICF} formalisms. The results were compared to experimental measurements using Gafchromic films in the mid-plane of the phantom. For a seed implant configuration of 8 seeds spaced 1.5 cm apart in a cubic structure, the gamma passing score for 2%/2 mm criteria improved from 40.8% to 90.5% when ICF was applied to TG-43 dose distributions.

  16. Evolution of brachytherapy for prostate carcinoma

    International Nuclear Information System (INIS)

    Qin Lan

    2005-01-01

    Brachytherapy is one of the most main management to prostate carcinoma. This method has been rapidly accepted in clinical application since it is a convenient, little-traumatic, and outpatient therapy. With the development of techniques of production of radio-seeds, imaging modality and three-dimensional radiotherapy plan system, brachytherapy has been made a virtually progress in improving curative-effect and reducing damage to surrounding normal tissue. (authors)

  17. Moving toward focal therapy in prostate cancer: dual-isotope permanent seed implants as a possible solution.

    Science.gov (United States)

    Todor, Dorin A; Barani, Igor J; Lin, Peck-Sun; Anscher, Mitchell S

    2011-09-01

    To compare the ability of single- and dual-isotope prostate seed implants to escalate biologically effective dose (BED) to foci of disease while reducing prescription dose to the prostate. Nine plans, using 125I, 103Pd, and 131Cs alone and in combination were created retrospectively for 2 patients. Ultrasound and MRI/MRS datasets were used for treatment planning. Voxel-by-voxel BED was calculated for single- and dual-isotope plans. Equivalent uniform BED (EUBED) was used to compare plans. The MRS-positive planning target volumes (PTVi) were delineated along with PTV (prostate+5 mm), rectum, and urethra. Single-isotope implants, prescribed to conventional doses, were generated to achieve good PTV coverage. The PTVi were prospectively used to generate implants using mixtures of isotopes. For mixed-radioisotope implants, we also explored the impact on EUBED of lowering prescription doses by 15%. The EUBED of PTVi in the setting of primary 125I implant increased 20-66% when 103Pd and 131Cs were used compared with 125I boost. Decreasing prescription dose by 15% in mixed-isotope implants results in a potential 10% reduction in urethral EUBED with preservation of PTV coverage while still boosting PTVi (up to 80%). When radiobiologic parameters corresponding to more-aggressive disease are assigned to foci, faster-decaying isotopes used in mixed implants have the potential to preserve the equivalent biological effect of mono-isotope implants considering less-aggressive disease distributed in the entire prostate. This is a hypothesis-generating study proposing a treatment paradigm that could be the middle ground between whole-gland irradiation and focal-only treatment. The use of two isotopes concurrent with decreasing the minimal peripheral dose is shown to increase EUBED of selected subvolumes while preserving the therapeutic effect at the level of the gland. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Three-dimensional viewing and dosimetric calculations of Au-198 implants of the prostate

    International Nuclear Information System (INIS)

    Avizonis, V.N.; Anderson, K.M.; Jani, S.K.; Hussey, D.H.

    1991-01-01

    Dose gradients for brachytherapy vary considerably in three dimensions, which complicates conventional two-dimensional dosimetry. Recent developments in computer graphics technology have enabled visualization of anatomy and radiation doses in three dimensions. The objective of this paper is to develop a three-dimensional viewing and dosimetry program for brachytherapy and to test this system in phantoms and in patients undergoing Au-198 implants in the prostate. Three-dimensional computer algorithms for the author's Silicon Graphics supercomputing workstation were developed, tested, and modified on the basis of studies in phantoms and patients. Studies were performed on phantoms of known dimensions and gold seeds in known locations to assess the accuracy of volume reconstruction, seed placement, and isodose distribution. Isodose curves generated with the three-dimensional system were compared with those generated by a Theratronics Treatment Planning Computer using conventional methods. Twenty patients with permanent Au-198 interstitial implants in the prostate were similarly studied

  19. Dosimetry consequences of the accuracy at the position of the seeds in a seeds implant of I-125 in prostate; Consecuencias dosimetricas de la exactitud en la posicion de las semilla en un implante de semillas de I-125 en prostata

    Energy Technology Data Exchange (ETDEWEB)

    Luquero Llopis, N.; Ferrer Gracia, C.; Huertas Martinez, C.; Huerga Cabrerizo, C.; Corredoira Silva, E.; Serrada Hierro, A.

    2013-07-01

    The quality control of equipment used to carry out implants of seeds of low rate in prostate, van destined to watch, the activity of seeds and the calculation of planning both positioning them on the inside of the patient. The objective of this work is, using the Nucletron Spot Pro and SeedSelectron, rating dosimetry possible consequences related to the position of the seeds. (Author)

  20. Needle displacement during HDR brachytherapy in the treatment of prostate cancer

    International Nuclear Information System (INIS)

    Damore, Steven J.; Syed, A.M. Nisar; Puthawala, Ajmel A.; Sharma, Anil

    2000-01-01

    Purpose: We used clinical patient data to examine implant displacement between high dose rate (HDR) brachytherapy fractions for prostate cancer to determine its impact on treatment delivery. Materials and Methods: We analyzed the verification films taken prior to each fraction for 96 consecutive patients treated with HDR brachytherapy boosts as part of their radiation therapy for definitive treatment of organ-confined prostate cancer at our institution. Patients were treated with 18-24 Gy in 4 fractions of HDR delivered in 40 hours followed by 36-39.6 Gy external beam radiation to the prostate. We determined the mean and maximum displacement distances of marker seeds placed in the prostate and of the implanted needles between HDR fractions. Results: Mean and maximum displacement distances between fractions were documented up to 7.6 mm and 28.5 mm, respectively, for the implant needles and 3.6 mm and 11.4 mm, respectively, for the gold marker seeds. All displacement of implant needles occurred in the caudal direction. At least 1 cm caudal displacement of needles occurred prior to 15.5% all fractions. Manual adjustment of needles was required prior to 15% of fractions, and adjustment of the CLP only was required in 24%. Most of the displacement for both the marker seeds and needles occurred between the first and second fractions. Conclusions: There is significant caudal displacement of interstitial implant needles between HDR fractions in our prostate cancer patients. Obtaining verification films and making adjustments in the treatment volume prior to each fraction is necessary to avoid significant inaccuracies in treatment delivery

  1. Interstitial prostate brachytherapy. LDR-PDR-HDR

    International Nuclear Information System (INIS)

    Kovacs, Gyoergy; Hoskin, Peter

    2013-01-01

    The first comprehensive overview of interstitial brachytherapy for the management of local or locally advanced prostate cancer. Written by an interdisciplinary team who have been responsible for the successful GEC-ESTRO/EAU Teaching Course. Discusses in detail patient selection, the results of different methods, the role of imaging, and medical physics issues. Prostate brachytherapy has been the subject of heated debate among surgeons and the proponents of the various brachytherapy methods. This very first interdisciplinary book on the subject provides a comprehensive overview of innovations in low dose rate (LDR), high dose rate (HDR), and pulsed dose rate (PDR) interstitial brachytherapy for the management of local or locally advanced prostate cancer. In addition to detailed chapters on patient selection and the use of imaging in diagnostics, treatment guidance, and implantation control, background chapters are included on related medical physics issues such as treatment planning and quality assurance. The results obtained with the different treatment options and the difficult task of salvage treatment are fully discussed. All chapters have been written by internationally recognized experts in their fields who for more than a decade have formed the teaching staff responsible for the successful GEC-ESTRO/EAU Prostate Brachytherapy Teaching Course. This book will be invaluable in informing residents and others of the scientific background and potential of modern prostate brachytherapy. It will also prove a useful source of up-to-date information for those who specialize in prostate brachytherapy or intend to start an interstitial brachytherapy service.

  2. Radiation Exposure Reduction to Brachytherapy Staff By Using Remote Afterloading

    International Nuclear Information System (INIS)

    Attalla, E.M.

    2005-01-01

    The radiation exposures to the personnel staff from patients with brachytherapy implants in a brachytherapy service were reviewed. Exposures to the brachytherapy personnel, as determined by Thermoluminescence Dosimeter (TLD) monitors, indicates a four-fold reduction in exposures after the implantation of the use of remote afterloading devices. Quarterly TLD monitor data for seven quarters prior to the use of remote afterloading devices demonstrate an average projected annual dose equivalent to the brachytherapy staff of 2543 Μ Sv. After the implantation of the remote afterloading devices, the quarterly TLD monitor data indicate an average dose equivalent per person of 153 Μ Sv. This is 76% reduction in exposure to brachytherapy personnel with the use of these devices

  3. The role of endorectal coil MRI in patient selection and treatment planning for prostate seed implants

    International Nuclear Information System (INIS)

    Clarke, Daniel H.; Banks, Stephen J.; Wiederhorn, A. Roger; Klousia, John W.; Lissy, Jeanne M.; Miller, Michelle; Able, Arnold M.; Artiles, Carlos; Hindle, William V.; Blair, Deborah N.; Houk, Russell R.; Sheridan, Michael J.

    2002-01-01

    Purpose: To assess the role of endorectal coil magnetic resonance imaging (MRI) staging for patients undergoing seed implantation (SI) with or without external beam radiotherapy (EBRT). Methods and Materials: Between October 1994 and December 1998, 390 patients underwent prostate SI (98% Pd-103, 2% I-125). Seventy-six percent of patients had a prostate serum antigen (PSA) 20. Ten percent of patients had a Gleason score (GS) of 4-5, 54% had GS 6, 29% had GS 7, and 7% had GS ≥ 8. Monotherapy was employed in 46% of patients, and the remaining 54% received combined EBRT and SI. Three hundred twenty-seven were staged by high-resolution phased array pelvic coil, or in most cases, an endorectal coil MRI. The MRI findings were used to guide stage-appropriate treatment recommendations, and to assist in the preplanning and optimization of seed distributions. The criteria utilized to determine MRI-based stage were founded on the reported literature from the University of Pennsylvania. All MRI studies were reviewed by C.A., D.B., or W.H., who were unaware of clinical stage at the time of their review. The biopsy report was available to them as the only clinical correlate. Results: Of the 327 patients staged by MRI, 70% were upstaged from the digital rectal examination-based clinical stage; 26% of T 1 , T 2 patients were upstaged to T 3 . Perineural invasion and the percentage of positive cores predicted for T 3 MRI stage (p 3 intermediate-risk group patients treated by combined therapy with a previous study of T 3 intermediate-risk group treated by radical prostatectomy (RP) at the University of Pennsylvania. Our 36-month PSA FFP was 94% compared with 21% for the previous study's RP patients. Conclusion: MRI is a valuable staging procedure for prostate cancer patients treated by SI. PSA FFP results appear to be improved by MRI staging. MRI T 3 disease can be treated more effectively by SI + EBRT than by RP

  4. Study and methodologies for fixing epoxy resin in radioactive sources used for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Bruna T.; Rostelato, Maria E.C.M.; Souza, Carla D.; Tozetti, Cíntia A.; Zeituni, Carlos A.; Nogueira, Beatriz R.; Silva, José T.; Júnior, Dib K.; Fernandes, Vagner; Souza, Raquel V.; Abreu, Rodrigo T., E-mail: bteigarodrigues@gmail.com, E-mail: elisaros@ipen.br, E-mail: carladdsouza@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade de São Paulo (USP), SP (Brazil)

    2017-07-01

    The World Health Organization (WHO) estimates that the number of new cancer cases worldwide will reach 15 million by 2020. The disease is already the second leading cause of death worldwide, being behind only cardiovascular disease. It is unquestionable that it is a public health problem, especially among developing countries. Prostate cancer is the most common among men, approximately 28.6%. The choice of type of treatment for prostate cancer should consider several factors such as: tumor size and extent, apparent aggressiveness (pathological characteristics), age, health. Among the methods applied, brachytherapy has been used in the initial and intermediate stages of the disease. Brachytherapy is a safe and effective treatment for localized prostate cancer. Brachytherapy is a form of radiotherapy in which radioactive seeds are placed in contact with or within the organ being treated. This technique allows a large dose of radiation to be released only on the target tumor that protects healthy surrounding tissues. Sources may have different shapes and sizes, but the one used for prostate cancer is usually 4.5 mm in length and 0.8 mm in diameter. About 80 to 120 seeds can be used per patient. Iodine-125 is the radioisotope most used in brachytherapy of the prostate, it emits 35,49keV X-rays in 100% of the decays, with average energy of 29 keV. The treatment of prostate cancer with permanent implantation of iodine-125 seeds has grown dramatically in the world in recent years. Most patients can return to normal life within three days with little or no pain. (author)

  5. Study and methodologies for fixing epoxy resin in radioactive sources used for brachytherapy

    International Nuclear Information System (INIS)

    Rodrigues, Bruna T.; Rostelato, Maria E.C.M.; Souza, Carla D.; Tozetti, Cíntia A.; Zeituni, Carlos A.; Nogueira, Beatriz R.; Silva, José T.; Júnior, Dib K.; Fernandes, Vagner; Souza, Raquel V.; Abreu, Rodrigo T.

    2017-01-01

    The World Health Organization (WHO) estimates that the number of new cancer cases worldwide will reach 15 million by 2020. The disease is already the second leading cause of death worldwide, being behind only cardiovascular disease. It is unquestionable that it is a public health problem, especially among developing countries. Prostate cancer is the most common among men, approximately 28.6%. The choice of type of treatment for prostate cancer should consider several factors such as: tumor size and extent, apparent aggressiveness (pathological characteristics), age, health. Among the methods applied, brachytherapy has been used in the initial and intermediate stages of the disease. Brachytherapy is a safe and effective treatment for localized prostate cancer. Brachytherapy is a form of radiotherapy in which radioactive seeds are placed in contact with or within the organ being treated. This technique allows a large dose of radiation to be released only on the target tumor that protects healthy surrounding tissues. Sources may have different shapes and sizes, but the one used for prostate cancer is usually 4.5 mm in length and 0.8 mm in diameter. About 80 to 120 seeds can be used per patient. Iodine-125 is the radioisotope most used in brachytherapy of the prostate, it emits 35,49keV X-rays in 100% of the decays, with average energy of 29 keV. The treatment of prostate cancer with permanent implantation of iodine-125 seeds has grown dramatically in the world in recent years. Most patients can return to normal life within three days with little or no pain. (author)

  6. The biocompatibility of titanium cardiovascular devices seeded with autologous blood-derived endothelial progenitor cells: EPC-seeded antithrombotic Ti implants.

    Science.gov (United States)

    Achneck, Hardean E; Jamiolkowski, Ryan M; Jantzen, Alexandra E; Haseltine, Justin M; Lane, Whitney O; Huang, Jessica K; Galinat, Lauren J; Serpe, Michael J; Lin, Fu-Hsiung; Li, Madison; Parikh, Amar; Ma, Liqiao; Chen, Tao; Sileshi, Bantayehu; Milano, Carmelo A; Wallace, Charles S; Stabler, Thomas V; Allen, Jason D; Truskey, George A; Lawson, Jeffrey H

    2011-01-01

    Implantable and extracorporeal cardiovascular devices are commonly made from titanium (Ti) (e.g. Ti-coated Nitinol stents and mechanical circulatory assist devices). Endothelializing the blood-contacting Ti surfaces of these devices would provide them with an antithrombogenic coating that mimics the native lining of blood vessels and the heart. We evaluated the viability and adherence of peripheral blood-derived porcine endothelial progenitor cells (EPCs), seeded onto thin Ti layers on glass slides under static conditions and after exposure to fluid shear stresses. EPCs attached and grew to confluence on Ti in serum-free medium, without preadsorption of proteins. After attachment to Ti for 15 min, less than 5% of the cells detached at a shear stress of 100 dyne / cm(2). Confluent monolayers of EPCs on smooth Ti surfaces (Rq of 10 nm), exposed to 15 or 100 dyne/cm(2) for 48 h, aligned and elongated in the direction of flow and produced nitric oxide dependent on the level of shear stress. EPC-coated Ti surfaces had dramatically reduced platelet adhesion when compared to uncoated Ti surfaces. These results indicate that peripheral blood-derived EPCs adhere and function normally on Ti surfaces. Therefore EPCs may be used to seed cardiovascular devices prior to implantation to ameliorate platelet activation and thrombus formation. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Three-dimensional tomosynthetic image restoration for brachytherapy source localization

    International Nuclear Information System (INIS)

    Persons, Timothy M.

    2001-01-01

    Tomosynthetic image reconstruction allows for the production of a virtually infinite number of slices from a finite number of projection views of a subject. If the reconstructed image volume is viewed in toto, and the three-dimensional (3D) impulse response is accurately known, then it is possible to solve the inverse problem (deconvolution) using canonical image restoration methods (such as Wiener filtering or solution by conjugate gradient least squares iteration) by extension to three dimensions in either the spatial or the frequency domains. This dissertation presents modified direct and iterative restoration methods for solving the inverse tomosynthetic imaging problem in 3D. The significant blur artifact that is common to tomosynthetic reconstructions is deconvolved by solving for the entire 3D image at once. The 3D impulse response is computed analytically using a fiducial reference schema as realized in a robust, self-calibrating solution to generalized tomosynthesis. 3D modulation transfer function analysis is used to characterize the tomosynthetic resolution of the 3D reconstructions. The relevant clinical application of these methods is 3D imaging for brachytherapy source localization. Conventional localization schemes for brachytherapy implants using orthogonal or stereoscopic projection radiographs suffer from scaling distortions and poor visibility of implanted seeds, resulting in compromised source tracking (reported errors: 2-4 mm) and dosimetric inaccuracy. 3D image reconstruction (using a well-chosen projection sampling scheme) and restoration of a prostate brachytherapy phantom is used for testi