The American Brachytherapy Society prostate brachytherapy LDR/HDR simulation workshops: Hands-on, step-by-step training in the process of quality assurance (original) (raw)
Related papers
International Journal of Radiation Oncology Biology Physics, 2016
With 73.7% of academic practices performing 12 brachytherapy implants per year, 24.8% performing 13 to 53 cases, and only 1.5% performing 53 cases per year, the question becomes whether academic training practices will have the ability to adequately teach future residents to perform prostate brachytherapy. Given these concerning trends, it must be determined how to reverse this trend to ensure this treatment modality is not lost in the future. Purpose: The use of prostate brachytherapy has continued to decline in the United States. We examined the national practice patterns of both academic and nonacademic practices performing prostate brachytherapy by case volume per year to further characterize the decline and postulate the effect this trend might have on training the next generation of residents. Methods and Materials: Men diagnosed with prostate cancer who had undergone radiation therapy in 2004 to 2012 were identified. The annual brachytherapy case volume at each facility was determined and further categorized into 12 cases per year (ie, an average of 1 cases per month), 13 to 52 cases per year, and 53 cases per year (ie, an average of 1 cases per week) in academic practices versus nonacademic practices. Results: In 2004 to 2012, academic practices performing an average of 1 brachytherapy cases per month increased from 56.4% to 73.7%. In nonacademic practices, this percentage increased from 60.2% to 77.4% (P<.0001 for both). Practices performing an average of 1 cases per week decreased among both academic practices (from 6.7% to 1.5%) and nonacademic practices (from 4.5% to 2.7%). Conclusions: Both academic and nonacademic radiation oncology practices have demonstrated a significant reduction in the use of prostate brachytherapy from 2004 to 2012. With the case volume continuing to decline, it is unclear whether we are prepared to train the next generation of residents in this critical modality.
Medical Physics, 1999
There is now considerable evidence to suggest that technical innovations, 3D image-based planning, template guidance, computerized dosimetry analysis and improved quality assurance practice have converged in synergy in modern prostate brachytherapy, which promise to lead to increased tumor control and decreased toxicity. A substantial part of the medical physicist's contribution to this multi-disciplinary modality has a direct impact on the factors that may singly or jointly determine the treatment outcome. It is therefore of paramount importance for the medical physics community to establish a uniform standard of practice for prostate brachytherapy physics, so that the therapeutic potential of the modality can be maximally and consistently realized in the wider healthcare community. A recent survey in the U.S. for prostate brachytherapy revealed alarming variance in the pattern of practice in physics and dosimetry, particularly in regard to dose calculation, seed assay and time/method of postimplant imaging. Because of the large number of start-up programs at this time, it is essential that the roles and responsibilities of the medical physicist be clearly defined, consistent with the pivotal nature of the clinical physics component in assuring the ultimate success of prostate brachytherapy. It was against this background that the Radiation Therapy Committee of the American Association of Physicists in Medicine formed Task Group No. 64, which was charged ͑1͒ to review the current techniques in prostate seed implant brachytherapy, ͑2͒ to summarize the present knowledge in treatment planning, dose specification and reporting, ͑3͒ to recommend practical guidelines for the clinical medical physicist, and ͑4͒ to identify issues for future investigation.
Initial analysis of Pro-Qura: A multi-institutional database of prostate brachytherapy dosimetry
Brachytherapy, 2007
The study aimed to analyze the Pro-Qura database in terms of patient implant sequence number for each institution to determine evidence for a dosimetric learning curve. METHODS AND MATERIALS: In the Pro-Qura database, 2833 of a total of 4614 postplans from 57 brachytherapists were analyzed for evidence of a dosimetric learning curve. The median time between implant and postimplant CT scan was 30 days. I-125 was used in 2123 patients (1687 monotherapy and 536 boost) and Pd-103 in 710 patients (367 monotherapy and 343 boost). Preimplant prostate volume was 35.3 and 32.9 cm 3 in the I-125 and Pd-103 cohorts, respectively. The mean I-125 seed activity was 0.32 and 0.26 mCi for monotherapy and boost, whereas for Pd-103 the mean seed activity was 1.59 and 1.27 mCi, respectively. Postimplant dosimetry was performed in a standardized fashion by overlaying the preimplant ultrasound and the postimplant CT scan. Criteria for implant adequacy included a D 90 O90% and a V 100 O80% for both isotopes. An adequate V 150 was defined as !60% for I-125 and !75% for Pd-103. RESULTS: The mean V 100 and D 90 were 88.9% and 101.9% of prescription dose, respectively. When analyzed in terms of patient sequence number for each institution, the mean V 100 for the first 10 patients was 87.4% and increased to 88.6% for patients 11e20 ( p 5 0.036). Similarly, the mean D 90 for the first 10 patients was 98.9%, whereas for the second cohort of 10 patients the mean D 90 increased to 102.2% ( p 5 0.001). In terms of mean V 100 and D 90 , there was minimal further change for subsequent 10 patient institutional groupings of patient sequence numbers. For the first 10 cases, 27.2% were deemed ''too cool'' (V 100 !80% and/or D 90 !90%). Approximately 16% of all implants were deemed ''too hot'' (D 90 O140% or V 150 O60% for I-125 or O75% for Pd-103). CONCLUSIONS: Although a learning curve exists for prostate brachytherapy, high-quality brachytherapy is achievable in approximately 75e80% of patients treated at community centers.
Clinical use of a digital simulator for rapid setup verification in high dose rate brachytherapy
International Journal of Radiation Oncology*Biology*Physics, 1995
Purpose: Fractionated high dose rate (HDR) brachytherapy provides a number of technical advantages over conventional implant therapy in that (a) it can be carried out on an outpatient basis, (b) personnel exposure is reduced to insignificant levels, and (c) patient motion during bradiation is minimized, resulting in a more accurate delivery of the planned radiation dose distribution to the target and critical structures. The patient discomfort associated with the repeated applicator insertions and/or treatment setups can be belay to the extent that the setup time is held to a ~nim~. Thii work describes the use of a prototype digital simuiator to obtain fast, hi~-qu~~ digital images for rapid setup verigcation. Methods and Mater&Is: The digital imaging system of the prototype simulator consists of a charge-coupled device (CCD) camera, which views the x-ray image optically transmitted from a conventional phosphor screen. Treatment is carried out with a remote afterloading HDR unit hnmediately after setup verification with the patient on the simulator stretcher. The high-resolution digital images are processed and displayed in about 5 s, as opposed to a minimum of approximately 2 mht for film. Results: The imaging system has been evaluated for a variety of implant types, both intracavitary and @%%ial.
Brachytherapy, 2019
PURPOSE: Permanent implant prostate brachytherapy plays an important role in prostate cancer treatment, but dose evaluations typically follow the water-based TG-43 formalism, ignoring patient anatomy and interseed attenuation. The purpose of this study is to investigate advanced TG-186 model-based dose calculations via retrospective dosimetric and radiobiological analysis for a new patient cohort. METHODS AND MATERIALS: A cohort of 155 patients treated with permanent implant prostate brachytherapy from The Ottawa Hospital Cancer Centre is considered. Monte Carlo (MC) dose calculations are performed using tissue-based virtual patient models. Doseevolume histogram (DVH) metrics (target, organs at risk) are extracted from 3D dose distributions and compared with those from calculations under TG-43 assumptions (TG43). Equivalent uniform biologically effective dose and tumor control probability are calculated. RESULTS: For the target, D 90 (V 100) is 136.7 AE 20.6 Gy (85.8% AE 7.8%) for TG43 and 132.8 AE 20.1 Gy (84.1% AE 8.2%) for MC; D 90 is 3.0% AE 1.1% lower for MC than TG43. For organs at risk, MC D 1cc 5 104.4 AE 27.4 Gy (TG43: 106.3 AE 28.3 Gy) for rectum and 80.8 AE 29.7 Gy (TG43: 78.4 AE 28.4 Gy) for bladder; D 1cc 5 185.9 AE 30.2 Gy (TG43: 191.1 AE 32.0 Gy) for urethra. Equivalent uniform biologically effective dose and tumor control probability are generally lower when evaluated using MC doses. The largest dosimetric and radiobiological discrepancies between TG43 and MC are for patients with intraprostatic calcifications, for whom there are low doses (cold spots) in the vicinity of calcifications within the target, identified with MC but not TG43. CONCLUSIONS: DVH metrics and radiobiological indices evaluated with TG43 are systematically inaccurate by upward of several percent compared with MC patient-specific models. Mean cohort DVH metrics and their MC:TG43 variances are sensitive to patient cohort and clinical practice, underlining the importance of further retrospective MC studies toward widespread clinical adoption of advanced model-based dose calculations.
Brachytherapy, 2013
We report on quality of dose delivery to target and normal tissues from low-dose-rate prostate brachytherapy using postimplantation dosimetric evaluations from a random sample of U.S. patients. METHODS AND MATERIALS: Nonmetastatic prostate cancer patients treated with external beam radiotherapy or brachytherapy in 2007 were randomly sampled from radiation oncology facilities nationwide. Of 414 prostate cancer cases from 45 institutions, 86 received low-dose-rate brachytherapy. We collected the 30-day postimplantation CT images of these patients and 10 test cases from two other institutions. Scans were downloaded into a treatment planning system and prostate/ rectal contours were redrawn. Dosimetric outcomes were reanalyzed and compared with calculated outcomes from treating institutions. RESULTS: Median prostate volume was 33.4 cm 3 . Reevaluated median V 100 , D 90 , and V 150 were 91.1% (range, 45.5e99.8%), 101.7% (range, 59.6e145.9%), and 53.9% (range, 15.7e88.4%), respectively. Low gland coverage included 27 patients (39%) with a D 90 lower than 100% of the prescription dose (PD), 12 of whom (17% of the entire group) had a D 90 lower than 80% of PD. There was no correlation between D 90 coverage and prostate volume, number of seeds, or implanted activity. The median V 100 for the rectum was 0.3 cm 3 (range, 0e4.3 cm 3 ). No outcome differences were observed according to the institutional strata. Concordance between reported and reevaluated D 90 values (defined as within AE10%) was observed in 44 of 69 cases. CONCLUSIONS: Central review of postimplantation CT scans to assess the quality of prostate brachytherapy is feasible. Most patients achieved excellent dosimetric outcomes, yet 17% had less than optimal target coverage by the PD. There was concordance between submitted target-coverage parameters and central dosimetric review in 64% of implants. These findings will require further validation in a larger cohort of patients. Ó
2017 American Brachytherapy Society’s Annual Meeting Report
Translational Andrology and Urology, 2017
Award recipients are selected through the ABS's meticulous scientific committee review process and the recipients' abstracts are presented in the Annual Meeting's plenary session. The 2017 Annual Meeting saw hundreds of abstract submissions, and four abstracts stood out to receive the award named for and established in the memory of Dr. Judith Stitt, who was very active in the ABS. The first recipient, Nicolae et al. presented the Evaluation of a Machine-Learning Algorithm for Treatment Planning in Prostate Low-Dose-Rate (LDR) Brachytherapy with initial findings suggesting that their prototype algorithm demonstrates the capability to generate LDR prostate brachytherapy pre-operative treatment plans (1). The authors found that their plans are comparable to the quality of plans which were simultaneously created by experts trained in brachytherapy (Figure 1) (1). The authors suggested that in looking to the future, automated planning algorithms for brachytherapy will improve uniformity of plans, reduce planning time, and decrease errors and the number of staff resources needed for brachytherapy (1). Researchers working on NRG/RTOG 0526, a prospective multicenter trial reporting on the outcomes of salvage LDR
Brachytherapy- State Of The Art Radiotherapy In Prostate Cancer
BJU international, 2015
Contemporary treatment options for prostate cancer are considered to have comparable efficacy. Therefore other differences such as treatment related toxicities, impact on quality of life, convenience, treatment time, and cost become important considerations in influencing treatment choice. The goal of brachytherapy is to achieve high precision, targeted radiotherapy utilising advanced computerised treatment planning and image guided delivery systems to achieve tailored ablative tumour dose to the prostate whilst sparing surrounding organs at risk to minimise potential toxicities. This article is protected by copyright. All rights reserved.
Accelerated Dose Calculation Engine for Interstitial Brachytherapy
IFMBE Proceedings, 2009
An accelerated Monte Carlo code ͓Monte Carlo dose calculation for prostate implant ͑MCPI͔͒ is developed for dose calculation in prostate brachytherapy. MCPI physically simulates a set of radioactive seeds with arbitrary positions and orientations, merged in a three-dimensional ͑3D͒ heterogeneous phantom representing the prostate and surrounding tissue. MCPI uses a phase space data source-model to account for seed self-absorption and seed anisotropy. A "hybrid geometry" model ͑full 3D seed geometry merged in 3D mesh of voxels͒ is used for rigorous treatment of the interseed attenuation and tissue heterogeneity effects. MCPI is benchmarked against the MCNP5 code for idealized and real implants, for 103 Pd and 125 I seeds. MCPI calculates the dose distribution ͑2-mm voxel mesh͒ of a 103 Pd implant ͑83 seeds͒ with 2% average statistical uncertainty in 59 s using a single Pentium 4 PC ͑2.4 GHz͒. MCPI is more than 10 3 and 10 4 times faster than MCNP5 for prostate dose calculations using 2-and 1-mm voxels, respectively. To illustrate its usefulness, MCPI is used to quantify the dosimetric effects of interseed attenuation, tissue composition, and tissue calcifications. Ignoring the interseed attenuation effect or slightly varying the prostate tissue composition may lead to 6% decreases of D 100 , the dose delivered to 100% of the prostate. The presence of calcifications, covering 1%-5% of the prostate volume, decreases D 80 , D 90 , and D 100 by up to 32%, 37%, and 58%, respectively. In conclusion, sub-minute dose calculations, taking into account all dosimetric effects, are now possible for more accurate dose planning and dose assessment in prostate brachytherapy.