Long-Term Second Malignancies in Prostate Cancer Patients Treated With Low-Dose-Rate Brachytherapy and Radical Prostatectomy.

PURPOSE: Second malignancy is a rare but potentially lethal event after prostate brachytherapy, but data remain scarce on its long-term risk. The objective of this study is to estimate the number of pelvic second malignancies following brachytherapy compared to radical prostatectomy (RP). MATERIALS AND METHODS: We retrospectively reviewed patients treated with low-dose 125I brachytherapy and RP in British Columbia from 1999 to 2010. Kaplan-Meier estimates for pelvic (bladder and rectum), invasive pelvic, any second malignancy, and death from any second malignancy were assessed. Cox multivariable analyses were performed adjusting for initial treatment type, age, post-RP adjuvant/salvage external beam radiation therapy status, and smoking history. RESULTS: Two thousand three hundred seventy-eight brachytherapy and 9089 RP patients were included. Median age was 66 years (interquartile range [IQR] 61-71) and 63 years (IQR 58-67), respectively. Median follow-up time to event or censured was 14 years (IQR 11.5-17.3). The Kaplan-Meier estimates for pelvic second malignancy at 15 and 20 years were 6.4% and 9.8%, respectively, after brachytherapy, and 3.2% and 4.2% after RP. Time to any second malignancy and time to death from any second malignancy were not significantly different (P > .05). On Cox multivariable analysis, brachytherapy, compared to surgery, was an independent factor for pelvic (hazard ratio [HR] 1.81 [95% CI 1.45-2.26], P < .001) and invasive pelvic second malignancy (HR 2.13 [95% CI 1.61-2.83], P < .001). Increased age and smoking were also associated with higher estimates of events (P < .001). CONCLUSIONS: After adjustment for age, post-RP adjuvant/salvage external beam radiation therapy status, and smoking status, numerically higher long-term HRs of pelvic and invasive pelvic second malignancy in patients treated with brachytherapy compared to RP were noted.

DNA Ploidy as a Potential Adjunct Prognostic Marker of Low-Risk Prostate Cancer Progression after Radical Prostatectomy.

PURPOSE: Post prostatectomy PSA kinetics and General Grade Groups (GGG) are the strongest prognostic markers of biochemical recurrence (BCR) and prostate cancer (PCa)-specific mortality after radical prostatectomy. Despite having low-risk PCa, some patients will experience BCR, for some, clinically significant BCR. There is a need for an objective prognostic marker at the time of prostatectomy to improve risk stratification within this population. In this study, we investigated the prognostic potential of DNA ploidy. MATERIALS AND METHODS: Prostatectomy samples from 97 patients with GGG1 and GGG2 with a low-risk CAPRA-S score were included in this study. PCa tissue with the worst Gleason pattern underwent tissue disaggregation, cell isolation and staining with a DNA stoichiometric stain. Using image cytometry, DNA ploidy was measured and a Ploidy Score (PS) was generated. RESULTS: Among the 97 patients, 79 had no BCR, 18 experienced BCR, of which 14 had a PSA doubling time (PSA-DT) >1 year (low-risk group) and 4 had a PSA-DT of <1 year (high-risk group). Using Logistic regression analysis, only pathological T stage (pT) and PS independently predicted BCR with PS being the most significant (p = 0.001). The number of aneuploid cells was significantly higher in the high-risk group compared to the other groups (p = 1.7x10-11). PS combined with GGG diagnosis further stratified risk groups of biochemical recurrence free survival within CAPRA-S low-risk cohort. CONCLUSION: DNA ploidy is an independent prognostic marker of BCR in low-risk PCa after radical prostatectomy, which could early on identify potentially aggressive PCa recurrences and introduce a more personalized approach to salvage treatments.

Salvage prostate brachytherapy in radiorecurrent prostate cancer: An international Delphi consensus study.

BACKGROUND AND PURPOSE: Local recurrences after previous radiotherapy (RT) are increasingly being identified in biochemically recurrent prostate cancer. Salvage prostate brachytherapy (BT) is an effective and well tolerated treatment option. We sought to generate international consensus statements on the use and preferred technical considerations for salvage prostate BT. MATERIALS AND METHODS: International experts in salvage prostate BT were invited (n = 34) to participate. A three-round modified Delphi technique was utilized, with questions focused on patient- and cancer-specific criteria, type and technique of BT, and follow-up. An a priori threshold for consensus of ≥ 75% was set, with a majority opinion being ≥ 50%. RESULTS: Thirty international experts agreed to participate. Consensus was achieved for 56% (18/32) of statements. Consensus was achieved in several areas of patient selection: 1) A minimum of 2-3 years from initial RT to salvage BT; 2) MRI and PSMA PET should be obtained; and 3) Both targeted and systematic biopsies should be performed. Several areas did not reach consensus: 1) Maximum T stage/PSA at time of salvage; 2) Utilization/duration of ADT; 3) Appropriateness of combining local salvage with SABR for oligometastatic disease and 4) Repeating a second course of salvage BT. A majority opinion preferred High Dose-Rate salvage BT, and indicated that both focal and whole gland techniques could be appropriate. There was no single preferred dose/fractionation. CONCLUSION: Areas of consensus within our Delphi study may serve as practical advice for salvage prostate BT. Future research in salvage BT should address areas of controversy identified in our study.

Outcomes after PD-103 versus I-125 for low dose rate prostate brachytherapy monotherapy: An international, multi-institutional study.

BACKGROUND AND PURPOSE: Pd-103 and I-125 are commonly used in low dose rate (LDR) brachytherapy for prostate cancer. Comparisons of outcomes by isotope type are limited, but Pd-103 has distinct radiobiologic advantages over I-125 despite its lesser availability outside the United States. We evaluated oncologic outcomes after Pd-103 vs I-125 LDR monotherapy for prostate cancer. MATERIALS AND METHODS: We retrospectively analyzed databases at 8 institutions for men who received definitive LDR monotherapy with Pd-103 (n = 1,597) or I-125 (n = 7,504) for prostate cancer. Freedom from clinical failure (FFCF) and freedom from biochemical failure (FFBF) stratified by isotope were analyzed by Kaplan-Meier univariate and Cox multivariate analyses. Biochemical cure rates (prostate-specific antigen level ≤ 0.2 ng/mL between 3.5 and 4.5 years of follow-up) by isotype were calculated for men with at least 3.5 years of follow-up and compared by univariate and multivariate logistic regression. RESULTS: Compared with I-125, Pd-103 led to higher 7-year rates of FFBF (96.2% vs 87.6%, P < 0.001) and FFCF (96.5% vs 94.3%, P < 0.001). This difference held after multivariate adjustment for baseline factors (FFBF hazard ratio [HR] = 0.31, FFCF HR = 0.49, both P < 0.001). Pd-103 was also associated with higher cure rates on univariate (odds ratio [OR] = 5.9, P < 0.001) and multivariate (OR = 6.0, P < 0.001) analyses. Results retained significance in sensitivity analyses of data from the 4 institutions that used both isotopes (n = 2,971). CONCLUSIONS: Pd-103 monotherapy was associated with higher FFBF, FFCF, and biochemical cure rates, and suggests that Pd-103 LDR may lead to improved oncologic outcomes compared with I-125.

Evidence Based Strategies in the Management of Localized Prostate Cancer and the Role of Brachytherapy.

Prostate cancer management is a critical component of men's health with ongoing controversies in screening and treatment. The purpose of this manuscript is to review contemporary evidence-based strategies in the management of localized prostate cancer to optimize patient outcomes, satisfaction, and shared decision making, to improve physician education and awareness, and to emphasize the importance of brachytherapy in the curative management of prostate cancer. The Bottom Line: 1. Selective screening and selective treatment reduces prostate cancer mortality rates. 2. Active surveillance is recommended for low risk prostate cancer. 3. Both radiation and surgery are appropriate options for patients with intermediate-risk and high-risk prostate cancer. 4. Quality of life and patient satisfaction favors brachytherapy for sexual function and urinary incontinence and surgery for urinary bother. 5. For patients with intermediate risk prostate cancer, brachytherapy achieves very high cure rates, acceptable sided effects, high patient satisfaction and is the most cost-effective treatment. 6. For patients with unfavorable intermediate-risk and high-risk prostate cancer, the combination of external beam radiation, brachytherapy, and ADT (Androgen Deprivation Therapy) achieves the highest rates of biochemical control and the lowest need for salvage therapies. 7. A collaborative shared decision making (SDM) process yields a well-informed, high-quality decision that is consistent with patients' preferences and value.

An Updated Analysis of the Survival Endpoints of ASCENDE-RT.

PURPOSE: Using the primary endpoint of time to biochemical progression (TTP), Androgen Suppression Combined with Elective Nodal and Dose Escalated Radiation Therapy (ASCENDE-RT) randomized National Comprehensive Cancer Network patients with intermediate and high-risk prostate cancer to low-dose-rate brachytherapy boost (LDR-PB) or dose-escalated external beam boost (DE-EBRT). Randomization to the LDR-PB arm resulted in a 2-fold reduction in biochemical progression compared with the DE-EBRT group at a median follow-up of 6.5 years (P < .001). Herein, the primary endpoint and secondary survival endpoints of the ASCENDE-RT trial are updated at a 10-year median follow-up. METHODS: Patients were randomly assigned to either the LDR-PB or the DE-EBRT arm (1:1). All patients received 1 year of androgen deprivation therapy and 46 Gy in 23 fractions of pelvic RT. Patients in the DE-EBRT arm received an additional 32 Gy in 16 fractions, and those in the LDR-PB arm received an 125I implant prescribed to a minimum peripheral dose of 115 Gy. Two hundred patients were randomized to the DE-EBRT arm and 198 to the LDR-PB arm. RESULTS: The 10-year Kaplan-Meier TTP estimate was 85% ± 5% for LDR-PB compared with 67% ± 7% for DE-EBRT (log rank P < .001). Ten-year time to distant metastasis (DM) was 88% ± 5% for the LDR-PB arm and 86% ± 6% for the DE-EBRT arm (P = .56). There were 117 (29%) deaths. Ten-year overall survival (OS) estimates were 80% ± 6% for the LDR-PB arm and 75% ± 7% for the DE-EBRT arm (P = .51). There were 30 (8%) patients who died of prostate cancer: 12 (6%) in the LDR-PB arm, including 2 treatment-related deaths, and 18 (9%) in the DE-EBRT arm. CONCLUSIONS: Men randomized to the LDR-PB boost arm of the ASCENDE-RT trial continue to experience a large advantage in TTP compared with those randomized to the DE-EBRT arm. ASCENDE-RT was not powered to detect differences in its secondary survival endpoints (OS, DM, and time to prostate cancer-specific death) and none are apparent.

The Impact of Parent and Family Caregiver Roles Among Canadian Radiation Oncologists.

PURPOSE: Working parents, and a rising number of adults delivering care for aging relatives, experience numerous challenges in their personal, family, professional, and financial lives owing to multiple responsibilities. This study describes the experiences of Canadian radiation oncologist (RO) parents and family caregivers, reporting challenges that may exist in providing family care with clinical and academic work commitments. METHODS AND MATERIALS: Canadian ROs, via RO heads of departments in cancer centers across Canada, and physician members of the Canadian Association of Radiation Oncology were invited to participate in an anonymous online survey between November 2021 and January 2022. The survey focused on demographics, experiences of pregnancy and leave, parenting and adult caregiving responsibilities, and self-care. RESULTS: A total of 103 staff ROs (38%) completed the survey and 78 (75.7%) identified as having a parental (76 [89.7%]) and/or other family caregiver (8 [10.3%]) role; 41% were female and 59% were male, with no difference between genders in the number of children (median, 2; interquartile range, 1-3; P = .17). More female respondents took parental leave for their first child compared with male respondents (mean, 29 vs 6 weeks; P < .001). Of male respondents who started caring for their first child during residency, 27% took parental leave, compared with 77% who started caring for their first child as a staff member (P = .003). The majority of respondents described "always/usually" having collegial support for each pregnancy and parental leave. Both genders described parental responsibilities as negatively affecting attendance at conferences (male, 65%; female, 77%; P = .31) and early or late work-related meetings (male, 76%; female, 79%; P = 1.0). More female respondents described parental responsibilities as negatively affecting their career (50% vs 29%; P = .085). Of female respondents, 52% (vs 26% of male respondents; P = .044) identified a physician mentor or positive role model around parenting issues. CONCLUSIONS: Parental and other family caregiving responsibilities are not gender unique in Canadian ROs, but competing work and family roles may affect genders differently.

After ASCENDE-RT: Biochemical and survival outcomes following combined external beam radiotherapy and low-dose-rate brachytherapy for high-risk and unfavourable intermediate-risk prostate cancer, a population-based analysis.

PURPOSE: To evaluate the outcomes of unfavorable intermediate-risk (UIR) and high-risk (HR) prostate cancer patients treated with combined external beam radiation therapy (EBRT) and low-dose-rate prostate brachytherapy (LDR-PB). METHODS AND MATERIALS: A population-based cohort of 568 prostate cancer patients treated with combined EBRT and LDR-PB from 2010 to 2016 was analyzed. All patients received EBRT followed by LDR-PB boost. Outcomes were compared with the results for the brachytherapy arm of the ASCENDE-RT trial. RESULTS: The median followup was 4.5 years. Sixty-nine percent (N = 391) had HR disease. Ninety-four percent of the HR and 57% of UIR were treated with androgen deprivation therapy (ADT) with a median duration of 12 months. The 5-year K-M biochemical progression-free survival (b-PFS), metastasis-free survival (MFS), and overall survival (OS) were 84 ± 2%, 90 ± 2%, and 88 ± 2%, similar to 89 ± 5%, 94 ± 4%, and 92 ± 4% for the ASCENDE-RT LDR-PB arm. The likelihood of achieving a PSA ≤0.2 ng/mL at 4 years was 88%, similar to 86% in the ASCENDE-RT LDR-PB arm. Thirty-three men (5.8%) would have been ineligible for ASCENDE-RT due to high-risk features. The 5-year K-M b-PFS, MFS and OS estimates were 86 ± 2%, 92 ± 1% and 89 ± 2% for the ASCENDE-RT eligible versus 56 ± 10% (p < 0.001), 73 ± 8% (p < 0.001), and 77 ± 9% (p = 0.098) for the ineligible patients. CONCLUSIONS: In this population-based cohort, combining LDR-PB with pelvic EBRT (+/- ADT) achieves very favorable b-PFS that compares to the LDR-PB arm of the ASCENDE-RT, supporting the generalizability of those results. Men ineligible for ASCENDE-RT, based on prognostic features, have a much higher risk of biochemical recurrence and metastatic relapse.

Evaluation of burnout in physician members of the American Brachytherapy Society.

PURPOSE: To evaluate the prevalence of burnout among brachytherapy specialists and to identify factors associated with burnout. METHODS AND MATERIALS: An anonymous, online, cross-sectional survey was administered to non-trainee physician members of the American Brachytherapy Society. Burnout was evaluated using the validated Maslach Burnout Inventory-Human Services Survey (MBI-HSS). Demographic and practice-specific questions were collected from respondents. Univariate and multivariable analysis of outcomes were performed using probabilistic index models. RESULTS: Overall, 51 of 400 physicians responded (13% response rate). Fifty-seven percent of respondents demonstrated at least one symptom of professional burnout. However, only 6% of respondents met strict criteria for high burnout. Analysis of the individual MBI-HSS subdomains demonstrated higher subscale scores for emotional exhaustion and depersonalization, but also higher scores for personal accomplishment. On multivariable analysis after adjusting for increased feelings of burnout due to the COVID-19 pandemic or total hours of work per week, younger age was associated with both increased subscale scores for emotional exhaustion (p = 0.026) and lower personal accomplishment (p = 0.010). Lastly, nearly half of all respondents (47%) reported increased feelings of burnout due to the COVID-19 pandemic. Respondents from academic facilities were significantly more likely to report increased burnout due to COVID-19 compared to those from non-academic facilities (odds ratio, 7.04; 95% CI 1.60-31.0; p = 0.010). CONCLUSIONS: Nearly 60% of brachytherapists demonstrated symptoms of professional burnout, which is higher than other radiation oncology groups (academic chairs, program directors, residents). Managing stressors related to workload, COVID and support for junior physicians are potential areas for improving feelings of burnout.

Patterns of Prostate Cancer Recurrence After Brachytherapy Determined by Prostate-Specific Membrane Antigen-Positron Emission Tomography and Computed Tomography Imaging.

PURPOSE: The aim of this study was to characterize the patterns of prostate cancer recurrence after brachytherapy (BT) using 2-(3-[1-carboxy-5-([6-18F-fluoropyridine-3-carbonyl]-amino)-pentyl]-ureido)-pentanedioic acid ([18F]DCFPyL) prostate-specific membrane antigen (PSMA) positron emission tomography (PET) and computed tomography (CT) imaging. METHODS AND MATERIALS: Patients were selected from an ongoing prospective institutional trial investigating the use of [18F]DCFPyL PSMA PET and CT in recurrent prostate cancer (NCT02899312). This report included patients who underwent BT (either monotherapy or boost) and experienced a biochemical failure (BF) defined by the Phoenix definition (prostate-specific antigen [PSA] > 2 ng/mL above nadir). RESULTS: Between March 2017 and April 2020, 670 patients underwent [18F]DCFPyL PSMA PET and CT imaging. Of these 670 patients, 93 were treated with BT; 73 underwent monotherapy, and 20 underwent BT boost (19 low-dose rate and 1 high-dose rate). To report on patterns of recurrence outcomes, 86 patients (median prescan PSA 6.0) with a positive [18F]DCFPyL PSMA PET and CT scan and true BF were included. The most common location of relapse was local; 62.8% had a component of local failure (defined as prostate and/or seminal vesicles), and 46.5% had isolated local failure only, with no other sites of involvement. Regional failure occurred in 40.7% of patients, and 36.0% had metastatic failure. Isolated local recurrence was seen in 54.3% of monotherapy patients versus only in 12.5% of boost patients. Metastatic failure was seen in 28.6% of monotherapy patients versus 68.8% of the boost patients. Local recurrences (69.0%) were found within the same prostate biopsy sextant involved with the tumor at diagnosis, and 76.0% of patients with seminal vesicle recurrences had prostate-base involvement at diagnosis. CONCLUSIONS: Contrary to previous evidence, our study suggests that in prostate BT patients with biochemical recurrence, the most common site of failure is local for the patients treated with monotherapy and metastatic for patients treated with a combination of external beam radiation and BT boost.

Low dose rate brachytherapy for primary treatment of localized prostate cancer: A systemic review and executive summary of an evidence-based consensus statement.

PURPOSE: The purpose of this guideline is to present evidence-based consensus recommendations for low dose rate (LDR) permanent seed brachytherapy for the primary treatment of prostate cancer. METHODS AND MATERIALS: The American Brachytherapy Society convened a task force for addressing key questions concerning ultrasound-based LDR prostate brachytherapy for the primary treatment of prostate cancer. A comprehensive literature search was conducted to identify prospective and multi-institutional retrospective studies involving LDR brachytherapy as monotherapy or boost in combination with external beam radiation therapy with or without adjuvant androgen deprivation therapy. Outcomes included disease control, toxicity, and quality of life. RESULTS: LDR prostate brachytherapy monotherapy is an appropriate treatment option for low risk and favorable intermediate risk disease. LDR brachytherapy boost in combination with external beam radiation therapy is appropriate for unfavorable intermediate risk and high-risk disease. Androgen deprivation therapy is recommended in unfavorable intermediate risk and high-risk disease. Acceptable radionuclides for LDR brachytherapy include iodine-125, palladium-103, and cesium-131. Although brachytherapy monotherapy is associated with increased urinary obstructive and irritative symptoms that peak within the first 3 months after treatment, the median time toward symptom resolution is approximately 1 year for iodine-125 and 6 months for palladium-103. Such symptoms can be mitigated with short-term use of alpha blockers. Combination therapy is associated with worse urinary, bowel, and sexual symptoms than monotherapy. A prostate specific antigen <= 0.2 ng/mL at 4 years after LDR brachytherapy may be considered a biochemical definition of cure. CONCLUSIONS: LDR brachytherapy is a convenient, effective, and well-tolerated treatment for prostate cancer.

Information Needs of Patients Diagnosed with Head and Neck Cancer Undergoing Radiation Therapy: a Survey of Patient Satisfaction.

Research suggests that the information needs of patients diagnosed with head and neck cancer can be particularly complex, given the frequent need for multidisciplinary treatments and resulting potential for profound functional impairments. This study was designed to identify head and neck cancer patients' reported informational needs and to evaluate their satisfaction with the written information they received. The study was divided into 2 phases: phase 1, prior to development of a new educational pamphlet, and phase 2, after its implementation. A survey was designed to evaluate several measures including content, amount, understanding, and timing of information delivery. It was distributed at two points during patients' treatment pathway for each phase: at their last radiation appointment and at their posttreatment follow-up appointment. Participant responses after the revised pamphlet indicated greater preparedness before their first treatment, as well as increased satisfaction with treatment option information. Most were satisfied with information timing, but about a third did indicate that additional information would have been helpful at variable time points. Open-ended responses demonstrated that overall, patients do still desire more information, particularly on side effect and self-care management information. While patients with head and neck cancer appear to be generally satisfied with the written information received, our findings suggest that there is still considerable variability in how the information is understood, when it should be delivered, and in which areas more would have been beneficial. These findings underscore the need to consider how best to balance available resources in order to provide more tailored yet comprehensive education for this group of patients.

The American Brachytherapy Society prostate brachytherapy LDR/HDR simulation workshops: Hands-on, step-by-step training in the process of quality assurance.

PURPOSE: Education and training on prostate brachytherapy for radiation oncology and medical physics residents in the United States is inadequate, resulting in fewer competent radiation oncology personnel to perform implants, and is a factor in the subsequent decline of an important, potentially curative cancer treatment modality for patients with cancer. The American Brachytherapy Society (ABS) leadership has recognized the need to establish a sustainable medical simulation low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy workshop program that includes physician-physicist teams to rapidly translate knowledge to establish high-quality brachytherapy programs. METHODS: The ABS, in partnership with industry and academia, has held three radiation oncology team-based LDR/HDR workshops composed of physician-physicist teams in Chicago in 2017, in Houston in 2018, and in Denver in 2019. The predefined key metric of success is the number of attendees who returned to their respective institutions and were actively performing brachytherapy within 6 months of the prostate brachytherapy workshop. RESULTS: Of the 111 physician/physicist teams participating in the Chicago, Houston, and Denver prostate brachytherapy workshops, 87 (78%) were actively performing prostate brachytherapy (51 [59%] HDR and 65 [75%] LDR). CONCLUSIONS: The ABS prostate brachytherapy LDR/HDR simulation workshop has provided a successful education and training structure for medical simulation of the critical procedural steps in quality assurance to shorten the learning curve for delivering consistently high-quality brachytherapy implants for patients with prostate cancer. An ABS initiative, intended to bend the negative slope of the brachytherapy curve, is currently underway to train 300 new competent brachytherapy teams over the next 10 years.

Multi-scale tissue architecture analysis of favorable-risk prostate cancer: Correlation with biochemical recurrence.

PURPOSE: Prostate cancer (PCa) with biopsy-based grade group (GG) 1 or 2 characteristics has a favorable outcome, yet some cases still progress after radical prostatectomy and present with biochemical recurrence (BCR). We hypothesized that the multi-scale tissue architecture (MSTA) analysis score would correlate with the aggressive PCa phenotype and could be used as a tool for risk assessment to improve the management of patients with favorable-risk PCa. MATERIALS AND METHODS: MSTA was evaluated in needle-biopsy samples from 115 patients with favorable-risk PCa, as defined by GG1 and GG2, a prostate-specific antigen (PSA) level of <10 ng/mL, a clinical stage of cT1c to cT2b, and general Gleason GG (GGG) and expert pathologist-assessed GG (EGG). Algorithms based on Voronoi diagrams were applied to all Feulgen-thionin-stained diagnostic areas. One hundred tissue architecture features were calculated and an MSTA score, a linear combination of the most discriminant features, was generated. Correlation of MSTA score with BCR and other clinical variables was investigated. RESULTS: In a univariate regression model, EGG, clinical stage, and MSTA were significant predictors of BCR (respective p-values: 0.0016, 0.016, and 0.028). Survival analysis showed that patients with a high MSTA score were more likely to experience BCR than were patients with a low MSTA score (odds ratio, 2.9). Combining MSTA with GG assessment resulted in a significant stratification of risk for BCR. CONCLUSIONS: MSTA score could be used as an objective adjunct risk stratification tool to pathologist assessments and could improve the management of patients with favorable-risk PCa.

Prostate brachytherapy intraoperative dosimetry using a combination of radiographic seed localization with a C-arm and deformed ultrasound prostate contours.

PURPOSE: The purpose of the study was to assess the feasibility of performing intraoperative dosimetry for permanent prostate brachytherapy by combining transrectal ultrasound (TRUS) and fluoroscopy/cone beam CT [CBCT] images and accounting for the effect of prostate deformation. METHODS AND MATERIALS: 13 patients underwent TRUS and multiview two-dimensional fluoroscopic imaging partway through the implant, as well as repeat fluoroscopic imaging with the TRUS probe inserted and retracted, and finally three-dimensional CBCT imaging at the end of the implant. The locations of all the implanted seeds were obtained from the fluoroscopy/CBCT images and were registered to prostate contours delineated on the TRUS images based on a common subset of seeds identified on both image sets. Prostate contours were also deformed, using a finite-element model, to take into account the effect of the TRUS probe pressure. Prostate dosimetry parameters were obtained for fluoroscopic and CBCT-dosimetry approaches and compared with the standard-of-care Day-0 postimplant CT dosimetry. RESULTS: High linear correlation (R2 > 0.8) was observed in the measured values of prostate D90%, V100%, and V150%, between the two intraoperative dosimetry approaches. The prostate D90% and V100% obtained from intraoperative dosimetry methods were in agreement with the postimplant CT dosimetry. Only the prostate V150% was on average 4.1% (p-value <0.05) higher in the CBCT-dosimetry approach and 6.7% (p-value <0.05) higher in postimplant CT dosimetry compared with the fluoroscopic dosimetry approach. Deformation of the prostate by the ultrasound probe appeared to have a minimal effect on prostate dosimetry. CONCLUSIONS: The results of this study have shown that both of the proposed dosimetric evaluation approaches have potential for real-time intraoperative dosimetry.

Brachytherapy education and certification-A Canadian approach.

The Royal College of Physicians and Surgeons of Canada has established a diploma certification program in brachytherapy, with the goal of standardizing brachytherapy training and standards. The diploma may be obtained either by way of a training route or a Practice Eligibility Route. Training is undergone through a Royal College-accredited brachytherapy program, analogous to a residency program with clearly defined curriculum, objectives, and expectations. The trainee submits a portfolio demonstrating achievement of the various competencies required and typically takes 12 months to complete. The trainee is then equipped to function as a competent specialist in brachytherapy, capable of an enhanced practice in this area. To date, the University of Toronto has the only Royal College-accredited training program in brachytherapy, but other Universities are in the process of applying for accreditation. Those already in practice may apply for accreditation through a Practice Eligibility Route, by submitting evidence of competency in brachytherapy. Either route can lead to the awarding of a diploma in brachytherapy, recognized by the designation DRCPSC. The overall goal of this program is to enhance quality of care and improve patient safety by setting pan-Canadian standards for training and practice in this area.

A biochemical definition of cure after brachytherapy for prostate cancer.

BACKGROUND AND PURPOSE: To identify a PSA threshold value at an intermediate follow-up time after low dose rate (LDR) prostate brachytherapy associated with cure, defined as long-term (10-15 year) freedom from prostate cancer. MATERIALS AND METHODS: Data from 7 institutions for 14,220 patients with localized prostate cancer treated with LDR brachytherapy, either alone (8552) or with external beam radiotherapy (n = 1175), androgen deprivation (n = 3165), or both (n = 1328), were analyzed. Risk distribution was 42.4% favorable, 49.2% intermediate, and 8.4% high-risk. Patients with clinical failure before 3.5 years were excluded. Kaplan-Meier analysis was used with clinical failure (local, distant, regional or biochemical triggering salvage) as an endpoint for each of four PSA categories: PSA ≤ 0.2, >0.2 to ≤0.5, >0.5 to ≤1.0, and >1.0 ng/mL. PSA levels at 4 years (±6 months) in 8746 patients without clinical failure were correlated with disease status at 10-15 years. RESULTS: For the 77.1% of patients with 4-year PSA ≤ 0.2, the freedom-from-recurrence (FFR) rates were 98.7% (95% CI 98.3-99.0) at 10 years and 96.1% (95% CI 94.8-97.2) at 15 years. Three independent validation cohorts confirmed 97-99% 10-year FFR rates with 4-year PSA ≤ 0.2. Successive PSA categories were associated with diminished disease-free rates at 10 and 15 years. PSA category was strongly associated with treatment success (p < 0.0005). CONCLUSIONS: Since 98.7% of patients with PSA ≤ 0.2 ng/mL at 4 years after LDR prostate brachytherapy were disease-free beyond 10 years, we suggest adopting this biochemical definition of cure for patients with ≥4 years' follow-up after LDR brachytherapy.