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Purpose: Low-dose-rate (LDR) brachytherapy and stereotactic body radiation therapy (SBRT) have both shown acceptable outcomes in the treatment of low- and intermediate-risk prostate cancer. Minimal data have been published directly comparing rates of biochemical control and toxicity with these 2 modalities. We hypothesize that LDR and SBRT will provide similar rates of biochemical control.Methods and Materials: All low- and intermediate-risk patients with prostate cancer treated definitively with SBRT or LDR between 2010 and 2018 were captured. Phoenix definition was used for biochemical failure. Independent t tests were used to compare baseline characteristics, and repeated measure analysis of variance test was used to compare American Urologic Association (AUA) and the Expanded Prostate Cancer Index Composite (EPIC) scores between treatment arms over time. Biochemical control was estimated using the Kaplan-Meier method. Differences in acute and late toxicity were assessed via Pearson χ2.Results: In the study, 219 and 118 patients were treated with LDR and SBRT. Median follow-up was 4.3 years (interquartile range, 3.1-6.1). All patients treated with LDR received 125.0 Gy in a single fraction. SBRT consisted of 42.5 Gy in 5 fractions. Five-year biochemical control for LDR versus SBRT was 91.6% versus 97.6% (P = .108). LDR patients had a larger increase in mean AUA scores at 1 month (17.2 vs 10.3, P < .001) and 3 months posttreatment (14.0 vs 9.7, P < .001), and in mean EPIC scores at 1 month (15.7 vs 13.8, P < .001). There was no significant difference between LDR and SBRT in late grade 3 genitourinary toxicity (0.9% vs 2.5%, P = .238); however, LDR had lower rates of late grade 3 gastrointestinal toxicity (0.0% vs 2.5%, P = .018).Conclusions: Our data show similar biochemical control and genitourinary toxicity rates at 5 years for both SBRT and LDR, with slightly higher gastrointestinal toxicity with SBRT and higher AUA and EPIC scores with LDR. [ABSTRACT FROM AUTHOR]

Purpose: This study presents a prospective phase 1, institutional review board-approved dose-escalated stereotactic body radiation therapy trial for prostate cancer (CaP) to assess the impact of dose level on quality of life, toxicity, and clinical outcomes.Methods and Materials: From 2011 to 2016, 26 patients with low- and intermediate-risk CaP received 40, 45, and 50 Gy in 5 fractions to the prostate in cohorts of 9, 10, and 7 patients. Self-reported quality of life was prospectively measured from the Expanded Prostate Cancer Index Composite and American Urological Association. Common Terminology Criteria for Adverse Events (version 4.03) data were collected to observe acute and late toxicities. The Phoenix definition was used to calculate outcome. No patients received androgen deprivation therapy.Results: Median follow-up was 67.2 months (range, 71-230 months). There was an increase in Expanded Prostate Cancer Index Composite and American Urological Association scores followed by a return to baseline over 2 years for all cohorts. There were no grade 3 or higher toxicities or significant differences in toxicity between treatment arms. The prostate-specific antigen (PSA) nadir was significantly lower in the 45-Gy and 50-Gy cohorts when compared with the 40-Gy cohort (P < .05). Two biochemical failures were observed in the 40-Gy arm after 43 and 62 months, resulting in a freedom from biochemical failure rate of 92%. PSA survival was 100%, and actuarial overall survival was 96%. PSA nadir was 0.6, 0.1, and 0.1 ng/mL, in the 40-Gy, 45-Gy, and 50-Gy cohorts, respectively.Conclusions: This prospective, phase 1 dose-escalation study of stereotactic body radiation therapy for CaP identified acceptable genitourinary and gastrointestinal toxicity for each dose level of 40, 45, and 50 Gy. Although there was no difference in biochemical failure between the groups, we showed that higher doses of 45 and 50 Gy are associated with improved PSA nadir. The results of this study will be used to develop a larger prospective study to confirm the findings. [ABSTRACT FROM AUTHOR]

We demonstrate that patients with oligometastatic castration-sensitive prostate cancer detected via molecular imaging alone have less aggressive disease, as indicated by fewer high-risk pathogenic DNA mutations, and better overall survival in comparison to patients with oligometastasis detected via conventional imaging. In metastatic castration-sensitive prostate cancer (mCSPC), disease volume plays an integral role in guiding treatment recommendations, including selection of docetaxel therapy, metastasis-directed therapy, and radiation to the prostate. Although there are multiple definitions of disease volume, they have commonly been studied in the context of metastases detected via conventional imaging (CIM). One such numeric definition of disease volume, termed oligometastasis, is heavily dependent on the sensitivity of the imaging modality. We performed an international multi-institutional retrospective review of men with metachronous oligometastatic CSPC (omCSPC), detected via either advanced molecular imaging alone (AMIM) or CIM. Patients were compared with respect to clinical and genomic features using the Mann-Whitney U test, Pearson's χ2 test, and Kaplan-Meier overall survival (OS) analyses with a log-rank test. A total of 295 patients were included for analysis. Patients with CIM-omCSPC had significantly higher Gleason grade group (p = 0.032), higher prostate-specific antigen at omCSPC diagnosis (8.0 vs 1.7 ng/ml; p < 0.001), more frequent pathogenic TP53 mutations (28% vs 17%; p = 0.030), and worse 10-yr OS (85% vs 100%; p < 0.001). This is the first report of clinical and biological differences between AMIM-detected and CIM-detected omCSPC. Our findings are particularly important for ongoing and planned clinical trials in omCSPC. Metastatic prostate cancer with just a few metastases only detected via newer scanning methods (called molecular imaging) is associated with fewer high-risk DNA mutations and better survival in comparison to metastatic cancer detected via conventional scan methods. [ABSTRACT FROM AUTHOR]