Purpose. To compare oncologic outcomes for patients with Gleason score (GS) ≥ 8 prostate adenocarcinoma treated with radical prostatectomy (RP) versus external beam radiotherapy combined with androgen deprivation (RT + ADT). Methods. Between 2001 and 2014, 121 patients with GS ≥ 8 were treated at our institution via RT + ADT (n = 71) or RP (n = 50) with ≥ 1 year of biochemical follow-up. Endpoints included biochemical failure (BF), distant metastasis, and initiation of salvage ADT. Results. The RT + ADT group was older, had higher biopsy GS, and had greater risk of lymph node involvement. All other pretreatment characteristics were similar between groups. Mean number of lymph nodes (LNs) sampled for patients undergoing RP was 8.2 (±6.18). Mean biochemical follow-up for all patients was 61 months. Five-year estimates of BF for the RT + ADT and RP groups were 7.2% versus 42.3%, (p < 0.001). The RT + ADT group also had lower rates of distant metastasis (2% versus 7.8%) and salvage ADT (8% versus 33.8%). Conclusion. In this analysis, RT + ADT was associated with improved biochemical and metastatic control when compared to RP with limited LN sampling. How RT + ADT compares with more aggressive lymphadenectomy, as is currently our institutional standard, remains an important unanswered question.

Purpose To determine if computed tomographic (CT) metrics of bone mineral density and muscle mass can improve the prediction of noncancer death in men with localized prostate cancer. Materials and Methods Institutional review board approval was obtained, with waiver of informed consent. All patients who underwent radiation therapy for localized prostate cancer between 2001 and 2012 with height, weight, and past medical history documented and who underwent CT that included the L4-5 vertebral interspace were included. On a single axial CT section obtained at the mid-L5 level, the mean CT attenuation of the trabecular bone of the L5 vertebral body (L5HU) was measured. The height-normalized psoas cross-sectional area (PsoasL4-5) was measured on a single CT section obtained at the L4-5 vertebral interface. Multivariable Cox proportional hazards models were used to assess effects on noncancer death. By using parameter estimates from an adjusted model, a prognostic index for prediction of noncancer death was generated and compared with age-adjusted Charlson Comorbidity Index (CCI) by using the Harrell c statistic. Results Six hundred fifty-three men met the inclusion criteria. Prostate cancer risk grouping, androgen deprivation, race, age-adjusted CCI, L5HU, and PsoasL4-5 were included in a multivariable model. Age-adjusted CCI (hazard ratio [HR] = 1.36, P < .001), L5HU (HR = 2.88 for L5HU < 105 HU, HR = 1.42 for 105 HU ≤ L5HU ≤ 150 HU, P < .001), PsoasL4-5 (HR = 1.95 for PsoasL4-5 < 7.5 cm2/m2, P = .003), and race (HR = 1.68 for African American race, HR = 1.77 for other nonwhite race, P = .019) were independent predictors of noncancer death. The prognostic index yielded a c value of 0.747 for the prediction of noncancer death versus 0.718 for age-adjusted CCI alone. Conclusion L5HU and PsoasL4-5, which are surrogates for bone mineral density and muscle mass, respectively, were independent predictors of noncancer death. The prognostic index that incorporated these measures with the CCI was associated with improved accuracy for prediction of noncancer death. © RSNA, 2016 Online supplemental material is available for this article.

120 Background: There have been no prospective randomized controlled trials comparing current treatment options for patients with high-risk localized prostate cancer. This study seeks to compare the biochemical and metastatic outcomes of patients that received definitive radiotherapy (dRT) or radical prostatectomy (RP) for localized prostate cancer with Gleason score ≥ 8 on initial biopsy. Methods: A total of 106 patients met the inclusion criteria of Gleason score ≥ 8 on initial biopsy and biochemical follow-up ≥ 1 year. Seventy-one patients were initially treated with dRT (96% also receiving androgen deprivation therapy) and 35 patients were initially treated with RP (with or without postoperative RT). Our primary endpoint was biochemical failure (BF). For dRT patients, BF was recorded according to the Phoenix Consensus or if extranodal metastasis was diagnosed. For surgical patients, BF was recorded according to American Urological Association guidelines or if extranodal metastasis occurred. If adjuvant/salvage RT was given postoperatively, BF was recorded if PSA ≥ 0.5 on two consecutive measures after completion of RT. Pretreatment characteristics were compared using Pearson Chi-square method and independent samples Mann-Whitney U test. Actuarial rates of BF and metastasis were calculated using the Kaplan-Meier method. Results: Median follow-up for all patients was 5.3 years. There was no statistical difference in clinical T-stage, initial PSA, or months of follow up between patients treated initially with radiotherapy vs. prostatectomy. Patients initially treated with dRT were significantly older than those treated with RP. The dRT group had a lower rate of BF compared to the RP group, p < 0.001. The Kaplan-Meier estimate of BF at 5 years was 7.6% in the dRT group compared to 34.5% in the RP group. Additionally, the Kaplan-Meier estimate of distant metastasis at 10 years was 22.7% in the dRT group compared to 55.9% of the RP group, p = 0.01. Conclusions: For our sample of patients with Gleason score ≥ 8 on initial biopsy, initial treatment with dRT was associated with lower rates of biochemical failure and extranodal metastasis when compared to initial treatment with prostatectomy.

PURPOSE:The purpose of this study was to determine whether radiation dose inhomogeneity within the prostate predisposes to late urinary strictures after moderately hypofractionated definitive external beam radiation therapy for prostate cancer. METHODS AND MATERIALS:One hundred seventy-three men with clinically localized prostate cancer met the inclusion criteria for this analysis. All patients received 70 Gy to the prostate delivered over 28 fractions, had at least 2 years of clinical follow-up, and had dose-volume histogram information available for review. The endpoint of this study was the development of a urethral stricture that required a procedural intervention such as urethral dilation or suprapubic catheterization. Dosimetric parameters were evaluated for effect on the rate of urethral stricture formation by univariate Cox proportional hazards modeling. RESULTS:The median follow-up was 49.5 months (range, 24.6-108 months). At 5 years, the actuarial rate of intervention for urethral strictures across all patients was 4.9%. The maximum point dose within the prostate (P = .034, hazard ratio = 1.006) and the mean prostate dose (P = .039, hazard ratio = 1.004) were the only parameters predictive of urethral stricture formation. All patients who developed a urethral stricture were treated by a plan with a maximum prostate dose of >75 Gy (median, 77.67 Gy). CONCLUSIONS:For patients receiving moderately hypofractionated prostate radiation therapy over 28 fractions, a maximum point dose of 75 Gy within the prostate was associated with an increased probability of developing a urethral stricture that required procedural intervention. The hypothesis that hypofractionation increases susceptibility to toxicity from heterogeneity within the prostate should be confirmed by analyzing data from randomized trials with a conventionally fractionated control arm for comparison.

To investigate added morbidity associated with the addition of pelvic elective nodal irradiation (ENI) to hypofractionated radiotherapy to the prostate.

OBJECTIVE To investigate the effect of hypofractionated external beam radiation therapy (RT) on sexual function in patients treated for localized prostate cancer, and also to determine the effect of radiation dose to the penile bulb or crura of the corpus cavernosum on sexual function outcome.MATERIALS AND METHODS Forty-one patients treated with hypofractionated RT without androgen deprivation were prescribed 67.6-70.2 Gy to the prostate, delivered in 26-28 fractions. The primary endpoint was erectile dysfunction (ED) category based on the Sexual Health Inventory for Men (SHIM) score closest to 2 years from RT. The penile bulb and crura were contoured and mean radiation dose calculated for each structure.RESULTS The mean pretreatment SHIM score was 19.8, and the mean posttreatment SHIM score was 15.1. The ED category was decreased by >= 2 in 50% of patients with a mean penile bulb of >20 Gy compared with that in 9% of patients with a mean penile bulb dose of <= 20 Gy (P = .003). Mean dose to the crura was highly correlated with mean dose to the penile bulb (Pearson correlation = 0.842; P <.001) but did not reach statistical significance as a predictor of ED after radiation.CONCLUSION Radiation dose to the penile bulb is predictive of posttreatment ED in patients treated with dose-escalated hypofractionated prostate RT. The cutpoint at which this effect was observed with this treatment is substantially lower than the previous reports. (C) 2014 Elsevier Inc.