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PURPOSE: To validate the association between body composition and mortality in men treated with radiation for localized prostate cancer (PCa). Secondarily, to integrate body composition as a factor to classify patients by risk of all-cause mortality. MATERIALS AND METHODS: Participants of NRG/Radiation Therapy Oncology Group (RTOG) 9406 and NRG/RTOG 0126 with archived computed tomography were included. Muscle mass and muscle density were estimated by measuring the area and attenuation of the psoas muscles on a single slice at L4-L5. Bone density was estimated by measuring the attenuation of the vertebral body at mid-L5. Survival analyses, including Cox proportional hazards models, assessed the relationship between body composition and mortality. Recursive partitioning analysis (RPA) was used to create a classification tree to classify participants by risk of death. RESULTS: Data from 2066 men were included in this study. In the final multivariable model, psoas area, comorbidity score, baseline prostate serum antigen, and age were significantly associated with survival. The RPA yielded a classification tree with four prognostic groups determined by age, comorbidity, and psoas area. Notably, the classification among older (≥70 years) men into prognostic groups was determined by psoas area. CONCLUSIONS: This study strongly supports that body composition is related to mortality in men with localized PCa. The inclusion of psoas area in the RPA classification tree suggests that body composition provides additive information to age and comorbidity status for mortality prediction, particularly among older men. More research is needed to determine the clinical impact of body composition on prognostic models in men with PCa.

Positron emission tomography using the fluorine-18 (18F) fluciclovine radiotracer has been approved for use in recurrent prostate cancer and is a useful tool for clinical decision making. However, 18F-fluciclovine is not specific for prostate cancer tumor cells, and false-positive results have been reported. In the present study, we have reported our experience with synchronous malignancies identified using 18F-fluciclovine and reviewed other reported cases, with a special emphasis on highlighting the clinical decisions that led to the correct diagnosis. [ABSTRACT FROM AUTHOR]

Introduction: For patients with high risk prostate cancer, conventionally fractionated treatment of the pelvic lymphatics and hypofractionated treatment to the prostate can be delivered simultaneously with dose painting. The purpose of this technical note is to highlight unexpected hot spots within the low dose lymphatic target volume as a clinical problem that we have observed with dose painting, and to describe a simple approach to account for this during treatment planning. Summary: We describe the creation of a control structure that can be incorporated into the optimization objective function. An upper constraint objective can be placed on the control structure such that heterogeneity within the plan is limited to the area near the high dose target volume and better emulates the dosimetry of a conventionally fractionated sequential boost plan. [ABSTRACT FROM AUTHOR]

Prostate cancer is the most common noncutaneous malignancy in American men. Its lymphatic drainage is very well established throughout literature. We report the case of a 72-year-old Caucasian male with elevated serum prostate-specific antigen and biopsy-confirmed high-risk prostate cancer who underwent multiparametric magnetic resonance imaging (MRI) for staging and treatment planning. The imaging revealed suspicious lymph nodes in the left ischiorectal and right obturator fossae that were biopsy confirmed as metastatic prostate adenocarcinoma. Herein, we present the divergence from the well-established lymphatic drainage of prostate cancer and the role of MRI in detecting this prostate cancer site of spread. [ABSTRACT FROM AUTHOR]

Objective: To determine if magnetic resonance imaging (MRI)/ultrasound fusion-targeted prostate biopsy (TB) would lead to increased recommendations of aggressive radiotherapy treatments for higher risk prostate cancer compared to systematic biopsy (SB) results.Methods: Clinicopathologic data of 533 men who underwent both TB and SB from 2014 to 2017 was analyzed. TB was performed in addition to SB in patients with detection of MRI suspicious lesions. Three patient cohorts were established: (1) biopsy naïve (80/533, 15.0%), (2) active surveillance (185/533, 34.7%), and (3) prior negative biopsy (268/533, 50.3%). Cancer risk categorical criteria were established with recommended radiotherapy treatment for each. Variation of risk classification due to biopsy method for all patients and within each cohort was analyzed using either a chi-squared statistic or Fisher's exact test. McNemar's pairwise analyses were performed for all risk categories between TB and SB to assess the effects of TB on high-risk cancer identification and subsequent radiotherapy recommendations.Results: Number of patients within cancer risk categories (1. "No Cancer or Low-Risk"; 2. "More Favorable Intermediate-Risk"; 3. "Less Favorable Intermediate-Risk"; 4. "High-Risk") varied significantly based on TB and SB pathology among all patients combined (P <.0001), in cohort 2 (P = .0005), and in cohort 3 (P <0.0001). Further, among all patients, TB increased cancer risk classification and correspondingly would result in more aggressive radiotherapy recommendations: "No Cancer or Low-Risk" to "Less Favorable Intermediate-Risk" (30/343, P <0.0001) and "No Cancer or Low-Risk" to "High-Risk" (31/353, P <.0001).Conclusion: Among men with prostate cancer, TB commonly led to reclassification to a higher risk group, which is accompanied by more aggressive radiotherapy treatment recommendations when compared with SB findings alone. [ABSTRACT FROM AUTHOR]

To investigate the addition of a computed tomography (CT)-based method of osteoporosis screening to FRAX without bone mineral density (BMD) fracture risk assessment in men undergoing radiotherapy for prostate cancer, we reviewed the records of all patients with localized prostate cancer treated with external beam radiotherapy at our institution between 2001 and 2012. The 10-yr probability of hip fracture was calculated using the FRAX algorithm without BMD. The CT attenuation of the L5 trabecular bone (L5 CT ) was assessed by contouring the trabecular bone on a single CT slice at the level of the midvertebral body and by averaging the Hounsfield units (HU) of all included voxels. L5 CT values of 105 and 130 HU were used as screening thresholds. The clinical characteristics of additional patients identified by each L5 CT screening threshold value were compared to patients whose estimated 10-yr risk of hip fracture was 3% or greater by FRAX without BMD. A total of 609 patients treated between 2001 and 2012 had CT scans available for review and complete clinical information allowing for FRAX without BMD risk calculation. Seventy-four (12.2%) patients had an estimated 10-yr risk of hip fracture of 3% or greater. An additional 22 (3.6%) and 71 (11.6%) patients were identified by CT screening when thresholds L5 CT  = 105 HU and L5 CT  = 130 HU were used, respectively. Compared to the group of patients identified by FRAX without BMD, the additional patients identified by CT screening at each L5 CT threshold level tended to be younger and heavier, and were more likely to be African–American or treated without androgen deprivation therapy. These results suggest that the addition of CT-based screening to FRAX without BMD risk assessment identifies additional men with different underlying clinical characteristics who may be at risk for osteoporosis and may benefit from pharmacological therapy to increase BMD and reduce fracture risk. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose To investigate added morbidity associated with the addition of pelvic elective nodal irradiation (ENI) to hypofractionated radiotherapy to the prostate. Methods and materials Two-hundred twelve patients, treated with hypofractionated radiotherapy to the prostate between 2004 and 2011, met the inclusion criteria for the analysis. All patients received 70 Gy to the prostate delivered over 28 fractions and 103 (49%) received ENI consisting of 50.4 Gy to the pelvic lymphatics delivered simultaneously in 1.8 Gy fractions. The mean dosevolume histograms were compared between the two subgroups defined by use of ENI, and various dose-volume parameters were analyzed for effect on late lower gastrointestinal (GI) and genitourinary (GU) toxicity. Results Acute grade 2 lower GI toxicity occurred in 38 (37%) patients receiving ENI versus 19 (17%) in those who did not (p = 0.001). The Kaplan-Meier estimate of grade ⩾ 2 lower GI toxicity at 3 years was 15.3% for patients receiving ENI versus 5.3% for those who did not (p = 0.026). Each rectal isodose volume was increased for patients receiving ENI up to 50 Gy (p ⩽ 0.021 for each 5 Gy increment). Across all patients, the absolute V70 of the rectum was the only predictor of late GI toxicity. When subgroups, defined by the use of ENI, were analyzed separately, rectal V70 was only predictive of late GI toxicity for patients who received ENI. For patients receiving ENI, V70 > 3 cc was associated with an increased risk of late GI events. Conclusions Elective nodal irradiation increases the rates of acute and late GI toxicity when delivered simultaneously with hypofractioanted prostate radiotherapy. The use of ENI appears to sensitize the rectum to hot spots, therefore we recommend added caution to minimize the volume of rectum receiving 100% of the prescription dose in these patients. [ABSTRACT FROM AUTHOR]

Purpose/objective(s): To assess subcutaneous adipose tissue characteristics by computed tomography (CT) as potential imaging biomarkers predictive of biochemical recurrence in men with high-risk prostate cancer receiving radiotherapy (RT).Materials and Methods: This retrospective study included men with high-risk prostate cancer (PSA>20ng/ml, Gleason score ≥8, or clinical extraprostatic extension) treated between 2001 and 2012. All patients received definitive, dose-escalated external beam RT along with a course of neoadjuvant, concurrent, and adjuvant androgen deprivation therapy (ADT). Each patient also had a treatment planning CT that included the L4-L5 vertebral interface and prostate specific antigen (PSA) measurements for at least 2 years following RT. The subcutaneous adipose tissue was contoured on a single axial CT slice at the level of L4-L5. The average CT attenuation, in Hounsfield units (HU), of the structure was calculated and defined as SATHU. SATAREA was defined as the cross-sectional area of the structure (in cm2) that was then normalized by the square of patient height. Biochemical failure (BF) was defined as a PSA rise of 2ng/ml from the nadir. Freedom from BF (FFBF) was calculated from start time of ADT using the Kaplan-Meier method. Estimates of FFBF were stratified by SATHU and SATAREA quartiles.Results: A total of 171 men met the inclusion criteria with a median follow-up of 5.6 years. The mean SATHU (±standard deviation) was -99.2HU (±6.1HU), and the mean SATAREA was 93.2cm2/m2 (±39.4cm2/m2). The 5- and 8-year rates of FFBF across all patients were 81.5% and 73.5%, respectively. Patients in the lowest quartile of SATHU experienced significantly higher FFBF compared to the other quartiles (Q4 vs. Q1, P = 0.017; Q4 vs. Q2, P = 0.045; Q4 vs. Q3, P = 0.044). No other differences in FFBF were observed between quartiles of SATAREA or other quartiles of SATHU.Conclusion: Lower subcutaneous adipose tissue density was associated with a lower rate of BF following RT with ADT for men with high-risk prostate cancer. Further research is needed to elucidate the biological underpinnings of this clinical finding and the role adipose tissue plays in modulating oncologic behavior and outcomes. [ABSTRACT FROM AUTHOR]

• Prospective, multicenter, phase I/II trial of 19 Gy single fraction prostate SBRT. • Urinary and rectal toxicity was mild at the 18-month follow-up. • Impact on quality of life was minimal and biochemical response rate acceptable. • Longer follow-up is needed to assess long-term toxicity and disease control. To assess in a prospective, multicenter, single-arm phase I/II study the early safety and efficacy profile of single fraction urethra-sparing stereotactic body radiotherapy (SBRT) for men with localized prostate cancer. Patients with low- and intermediate-risk localized prostate cancer without significant tumor in the transitional zone were recruited. A single-fraction of 19 Gy was delivered to the prostate, with 17 Gy dose-reduction to the urethra. Intrafraction motion was monitored using intraprostatic electromagnetic transponders with intra-fraction correction of displacements exceeding 3 mm. Genitourinary (GU), gastrointestinal (GI), and sexual toxicity during the first 18 months were evaluated using the CTCAE v4.0 grading scale. Quality of life was assessed using the International Prostate Symptom Score, the Expanded Prostate Cancer Index composite 26 score, and the International Index of Erectile Function score. Among the 45 patients recruited in 5 centers between 2017 and 2022, 43 received the single fraction without protocol deviations, and 34 had a minimal follow-up of 18 months. The worst GU toxicity was observed at day-5 after SBRT (42.5 % and 20 % with grade 1 and 2, respectively), returning to baseline at week-12 and month-6 (<3% with grade 2), with a 12 % grade 2 flare at month 18. Gl toxicity was mild in the acute phase, with no grade ≥ 2 events (12 % grade 1 at month 6). Grade-3 proctitis was observed in one patient at month 12, with < 3 % grade 2 toxicity at month 18. Mean GU and GI bother scores showed a decline at day 5, a complete recovery at month 6, and a flare between month 12 and 18. Mean PSA dropped from 6.2 ng/ml to 1.2 ng/ml at month 18 and 0.7 ng/ml at month 24. After a median follow-up time of 26 months, 3 biochemical failures (7 %) were observed at month 17, 21 and 30. In this multicenter phase I/II trial, we demonstrated that a 19 Gy single-fraction urethra-sparing SBRT is feasible and associated with an acceptable toxicity rate, mostly returning to the baseline at week-12 and with a symptoms flare between months 12 and 18. Longer follow-up is needed to assess the potential long-term adverse effects and the disease control efficacy. [ABSTRACT FROM AUTHOR]