An overlooked opportunity? SBRT + ADT for aggressive prostate cancer in the elderly.

Background: Elderly PCa patients often present with comorbidities, increasing the risk of complications of pelvic RT and long-term ADT. The aim of the present study is to evaluate the efficacy and safety of personalized UHRT+/- ADT in this setting. Methods: Men aged ≥75 years with localized PCa who underwent curative UHRT to the prostate (5 fractions every other day, 6.5-7.25 Gy/fraction) were retrospectively included. Adverse events (AEs) were assessed according to RTOG scale. Biochemical recurrence (BR) and clinical progression (CP) progression-free survival (PFS) were analyzed using Kaplan-Meier estimator. Results: A total of 226 patients was included. Median age at diagnosis was 79 years; Median CCI was 4. The majority (53%) were diagnosed with high or very high risk PCa. Concomitant ADT was administered to 165 (73%) with a median duration of 12 months.At a median follow-up of 2.3 years (available for 217/226), 44 (20%) experienced BR and among these, 31/44 (70%) developed CP. Patients who developed CP were predominantly in high- and unfavorable intermediate-risk groups. Most CPs (61%) were oligoprogressive, and 9 occurred within the treatment field. The 1-, 2-, and 3-year BR-free survival (BRFS) of 98%, 88%, and 82%, respectively. No clinical or treatment-related factor was significantly associated with BRFS or CPFS in the univariate analysis.Acute AEs were limited, with no acute GI in 91% and no acute GU in 56% of patients. Late AEs were also favorable, with 75% and 88% reporting no late GU and GI AEs, respectively. Acute GU AEs correlated with older age and higher comorbidity burden, while acute GI AEs were associated with larger prostate CTV volumes. Conclusions: These findings suggest that personalized UHRT ± ADT provides an acceptable disease control with a safe AE profile in elderly PCa patients, representing a feasible alternative to conventional treatment approaches.