ESTRO 2024 - Abstract Book

S2457

Clinical - Urology

ESTRO 2024

BP was reported as the first event in 53% of patients with a median follow-up of 27 months (IQR 16 – 36), (32 (60%) enrolled in ARM A vs 21 (40%) in ARM B, respectively). Median PSA reported at BP was 2.36 ng/ml (IQR 1.31 – 5.38).

Radiological progression was reported as the first CPFS event in 44 patients (44%): 29 (66%) patients enrolled in ARM A and 15 (34%) in ARM B, respectively. Addition of ADT significantly improved CPFS, with a Hazard Ratio in favor of the ADT + SBRT arm B (P < 0.0001) ( Figure 1a ). Median time to CPFS was 15 months for arm A and 33 months for arm B (SBRT + ADT). ARM of treatment was found to be significantly associated with CPFS, and the result is confirmed also at multivariate analysis. PSA at diagnosis and PSA pre-RT were also found to be associated with CPFS. Survival analysis of CP dividing patients according to the main factors is shown in Figure 1b . The additional advantage of the combined treatment results is evident for all the subgroups of patients, with the exception of the following subgroups: N stage at diagnosis = 1, time from first treatment to RT < 43 months, site of metastases M1a. The second line treatment for patients who experienced radiological progression (29 oligo-progression vs 15 poli progression) was ADT alone, SBRT to metastatic sites alone, and SBRT+ADT in 19, 16, and 9 patients respectively. OS was 98% (2 patients died from non-PCa-related causes). An additional evaluation of the testosterone was assessed to compare levels at baseline ( Table 1 ) and at 1 year after SBRT for the two arms. Testosterone levels at 1 year were 4.2 ng/ml (IQR 3.0 – 4.9) and 3.8 ng/ml (IQR 2.1 – 5.5) for ARM A and ARM B, respectively (data available for 43 patients (ARM A) and 43 patients (ARM B)). No difference was found between the two arms, confirming a complete testosterone recovery even after a short course of ADT.