ESTRO 2025 - Abstract Book

S1879

Clinical - Urology

ESTRO 2025

log-rank test was used for the univariate analysis and the Cox proportional-hazards model for the multivariate analysis.

Results:

The cohort had an a

verage age of 66 years (range, 45 – 85). A significant proportion of patients (72.8%) presented with clinical T3a or higher stage disease, and more than half (53.3%) exhibited regional lymph node metastasis. The median duration of ADT was 24 months (range, 8-38 months). SIB FB to IPL was conducted on 46.7% of patients. At a median follow-up time of 73 months, the 5-year FFBF, PCSS, DMFS, and OS rates were 59.2%, 77.0%, 62.9% and 67.6%, respectively. Disease progression was observed in 39 patients (442.4%), with most cases manifesting as distant metastasis (DM). Significant improvements in 5-year FFBF (74.8% vs. 48.1%; p = 0.02) and DMFS rates (80.5% vs. 51.5%; p = 0.02) were achieved with SIB. Patients receiving SIB also had borderline significant improvements in 5-year PCSS (83.5% vs. 72.0%; p = 0.06) and OS (71.3% vs. 64.0%; p = 0.1) (Figure 1).The 5-year FFBF (74.4% vs. 41.2%; p=0.02) and PCSS rates (90.0% vs. 62.6%; p=0.02) were significantly different between PSMA-PET/CT and conventional imaging patients. Patients with PSMA-PET/CT staging had higher 5-year DMFS (70.8% vs. 53.3%; p=0.17) and OS (76.4% vs. 57.2%; p=0.1) rates (Figure 2). No significant difference was found between groups. In the multivariable analysis, ADT duration of 18 months or more was associated with improved FFBF, PCSS, DMFS, and OS. The utilization of SIB technique was an additional independent predictor for improved FFBF, while staging with PSMA-PET/CT was associated with better PCSS.