ESTRO 2025 - Abstract Book

S2039

Clinical - Urology

ESTRO 2025

Results: Eighty-six patients were identified, of whom 37 (43%) met the high-risk BCR criteria based on the EMBARK study. Of these, 30 (81%) were in the SRT group, and 7 (19%) were in the definitive radiotherapy group. The median age was 63.8 years. During a median follow-up of 79 months, 12 patients (32.43%) experienced BCR, 3 (8.1%) had local recurrence, 11 (29.7%) had lymph node recurrence, and 15 (40.5%) had distant recurrence. The median progression-free survival (PFS) was 32.2 months for BCR, 76.3 months for local progression, 63.1 months for regional lymph node progression, and 62.4 months for distant progression. The overall survival rate was 100%. Statistically significant differences were observed between patients receiving definitive RT and those undergoing SRT regarding local recurrence (p = 0.028), though no significant differences were found for regional lymph node or distant recurrences. Thirteen patients (35.1%) received androgen receptor-targeted agents (ARTA) during follow-up, with a median time to ARTA initiation of 36.2 months. At the time of analysis, 70% of patients had disease control. Conclusion: Enzalutamide improves metastasis-free survival in high-risk BCR patients. These results emphasize the importance of timely intervention and suggest that SRT plays a critical role in reducing local recurrence. Molecular imaging is vital, significantly enhancing occult metastasis detection and optimizing therapeutic decisions. Our results correlate with others in the literature. Digital Poster Adoption of hypofractionation radiotherapy for localised prostate cancer and quality of life outcomes in an Australian population-based cohort Wee Loon Ong 1,2 , Therese Kang 1,3 , Jeremy Millar 1 1 Department of Radiation Oncology, Alfred Health, Melbourne, Australia. 2 Department of Radaition Oncology, Barwon Health, Geelong, Australia. 3 Department of Radiation Oncology, Barwon Health, Geelong, Australia Purpose/Objective: Multiple randomised trials have shown that hypofractionated radiotherapy (HFRT) is non-inferior to conventional fractionated radiotherapy (CFRT) in terms of oncological and quality of life (QOL) outcomes for localised prostate cancer. We aim to evaluate the adoption of HFRT and QOL outcomes for prostate cancer at a population-based level in Australia. Material/Methods: This is an Australian population-based cohort of men with localised prostate cancer who had primary radiotherapy between 2016 and 2023. QOL was assessed using the EPIC-26 questionnaire at 12 months post-treatment. The primary outcomes were the adoption of HFRT and QOL. Time trend in adoption of HFRT was evaluated using Cochran-Armitage test. Multivariable logistic regressions were used to evaluate the likelihood of HFRT. Differences in the EPIC26 urinary and bowel function domain scores between CFRT and HFRT were estimated using multivariable linear regressions. Covariables evaluated were age, NCCN risk group, socioeconomic group, area of residence, treatment institutions (metropolitan/ regional, and public/ private). Results: There were 3,647 men included in this study – 213 (6%) low-risk (LRPC), 1799 (49%) intermediate-risk (IRPC), and 1635 (45%) high-risk prostate cancer (HRPC). Overall, there were 1,729 (47%) men who had HFRT – 56%, 61% and 31% in LRPC, IRPC, and HRPC respectively. HFRT increased from 3% in 2016 to 71% in 2023 for all men (P trend<0.001) – from 4% in 2016 to 87% in 2023 for LRPC/IRPC (P-trend<0.001) and from 2% in 2016 to 52% in 2023 Keywords: EMBARK, PET, salvage radiotherapy 3187