ESTRO 2025 - Abstract Book

S2024

Clinical - Urology

ESTRO 2025

Figure 1. The Kaplan-Meier curves of FFBF, PCSS, and OS.

Conclusion: In this multicenter study with a relatively long follow-up, we found that definitive RT is a safe and effective treatment option for patients aged 55 years and younger. However, prospective trials are needed to confirm and strengthen these findings.

Keywords: prostate cancer, young age, radiotherapy.

References: [1] Freedman GM, Hanlon AL, Lee WR, Hanks GE. Young patients with prostate cancer have an outcome justifying their treatment with external beam radiation. Int J Radiat Oncol Biol Phys. 1996;35:243-50. [2] Klayton TL, Ruth K, Horwitz EM, Uzzo RG, Kutikov A, Chen DY, et al. Young age under 60 years is not a contraindication to treatment with definitive dose escalated radiotherapy for prostate cancer. Radiother Oncol. 2011;101:508-12.

2963

Digital Poster Shift in radiotherapy planning from original to post-PSMA intent-to-treat in patients with biochemical recurrence of prostate cancer Francesco Amorelli 1 , Pedro Jose Plaza 2 , Augusto Octavio Natali 3 , Juan Sebastian Blanco 2 , Palmira Foro 1 1 Radiation Oncology, Hospital del Mar, Barcelona, Spain. 2 Nuclear Medicine, Hospital del Mar, Barcelona, Spain. 3 Clinical Analysis, Hospital Josep Trueta, Girona, Spain Purpose/Objective: To evaluate the impact of PET/CT-18F-DCFPyL (PSMA) on radiotherapy planning by assessing potential changes in the treatment field in patients with biochemical-recurrence (BCR) of prostate cancer (PC) after radical prostatectomy (RP). Material/Methods: We retrospectively analyzed 85 PC patients with BCR after RP. These included patients with PSA levels of 0.2 – 1.0ng/mL considered for salvage-radiotherapy (SRT) and those with persistent-PSA-levels despite prior radiotherapy to prostate-bed (PB). Conventional imaging (CT, bone-scintigraphy and pelvic-MRI) showed no evidence of local/distant disease. All patients underwent PET/CT-18F-DCFPyL-PSMA. Positive results were categorized into local recurrence, pelvic/extra-pelvic lymph nodes (LN) and bone/visceral disease. We assessed the impact of PET/CT PSMA on radiotherapy planning from original-intent to post-PSMA intent-to-treat. The original-intent-to-treat included PB-radiotherapy (PBRT) 66Gy (2Gy/fraction) for patients without prior radiotherapy, prophylactic-pelvic-LN radiotherapy 46Gy (2Gy/fraction) with androgen deprivation therapy (ADT) for high-risk patients. For those with previous adjuvant/salvage radiotherapy (ART/SRT) ADT or watchful-waiting-