ESTRO 2025 - Abstract Book

S2037

Clinical - Urology

ESTRO 2025

Univariate analysis of HR group showed that SRT or BT alone had better OS compared to other groups (p=0.002). Inferior outcome was observed in patients with elective nodal irradiation (5-year OS of 62%vs.75%,p=0.002) and those with GUG≥2 and GIG≥2 toxicity during RT (GU:5 -year OS 73%vs.47% for G0- 1vs.G≥2, respectively,p=0.012; GI:5-year OS 70%vs.55% for G0- 1vs.G≥2, respectively,p=0.003). In multivariate analysis, only elective irradiation had statistically significant negative impact on OS (p=0.046,HR1.48).The presence of BF/RR/DR didn't influence OS (p=0.37,p=0.12 and p=0.22,respectively). BFFS and MFS were better in HR patients without nodal irradiation (p=0.031 and p=0.011, respectively). HR patients who received ADT had less BF (p=0.02), however BFFS didn't differ between ADT and no-ADT group (0.27).

Conclusion: Patients over 80 years old don’t have inferior outcome due to the co -morbidities. The omission of elective irradiation in HR group improves treatment tolerability and survival.

Keywords: radiotherapy, old adult oncology, national studies

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Digital Poster Salvage stereotactic body radiotherapy (SBRT) for intraprostatic relapse after primary radiotherapy for prostate cancer María Cerrolaza 1 , Agustina Méndez 1 , Victoria Navarro 2 , Claudia Colom 1 , Cristina García 1 , Ana Galán 1 , Claudia Laborda 1 , Martin Tejedor 1 1 Radiation Oncology, Miguel Servet University Hospital, Zaragoza, Spain. 2 Radiation Oncology, Lozano Blesa University Clinical Hospital, Zaragoza, Spain Purpose/Objective: The management of locally recurrent prostate cancer after definitive radiotherapy remains a subject of debate, primarily due to the high rates toxicity associated with any form of local salvage treatment. However, stereotactic body radiation therapy (SBRT) has emerged as a promising approach for reirradiation offering a potential alternative that may reduce the risk of severe side effects while providing effective tumor control. The objective of this study was to assess the feasibility, safety, and clinical outcomes of SBRT for reirradiation in patients with locally recurrent prostate cancer. Material/Methods: We retrospectively studied patients with evidence of isolated local recurrence of prostate cancer following external beam radiotherapy or LDR- brachytherapy who received SBRT as reirradiation. Pre-treatment imaging included magnetic resonance imaging (MRI) and either choline or PSMA-positron emission tomography (PET) scans, with histologic confirmation. Patients with late toxicities greater than grade 2 were excluded. Androgen deprivation therapy (ADT) was administered for 6 to 12 months. Treatment consisted of 35 Gy delivered in 5 fractions once a