ESTRO 2025 - Abstract Book

S2101

Clinical - Urology

ESTRO 2025

4164

Digital Poster Ultra Hypo RT in elderly PCa patients with aggressive disease: still a space for curative approach? Chiara Lorubbio 1,2 , Ilaria Repetti 1,2 , Federico Mastroleo 1,2 , Maria Giulia Vincini 1 , Mattia Zaffaroni 2 , Cristiana Iuliana Fodor 1 , Giovanni Carlo Mazzola 1 , Dario Zerini 1 , Stefano Luzzago 3 , Francesco Alessandro Mistretta 3 , Sarah Alessi 4 , Giuseppe Petralia 4 , Gennaro Musi 3 , Ottavio De Cobelli 3 , Roberto Orecchia 5 , Giulia Marvaso 1,2 , Barbara Alicja Jereczek Fossa 1,2 1 Division of Radiation Oncology, IEO, European Institute of Oncology, IRCCS, Milan, Italy. 2 Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy. 3 Department of Urology, IEO, European Institute of Oncology, IRCCS, Milan, Italy. 4 Division of Radiology, IEO, European Institute of Oncology, IRCCS, Milan, Italy. 5 Scientific Directorate, IEO, European Institute of Oncology, IRCCS, Milan, Italy Purpose/Objective: Longer life expectancy has led to an increase in number of elderly patients (pts) with localized PCa. Elderly pts often present a high prevalence of comorbidities which makes difficult to propose RT including both prostate, pelvis and associated long-term ADT. The aim of the present study is to evaluate the efficacy and safety of personalized UHRT+/- ADT in this cohort of pts. Material/Methods: Men aged ≥75 years with localized PCa who underwent curative UHRT between 2012 and 2021 were retrospectively included. Continuous variables were summarized as mean, median and interquartile range (IQR), while frequency analysis was performed for categorical variables. Toxicities were collected according to RTOG scale and biochemical PFS was analysed with KM method. Results: A total of 226 pts was included. Median age at diagnosis was 79 years (IQR 78 – 81) with a median Charlson Comorbidity Index of 4 (IQR 3-4). The majority of the pts (52.6%, 119) was diagnosed with high or very high risk, while the remainings (47.4%, 107) were unfavorable intermediate risk. All pts underwent UHRT on prostate in 5 fx every other day with a dose/fx within 6.5 and 7.25 Gy. Ninety-eight pts (43.4%) received a boost on DIL with a total dose within 37.5 Gy and 40 Gy. Concomitant ADT was administered to 165 pts (73%) with a median duration time of 12.0 months (IQR 6.0 – 12.0). General cohort characteristics are summarized in Table 1. After a median follow-up of 28.1 months (IQR 16.3 – 43.2), 44/226 pts (19.5%) experienced a biochemical recurrence and 31/44 pts (70.5%) developed a clinical progression of disease with a median time to CP of 2.17 years (IQR 1.45 – 3.68). At last follow up, 157 pts (69.4%) were alive with no evidence of disease, 39 (17.3%) were AWD and 2 (0.9%) died for other causes than PCa. The majority of pts reported no acute GI (90.7%) and GU (55.7%) toxicity. Two patients (1%) experienced a G>3 GU toxicity while no G>3 GI were registered. Data about late toxicities were available for 213/226 pts: 70.4% and 82.7% of pts reported respectively a G0 GU and GI toxicity. One patient (0.4%) reported a G3 GU maximum late toxicity, while 1 patient (0.4%) experienced a G3 GI toxicity. Toxicities are listed in Table 2.