ESTRO 2024 - Abstract Book

S2349

Clinical - Urology

ESTRO 2024

738

Digital Poster

High-dose bicalutamide is equivalent to LHRH agonist in combination with EBRT of prostate cancer

Filippo Mammini 1,2 , Patrick Duhanxhiu 2 , Elena Natoli 1,2 , Maria Ntreta 1 , Letizia Cavallini 1,2 , Silvia Paolinelli 1,2 , Erika Galietta 1,2 , Viola Laghi 1,2 , Milly Buwenge 2 , Giorgio Coco 1,2 , Alessandra D'Alterio 1,2 , Gabriella Macchia 3 , Francesco Deodato 3,4 , Selena Ciabatti 5 , Annalisa Cortesi 6 , Michele Benedetti 7 , Antonio Malorgio 8 , Ilaria Moschini 9 , Francesca Maurizi 10 , Savino Cilla 11 , Claudio Malizia 12 , Silvia Cammelli 1,2 , Alessio G. Morganti 1,2 , Alessandra Arcelli 1 1 Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy. 2 Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum University of Bologna Italy., Bologna, Italy. 3 Radiation Oncology Unit, Gemelli Molise Hospital - Università Cattolica del Sacro Cuore, Campobasso, Italy. 4 Istituto di Radiologia, Università Cattolica del Sacro Cuore, Roma, Italy. 5 Radiotherapy Department, Ospedale Bellaria, Bologna, Italy. 6 Radiotherapy Unit, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) "Dino Amadori", Meldola, Italy. 7 Radiotherapy Department, Ospedale degli Infermi, Rimini, Italy. 8 Department of Radiotherapy, Azienda Ospedaliero-Universitaria di Ferrara, Ferrara, Italy. 9 Radiotherapy Department, Azienda Ospedaliera di Piacenza, Piacenza, Italy. 10 Radiation Oncology, A.O. Ospedali Riuniti Marche Nord, Pesaro, Italy. 11 Medical Physics Unit, Gemelli Molise Hospital – Università Cattolica del Sacro Cuore, Campobasso, Italy. 12 Nuclear Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy

Purpose/Objective:

Luteinizing hormone-releasing hormone (LHRH) agonists have improved outcomes in prostate cancer (PCa) when combined with external beam radiotherapy (EBRT). However, their side effects can negatively impact patients' quality of life (QoL). High-dose bicalutamide (HDB; 150 mg/day) has been suggested as an alternative to LHRH agonists to reduce castration-related effects. This analysis aims to compare therapeutic outcomes in PCa patients undergoing EBRT and androgen deprivation therapy (ADT), specifically comparing LH-RH agonists with HDB.

Material/Methods:

The study examined various endpoints, including biochemical relapse-free survival (bRFS), local control (LC), regional control (RC), metastasis-free survival (MFS), disease-free survival (DFS), and overall survival (OS). Data was obtained from a multicenter observational study, which included patients treated with definitive EBRT for PCa. Among these patients, 519 received ADT with LH-RH agonists, while 281 received HDB. Univariate (log-rank) and multivariate (Cox) analyses incorporated parameters related to patient characteristics (e.g., age and Charson's comorbidity index), tumor characteristics (e.g., PSA level, Gleason score, cT stage, cN stage), and treatment specifics (e.g., prophylactic lymph node irradiation, seminal vesicles irradiation, previous TURP, ADT [LH-RH agonists or HDB] and its duration, EBRT fractionation and technique, image- guidance systems, CTV to PTV margin, and EQD2α/β=1.5 to prostate, seminal vesicles, and pelvic nodes.

Results: