ESTRO 2021 Abstract Book

S598

ESTRO 2021

Conclusion Results from the EORTC QLQ-C30 highlighted a large variability in the deterioration of functional and symptom scales with time. Moderate hypofractionation impacts the QoL acute perception of prostate cancer patients, while diabetes strongly affects the late phase after a better acute condition than the other analyzed characteristics. PD-0767 Predictors of urinary incontinence 2 years after RT with different intents for prostate cancer C. Cozzarini 1 , G. Sanguineti 2 , V. Vavassori 3 , F. Munoz 4 , B. Avuzzi 5 , E. Garibaldi 6 , D. Cante 7 , J.M. Waskiewicz 8 , A. Magli 9 , A. Faiella 10 , E. Villa 3 , L. Ferella 4 , M. Gatti 11 , B. Noris Chiorda 5 , C. Piva 7 , P. Ferrari 12 , T. Rancati 13 , F. Badenchini 13 , G. Girelli 14 , E. Moretti 15 , R. Valdagni 16 , A. Bresolin 17 , N. Di Muzio 18 , C. Fiorino 17 1 San Raffaele Scientific Institute, Radiotherapy, Milan, Italy; 2 IRCCS Istituto Nazionale dei Tumori “Regina Elena", Radiotherapy, Rome, Italy; 3 Cliniche Gavazzeni Humanitas, Radiotherapy, Bergamo, Italy; 4 Ospedale Regionale Parini-AUSL Valle d’Aosta, Radiotherapy, Aosta, Italy; 5 Fondazione IRCCS Istituto Nazionale dei Tumori, Radiotherapy, Milan, Italy; 6 A.O. SS. Antonio e Biagio, Radiotherapy, Radiotherapy, Alessandria, Italy; 7 Ospedale di Ivrea, Radiotherapy, Ivrea, Italy; 8 Azienda Sanitaria dell’Alto Adige, Radiotherapy, Bolzando, Italy; 9 Azienda Ospedaliero Universitaria S. Maria della Misericordia, , Radiotherapy, Udine, Italy; 10 IRCCS Istituto Nazionale dei Tumori “Regina Elena”, Radiotherapy, Rome, Italy; 11 IRCC Candiolo, Radiotherapy, Candiolo, Italy; 12 Azienda Sanitaria dell’Alto Adige, Radiotherapy, Bolzano, Italy; 13 Fondazione IRCCS Istituto Nazionale dei Tumori - Prostate Program, Radiotherapy, Milan, Italy; 14 Ospedale degli Infermi, Radiotherapy, Biella, Italy; 15 Azienda Ospedaliero Universitaria S. Maria della Misericordia, Radiotherapy, Udine, Italy; 16 Fondazione IRCCS Istituto Nazionale dei Tumori, Prostate Program - Università degli Studi Milano, Radiotherapy, Milan, Italy; 17 San Raffaele Scientific Institute, Medical Physics, Milan, Italy; 18 Università Vita Salute San Raffaele, Radiotherapy, Milan, Italy Purpose or Objective To identify predictors of patient-reported urinary incontinence (PRUI) two years after radical, adjuvant or salvage (RAD, ADV, SALV) radiotherapy for prostate cancer (PCa). Materials and Methods A prospective cohort of 407 men enrolled in a multi-Institutional, observational registered study investigating radiation-induced toxicity, with complete ICIQ-SF questionnaire at baseline and 2 years after RT start, was analyzed. Patient characteristics: RAD n=141, cT1/T2/T3a/T3b 19/37/33/11%, median 2-Gy equivalent dose (mEQD2) 80 Gy; ADV n=104, pT2/pT3a/pT3b 8/36/56%, mEQD2 70.41 Gy, median time to RT (mTTRT) from prostatectomy 3.9 months; SALV n=162, pT2/pT3a/pT3b 45/33/22%, mEQD2 74 Gy, mTTRT 19.1 months. Androgen deprivation was given to 95%, 56% and 37% of pts treated with RAD, ADV and SALV intent, respectively, for a median of 24 months. Frequency and amount of urine leakage and their impact on self- perceived QoL (ICIQ-SF3, 4 and 5, respectively) were analyzed, as well as the overall ICIQTOT score. The 75 th percentiles of ICIQ-SF3, 4, 5 and TOTAL worsening at 2 years with respect to the baseline were considered as end-points. Severe PRUI (ICIQTOT≥13 points) at two years was also analyzed. The association between these end-points and many clinical and dosimetric variables, including 2-Gy equivalent RT doses (EQD2), RT intent, use of concomitant ADT, comorbidities, patient personality as measured by the EPQR questionnaire, baseline Bowel, Emotional, Social and Systemic Domains as evaluated by the IBDQ questionnaire, was investigated by univariable (UVA) analyses. Variables with a è-value <0.20 at UVA were entered into a multivariable backward logistic regression analysis (MVA). Results No role emerged (even at UVA) for EQD2. Only baseline ICIQTOT (OR 1.32, p>0.0001) and SALV intent (OR 3.143, p=0.004) independently predicted an ICIQTOT score at 2 years ≥13 points. A summary of the predictors