ESTRO 2020 Abstract book

S24 ESTRO 2020

ng/mL (favorable group), ADT for at least 12 months lead to superior bRFS compared to ≤ 9 months of ADT (P value 0.036). However, no significant difference in bRFS was seen when examining the value of receiving ADT beyond 12, 15, 18, 21 or 24 months, respectively. On univariate analysis for bRFS, the use of ADT for at least 12 months was significant (HR 0.224; 95% CI 0.070-0.720; P value 0.012) as well as time to nadir PSA tnPSA (≤ 6 vs >6 months); (HR 3.387; 95% CI 1.041-11.023; P value 0.043). The presenting T-stage was borderline significant (HR 3.074; 95% CI 0.972-9.719; P value 0.056), while PSA at presentation, Gleason Score and age were not. On multivariate analysis, the use of ADT for 12 months (HR 0.224; 95% CI 0.070-0.720; P value 0.012) and tnPSA (≤ 6 vs >6 months); (HR 4.369; 95% CI 1.096-17.421; P value 0.037) remained significant. In patients who failed to reach a nPSA target of 0.06 ng/mL (unfavorable group), receiving ADT beyond 9, 12 and 15 months was associated with improved bRFS (P values of 0.044, 0.019, 0.026, respectively). However, beyond 18 months, there was no significant difference. On univariate analysis for bRFS, the only factor that was found to be associated with bRFS was the use of ADT for at least 18 months (HR 0.319; 95% CI 0.110-0.921; P value 0.035). Conclusion In HR localized prostate cancer patients treated with definitive RT and ADT, the total duration of ADT may be adjusted according to treatment response using nPSA. In patients reaching a nPSA below 0.06 ng/mL, a total of 12 months of ADT may be sufficient, while in those not reaching a nPSA below 0.06 ng/mL, a total duration of 18 months is required. PD-0059 Patient-reported baseline incontinence at post-prostatectomy RT: its dependence on time from surgery F. Munoz 1 , G. Sanguineti 2 , P. Gabriele 3 , A. Bresolin 4 , D. Cante 5 , V. Vavassori 6 , J.M. Waskiewicz 7 , G. Girelli 8 , B. Avuzzi 9 , A. Faiella 2 , E. Garibaldi 3 , E. Villa 6 , A. Magli 10 , B.N. Chiorda 9 , M. Gatti 3 , T. Rancati 11 , R. Valdagni 11 , N. Di Muzio 12 , C. Fiorino 13 , C. Cozzarini 12 1 Ospedale Regionale Parini-AUSL Valle d’Aosta, Radiotherapy, Aosta, Italy ; 2 Istituto Nazionale dei Tumori “Regina Elena”, Radiotherapy, Rome, Italy ; 3 Istituto di Candiolo - Fondazione del Piemonte per l'Oncologia IRCCS, Radiotherapy, Turin, Italy ; 4 Fondazione Centro San Raffaele, Department of Medical Physics, Milan, Italy ; 5 Ospedale di Ivrea, Radiotherapy, Ivrea, Italy ; 6 Cliniche Gavazzeni-Humanitas, Radiotherapy, Bergamo, Italy ; 7 Comprensorio Sanitario di Bolzano, Radiotherapy, Bolzano, Italy ; 8 Ospedale degli Infermi, Radiotherapy, Biella, Italy ; 9 Fondazione IRCCS Istituto Nazionale dei Tumori, Radiotherapy, Milan, Italy ; 10 Azienda Ospedaliero Universitaria S. Maria della Misericordia, Radiotherapy, Udine, Italy ; 11 Programma Prostata- Fondazione IRCCS Istituto Nazionale dei Tumori, Radiotherapy, Milan, Italy ; 12 Istituto Scientifico Ospedale San Raffaele, Radiotherapy, Milan, Italy ; 13 Istituto Scientifico Ospedale San Raffaele, Department of Medical Physics, Milan, Italy Purpose or Objective Baseline urinary incontinence (UI) is expected to strongly influence UI recovery after post prostatectomy radiotherapy (PORT), inducing clinicians, both radiation oncologists and urologists, to postpone “as much as possible” PORT, with the hope of maximizing UI recovery after prostatectomy. On the other hand, there is growing evidence that a longer time elapsed between prostatectomy and PORT (TTRT), possibly leading to higher PSA values at radiotherapy start, may be detrimental for patient’s outcome. The goal of current study was to analyze the trend of UI recovery and its predictors at PORT start.

Material and Methods A population of 408 patients treated with PORT was enrolled in a registered cohort study originally aimed at developing predictive models of radiation-induced toxicities: prospectively collected baseline UI and individually assessed clinical and personality information were available, including TTRT. Self-reported UI was evaluated by means of ICIQ-SF (ICIQ); personality traits were also evaluated by means of the abbreviated 24-item version of the revised Eysenck personality questionnaire (EPQ-R). Both questionnaires were administered at PORT start. Several end-points based on baseline ICIQ-SF were investigated: frequency and amount of urine leakage (ICIQ3 and ICIQ4, respectively), “objective” UI (OBJ, ICIQ3+4), “subjective” UI (ICIQ5) and TOTAL UI (ICIQ3+4+5). The relationship between each end-point and TTRT was investigated. The association between clinical and personality variables and each end-point was tested by uni- and multivariable logistic regression analysis. Mean ICIQ scores representative of each decile in the ICIQ vs TTRT plot were fitted by a sigmoid curve. Analyses were performed with MedCalc and R software. Results TTRT was the strongest predictor of all end-points (p- values ≤0.001); all scores improved between 4 and 8 months after prostatectomy, without any additional long- term recovery (see for example Figure 1 related to TOTAL UI): the most-informative cut-offs ranged between 6.7 and 7.8 months (OR: 2.5-3.6). Neuroticism independently predicted SUBJ, TOTAL and daily frequency. Similarly, the fraction of completely dry patients (i.e.: OBJ=0) at PORT start heavily depended on TTRT (<6.9 months, OR:0.24) and older age (OR:0.94), showing a rapid increment in the first 4-8 months after surgery and then reaching a plateau value at about 10 months after prostatectomy (Figure 2).