ESTRO 2023 - Abstract Book

S450

Sunday 14 May 2023

ESTRO 2023

Although probably lower than what used to be delivered with older techniques, testicular dose delivered with modern prostate radiotherapy is not negligible and is often underestimated because the contribution of daily repositioning imaging is not taken into account and most Treatment Planning Systems underestimate the out of field dose. Radiation oncologists should be aware of the possible impact of prostate radiotherapy on fertility and gonadal endocrine secretion. Men should be counselled at first consult and offered a sperm preservation strategy if they have a paternity wish.

PD-0569 Quality of life results from the Prostate Cancer Outcome Study (PCO) after primary radiotherapy B. Polat 1 , N.T. Sibert 2 , S. Wesselmann 2 , S. Dieng 3 , G. Feick 4 , E. Carl 4 , J. Fichtner 5 , M. Burchardt 6 , R. Kosmala 1 , J. Tamihardja 1 , T. Wiegel 7 , M. Flentje 8 , C. Kowalski 2 1 University hospital Würzburg, Department of radiation oncology, Würzburg, Germany; 2 German Cancer Society, -, Berlin, Germany; 3 OnkoZert GmbH, -, Neu-Ulm, Germany; 4 Federal Association of German Prostate Cancer Patient Support Groups, -, Bonn, Germany; 5 Johanniter Krankenhaus Oberhausen, Department of Urology, Oberhausen, Germany; 6 University Medicine Greifswald, Department of Urology, Greifswald, Germany; 7 University Hospital Ulm, Department of Radiation Oncology, Ulm, Germany; 8 University hospital Würzburg, Department of radiation oncology , Würzburg, Germany Purpose or Objective The ongoing observational PCO (Prostate Cancer Outcomes) study compares differences in treatment quality between participating centers in patients with non-metastatic prostate cancer treated with primary radical prostatectomy, definitive radiotherapy (RT) or being under active surveillance or watchful waiting. Here we present quality of life (QoL) data for the RT group. Materials and Methods Prospective data from certified mainly German prostate cancer centers were evaluated. QoL was measured using the EPIC 26 questionnaire at baseline before treatment initiation and at 12 months thereafter. Questions are categorized within five domains and scored from 0 – 100 points (higher values correspond to better functioning): incontinence, irritative/obstructive functions, bowel function, sexual and vitality/hormonal function. To discriminate between statistically and clinically relevant differences we used MIDs (minimally important differences) with reference values from the literature: incontinence 6, irritative/obstructive 5, bowel function 4, sexual 10 and hormonal 4 points. Student’s t-test for paired samples was applied for comparison of the two time points with a p-value of 0.05 set as statistically significant. Results From August 2016 to May 2021 a total of 3,440 RT patients out of 103 centers were enrolled. With 2,603 available questionnaires at 12 months, we reached a response rate of 75.7 %. Median age was 74 years and patients presented with low, intermediate and high-risk/(locally) advanced prostate cancer in 14, 42 and 42%. Median PSA (at follow-up) was 0.39 ng/ml. In total 3,209 (93.3%) patients were treated with external beam RT and 231 (6.7%) with LDR-brachytherapy. Concomitant ADT was given in 851 (24.7%) patients. The main QoL outcome values for each time point and domain were as follows (baseline, 12 months, mean values): 91, 87 for incontinence, 86, 83 for irritative/obstructive, 95, 87 for bowel functions, 42, 28 for sexual and 88, 79 for hormonal functions. All changes were statistically significant (p<0.01). Patients receiving ADT had a relevant decline in the sexual and hormonal domains at one year: 29 vs 19 and 83 vs 71. Conclusion One year after definitive RT, changes in continence and irritative/obstructive complaints were minimal and within the MID boundaries. For the other domains, minor but clinically relevant changes were observed. PD-0570 The value of PROMs for predicting erectile dysfunction in prostate cancer patients B. Osong 1 , H. Hasannejadasl 1 , H. van der Poel 2 , B. Vanneste 3 , J. van Roermund 4 , K. Aben 5,9 , I. Bermejo 1 , J. Van Soest 1 , L. Kiemeney 5 , I. Van Oort 6 , R. Verwey 7 , L. Hochstenbach 7 , E.J.B. van Gurp 8,7 , A. Dekker 1 , R.R. Fijten 1 1 Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands; 2 Department of Urology, Netherlands Cancer Institute, Amsterdam, The Netherlands; 3 Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands; 4 Department of Urology, Maastricht University Medical Center+, Maastricht, The Netherlands; 5 Department of Research & Development,