ESTRO 2025 - Abstract Book

S2032

Clinical - Urology

ESTRO 2025

3057

Digital Poster PROMs in prostate cancer radiotherapy: a prospective cohort study comparing online adaptive radiotherapy versus conventional IGRT Goda Kalinauskaite 1,2 , Luise Anne Künzel 1 , Thao Nguyen 3 , Kerstin Rubarth 3 , Jakob Dannehl 1 , Celina Mandy Höhne 1 , Christian Robke 1 , Daniel Zips 1 , Carolin Senger 1 1 Department of Radiation Oncology and Radiotherapy, Charité – Universitätsmedizin Berlin, Berlin, Germany. 2 Berlin Institute of Health at Charité, Universitätsmedizin Berlin, Berlin, Germany. 3 Institute of Biometry and Clinical Epidemiology, Charité, Charité – Universitätsmedizin Berlin, Berlin, Germany Purpose/Objective: Online adaptive radiotherapy (online-ART) has the potential to optimise treatment precision by improving target coverage while sparing healthy tissue. Evidence on its impact on PROMs is limited. This prospective cohort study (NCT06116019) evaluates PROMs in prostate cancer patients treated with either daily online-ART or conventional IGRT, focusing on urinary, bowel and sexual function outcomes. Material/Methods: A total of 50 patients treated with CT-guided ART or conventional IGRT was analyzed. Patients from all risk groups underwent radiotherapy with 62 Gy delivered in 20 fractions (SIB, PTV margins: 5 mm/3 mm dorsal). Patients were assigned to either the ART group (daily online ART) or the IGRT group (daily IGRT with CBCT) based on the availability of online ART slots. To minimize prescription bias, these slots were made available throughout the entire recruitment period, with a predefined maximum of six slots. Patient-reported outcomes, including IPSS and EORTC QLQ-PR25, were collected at baseline and post-treatment. Descriptive statistics and t-tests, adjusted for individual baseline differences, were used to evaluate symptom scores and QLQ-PR25 subdomains (urinary symptoms [GU], incontinence aid use, bowel symptoms [GI], sexual activity, and sexual functioning) at the end of treatment. Statistical significance was set at p < 0.05. Results: In total, 46 patients completed questionnaires at baseline and post-treatment, with 26 in the ART group and 20 in the IGRT group. The baseline-adjusted mean (SD) difference in total IPSS was 3.00 (5.52) for the ART group and 4.50 (6.19) for the IGRT group (p = 0.24). For the EORTC QLQ-PR25, the mean GU symptom score increased post treatment by 10.8 (15.5) in the ART group and 14.8 (19.2) in the IGRT group (p = 0.29). Incontinence aid use remained rare in both groups. For GI symptoms, the mean score increased post-treatment by 4.08 (11.5) in the ART group and 7.29 (13.0) in the IGRT group (p = 0.23). No significant differences were observed in functional outcomes related to sexual activity or sexual functioning. Conclusion: In our small study population, baseline-adjusted differences in PROMs did not show statistically significant differences between ART and IGRT. However, albeit not statistically significant, differences in urinary and bowel symptoms in the ART group compared to the IGRT group may suggest potential benefits of ART, supporting the need for further trials.

Keywords: adaptive radiotherapy, PROMs, prostate cancer