ESTRO 2024 - Abstract Book

S409

Brachytherapy - Urology

ESTRO 2024

4 Universitary Hospital of Navarre, Oncology Nursing, Pamplona, Spain. 5 Universitary Hospital of Navarre, Medical Physics, Pamplona, Spain

Purpose/Objective:

To assess the patient-reported toxicity of HDR brachytherapy boost (HDR-BT) against exclusive external beam radiotherapy (EBRT) in high-risk and very-high-risk prostate cancer patients.

Material/Methods:

We performed a single institutional study evaluating patient-reported outcomes measures ( PROMs ). We compare the results of genitourinary toxicity and gastrointestinal toxicity in a subgroup of patients diagnosed with high and very-high risk prostate cancer treated with exclusive EBRT and HDR brachytherapy boost (HDR-BT). EBRT group received exclusive EBRT including pelvis with a prostate dose of 60 Gy while HDR-BT group received 44 Gy followed by a HDR-BT in 1 fractions of 15Gy. Androgen deprivation therapy was administered in all patients during 30 months. EORTC QLQ-C30 and EORTC QLQ-PR25 were used to evaluate urinary, bowel and sexual toxicity at baseline (M0), at the end of treatment (M1) and 4 months after treatment (M4). Lower scores on this test indicate better function. Low scores on a functional scale correspond to better functioning, while high scores on a symptom scale correlate to increased symptom burden. Minimal Important Differences (MID) were defined as small differences (5-10 points), moderated differences (10-20) and large differences (above 20). Clinical important differences were defined above 10 points.

Results:

A preliminary analysis after the enrollment of the first 100 patients was performed. 79 of the first 100 patients were treated for prostate cancer between 2022 and 2023. 49 patients had high and very high risk prostate cancer. 53% of these patients were treated with exclusive EBRT and 47% with HDR brachytherapy. Urinary function (compared with baseline, M0) was 38.14 (vs. 13,47) at M1 and 12.66 (vs. 13,47) at M4 in EBRT group, and 29,89 (vs. 15,03) at M1 and 14,85 (vs. 15,03) at M4 in HDR-BT group. Bowel function (compared with M0) was 12,82 (vs.0,96) at M1 and 2,33 (vs. 0,96) at M4 in EBRT group, and 10,14 (vs.2,53) at M1 and 2,17 (vs. 2,53) at M4 in HDR-BT group. Image 1 .

Image 1 .