ESTRO 2024 - Abstract Book

S2300

Clinical - Urology

ESTRO 2024

References: ClinicalTrials.gov Identifier: NCT04262609

212

Digital Poster

Experience of Rectal Spacers in Stereotactic Ablative Radiotherapy for Patients with Prostate Cancer

Jocelyn Saunders 1 , Kirsty Nash 1 , Carolynn Lamb 1 , Norma Sidek 1 , David Dodds 1 , Fiona Birrell 1 , Stephen McKay 1 , Nicholas MacLeod 1 , Helena Belikova 1 , Brendan McCann 1 , Jan Wallace 1 , Imran Ahmad 2 , Abdulla Alhasso 1 1 Beatson West of Scotland Cancer Centre, Oncology, Glasgow, United Kingdom. 2 Queen Elizabeth University Hospital, Urology, Glasgow, United Kingdom

Purpose/Objective:

Prostate cancer is the most common cancer of males in the United Kingdom. Radiotherapy is a key curative treatment modality for patients with localised disease. There continues to be advances in radiotherapy technique which have led to improvements in both acute and long term toxicity from radical prostate radiotherapy. Stereotactic ablative radiotherapy (SABR) enables precise hypofractionated treatment delivered over five fractions.[1] Despite these advances, and given the proximity of the rectum to the prostate, patients are at risk of developing side effects which impact quality of life including radiation proctitis.[2] Recently, biodegradable spacers have been developed to increase the prostate-rectal distance and decrease the radiation exposure to the rectum.[3] We describe our experience of Hydrogel Vue Biodegradable spacers inserted in patients receiving SABR to the prostate.

Material/Methods:

Patients with prostate cancer who received SABR, 3625cGy in five fractions, between December 2020 and October 2023 with a Hydrogel Vue spacer device were identified using electronic patient records. For comparison, 30 patients who had received SABR without a spacer were randomly selected. In all patients, radiotherapy was delivered using an Intensity Modulated Image Guided technique with fiducial markers, 3625cGy in 5 fractions. Radiotherapy was planned identifying the prostate, rectum and spacer. Data was collected on patient characteristics, prostate cancer risk group, radiotherapy parameters, and dose to rectum. Acute gastrointestinal toxicity was graded using Common Terminology Criteria for Adverse Events (CTCAE) version 5.1, at one week, two weeks and six weeks post commencement of SABR.

Results:

A total of 26 patients had a Hydrogel Vue spacer inserted. The average age was 69 years, age range 52 to 78 years. The average age of patients without a spacer was 70 years (ranging from 59 to 80 years). Spacers were inserted without complication. The rectal volume receiving ≥18Gy (V18), V29 and V36 was calculated. A mean dose to the rectum for the V18, V25 and V26 was calculated for the 26 patients with spacers inserted and compared to the patients with no spacers. Results demonstrated that patients with a spacer inserted had a lower dose to the rectum