Long-term follow-up after radiotherapy for prostate cancer with and without rectal hydrogel spacer: A pooled prospective evaluation of quality of life.

39Background: Hydrogel spacers are a tool to improve dosimetry and overall quality of life with limited follow-up in men receiving radiotherapy for prostate cancer. This present study is a pooled analysis of a prospective cohorts with long-term follow-up quality of life (QOL) data with or without hydrogel spacers to minimize dose adjacent organs at risk. Methods: QOL was examined using the Expanded Prostate Cancer Index Composite (EPIC) to compare mean changes from baseline. A total of 215 patients from a randomized multi-institutional trial of radiation with or without hydrogel spacer with a QOL end-point were pooled with 165 non-randomized patients from a single institution with prospective QOL collection in both patients with or without hydrogel spacer. The proportions of men with minimally important differences (MIDs) relative to pre-treatment baseline in each domain were tested using repeated measures logistic models with pre-specified thresholds for clinically significant decline. Results: A total o...