Variability Analysis of Clinical Target Volume Outlining for Prostate Stereotactic Body Radiotherapy within the Multicentre PACE Trial

Abstract

Purpose: The PACE trial is a randomised multicentre trial comparing stereotactic body radiotherapy (SBRT) with conventional treatment in low- and intermediate-risk prostate cancer. SBRT is associated with a small margin for error, and it is therefore vital to ensure accuracy of clinical target volume (CTV) delineation. As part of the PACE trial quality assurance programme, centres are required to successfully complete a benchmark planning exercise using CT and MRI from a set intermediate-risk cases. The aim of this study was to analyse CTV outlining variability between centres.