Intrafraction Variation in Tumor Position during Stereotactic Body Radiotherapy for Lung Cancer

Abstract

Cone beam CT (CBCT) has demonstrated remarkable promise for pre-treatment target positioning. Questions remain, however, as to whether this pre-treatment position remains stable throughout the treatment fraction, particularly for the relatively long treatment times of stereotactic body radiotherapy (SBRT). The goal of this study was to quantify the change in tumor position from beginning to end of an SBRT fraction.