Analysis of components of variance determining probability of setup errors in CBCT-guided stereotactic radiotherapy of lung tumors

摘要

Purpose: Online tumor matching for SABR lung setup requires margins for inaccuracies due to intra-fraction variability of breathing-averaged tumor position (BATP) and CBCT image guidance. We studied intra-fraction variability during SABR delivery using VMAT, corrected these for measurement inaccuracies, and quantified the CBCT image-guidance uncertainties.