The survey provided significant information on the current PSQA methods, instruments, and techniques used by different hospitals practicing IMRT and VMAT techniques. There was variation in the practice of PSQA, the equipment used, their methodology, and the analysis followed. The most common PSQA analysis followed was ±3% for ion chamber measurements and 3% dose difference and 3 mm distance to agreement for gamma-analysis. Additionally, limited use of a heterogeneous phantom for PSQA was observed in clinical settings.
Katake et al. (Thu,) studied this question.