SBRT/SRS patient-specific QA using GAFchromic^TM EBT3 and FilmQA^TM Pro software

The aim of this work is to verify the potential use of GAFchromic^TM EBT3 and FILMQA^TM pro software for patient specific quality assurance (QA) for stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT) treatment plans in clinical routine use. In particular, encephalic, pulmonary and lymph node treatments plans were selected for this study. The agreement between the calculated and measured dose distributions were evaluated in terms of ɣ index with 3%3mm, 2%2mm, 1.5%1.5mm and 3%1.5mm criteria. The obtained results were then compared to the routine pre-treatment verification method which uses electronic portal imaging device (EPID) and EPIQA analysis software. EBT3-FilmQA method results show a mean ɣ index passing rate >95% with 2%1.5mm analysis criteria and an improvement of about 7% compared with EPID-EPIQA method results.