Comprehensive physical evaluation and clinical validation of the high resolution digital detector array for Stereotactic Radiosurgery(SRS) quality assurance

This study aims to ensure that the clinical accuracy of the IBA myQA SRS detector used in the clinic is tested according to the Gamma index criteria by generating pre- and post- modelling corrected and uncorrected models (-0,05 mm in the MLC offset value and 0,99 for absolute dose correction were done.). The plan of 17 patients was retroactively measured at the Monaco TPS with the myQA SRS dosimeter system. For 10 of these plans, IBA myQA SRS results were compared with EBT-XD radiochromic films based on GPR values. The maximum minimum volumes and distances of the lesions are in the range of 0,087 cc and 16,815 cc; 8,5 cm and 1,5 cm respectively. the myQA SRS dosimeter has an average GPR value of 91,99%, 87,32% and 71,89% before modeling, according to the measurements of 3%/2mm, 2%/2mm and 2%/1mm gamma criteria respectively; after modeling it has GPR values of 92,56%, 88,54% and 75,91% respectively. The film dosimeter has an average GPR value of 93,59%, 89,26% and 72,13% prior to modeling, respectively for 3%/2mm, 2%/2mm and 2%/1mm gamma criteria, and 94,06%, 90,66%, and 72,83% after modeling. Both the film myQA SRS and the film showed more distinctly the difference in MLC in patients with the smallest lesions at the 2%/1mm criterion, and both detector systems were able to detect the difference of MLC at the same rate. The myQA detector system is a quality detector that can detect as well as a film.