3-D dose verification by cone-beam optical CT scanning of PRESAGE dosimeter

Abstract

There is a clear need for an accurate and practical dosimeter that is able to verify 3-D dose distributions from complex radiation treatments. The purpose of this study is to evaluate the dosimetric performance of PRESAGE radiochromic plastic dosimeter in conjunction with a cone-beam optical CT scanner, Vista^TM, for 3-D dosimetry. The cone-beam optical CT scanner presented in this study can perform optical readout in less than 30 min, which makes same day dose verification for treatment possible. For dosimetric accuracy, a complete 3-D dose verification procedures were performed, including dose response calibration with a 12 MeV electron beam, a 6 MV photon square field irradiation, as well as a 5-field IMRT irradiation. This study shows that 3-D dose verification with fast optical CT scan of PRESAGE dosimeter is feasible. First-generation optical CT scanner can be used as a gold standard for optical readout of dosimeters.