Characterization of a reusable PRESAGE® 3D dosimeter

This study investigates a reusable PRESAGE® 3D dosimeter (Presage-RU), which would improve cost-effectiveness and facilitate wider implementation of comprehensive, high resolution 3D dosimetry. Small (1x1x4.5 cm) and large (8 cm diameter, 4.5 cm length) sample dosimeters were irradiated multiple times to characterize dose response (i.e. radiation-induced change in optical density (∆OD)), optical clearing rate, and dose distribution stability. PresageRU exhibited an initial dose response sensitivity of 0.0119 ∆OD/(cm∙Gy), a reduction in response with subsequent irradiations, and a small, permanent ∆OD (~1-6% of initial signal) following each irradiation. Dosimeters optically cleared at an exponential rate (average T1⁄2 = 24.8±3.6 h), and were effectively cleared after ~5-8 days. 3D gamma analysis (3%/3mm, 10% dose threshold) of a 4-field box plan applied to the large dosimeter showed good agreement following initial irradiation (96.6% passing), but a reduction in passing rate (89.1% passing) with subsequent irradiation. Further study is warranted to fully assess and quantify the performance of Presage-RU for repeat irradiations.