Feasibility of dosimetric measurements using Al2O3:C OSL dosimeter during fluoroscopy-guided procedures

Abstract

This study investigated the feasibility of dosimetric measurements using Al2O3:C optically stimulated luminescence (OSL) dosimeters during fluoroscopy-guided procedures. The linearity and energy dependence of Al2O3:C OSL dosimeters were evaluated, and the air kerma rate at the operator’s position was measured. The response of Al2O3:C OSL dosimeters to short, repetitive irradiations was compared to that of long uninterrupted irradiation. The change in response of the Al2O3:C OSL dosimeter under automatic exposure rate control (AERC) was evaluated with the use of various thicknesses of polymethyl-methacrylate (PMMA) plates (15–30 cm). The Al2O3:C OSL dosimeters could detect 5 µGy and showed good linearity in doses of ≥10 µGy (R2: 0.997–0.999, p < 0.001). The relative response of the Al2O3:C OSL dosimeter normalised to that of 36.8 keV was 0.828–1.101 at the energies investigated (30.6–46.0 keV). The air kerma rate at the operator’s position was estimated to be 2.61–7.17 µGy min−1 depending on the heights representing different body parts. Repetitive short irradiations had no significant impact on the relative response of the Al2O3:C OSL dosimeters (p > 0.05). Despite a high energy dependence on the low energy beam used in fluoroscopy, the change in relative response of the Al2O3:C OSL dosimeter under AERC was within 5.7% depending on the thickness of the PMMA plates. Dosimetric measurement using Al2O3:C OSL dosimeters for patients and operators is feasible. However, one should be cautious about high standard deviations when measuring small doses of ≤20 µGy using Al2O3:C OSL dosimeters. It is essential to perform intensive bleaching before measuring very small doses to minimise pre-irradiation counts.