Characterization of Optically Stimulated Luminescence Detectors for Organ Dose Phantom Measurement in Diagnostic Radiology
M Rodriguez1*, E Yukihara2, S Ahmad1, C Ruan1, (1) University of Oklahoma Health Science Center, OKLAHOMA CITY, OK (2) Oklahoma State University, Stillwater, OKMO-F-213CD-4 Monday 4:30:00 PM - 6:00:00 PM Room: 213CD
Purpose: To evaluate the feasibility and accuracy of using aluminum oxide doped with carbon (Al2O3:C) and beryllium oxide (BeO) optically stimulated luminescence (OSL) detectors for the purpose of measuring organ dose in a phantom for diagnostic radiology.
Methods: The energy response of each type of detector as a function of kVp and in-phantom depth was determined using blocks of Polymethyl methacrylate (PMMA) and an ionization chamber (0.4 cm³). The Al2O3:C detectors used in this study were cut from LuxelTM tape into 4 mm diameter circles of thickness 0.3 mm. The BeO detectors used in this study are ~4.7 mm x ~4.7 mm x 0.5 mm chips. Clinical irradiations were performed using a radiographic unit. The BeO signal was read using a Risø¸ TL/OSL-DA-15 automated reader and the Al2O3:C signal was read using a custom-built light emitting diode (LED)-based reader system. The results were compared to those obtained from LiF:Mg,Ti thermoluminescence detectors (TLD).
Results: The energy-dependent response as a function of depth within the phantom for BeO and Al2O3:C were found to be < 8% and < 10%, respectively. For comparison, the TLDs were found to have an energy-dependent response of ~8%. The OSL detectors both offered reproducibility better than 5%.
Conclusions: The proposed method of using BeO and Al2O3:C OSL detectors to perform in-phantom measurements has a comparable in-phantom energy response to that of TLD's and shows improved reproducibility of the measurements when compared to TLD's. Given the flexibility and accuracy of OSL detectors for various readout techniques, OSL detectors have a great potential to be used in clinical organ dose measurement for diagnostic x-ray exams.