Characterization Of Optically Stimulated Luminescent Dosimeters Used For Dosimetry In Mammography

Abstract

Mammography is currently the most effective method for detecting breast cancer early. As it is an exam that uses ionizing radiation, it is necessary to monitor and optimize the doses received by patients, to guarantee high quality images with the lowest dose. One method of monitoring dose to the breast is by measuring skin entry kerma using dosimeters and calculating the mean glandular dose (MGD). There are several dosimeters that can be used for this, such as thermoluminescent dosimeters (TLD) and optically stimulated dosimeters (OSLDs). However, as the response of the OSL dosimeter differs depending on the energy used, to guarantee the use of this type of dosimeter, there is a need to characterize its limits, reproducibility, precision and evaluate the energy dependence. The objective of this work is to characterize the OSLDs for the energy range used in mammography and evaluate results of measurements carried out in mammography services in the country between the years 2020 and 2022 using this type of dosimetry. For this, the lower limit of detection (D_LID), reproducibility, statistical precision, sensitivity factor and calibration factors were determined. As a result, D_LID = 18.5035 ± 0.0009 µGy, sensitivity factors between 0.91 and 1.07 and calibration factors between 0.248916 and 0.294323 µGy/Reading were found. It was concluded that the lower limit of detection of OSLDs is capable of detecting values close to 98% lower than the minimum dose used in mammography exams and that the sensitivity factors determined improve the reproducibility of dosimeters when using large batches.