Characterization of commercial MOSFET detectors and their feasibility for in-vivo HDR brachytherapy

Abstract Aim The present study was to investigate the use of MOSFET as an vivo dosimeter for the application of Ir-192 HDR brachytherapy treatments. Material and methods MOSFET was characterized for dose linearity in the range of 50–1000 cGy, depth dose dependence from 2 to 7 cm, angular dependence. Signal fading was checked for two weeks. Result and discussion Dose linearity was found to be within 2% in the dose range (50–1000 cGy). The response varied within 8.07% for detector-source distance of 2–7 cm. The response of MOSFET with the epoxy side facing the source (0 degree) is the highest and the lowest response was observed at 90 and 270 degrees. Signal was stable during the study period. Conclusion The detector showed high dose linearity and insignificant fading. But due to angular and depth dependence, care should be taken and corrections must be applied for clinical dosimetry.