Implementation of in-vivo diode dosimetry for intensity modulated radiotherapy as routine patients' quality assurance

The implementation of an in-vivo diode for dose verification of the intensity-modulated radiotherapy (IMRT) during the actual treatment being rare. This work aims to implement in-vivo and in-vitro diode dosimetry for the IMRT technique to verify the accuracy of the dose delivered to the patients undergoing radiation treatment. In total, 279 fields have been investigated for dose verification from 33 cases, including head and neck, prostate, bladder, and breast cancer patients. Additionally, these fields were compared with in-vitro measurements on a perspex phantom. Beforehand, the measurements were tested for an Alderson Rando phantom. In-vivo measurements revealed that 87.1% of the measured doses were within +/- 5% of the calculated doses. Of the other 12.9%, about 11.1% were more than +/- 5% and less +/- 10% and only 1.8% were outside the +/- 10% of the calculated doses. The corresponding fields for in-vitro measurements show that 96.1% of the measured doses within +/- 5% and only 3.9% were outside the +/- 5% of the calculated doses. The results in this study indicated that in-vivo diode dosimetry for IMRT is reliable as a quality assurance (QA) tool in the radiotherapy departments. Moreover, measurements with diodes are a real-time readout during actual treatment compared to the verification tools that have been used for routine IMRT QA. Additionally, the measurements were carried out comfortably and well tolerated by the patients.