Investigation of the effect of dental implants on dose distribution of high energy electron beams with Monte Carlo method

The accuracy of the dose calculated by treatment planning systems is very important for the success of treatment in cancer patients receiving radiation therapy. Titanium dental implants of the patient who has a radiation treatment of head and neck cancer, have a high atomic number and has a significant effect on the dose distribution. In this study, dose distributions on a dental phantom with different number of titanium implants were obtained by Monte Carlo algorithm and GAFChromic EBT3 radiochromic film in treatment planning system. The dental phantom with different number of titanium alloy dental implants was designed and produced by us to examine the effect of radiation implants on the dose distribution of the dental implants. On the produced dental phantom that irradiated with 15 MeV energy electron beam and 6 MV energy photon beam, the dose distribution which is calculated by with Monte Carlo algorithm in the treatment planning system had compared with measured dose by GAFChromic EBT3 radiochromic film. Effects of titanium implants on dose distribution were determined by 3-D gamma index analysis. Comparisons of dose distribution which is measured by GAFChromic EBT3 film and is calculated by TPS, were made by 3-D gamma analysis method with selection of 3 mm as DTA criterion and 3% DD as global maximum dose. It was seen that the results of the gamma analysis of the comparisons are between 97% and 98.1% for the photon beam and between 95.9% and 98% for the electron beam.