Assessment of dose change depending on different radiation energy for different tooth fillings in radiotherapy applications

Objective: Assessment of the dose distribution calculated in the treatment planning syatem in head and neck patients with dental fiiling material and testing of the accuray with dosimetric systems. Method: In our study, phantoms created using different tooth filling materials, CT images were taken and treatment plans were applied at different energies. In computed tomography (CT) images taken during radiotherapy treatment planning of head and neck patients, it was understood that artefacts arising from the dental fill material adversely affected both image quality and uncertainties in Hounsfield Unit (HU) values required for planning. The plans were divided into two groups, artefact corrected and artefact corrected, using 6 MV and 18 MV energies, and the variation of the isodose distribution according to the parameters indicated was investigated. Then phantoms formed in the linear accelerating device were subjected to two-dimensional dose distribution with Matrixx and point dose measurements with the ion chamber. Result: The profiles obtained in the Matrixx measurements show the variation of the dose, the profile reflection of the actual length of the material used, and the back scattering and weakening of the beam by the two-dimensional dose intensity map, depending on the material used. Ion chamber measurements have also investigated the change in dose in phantoms created using tooth fill material. This change was measured in the most prominent amalgam, while the teeth and the least composite were measured. Conclusion: Artifacts arising from dental filling materials that are encountered in the treatment areas of head and neck patients need to be corrected while planning. The inability of the planning system to accurately detect materials that are particularly dense, to calculate backscatter and reductions in the dose causes uncertainty in the dose given to the patient to increase. Keywords: Radiotherapy, Computed Tomography, Treatment Planning System, Dental Filling Materials