Investigation of the effect of planning techniques on thyroid and lens absorbe doses in radiotherapy of left breast cancer by in vivo dosimetry: a prospective study

This prospective study aimed to measure the absorbe dose received by the thyroid and lens using thermoluminescent dosimeters (TLD) during treatment with three-dimensional conformal radiotherapy (3-DCRT) and intensity-modulated radiotherapy (IMRT) techniques for radiotherapy after breast-conserving surgery (BCS + RT) and radiotherapy after mastectomy (PMRT) patients and also to examine the accuracy of treatment planning system (TPS) doses. Computed tomography images of 40 breast cancer patients were obtained. A significant difference was observed between the TPS and TLD doses of the right and left lenses (p < 0.05). The mean thyroid dose measured in BCS + RT treatment was 598.0 and 1268.5 cGy for 3DCRT and IMRT techniques, respectively. In PMRT treatment, this value was 579.3 and 1148.1 cGy for 3DCRT and IMRT techniques, respectively. When evaluating the plans, the choice of treatment technique should be made taking into account that TPS data are incomplete.