Thyroid dose as a result of radiation therapy for head and neck malignancies in Ramezanzadeh radiotherapy center of Yazd

In recent decades, radiotherapy has been had a fundamental role in the treatment of cancers.The tumor control probability (TCP) and lowest risk in normal tissue is the aim of radiotherapy techniques. The radiation sensitivity of thyroid glands increases cancer risk of scattering radiation and induces hypothyroidism. In this study, the average thyroid dose due to head and neck radiotherapy in the patients referred to Ramezanzadeh radiotherapy center of Yazd was measured.Dosimetry was achieved by TLD measurement and TPS calculations methods.The results showed that the absorbed dose of thyroid in head and neck radiotherapy and in whole-brain radiotherapy were 4.37 and 0.7 percent of the prescription dose, respectively. The mean of thyroid absorbed dose was less than the tolerance threshold dose.