Sonographic appearance of thyroid glands in patients treated with intensity-modulated radiotherapy or conventional radiotherapy for nasopharyngeal carcinoma

ABSTRACT Background This study aimed to investigate the sonographic appearances of the thyroid glands in nasopharyngeal carcinoma (NPC) patients whose cervical lymph nodes were treated with conventional radiotherapy (RT) or intensity‐modulated radiotherapy (IMRT). The post‐RT sonographic appearances of the thyroid glands in NPC patients were also correlated with the thyroid function. Methods One hundred and three NPC patients who had completed RT of cervical lymph nodes using the anterior cervical field, 30 NPC patients who had completed RT of cervical lymph nodes using IMRT, and 61 healthy subjects were included in the study. Thyroid glands were sonographically assessed for their size, echogenicity, vascularity, and internal architecture. Thyroid function tests were also performed on each subject. Results In comparison with the patients with abnormal thyroid function, the thyroid glands of the patients with normal thyroid function tended to be homogeneous and to have greater volume and echogenicity index (p