Retrospective study of association of thyroid radiation dose with thyroid dysfunction in LA NSCLC patients receiving CCRT followed by maintenance immunotherapy

A retrospective study at Yonsei University College of Medicine (Seoul, South Korea) included 250 locally advanced non-small cell lung cancer patients receving concurrent chemoradiotherapy (CCRT) followed by maintenance immunotherapy (IO). During CCRT, 64 of these patients received incidental irradiation of the supraclavicular fossa occurred (SCFi group). By a median follow-up time of 16.6 months, 23 of 64 patients (35.9%) in the SCFi group and 27/186 patients (14.5%) in the non-SCFi group developed thyroid dysfunction (p<0.001). The authors conclude that incidental irradiation of the thyroid during CCRT is associated with an increased risk of thyroid dysfunction during maintenance IO. This supports the need to minimize the thyroid dose.