Tomohiro Itonaga1, Kazuhiro Saito1, Norihiko Ikeda2, Ryuji Mikami1. 1. Department of Radiology, Tokyo Medical University Hospital, Tokyo, Japan. 2. Department of Thoracic Surgery, Tokyo Medical University Hospital, Tokyo, Japan.
Abstract
BACKGROUND: Fully human IgG4 programmed cell death-1 (PD-1) immune checkpoint inhibitors are effective against non-small-cell lung cancer (NSCLC). PD-1-targeted antibodies induce autoimmune adverse events that are not caused by conventional chemotherapy. PURPOSE: To clarify the association between morphological changes of the thyroid gland and the efficacy of PD-1 immune checkpoint inhibitor treatment for lung cancer. MATERIAL AND METHODS: The study enrolled 29 patients who received PD-1 immune checkpoint inhibitor treatment. The thyroid volume was measured using computed tomography (CT) at the following three timepoints: pre-treatment (baseline); three months after the initial administration (early treatment); and at the last CT scan during the observation period (late treatment). Thyroid volume ratios were calculated as follows: early treatment/baseline thyroid volume at CT (E/B-CT ratio) and late treatment/baseline thyroid volume at CT (L/B-CT ratio). Thyroid dysfunction was assessed according to thyroid hormone levels. RESULTS: The E/B-CT ratio was significantly higher in patients with adverse events of grade 3 or higher than in the other patients (P = 0.013). The L/B-CT ratio was significantly lower in patients with thyroid dysfunction than in those without thyroid dysfunction (P = 0.001). Complete response (CR) was achieved in three patients at the time of the final CT. The E/B-CT ratio was significantly higher in patients with CR than in the other patients (1.48 vs. 0.99, P = 0.029). CONCLUSION: Changes in thyroid volume after administration of PD-1 immune checkpoint inhibitors might be a useful radiographic marker of therapeutic efficacy in patients with lung cancer.
BACKGROUND: Fully human IgG4 programmed cell death-1 (PD-1) immune checkpoint inhibitors are effective against non-small-cell lung cancer (NSCLC). PD-1-targeted antibodies induce autoimmune adverse events that are not caused by conventional chemotherapy. PURPOSE: To clarify the association between morphological changes of the thyroid gland and the efficacy of PD-1 immune checkpoint inhibitor treatment for lung cancer. MATERIAL AND METHODS: The study enrolled 29 patients who received PD-1 immune checkpoint inhibitor treatment. The thyroid volume was measured using computed tomography (CT) at the following three timepoints: pre-treatment (baseline); three months after the initial administration (early treatment); and at the last CT scan during the observation period (late treatment). Thyroid volume ratios were calculated as follows: early treatment/baseline thyroid volume at CT (E/B-CT ratio) and late treatment/baseline thyroid volume at CT (L/B-CT ratio). Thyroid dysfunction was assessed according to thyroid hormone levels. RESULTS: The E/B-CT ratio was significantly higher in patients with adverse events of grade 3 or higher than in the other patients (P = 0.013). The L/B-CT ratio was significantly lower in patients with thyroid dysfunction than in those without thyroid dysfunction (P = 0.001). Complete response (CR) was achieved in three patients at the time of the final CT. The E/B-CT ratio was significantly higher in patients with CR than in the other patients (1.48 vs. 0.99, P = 0.029). CONCLUSION: Changes in thyroid volume after administration of PD-1 immune checkpoint inhibitors might be a useful radiographic marker of therapeutic efficacy in patients with lung cancer.