ODP468 Checkpoint Inhibitor Immunotherapy- related Thyroid Disorders and Iodine Contrast Studies

INTRODUCTION: Checkpoint Inhibitor Immunotherapy (CII) has been linked to multiple endocrinopathies. Thyroid dysfunction is more frequently associated with anti-PD-1 and anti-PD-L1 monoclonal antibody use, yet there are no good predictors for the development of thyroid complications after immunotherapy treatment. Iodinated contrast studies have been related to the development of thyroid dysfunction, and are frequently used in the oncology patient population for surveillance of malignancy and response to treatment. METHODOLOGY AND RESULTS: We conducted a retrospective observational study to identify any potential association between the development of thyroid dysfunction and exposure to iodinated contrast studies in patients receiving CII. A chart review was conducted from 2012-2020. Data analysis was performed using Chi-square. Using ICD codes, 236 patients with new thyroid dysfunction after initiation of CII, and no alternative etiology for the thyroid dysfunction, were included. Out of these, 162 (68.6%) patients developed hypothyroidism, 71 (30%) developed thyrotoxicosis initially and subsequently developed hypothyroidism, and 3 (1.27%) developed hyperthyroidism. Of the total patients who developed thyroid dysfunction following CII, 145 vs.91 patients received ≥3 contrast studies, (p. 0. 0004). DISCUSSION: These findings suggest that there is an association with the use of three or more iodinated contrast studies and the development of thyroid dysfunction in patients receiving CII. More research is needed to identify additional predictors that could be utilized in clinical practice for earlier detection of patients at risk of developing CII related thyroid dysfunction. CONCLUSION: Thyroid dysfunction following the use of CII, namely anti-PD-1 and anti-PD-L1 therapies, remains prevalent; however, it has been difficult to identify who is most at risk for this complication. This is the first study examining exposure to iodinated contrast and its potential contribution to CII thyroid endocrinopathy, and it warrants further investigation. Presentation: No date and time listed