Date of Award
Medical Doctor (MD)
As the use of immunotherapy continues to expand in the field of cancer treatment, adverse effects including immune checkpoint inhibitor (ICI)-induced thyroiditis are commonly seen. The purpose of this study was to examine the role of 18F-FDG-PET/CT imaging in the detection of ICI-induced thyroiditis. Fourteen patients treated with ICI therapy for metastatic cancer between September 2016 and November 2019 were identified through a retrospective chart review and confirmed to have thyroid dysfunction on PET/CT scans and laboratory analysis. Eight patients treated with ICI therapy who had PET/CT imaging and no thyroiditis were selected to be the control group. SUVmax and SUVmean of the thyroid and liver on baseline and post-therapy scans were evaluated. Thyroid SUVmax and SUVmean values on post-therapy scans among patients with thyroiditis were found to be significantly higher compared to patients without thyroiditis (mean SUVmax = 5.30, 2.02, respectively; P = .002; mean SUVmean = 4.47, 1.60; P = .001). Objective threshold values of thyroid SUVmax > 2.9, thyroid SUVmean > 2.4, and thyroid SUVmax/liver SUVmean > 1.25 could perfectly distinguish the thyroiditis patient group from the control group. Other effective methods of identification were thyroid SUVmax > liver SUVmax and a Deauville 5-Point Scale score of 4 or greater.
Zhang, Amy, "The Role Of Pet/ct In The Identification Of Immunotherapy-Related Thyroiditis" (2021). Yale Medicine Thesis Digital Library. 4044.