The Role of Trop2 in Radioactive Iodine-131 Therapy Sensitivity in Papillary Thyroid Carcinoma

Clinincal data and pathological specimens from patients who had undergone at least one radioactive iodine-131 (\^131I) therapy in the Department of Nuclear Medicine at Jiangxi Cancer Hospital over the past 8-10 years were retrospectively collected (approximately 30-50 cases each in the \^131I treatment-responsive group vs. the \^131I treatment-resistant group). Patients in the \^131I treatment-resistant group underwent \^18F-Trop2 PET-CT imaging. Inclusion criteria: 1. History of total thyroidectomy with postoperative pathology confirming papillary thyroid carcinoma (PTC); 2. At least one course of \^131I internal radiotherapy. Exclusion criteria: 1. Presence of other severe comorbidities; 2. Incomplete clinical or follow-up data. The clinicopathological characteristics and Trop2 expression levels in tissue samples were compared between the \^131I treatment-responsive group and the \^131I treatment-resistant group. Within the \^131I treatment-resistant group, comparisons were made between the rapidly progressing subgroup and the stable-disease subgroup under TSH-suppressive therapy in terms of clinicopathological features, tissue Trop2 expression levels, and SUVmax of metastatic lesions on \^18F-Trop2 PET-CT imaging. Factors influencing progression-free survival and overall survival in \^131I-resistant patients were analyzed.