Radioactive iodine therapy for follicular thyroid cancer: a 15 years follow-up study of Chinese patients.

PURPOSE: To identify long-term predictors of distant metastases (DM) and the overall survival (OS) of follicular thyroid cancer (FTC) patients who underwent radioactive iodine (RAI) therapy. And to expand the knowledge about the clinical course and experience of RAI treatment for FTC. MATERIALS: A total of 117 FTC patients who underwent RAI therapy at our institution from 2005 to 2020 were retrospectively studied. Patient characteristics, serum stimulating thyroglobulin (sTg) and thyroglobulin antibody levels, treatment process and follow-up data were collected until 26 April 2022. RESULTS: A total of 16 patients (13.7%) were lost to follow-up. A total of 23 (19.7%) patients with DM died and all FTC without DM were still alive. DM was seen in 58.4% (59/101) of patients. The most common location for metastatic lesions was the lung. Then was bone. The mean survival time of FTC with RAI was 156 months [95% confidence interval (CI): 142-171]. Five-year and 10-year cumulative survival rates of them were 88.8% and 67.4%, respectively. As for patients with DM were 80.4% and 41.3%, respectively. Age at diagnosis [odds ratio (OR) = 1.080, P  = 0.009], RAI therapy sessions (OR = 2.959, P  = 0.001) and sTg level (OR = 1.006, P  = 0.002) were predictive of DM occurrence in FTC with RAI. In the group of FTC with DM, survival analysis showed that males were more likely to have a lower OS than females ( P  = 0.039). CONCLUSION: Age, number of RAI therapy sessions, and sTg level were predictive of the occurrence of DM in FTC patients with RAI. Sex would influence the OS of FTC patients with DM.