Retrospective evaluation of radioactive iodine ablation therapy in the Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features (NIFTP) and Thyroid tumors with uncertain malignity potential

Abstract

Background: Noninvasive Follicular Thyroid Neoplasm (NIFTP), Well differantiated thyroid tumor with uncertain malignity potential (WDT-UMP), follicular thyroid tumor with uncertain malignity potential (FT-UMP), and Hurtle cell neoplasia with uncertain malignity potential (HCN-UMP) have been included in the classification of thyroid tumors by WHO, with the incidence of thyroid cancer increasing every passing year. There is no consensus regarding the follow-up and treatment processes of these tumors. Our study aims to shed light on our clinical practice by evaluating the follow-up processes of the groups with and without radioactive iodine ablation in patients followed up with these diagnoses.
 Material and Methods: The 49 patients older than 18 years of age and followed for at least 12 months, who were performed subtotal and total thyroidectomy between 2015 and 2020 and were diagnosed with WDT- UMP, FT-UMP, HCN-UMP, and NIFTP according to histopathological examination were included to the study.
 Results: Tumor type rates did not differ between the groups that received and did not receive RAI treatment (p=0.361). The mean follow-up period did not differ between the groups that received and did not receive RAI treatment. Also the rates of RAI treatment according to tumor size did not differ (p=0.413). Tumor size was larger than 4 cm in 13 patients, and 1 patient from this group had received RAI treatment. Recurrence was not detected in the 49 patients included in our study who received or not receive RAI treatment. 
 Conclusions: Some studies recommend giving RAI to these borderline thyroid tumors larger than 4 cm. But in our study no recurrence was detected in patients who did not receive RAI. That supports the view that patients could be followed without RAI treatment even if they are large tumors.