Abstract Disclosure: R. Zweifler: None. J.G. Sanchez: None. D. Kuriloff: None. E.P. Liao: None. L. Poretsky: None. Background: Alternatives to surgery for thyroid microcarcinomas and symptomatic benign thyroid nodules include active surveillance and radiofrequency ablation (RFA). However, there is paucity of information regarding these management options for Hispanic Americans. Current data suggest that non-white Americans present with larger cancer-harboring nodules making the use of active surveillance less certain. Furthermore, no RFA studies to date specifically address this population. This study will create a registry of Latinx patients with thyroid neoplasms and investigate these nonsurgical interventions for benign and malignant lesions.Methods: This study involves a registry of adult Hispanic Americans with thyroid nodules and two branching studies. The registry will collect results of FNA, prior ultrasound, and thyroid function tests. Subjects will fill out THYPRO39 (thyroid-specific quality of life questionnaire), LUMP (laryngopharyngeal measure of perceived sensation questionnaire), and have cosmetic scorings. Evaluation will recur every 6 months. Eligible subjects may enroll in one of the branching studies. The first is active surveillance for registry patients diagnosed with small, low-risk papillary thyroid carcinoma wherein subjects would be monitored every 6 months with ultrasound as an alternative to surgery. Inclusion criteria are solitary thyroid nodule ≤ 1cm, well-defined tumor margin, tumor surrounded by ≥ 2 mm of normal thyroid parenchyma, and previous ultrasound-documented stability. Exclusion criteria are metastases to regional lymph nodes, local tumor invasion, tumor growth by 3 mm or ≥50% in volume, appearance of new nodules, or other thyroid or parathyroid disease requiring surgery. The outcomes are percentage change in volume and rates of conversion to surgery. The second branching study is RFA for subjects with benign symptomatic nodules. This subset would exclude subjects who are or planning to become pregnant, breastfeeding, have a cardiac pacemaker/defibrillator, have a nodule that is not predominantly solid, or who are on anticoagulants or dual anti-platelet therapy. Subjects would have visits at 1, 3, 6, 12, and 18 months for ultrasound, thyroid function tests, questionnaires, and cosmetic scorings. The primary endpoint is percent change of nodule size from baseline to 12 months. Adverse events, total ablation time, power emitted per subject, and conversion to surgery within 18 months will also be documented. After 12 months, if a nodule has not reduced by 50%, repeat ablation will be offered. Discussion: We hypothesize that active surveillance is a valid alternative to surgery for small, low risk papillary thyroid carcinoma and that RFA is a safe and effective alternative to surgery for benign, symptomatic thyroid nodules in Hispanic Americans. Our results will broaden knowledge of a population that has been under-represented in this field. Presentation Date: Saturday, June 17, 2023