LBODP095 Radiofrequency Ablation Performed By Endocrinologists Is A Viable Treatment Option For Recurrent Thyroid Cancer In The Outpatient Community Setting In The United States

OBJECTIVE: To determine if radiofrequency ablation (RFA) performed by endocrinologists for recurrent thyroid cancer in the neck is a treatment option in the outpatient community setting in the USA. METHODS: A review of 9 patients with 12 recurrent thyroid cancer lesions in the neck who were treated with RFA was conducted (July 2020 to November 2021). Recurrence was defined as biochemical and structural identification of disease. Recurrence was confirmed with ultrasound guided fine needle aspiration (US-FNA) cytology and measurement of thyroglobulin (Tg) washout concentration in cases of papillary thyroid cancer (PTC) and calcitonin washout concentration in medullary thyroid cancer (MTC). Informed consent was obtained. RFA was done in the outpatient setting with standard aseptic techniques, conscious sedation, and local anesthesia. Real time US imaging was used to perform hydro-dissection and a limited "moving shot" technique with a medial to lateral approach. Node volume in mL (length x depth x width×0.525) and tumor markers were recorded before at 6 to 12 weeks and at 6 months (m) after RFA. The volume reduction percentage (VRP) for each nodule was calculated using the following equation: VRP = {[baseline volume in mL - final volume in mL]/baseline volume in mL}×100 A VRP of more than 50% was considered a significant response, and VRP of 100% was considered complete response. RESULTS: A total of 9 patients with 12 nodes were included in the study. 7 patients had nodal recurrence of PTC in the neck. RFA was recommended for 1 patient as palliative treatment while on treatment with chemotherapy. 1 patient had recurrent MTC. There were no serious complications. 6 m data was unavailable for 2 patients. 9 of 10 (90%) nodes for which data is available had a volume decrease of at least 50% at 6 m. The only patient without at least a partial response to therapy was on chemotherapy. 4 of the 10 (40%) metastatic nodes of papillary thyroid cancer had a complete response. Mean volume reduction for all lesions at 6 mos was 0.339 mL, P = 0. 012. Median change in Tg level at 6 months was 0.4 IU/ml with a downward trend in 4/5 (80%) of patients with recurrent papillary thyroid cancer who were not receiving chemotherapy. DISCUSSION: Complete response may be expected in about 40% of patients after RFA at 6 m, however, this may potentially be improved with extended follow up time or multiple RFA sessions. Patients who are not surgical candidates, refuse surgery, or require palliative treatment may be potential candidates for this procedure. Therefore, RFA appears to be a viable treatment option in selected patients with recurrent thyroid carcinoma. Presentation: No date and time listed