Endocrine Abstracts

Introduction: Childhood papillary thyroid carcinoma (CPTC), despite bilateral thyroidectomy (BT), nodal resection and radioiodine remnant ablation (RRA), recurs within neck nodal metastases (NNM) in >30% within 20 postoperative years. However, these NNM are usually treated with re-operation or further radioiodine; US-guided ethanol ablation (EA) may be considered (j.sempedsurg.2020.150920) for patients with limited numbers of NNM

Methods: We studied long-term results of EA in 14 patients presenting with intermediate or high-risk CPTC during 1978-2013 and having EA for NNM at Mayo Clinic during 2001-18. Prior to EA, all had undergone BT and in 93% RRA. Cytologic diagnosis of 20 NNM (median diameter 9mm; median volume 203 mm³) was confirmed by US-guided biopsy. EA was typically performed during two outpatient sessions under local anesthesia; total volume injected ranged from 0.1-2.8cc, median 0.7cc. All ablated patients were followed regularly by sonography and underwent volume re-calculation and intra-nodal Doppler flow measurements at each visit. Successful ablation required elimination of nodal vascularity and reduction in NNM volume.

Results: The ablated patients were followed for 46-209 months since EA (median 14.3 years). There were no complications, including post-procedure hoarseness. All 20 NNM shrank (mean 87%) and Doppler flow eliminated in 93%. Median NNM volume reduction in 7 identifiable foci was 72%; after EA 13 NNM (65%) disappeared on sonography; 89% disappearing in early recurrences and 45% in those diagnosed after 7-31 postoperative years (median 19). Median serum thyroglobulin post-EA was 0.6 ng/mL. 19 ablated NNM exhibited no tumor regrowth; one (of 20) was re-ablated after 15 years. Two patients with new recurrent NNM chose re-operation.

Discussion/Conclusions: EA of NNM in CPTC is effective and safe. Our results suggest that for CPTC patients, who do not wish further surgery and are uncomfortable with active surveillance of biopsy-proven NNM, EA represents a minimally invasive management option.