Safety and Effectiveness of Percutaneous Ethanol Injection as a Treatment for Locally Recurrent Papillary Thyroid Carcinoma

Background: Reoperation for recurrent papillary thyroid cancer (PTC) is associated with a high risk of complications and limited success in achieving sustained remission. Percutaneous ethanol injection (PEI) presents a potential non-surgical alternative for managing locally recurrent PTC. Objectives: This study aimed to evaluate the safety and effectiveness of PEI in treating recurrent PTC. Methods: From October 2017 to September 2021, PEI was administered to 39 recurrent lesions (23 lateral and 16 central) in 17 patients with PTC. The median follow-up duration was 21.4 months (range, 4.1 - 37.9), with ethanol injections delivered every 3 months under ultrasound (US) guidance as needed. Results: Most patients tolerated the treatment well, experiencing only mild local pain, though one patient reported Homer syndrome following the procedure. In terms of treatment frequency, 31 lesions required 3 or fewer injections, while the remaining lesions required more. The mean initial volume of the lesions decreased from 0.12 mm3 (range: 0.06 - 034 mm3) to 0.03 mm3 (range: 0.0 - 0.14 mm3), representing an average reduction of 72.6% (range: 20.0 - 100.0%). Of the 39 lymph nodes treated in 17 patients, 21 lymph nodes (54%) were completely resolved. Seven lymph nodes remain under ongoing ethanol treatment, while 11 lymph nodes in 4 patients were addressed with alternative treatments, including surgery. Conclusions: Percutaneous ethanol injection appears to be a safe and effective treatment option for managing locally recurrent thyroid carcinomas in select patients. However, further comparative, prospective, long-term studies are needed to evaluate PEI's impact on patient survival and recurrence rates.