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

## TL;DR

Percutaneous ethanol injection is a safe and effective non-surgical treatment for locally recurrent papillary thyroid cancer, reducing tumor size and avoiding reoperation risks.

## Contribution

Demonstrates PEI as a viable alternative to surgery for recurrent papillary thyroid cancer with favorable safety and effectiveness outcomes.

## Key findings

- PEI reduced lesion volume by an average of 72.6% in patients with recurrent papillary thyroid cancer.
- 54% of treated lymph nodes were completely resolved following PEI treatment.
- Most patients tolerated PEI well with only mild side effects, though one case of Horner syndrome was reported.

## Abstract

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.

This study aimed to evaluate the safety and effectiveness of PEI in treating recurrent PTC.

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.

Most patients tolerated the treatment well, experiencing only mild local pain, though one patient reported Horner 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 - 0.34 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.

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.