Radiofrequency ablation and percutaneous ethanol injection treatment for recurrent local and distant well-differentiated thyroid carcinoma

Abstract

Objective: To assess the long-term efficacy of radiofrequency ablation (RFA) and percutaneous ethanol (EtOH) injection treatment of local recurrence or focal distant metastases of well-differentiated thyroid cancer (WTC).

Background: RFA and EtOH injection techniques are new minimally invasive surgical alternatives for treatment of recurrent WTC. We report our experience and long-term follow-up results using RFA or EtOH ablation in treating local recurrence and distant focal metastases from WTC.

Methods: Twenty patients underwent treatment of biopsy-proven recurrent WTC in the neck. Sixteen of these patients had lesions treated by ultrasound-guided RFA (mean size, 17.0 mm; range, 8-40 mm), while 6 had ultrasound-guided EtOH injection treatment (mean size, 11.4 mm; range, 6-15 mm). Four patients underwent RFA treatment of focal distant metastases from WTC. Three of these patients had CT-guided RFA of bone metastases (mean size, 40.0 mm; range, 30-60 mm), and 1 patient underwent RFA for a solitary lung metastasis (size, 27 mm). Patients were then followed with routine ultrasound, I whole body scan, and/or serum thyroglobulin levels for recurrence at the treatment site.

Results: No recurrent disease was detected at the treatment site in 14 of the 16 patients treated with RFA and in all 6 patients treated with EtOH injection at a mean follow-up of 40.7 and 18.7 months, respectively. Two of the 3 patients treated for bone metastases are free of disease at the treatment site at 44 and 53 months of follow-up, respectively. The patient who underwent RFA for a solitary lung metastasis is free of disease at the treatment site at 10 months of follow-up. No complications were experienced in the group treated by EtOH injection, while 1 minor skin burn and 1 permanent vocal cord paralysis occurred in the RFA treatment group.

Conclusions: RFA and EtOH ablation show promise as alternatives to surgical treatment of recurrent WTC in patients with difficult reoperations. Further long-term follow-up studies are necessary to determine the precise role these therapies should play in the treatment of recurrent WTC.

Figures

FIGURE 1. A 42-year-old woman with previous thyroidectomy for papillary carcinoma develops a 1.5-cm solitary lymph node metastasis in the right jugular chain. The patient refused surgery. Sagittal gray scale ultrasound image prior to ablation shows a rounded hypoechoic metastatic lymph node (arrow).

FIGURE 2. Color Doppler image of metastatic lymph node displayed in gray scale shows extensive hypervascularity (arrow).

FIGURE 3. Sagittal gray scale ultrasound image of treated lymph node 3 months after RFA shows increased internal echogenicity (arrow).

FIGURE 4. Color Doppler image of metastatic lymph node displayed in gray scale 3 months after RFA shows loss of the internal hypervascularity (arrow). At 51 months of follow-up, the patient remains disease free.