Percutaneous Ultrasound-Guided Laser Ablation Is Effective for Treating Selected Nodal Metastases in Papillary Thyroid Cancer

Abstract

Mini-invasive procedures may be useful for control of local neck nodal metastases of papillary thyroid cancer (PTC) in high-risk patients. Our objective was to assess the effectiveness and safety of ultrasound (US)-guided laser ablation (LA) for nonsurgical treatment of small-size neck metastases of PTC. We conducted a pilot study on a surgically controlled metastasis, followed by a prospective trial with a 12-month follow-up. Participants included five patients with previous total thyroidectomy and neck dissection for PTC, with eight new lymph node metastases in an area already treated with surgical dissection and lymph node volume less than 2 ml and absent radioiodine uptake. We evaluated thyroglobulin (Tg) and US changes of the lymph nodes 6 and 12 months after LA as well as tolerability and side effects of the procedure. A single LA treatment induced progressive volume reduction of the eight metastatic lymph nodes. Mean baseline volume decreased from 0.64 ± 0.58 to 0.07 ± 0.06 ml at 12-month control. Mean volume reduction was 64.4 ± 0.19% at 6 months (P < 0.02 vs. baseline) and 87.7 ± 0.11% at 12 months (P < 0.01 vs. baseline). No regrowth was registered. Mean serum Tg on LT4 decreased from 8.0 ± 3.2 ng/ml to 2.0 ± 2.5 ng/ml at 12-month control (P < 0.02 vs baseline). In three patients (60%) Tg levels were undetectable at 12-month control. Pain was tolerable in two cases and mild in three cases. Transient dysphonia in one patient was the only complication. After 1 yr, no cancer seeding was present. LA is a well-tolerated outpatient procedure that results in a rapid cytoreduction of cervical nodal metastases of PTC. Mini-invasive procedures may be used in lieu of surgery as an adjunctive therapy for small-burden local/regional disease recurrence. They are occasionally associated with an anatomical or biochemical cure, but long-term follow-up or controlled trials are needed.