By Robert Saunders

NEW YORK (Reuters Health) – When papillary thyroid cancer spreads to lymph nodes in the neck, percutaneous laser ablation may spare patients further invasive surgery.

That conclusion is from a study conducted in Italy and Israel. “Our results have to be considered as preliminary, because they are based on a small series of patients,” lead investigator Dr. Giovanni Mauri commented via email. “So no strong recommendation can be made on the basis of this article, but it is crucial to perform further studies, because the results are very promising.”

Still, he added, “We are very happy about our results, because we were able to treat successfully a large majority of patients who were referred to us because surgeons thought it would have been highly risky to operate on their neck again — all patients had a history of several neck surgeries.”

Dr. Mauri, at Azienda Ospedaliera Ospedale di Circolo di Busto Arsizio in Italy, and colleagues performed percutaneous laser ablation (PLA) in 15 patients with 24 cervical nodal metastases who had already undergone resection of papillary thyroid cancer with radioiodine ablation.

“The technique requires confidence with percutaneous ablations, and particularly with laser ablation, and has to be reserved to experienced interventional oncologists,” Dr. Mauri cautioned.

As described in the Journal of Clinical Endocrinology and Metabolism online May 10, the laser ablation procedure is performed under local anesthesia with contrast-enhanced ultrasound guidance. “One or two (according to lymph node size and shape) introducer needles were inserted into the lymph node. Subsequently, a 300-micrometer quartz bare optic fiber with a plane cut tip was introduced and advanced up to the introducer needle tip. The introducer needle was then withdrawn to expose the fiber by at least 5 mm. The optic fibers were then connected with the laser source, a continuous-wave Nd-YAG laser operating at 1.064 mm.”

The procedure proved technically feasible in all cases, according to the report. Complete ablation of the node, as visualized by contrast-enhanced ultrasound, was 100% successful.

On follow-up at six months, local control was documented in 11 of the 15 patients. Using PET/CT imaging, the authors found that 20 of the 24 nodes were negative; the other four were positive.

By 12 months, one patient with extensive disease had been excluded from the study. Among the remaining 14 patients, local control was still evident in 10, and 16 of 20 nodes were negative.

There were no serious complications, the team reports. One case of neck discomfort and change in voice tone resolved spontaneously after a month.

Three patients had distant metastases at follow-up. “In these patients the morbidity of a highly invasive radical neck dissection was spared,” Dr. Mauri pointed out in his email. In fact, he added, “PLA may be useful as part of a “test-of-time” approach to spare the morbidity of complex surgical resections in patients who will ultimately develop additional metastases.”

Whether lymph node dissection should be routine at the time of thyroidectomy or performed only if patients develop positive nodes, is currently debated, the authors note in their paper.

“If our results are confirmed,” they suggest, “we envision a scenario where low-risk patients could be treated with thyroidectomy alone and with PLA in case of development of metachronous lymph node metastases, with the advantage of reducing the number of unnecessary preventive dissections and of minimizing the morbidity of a second operation in patients with metachronous lymph node metastases.”

SOURCE: Percutaneous Laser Ablation of Metastatic Lymph Nodes in the Neck From Papillary Thyroid Carcinoma
J Clin Endocrin Metab 2013.