A new radioguided procedure for localization and surgical treatment of neck node metastasis of papillary thyroid cancer

Abstract

We intended to use a radioguided technique for pre-operative localization of neck node recurrences in patients with papillary thyroid cancer (PTC) already submitted to thyroidectomy and radioiodine treatment. We selected 20 patients affected by PTC with evidence of neck nodes recurrences at ultrasound examination. Our method has been derived from the Radioguided Occult Lesion Localization technique used for pre-operative localization of occult breast lesions. The technique involves the inoculation of human albumin macroaggregates labeled with radioactive technetium (0.4 mCi in a volume of 0.05 ml) directly in the suspicious lesion, under ultrasound guidance. The persistence of the radioactive tracer in the nodes is confirmed by a scintigraphy performed 2 h after injection. During surgery, a gamma detecting probe is used to locate the suspicious lesions as "hot spots". Fifty lymph-nodes were injected with the tracer. All radiolabeled lymph-nodes were located and removed during surgery. At histology, metastasis of PTC was confirmed in 38/50 (76%) lymph-nodes. At least one metastatic lymph-node per patient was removed. In 8/20 (40%) patients, reactive lymphoid hyperplasia was found in 12/50 (24%) lymph-nodes. This radioguided technique has been highly effective for localization and surgical treatment of suspicious lymph-node detected at neck ultrasound and may play a valuable role in case of node metastases of thyroid cancer that show no radioiodine uptake.