Aim of the study: 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.
Patients and methods: 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".
Results: 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.
Conclusions: 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.