Radio-guided excision of metastatic lymph nodes in thyroid carcinoma: a safe technique for previously operated neck compartments.

Background: Better follow-up of patients with papillary thyroid cancer (PTC) and more sensitive detection leads to detection of recurrences in the neck. Despite excellent outcomes, the major challenge is controlling locoregional recurrence. We aimed to investigate whether the radio-guided excision of metastatic lymph nodes makes it possible to find the affected lymph nodes in patients with previously operated neck compartments.

Method: This prospective study included 46 patients with recurrent/persistent PTC who had previously undergone operation of the neck compartment. Prior to operation, the pathologic node was localized by ultrasound (US) and radiotracer ((99m)Tc-labeled rhenium colloid) was injected directly into the pathologic node. Careful dissection was carried out following the area of maximum radioactivity until the metastatic lymph node(s) were identified and excised.

Result: One affected lymph node was removed in 17 patients, and more than one lymph node (affected or additional nodes) was removed in 29 patients. The median count from the lesion was significantly higher than values from the lesion bed (background activity) (16,886 counts/20 s versus 52 counts/20 s; p < 0.001). During follow-up, four patients were lost to follow-up and 27 patients had negative US and basal thyroglobulin (Tg). Five patients had suspicious lymph nodes on the operated side. Although the basal Tg level remained above the normal limit, moderately high in 8 patients, no metastases were detected in the neck.

Conclusions: Radio-guided excision of metastatic lymph nodes can be performed safely for the detection and excision of recurrent thyroid cancer in the central and lateral neck.