Localization of recurrent thyroid cancer using intraoperative ultrasound-guided dye injection

Background: Small, nonpalpable lymph node recurrences are frequently identified in the follow-up of patients with thyroid cancer, and finding and removing these lesions in a reoperative field can be very challenging. The goal of this study was to evaluate the utility of preincision ultrasound-guided injection of blue dye into the abnormal lymph nodes to facilitate their safe and efficient removal. Methods: We performed a prospective study between January and June 2007 at a single academic institution. Ten patients with isolated, nonpalpable nodal recurrences of papillary thyroid cancer underwent an operation for a neck recurrence (8 central, 2 lateral). A preincision ultrasound was performed in the operating room to localize the lesions, and 0.1 ml of blue dye was injected under ultrasound guidance into each abnormal lymph node. We examined the feasibility of the injection procedure, the accuracy of identifying pathologic lymph nodes, and the complications of injection. Results: The pathologic lymph nodes averaged 11 mm in size (range = 6-16 mm) and were detectable by ultrasound in all cases. Ultrasound-guided blue dye injection was successful in all cases. There were no complications related to dye injection. The blue node was easily identified and removed in all cases. The mean operative time was 80.4 min (range = 37-157 min). Conclusions: Blue dye injection was feasible and was very useful for the identification of lymph node recurrences, especially in the reoperative neck. There were no complications related to the injection in this series. Further study is needed to determine the widespread safety and efficacy of this technique.