SENTINEL NODE IN DIFFERENTIATED THYROID CANCER: COMPARISON BETWEEN VITAL-DYE PATENT BLUE, LYMPHOSCINTIGRAPHY AND COMBINED TECHNIQUE

Obiettivo dello studio : aim of the study is to evaluate the role of sentinel node (SN) identification in the treatment of differentiated thyroid cancer (DTC). We also aim to assess feasibility and reproducibility of the SN techniques with vital-dye patent blue, radiotracer and combined technique Materiali e metodi : the study is multicentric, prospective, randomized three arms open. We expect to enroll 120 patients in 2 years. Patients have to be preoperative diagnosis of DTC. Exclusion criteria are previous cervical surgery, medullary cancer, nodes metastasis and multifocal tumor. All patients undergo total thyroidectomy, SN identification and central compartment (CC) dissection: in Arm A SN identification is obtained with vital-dye Patent blue technique, in Arm B with lymphoscintigraphy and in Arm C with combined technique. Specimen histopathology provides information about the characteristics of primary tumor, SN and the remaining nodes with specific immuno-histochemistry protocols Principali risultati : so far we enrolled 42 patients Arm A (26 pts): 18 patients (69.2%) had negative SN and nonSN; 1 (3.8%) with negative SN had micrometastasis in 2 nodes of CC; 2 (7.6%) with macrometastasis in the SN had metastatic nodes in the CC and 1 (3.8%) had macrometastasis in the SN with no other positive nodes. In 4 (15.2%) patients identification of the SN wasn't possible and there was no evidence of metastasis in all nodes removed Arm B: 2 patients (100%) had negative SN and nonSN Arm C (14 pts): 4 patients (28.6%) had negative SN and nonSN; 1 (7.1%) with negative SN had macrometastasis in 2 nodes; 4 (28.6%) with macrometastasis in the SN had metastatic nodes in the CC and 1 (7.1%) had macrometastasis in the SN with no other positive nodes. In 4 (28.6%) patients identification of the SN wasn't possible and in 3 of them there was no evidence of metastasis Conclusioni : so far the data we gathered are too few to make statistic significant conclusions. Once adequate scientific evidence is available, detection of the SN could become a routine procedure in DTC treatment, avoiding central compartment dissection in patients with negative SN. The achievement of a standard protocol of SN detection remains an important issue to solve, although both techniques had shown a good rate of detection of the SN, several studies report that the combined method could reduce false negatives and increase detection rates of SN metastases