Background: Radiotracers have become a routine technical component of the new procedure of intraoperative lymphatic mapping and selective lymphadenectomy. Because different colloids have differing physicochemical properties, their distribution and uptake may be different. For this reason, the optimal colloid to identify and localize the sentinel node remains controversial.
Methods: Nineteen consecutive patients with cutaneous malignancies underwent diagnostic lymphoscintigraphy with99mTc-labeled human serum albumin (99mTc-HSA) and preoperative lymphoscintigraphy with99mTc-labeled sulfur colloid (99mTc-SC). The results of intraoperative lymphatic mapping and selective lymphadenectomy were reviewed.
Results: Intraoperative lymphatic mapping and selective node dissection were successful in 21 of 22 lymphatic basins (18 of 19 patients). There was excellent correlation between the “hot” marker placed on the skin surface when99mTc-HSA was used compared with the use of99mTc-SC. In 20 of 21 lymphatic basins the sentinel node both was “hot” and was stained with isosulfan blue.
Conclusions: No discernible difference between the ability to localize in the sentinel node with these two radiocolloids was identified. For logistical reasons,99mTC-SC appears to be the colloid of choice in intraoperative lymphatic mapping.
MelanomaSentinel lymph nodeTechnetium-labeled human serum albuminTechnetium-labeled sulfur colloid