ONCOLOGY, Santos AO

Abstracts XIX Brazilian Congress of Nuclear Medicine

7. ONCOLOGY

7.6 - DETECTION OF SENTINEL LYMPH NODE IN PATIENTS WITH MALIGNANT MELANOMA.

Santos AO, Martins AS, Tincani AJ, Melo GM, Steck JH, Lage HT, Valerio JB, Barros FB, Etchebehere ECSC, Ramos CD, Camargo EE. Division of Nuclear Medicine, Department of Radiology, Division of Head and Neck Surgery, Department of Surgery, Campinas State University (UNICAMP), and Medicina Nuclear de Campinas and MN&D - Medicina Nuclear Diagnóstico e Terapia - Campinas, Brazil.

allan@mn-d.com

Many reports have described the sentinel lymph node as the first lymph node infiltrated by regional lymphatic metastases. Selective biopsy of this node allows a more accurate staging of malignant melanoma and identifies patient (pts) groups that will benefit from lymph node dissection. Nine pts with malignant cutaneous melanoma (Clark IV, Breslow 1.8 – 3.5 mm, mean 2.7 mm) were studied. Six intradermal 1mCi injections of [Tc-99m] Dextran were performed around the lesion or biopsy scar. Dynamic images were acquired for 10 minutes, followed by static images with 30,000 counts every 5 minutes until visualization of the sentinel lymph node. The projection of the sentinel lymph node was labeled on the skin. The next day, at surgery, pts received an intradermal injection of toluidin blue. Surgical incision was performed at the site of the skin label and the sentinel lymph node identified by the dye stain. After excisional biopsy the lymph node was surveyed for radioactivity, and then sent to histopathology. Demonstration of the sentinel lymph node was possible in all pts. Histopathology showed micrometastases in 2 pts, that were then submitted to lymph node removal. In 7 pts the sentinel lymph nodes were not infiltrated and the surgical procedure was terminated. The detection of the sentinel lymph node was crucial to determine the surgical approach in all pts.