[Sentinel lymph node identification in the staging of cutaneous melanoma. Blue dye vs. radioguided localization]

The purpose of this study is to emphasize the usefulness of combined intraoperative gamma-detecting-probe (C-Trak) and blue dye guided research of sentinel nodes (SN) in the treatment of cutaneous melanoma.

At the Department of General Surgery of Macerata Hospital, after informed consent, 22 consecutive patients (10 males and 12 females) with mean age 53 years (20-78 years) affected by histologically proved cutaneous malignant melanoma in stage I (TC, ultrasonography and bone scintigraphy) were studied by dynamic lymphoscintigraphy with 10.8-22.2 MBq of 99mTc albumin microcolloids 18-22 hours before surgery and by intradermal injection of blue dye at induction of anaesthesia. Intraoperative mapping technique to localize SN has been done by using a combination of a vital blue dye and a radioactive tracer.

A total of 42 SN were identified. Micrometastases were found in 2 (9.1%) patients; 13 SN were well-coloured (31%), 23 SN were poorly-coloured (55%), and 6 SN were not coloured (14%). Overall localization with blue dye was 86%. All SN were radiolabeled, but identification with gamma detecting probe was possible only in 41 cases (95%). Combined techniques was effective in 100% of cases.

Combined use of radiocolloids and blue dye is the gold standard for correct identification and biopsy of SN with 100% of favourable results. The technique is simple, fast and effective and permits to select the patients that need other surgical and oncologic procedures.