Sentinel node biopsy in melanoma using technetium-99m rhenium colloid: the London experience

Area of Science:

• Oncology
• Surgical Oncology
• Nuclear Medicine

Background:

• Nodal metastases in melanoma significantly reduce survival by 50%.
• Elective lymph node dissection (ELND) effectiveness in improving survival remains controversial.
• Sentinel node biopsy (SNB) offers an accurate staging method for melanoma by tracing metastatic progression.

Purpose of the Study:

• To evaluate the efficacy and safety of sentinel node biopsy (SNB) in staging melanoma patients.
• To assess the accuracy of preoperative lymphoscintigraphy and intraoperative blue dye in SNB.
• To compare complication rates between SNB and completion lymphadenectomy.

Main Methods:

• Prospective study of 56 consecutive stage 1b or 2 melanoma patients.
• Preoperative lymphoscintigraphy using technetium 99m (99mTc) rhenium colloid or filtered sulfur colloid.
• Intraoperative guidance with a gamma probe and isosulfan blue dye for sentinel node identification.

Main Results:

• SNB achieved a 98% localization success rate (55/56 patients).
• Positive sentinel nodes were found in 12 patients, with a higher mean tumor thickness (3.7 mm) compared to negative SNB (1.8 mm).
• Complication rates were significantly lower for SNB alone (9%) versus completion lymphadenectomy (45%).

Conclusions:

• Sentinel node biopsy is a feasible and highly successful technique for accurate melanoma staging.
• SNB provides valuable staging information and is associated with fewer complications than traditional ELND.
• The study validates the clinical utility of 99mTc rhenium colloid for lymphoscintigraphy in SNB procedures.