Staging patients with cutaneous malignant melanoma by same-day lymphoscintigraphy and sentinel lymph node biopsy: a single-institutional experience with emphasis on recurrence.

BACKGROUND AND OBJECTIVES: Different techniques have been employed in mapping sentinel lymph nodes (SLN) in patients with malignant melanoma (MM). We present a single-institutional experience.

METHODS: Sentinel lymph node biopsies were performed in a consecutive series of 278 patients with 279 cutaneous MMs in clinical stage I. All underwent dynamic lymphoscintigraphy with 15-20 MBq 99mTc-rhenium-colloid followed on the same day by radioprobe-guided surgery completed approximately 4 hr after injection of radiopharmaceutical.

RESULTS: In 274 (98.2%) cases, a median of two SLNs (range 1-7) were removed. In five patients, no SLN was removed. Seventy-nine patients (28%) had metastatic SLNs. Median Breslow thickness in this group was 2.3 mm. Nodal dissection of the positive basin was done in 75 of these 79 patients and revealed further positive lymph nodes in 10 (13%). Eighteen of the 79 (23%) patients died after a median of 17.5 months post-operatively from metastatic disease. In 195 cases (194 patients) (70%), removed SLNs were negative. The median Breslow thickness in this group was 1.6 mm. Four patients (2%) had regional lymph node recurrence ("false negative SLN procedures"). Eight of the 194 patients (4.1%) died after a median of 24.5 months post-operatively from metastatic disease. One of these was one of the four patients with a false negative SLN procedure, and in all eight, histological re-evaluation of SLNs was negative. Local recurrence occurred in 6 of the 195 cases. The rate of recurrence at any site among the SLN-negative cases was 8.8%. The complication rate was 5%.

CONCLUSIONS: Same-day lymphoscintigraphy and radioprobe-guided surgery identified, with a high sensitivity and a low false negative rate, MM patients with microscopic nodal disease. Our results do at least equal other comparable studies.