Ratio of marked and excised sentinel lymph nodes and scintigraphic appearance time in melanoma patients with negative sentinel lymph node

Abstract 

Aim

Metastases can occur in up to 15% of all melanoma patients with negative sentinel lymph node examination (SN –). We retrospectively investigated the number of preoperatively marked sentinel lymph nodes (SNs) with lymphoscintigraphy and effectively surgically removed SNs in SN – patients with cutaneous melanoma ≥0.5 mm. Ratio of these parameters was calculated and impact of this ratio as well as impact of scintigraphic appearance time (SAT) on disease progression was studied.

Materials and methods

Data on 122 SN – patients — 70 women (58%), mean age 56.5 years — were analyzed. Mean follow-up time was 58 months.

Results

Mean tumour thickness of all patients was 2.3 mm. In 51 patients (42%) the number of SNs marked in lymphoscintigraphy was higher than excised in surgery, in 47 patients (38%) the same number as marked was excised and in 24 patients (20%) a lower number was marked than excised. Metastases occurred in 17 patients (14%) after a mean time of 24.8 months. Mean tumour thickness (5.4 mm) was significantly higher in these patients than in the other patients (p = 0.000). Ratio of marked and excised SNs had no influence on disease progression; the only parameter influencing outcome was tumour thickness (p = 0.000). Short SAT was significantly associated with higher tumour thickness (p = 0.004).

Conclusion

Our study indicates that, in routine clinical practice, it suffices to harvest the first SN, as the ratio of marked and excised SNs has no impact on disease progression.

Keywords: Negative sentinel lymph node biopsy, Melanoma, Metastasis, lymphoscintigraphy, Scintigraphic appearance time