Timing of sentinel lymph node biopsy and lymphoscintigraphy before surgery for melanoma: A systematic review and meta-analysis.

Introduction: The management of malignant melanomas often involves performing a sentinel lymph node biopsy (SLNB) aided by imaging with lymphoscintigraphy. Whether lymphoscintigraphy should be performed on the same day as the SLNB operation (SD) or the day before (DB) surgery remains debated. This study aims to summarise existing evidence regarding the impact of the relative timings of lymphoscintigraphy and SLNB on clinical outcomes in melanoma.

Methods: A PRISMA-compliant search was conducted from inception to 28th May 2024. Data were collected on SLNB in melanoma patients who underwent either an SD or DB approach. The following outcomes were extracted from the articles: node identification, recurrence rate and survival outcomes. Pooled effects of outcomes were estimated using the DerSimonian and Laird random-effects model/generalised linear mixed model, where applicable.

Results: A total of 9 studies met the inclusion criteria. Six studies (n = 10, 216) compared SD and DB approach outcomes, while 3 studies (n = 153) compared SD and DB SLNB within the same patient cohort. In the former, no significant difference was found in positivity rates between SD and DB groups (RR 1.03, 95% CI 0.94-1.13, p = 0.475), and recurrence rates were comparable (RR 0.90, 95% CI 0.75-1.07, p = 0.233). SD approach was associated with significantly shorter hospital stays and lower costs, but conflicting results were observed in survival outcomes. In the latter studies, all 3 reported discrepancies between the results of the SD and DB approaches.

Conclusion: Current evidence is insufficient to provide a definitive answer. Further research is warranted to conclusively evaluate the impact of SLNB timing on melanoma outcomes and patient care.