Effect of delay between nuclear medicine scanning and sentinel node biopsy on outcome in patients with cutaneous melanoma.

Background Sentinel lymph node biopsy (SLNB) is an important staging tool for the management of melanoma. A multicentre study was done to validate previous findings that the timing of lymphoscintigraphy influences the accuracy of SLNB and patient outcomes, particularly survival. Methods Data were reviewed on patients undergoing SLNB for melanoma at three centres in the UK and Sweden, examining the effect of timing of SLNB after nuclear medicine scanning. Kaplan-Meier survival analysis was used to assess overall (OS), disease-specific (DSS) and progression-free (PFS) survival, stratified by timing of lymphoscintigraphy. Independent risk factors for survival were identified by Cox multivariable regression analysis. Results A total of 2270 patients were identified. Median follow-up was 56 months. Univariable analysis showed a 4 center dot 2 per cent absolute and 35 center dot 5 per cent relative benefit in DSS (hazard ratio 1 center dot 36, 95 per cent c.i. 1 center dot 05 to 1 center dot 74; P = 0 center dot 018) for 863 patients whose SLNB was performed up to 12 h after lymphoscintigraphy compared with 1407 patients who had surgery after more than 12 h. There were similar OS and PFS benefits (P = 0 center dot 036 and P = 0 center dot 022 respectively). Multivariable analysis identified timing of lymphoscintigraphy as an independent predictor of OS (P = 0 center dot 017) and DSS (P = 0 center dot 030). There was an excess of nodal recurrences as first site of recurrence in the group with delayed surgery (4 center dot 5 versus 2 center dot 5 per cent; P = 0 center dot 008). Conclusion Delaying SLNB beyond 12 h after lymphoscintigraphy with Tc-99-labelled nanocolloid has a significant negative survival impact in patients with melanoma.