Background:
Results of the MSLT-II trial, released in 2017, revolutionised melanoma treatment by demonstrating that clearance lymph node dissection (CLND) had no survival benefit over sentinel lymph node biopsy (SLNB).1 A new paradigm of post-positive-SLNB surveillance was born. However, although Fairies, et al described 4 sonographic lymph node abnormalities, the threshold for “suspicious” was not described. Use of USS for lymph nodes, and what qualifies as abnormal, has long been a point of contention, and a technical challenge due to inter-operator differences.2 Without an explicit suggested follow-up protocol, there is room for varied interpretation. This literature review seeks to establish how melanoma treatment and follow-up care, specifically that guided by USS, has been affected by the publication of MSLT-II.
Methods:
A PubMed search of (Melanoma) AND (Ultrasound) AND (Sentinel node), English language papers from 2018 to 2020. Exclusion criteria: no reference to MSLT-II, study performed prior to MSLT-II, non-human models. 92 abstracts were reviewed for relevance, full papers reviewed when the abstracts were inadequate, and 79 immediately excluded. Closer scrutiny of the remaining 13 left 5 eligible papers.
Results:
5 papers: 2 national guidelines, 2 reviews, 1 prospective observational study.3,4,5,6,7
All papers supported the change in melanoma management from CLND to follow-up with surveillance USS in low risk patients with positive SLNBs. 3 papers described a concern regarding access to routine USS follow-up. There was no critique of the new standard of care in any paper. None specified an USS methodology or suggested criteria for an abnormal node on USS.
Conclusion:
3 years after the release of MSLT-II results, 5 papers demonstrate that international treatment of melanoma SLNB-positive patients is changing from CLND to surveillance. This review, however, highlights the absence of a published protocol to ensure reliable and reproducible surveillance of eligible melanoma patients.