Abstract
BACKGROUND: Acral melanoma is characterized by high propensity of lymph node metastasis. Accurate diagnosis and staging are important for patient management. OBJECTIVE: This study aimed to evaluate the efficacy of carbon nanoparticle suspension (CNS) as a tracer in SLNB for AM and to compare its performance with methylene blue (MB) and (99m)Tc. And it aimed To improve the technology of accurate diagnosis and treatment in melanoma. METHODS & MATERIALS: A retrospective analysis was conducted on 71 patients who underwent surgery between January 2022 and August 2024 at our hospital. Patients were divided into CNS group (Group 1 ; n = 46), and methylene blue group (Group 2 ; n = 25). In Group 1, 10 patients of all patients underwent (99m)Tc-single-photon emission computed tomography (SPECT) to assess lymphatic drainage. The sentinel lymph node (SLN) detection rate, lymph node metastasis rate, and number of lymph nodes detected were compared between the two groups. Two-tailed t-testsm Chi-square tests and Fisher tests were used in this study. RESULTS: Group 1 achieved a significantly higher SLN detection rate (100% vs. 84%, P = 0.013) and identified more nodes on average. No significant difference was observed in the detection rate of patients with metastasis between the groups(30.4% vs. 24%, P = 0.565). The CNS tracer showed highly concordance with the SPECT findings in subgroup of Group 1, indicating its effective lymph node tracing. CONCLUSION: CNS is an effective tracer in SLNB, surpassing methylene blue in efficacy. It significantly improved the detection rate of sentinel lymph nodes. Its use enhances surgical precision and offers a valuable method for the accurate staging and management of acral melanoma. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12957-025-04136-y.