Sonazoid-enhanced ultrasound for preoperative localization and characterization of sentinel lymph nodes in patients with cutaneous melanoma.

Abstract

Accurate sentinel lymph node (SLN) identification is essential for the staging of cutaneous melanoma. Contrast-enhanced ultrasound using Sonazoid (Sonazoid-CEUS), which is based on a perfluorobutane microbubble contrast agent with reticuloendothelial uptake properties, was evaluated for SLN detection in patients with stage Ib-II melanoma. In this prospective single-arm cohort study, 71 eligible subjects underwent perilesional intradermal Sonazoid-CEUS, followed by lymphoscintigraphy and SLN biopsy. The numbers of SLNs detected via CEUS and lymphoscintigraphy were compared by using non-parametric paired analysis (Wilcoxon signed-rank test). The diagnostic accuracy of CEUS for metastatic involvement was evaluated against histopathological results. Sonazoid-CEUS achieved a 97.3% success rate in identifying SLNs, detecting 148 SLNs, with an average of 2.1 ± 1.1 SLNs per patient. Most patients (93.0%) had single-basin lymphatic drainage. For metastasis detection, CEUS demonstrated 82.1% sensitivity, 88.4% specificity, and 85.9% accuracy. Ulceration, high mitotic count, and HMB45 positivity in primary lesions were significantly associated with SLN metastasis. No contrast-related adverse events were observed. Sonazoid-CEUS is a safe and accurate non-radioactive technique for SLN identification and preoperative diagnosis in patients with cutaneous melanoma; moreover, it exhibits potential value as a complementary imaging modality within established SLNB workflows. Question Can a non-radioactive contrast-enhanced ultrasound technique using Sonazoid improve preoperative localization and characterization of sentinel lymph nodes in patients with cutaneous melanoma? Findings In this prospective study, Sonazoid-CEUS identified sentinel lymph nodes in 97.3% of patients and showed high diagnostic accuracy without contrast-related adverse events. Clinical relevance Sonazoid-CEUS provides a non-radioactive adjunct for preoperative sentinel lymph node mapping and characterization in cutaneous melanoma, thereby potentially improving surgical planning while offering complementary functional information alongside conventional lymphoscintigraphy.