Sentinel node detection in melanomas using contrast-enhanced ultrasound

Area of Science:

• Medical Imaging
• Oncology
• Surgical Innovation

Background:

• Sentinel node (SN) biopsy is a standard clinical procedure combining radionuclide tracers and dye techniques.
• Contrast-enhanced ultrasound (CEUS) has shown promise for SN detection in animal models.
• Human application of CEUS for SN detection remains largely unexplored.

Purpose of the Study:

• To evaluate the feasibility of using CEUS for sentinel lymph node (SLN) detection in patients with malignant melanoma (MM).
• To optimize CEUS for SLN detection by varying contrast agent concentrations and extremity positioning.

Main Methods:

• Ten MM patients and one healthy volunteer received subcutaneous injections of a CEUS contrast agent.
• Low-mechanical-index CEUS and stimulated acoustic emission were used to visualize lymph channels and nodes.
• Lymphoscintigraphy and standard surgical SN identification methods (gamma-probe, blue dye) were employed for comparison.

Main Results:

• CEUS successfully visualized two inguinal lymph nodes in one patient, correlating with scintigraphic findings.
• No other contrast-enhanced lymph channels or nodes were detected in the remaining patients or the volunteer.
• Pre-clinical mouse studies confirmed no adverse tissue reactions to the contrast agent.

Conclusions:

• Current CEUS techniques are not sufficiently effective for detecting sentinel lymph nodes in human melanoma patients.
• The potential of CEUS for SLN detection in humans warrants further investigation with modified approaches or contrast agents.