Real-Time Visualization of Lymphatic Flow to Sentinel Lymph Nodes by Contrast-Enhanced Ultrasonography with Sonazoid in Patients with Breast Cancer

Abstract

Contrast-enhanced ultrasonography with Sonazoid (SNZ) enables real-time visualization, resulting in more precise identification of lymphatic flow to sentinel lymph nodes (SLNs). This study aimed to classify lymphatic drainage patterns to SLNs. Patients (n = 75) with T1–2 N0 M0 breast cancer received a periareolar injection of SNZ to identify SNZ-enhanced SLNs (SNZ-SLNs), followed by SLN biopsy with blue dye. The lymphatic drainage patterns were classified into four types: type A, single lymphatic route/single SLN; type B, multiple lymphatic routes/single SLN; type C, single lymphatic route/multiple SLNs; and type D, multiple lymphatic routes/multiple SLNs. SLNs were successfully identified in all patients using both blue dye and SNZ. The drainage lymphatic pathways identified were as follows: type A in 53 cases (70.7%), type B in seven (9.3%), type C in eight cases (10.7%) and type D in seven (9.3%). SNZ-SLN biopsy is a technically simple method with a 100% identification rate, enabling the real-time visualization of lymphatic flow to SNZ-SLNs.