Abstract P2-01-27: Sentinel lymph node biopsy by contrast-enhanced ultrasonography with sonazoid in patients with breast cancer - Prospective multicenter study

Abstract

Abstract Background: The aim of this prospective study is to evaluate feasibility of the periareolar injection of contrast agent (Sonazoid (SNZ)) followed by ultrasonography (US) for identification of sentinel lymph node (SLN) in breast cancer patients with clinically negative node. Patients and Methods: Patients with T1-2N0M0 breast cancer were recruited in this study. They received the periareolar injection of SNZ followed by US to identify contrast-enhanced SLN. Fine needle aspiration biopsy (FNAB) was done for each CE-SLN. Then, they underwent SLN biopsy with the conventional method, blue dye and/or radiotracer (B/R). Results: In almost all cases, contrast-enhanced lymphatic vessels were clearly visualized US soon after the periareolar injection of SNZ, and SLN, into which lymphatic flow was draining, was easily identified. The identification rate of SLN was 98% (98/100) by SNZ and 100% (100/100) by B/R. The number of SLNs identified by SNZ (mean per patient, 1.52) was significantly (P < 0.001) lower than that of those by B/R (2.22). Twenty-five patients had at least one metastasis in the SLNs identified by SNZ and/or B/R. In these patients, SLNs (n=39) identified by both SNZ and B/R showed a significantly (P < 0.0001) higher positivity (74.4%) for metastases than those (n=19) identified by B/R alone (21.1%). Conclusion: Identification of SLN by periareolar injection of SNZ followed by US is a technically easy method and the identification rate of SLN was as high as 98%, being comparable to the conventional B/R. SLNs detected by SNZ seem to represent the true SLNs which first receive lymphatic flow from the tumor among the SLNs detected by B/R. Citation Format: Shimazu K, Ito T, Uji K, Miyake T, Motomura K, Noguchi S. Sentinel lymph node biopsy by contrast-enhanced ultrasonography with sonazoid in patients with breast cancer - Prospective multicenter study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-27.