-Original-

Sentinel Lymph Node Detection, Location, and Number on SPECT/CT Can Help Predict Pathological Axillary Lymph Node Metastasis in Women with Breast Cancer

Meishi Hankyo¹, Ryusuke Murakami², Hiroyuki Takei¹, Keiko Yanagihara³, Tomoko Kurita¹, Takashi Sakatani⁴, Ryuji Ohashi⁴ and Shinichiro Kumita²

¹Department of Breast Surgery and Oncology, Nippon Medical School Hospital, Tokyo, Japan
²Department of Radiology, Nippon Medical School Hospital, Tokyo, Japan
³Department of Breast Surgery and Oncology, Nippon Medical School Tama Nagayama Hospital, Tokyo, Japan
⁴Department of Diagnostic Pathology, Nippon Medical School Hospital, Tokyo, Japan

Background: Use of radiocolloids for sentinel lymph node (SLN) detection in breast cancer (BC) offers the advantage of utilizing single-photon emission computed tomography/computed tomography (SPECT/CT). This study explored whether SPECT/CT findings can predict pathological axillary lymph node (ALN) metastasis.
Methods: A consecutive series of patients with invasive BC (clinical stage, T1-3, N0, and M0) who underwent SLN biopsy (SLNB) using SPECT/CT between January 2011 and December 2016 were included. SLN detection, location, and number on SPECT/CT, number of excised SLNs, and clinical and pathological characteristics were analyzed in relation to pathological ALN metastasis.
Results: Data from 408 patients (412 cases) with BC were analyzed. Patient age ranged from 28 to 93 years (mean: 59). SPECT/CT identified one to four SLNs (mean: 1.3) in 407 cases (98.8%) and no SLNs in 5 cases (1.2%). Of the 407 cases with at least one identified SLN, SLNs were solely in level I of the axilla in 394 cases (96.8%), both in and outside level I in 12 (2.9%), and solely outside of level I in 1 (0.2%). The number of ALNs removed via SLNB ranged from one to eight (mean: 2.0). SPECT/CT findings, including absence of SLN detection (P<0.001), SLN locations outside of axillary level I (P<0.001), and an increased number of SLNs (P=0.034), as well as removal of ≥3 SLNs (P=0.028), were significantly correlated with pathological ALN metastasis.
Conclusions: SLNB with SPECT/CT yields useful information on pathological ALN metastasis in BC patients.

J Nippon Med Sch 2025; 92: 170-180

Keywords
breast cancer, sentinel lymph node biopsy, SPECT/CT, axillary lymph node metastasis

Correspondence to
Hiroyuki Takei, MD, PhD, Department of Breast Surgery and Oncology, Nippon Medical School Hospital, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan
takei-hiroyuki@nms.ac.jp

Received, November 16, 2024
Accepted, December 25, 2024