Application value on localization and evaluation of sentinel lymph nodes in early-stage breast cancer with CT lymphography

Abstract

Objective: To explore the clinical value of CT lymphography (CT-LG) on the localization and evaluation of sentinel lymph node (SLN) in patients with early-stage breast cancer. Methods: Thirty-six patients with early-stage breast cancer were enrolled in this study from September 2014 to June 2016 in the First Hospital of Zhengzhou University.The diagnoses were confirmed by puncture or local surgical pathology with negative clinical palpation of axillary lymph nodes, and sentinel lymph node biopsy (SLNB) was planned.The patients received CT-LG examination.The first one or several lymph nodes along the lymph duct draining from the injection site to axilla was/were defined as SLN(s), and the results were compared with the SLNB.Wilcoxon signed ranks test was used to compare the number of SLN detected by CT-LG and SLNB; according to the pathologic results, Student t test or chi-square test was used to compare the differences of the positive SLNs with negative ones. Results: SLNs were successfully identified in all 36 patients, 32 cases (88.9%) had high-quality images (with both SLN and lymphatic vessel visible); 36 SLNs were located by CT-guided wire with a success rate of 100%.A total of 88 SLNs were identified by CT-LG in 36 patients, and 102 SLNs were obtained by SLNB (Z=-2.646, P=0.008). The long-short diameter ratio (L/S) of SLN obtained by SLNB was significantly smaller than that of CT-LG (1.7±0.3 vs 1.9±0.4, t=2.880, P=0.004). Compared with pathology, CT-LG showed 21 positive SLNs and 67 negative SLNs, and the short diameter of positive SLNs was bigger than that of negative ones[(5.9±2.1) vs (4.8±1.8) mm, t=2.235, P=0.028]. Of 67 negative SLNs, 61(91.04%) appeared homogenously contrast agent filling, and 13(61.90%) of the 21 positive SLNs were found filling defect changes, and the differences in filling defect changes between positive and negative SLNs were statistically significant (χ(2)=26.479, P<0.001). Conclusion: CT-LG can accurately locate the SLN for early-stage breast cancer, and both the short diameter and filling defect changes can help evaluate the status of SLN.