ABSTRACT
Background: In patients with T1/T2 breast cancer (BC), sentinel lymph node (SLN) status is essential for prognosis and treatment. This study investigated the value of conventional ultrasound combined with double contrast-enhanced ultrasound in diagnosing the metastasis of SLNs in patients with T1/T2 BC. Methods: This study employed a prospective design (this diagnostic study was not registered on a clinical trial platform), and the participants formed a convenience series. Based on the inclusion and exclusion criteria, 163 patients with BC who received treatment in the First Affiliated Hospital of Soochow University from July 2017 to December 2021 were included in this study. A total of 165 SLNs from 163 patients with T1/T2 BC were analyzed. All patients underwent percutaneous contrast-enhanced ultrasound (PCEUS) to trace SLNs before the operation. Subsequently, all patients underwent conventional ultrasound and intravenous contrast-enhanced ultrasound (ICEUS) examinations to observe the SLNs. The results of the conventional ultrasound, ICEUS, and PCEUS of the SLNs were analyzed. The associations between the risk of SLN metastasis and imaging features were evaluated via a nomogram based on the pathological results. Results: Overall, 54 metastatic SLNs and 111 nonmetastatic SLNs were evaluated. Metastatic SLNs displayed a greater cortical thickness, area ratio, eccentric fatty hilum, and hybrid blood flow on conventional ultrasound compared with nonmetastatic SLNs (P<0.001). According to PCEUS, 75.93% of metastatic SLNs showed heterogeneous enhancement (type II and III), and 73.88% of nonmetastatic SLNs showed homogeneous enhancement (type I; P<0.001). According to ICEUS, heterogeneous enhancement (type B/C, 20.37% vs. 11.71%) and overall enhancement (55.56% vs. 23.42%) were more common in metastatic SLNs than in nonmetastatic SLNs (P<0.001). Logistic regression analysis showed that the cortical thickness and enhancement type of PCEUS were independent predictors of SLN metastasis. Moreover, a nomogram combining these factors showed a high diagnostic ability for SLN metastasis (unadjusted concordance index 0.860, 95% CI: 0.730-0.990; bootstrap-corrected concordance index 0.853). Conclusions: The nomogram of cortical thickness and enhancement type of PCEUS could effectively diagnose SLN metastasis in patients with T1/T2 BC.
ABSTRACT
BACKGROUND: Tumor size affects clinical staging and is closely related to prognosis. Therefore, early diagnosis of breast cancer is one of the most important methods to reduce mortality and improve prognosis. However, minimal breast cancer is difficult to differentiate from small benign breast masses due to insufficient typical malignant signs. The significantly increased range of enhancement can be an important indication for the prediction of malignancy; however, quantitative studies on the extent of enhancement are rarely reported. The purpose of this study was to investigate the value of contrast-enhanced ultrasound (CEUS) area ratio in finding benign and malignant small breast masses. METHODS: A retrospective analysis was conducted on 88 patients with breast masses confirmed by surgery or needle biopsy (the maximal diameter not over 1 cm). 88 breast masses were divided into the younger age group (not over 40 years old) and older age group (over 40 years old) according to the patient's age. The receiver operating characteristic (ROC) curve was used to determine the cutoff values of CEUS area ratio in diagnosing benign or malignant small breast masses in each group. The efficiency of different cutoff values in finding benign and malignant small breast masses of the distinct groups was analyzed. RESULTS: The CEUS area ratio of malignant mass was larger than benign masses (P<0.05). The CEUS area ratio of malignant masses in the younger age group was larger than that in the older age group (P<0.05). The results of the ROC curve analysis showed that the area under the curve (AUC) and the cutoff values of the entire group, the younger age group, and the older age group were 0.887, 1.65; 0.909, 1.95; and 0.908, 1.22, respectively. When the cutoff value of the older age group was reduced from 1.65 to 1.22, its diagnostic sensitivity was improved significantly (P<0.05). CONCLUSIONS: CEUS area ratio has specific application value in finding benign and malignant small breast masses. Proper reduction of the cutoff value of elderly patients can further improve its diagnostic sensitivity without significantly reducing the specificity.
