Clinical Application Of Contrast-enhanced Ultrasound Combined With Dye In Sentinel Lymph Node Biopsy Of Breast Cancer

Objective Through a comparison of preoperative contrast-enhanced ultrasound with methylene blue staining and intraoperative methylene blue staining alone,we investigate the clinical value of applying contrast-enhanced ultrasound to sentinel lymph node biopsy and preoperative axillary assessment in early breast cancer.Methods A total of 64 patients diagnosed with early-stage breast cancer by pathological biopsy through punctured in the Department of Breast Surgery of the Second Affiliated Hospital of Fujian Medical University from October 2018 to December 2019 were randomly divided into group A(experimental group,n = 32)and group B(control group,n = 32).In group A,the nature of axillary lymph nodes was determined by contrast-enhanced ultrasonography and the sentinel lymph nodes were tracked and localized by CEUS before surgery.In addition,they were localized by methylene blue during the operation.Axillary lymph node dissection was performed after sentinel lymph node biopsy in group B.Besides,sentinel lymph nodes were traced and localized by methylene blue during the operation.Axillary lymph node dissection was operated after sentinel lymph node biopsy.The sentinel lymph nodes resected in the experimental group and the control group were diagnosed by frozen section examination,and all lymph nodes were histopathologically examined after axillary lymph node dissection.The detection rate,accuracy rate,false negative rate,average detection number,and average biopsy operation time were calculated for comparison.At the same time,the judgment results of sentinel lymph node properties of preoperative contrast-enhanced ultrasound in the experimental group were compared with postoperative pathology by calculating related values,including specificity,sensitivity,positive predictive value and negative predictive value of contrast-enhanced ultrasound for sentinel lymph node evaluation.Results There were no significant differences in age,tumor size,tumor location,pathological type and surface receptors between the experimental group and the control group(P> 0.05).Higher detection rate and average number of sentinel lymph nodes(96.88%,2.33±1.24)were found in the experimental group than that in control group(87.50%,1.50 ± 1.41)and the differences were statistically significant(P < 0.05).No significant differences were found in the false negative rate and accuracy rate of sentinel lymph nodes between the experimental group and the control group(P > 0.05).Moreover,the mean operation time of sentinel lymph node biopsy in the experimental group(19.67±2.25 min)was significantly shorter than that in the control group(27.98±3.27)with a significant difference(P<0.05).In the experimental group,a total of 31 cases was detected and located sentinel lymph nodes by contrast-enhanced ultrasonography.The number of diagnosed patients with metastasis by pathology after axillary lymph node dissection and CEUS was 6 and 9 respectively.The sensitivity(83.33%),specificity(84.00%),positive predictive value(55.56%)and negative predictive value(95.45%)of CEUS to early-stage breast cancer were also obtained in this work.Conclusion Contrast-enhanced ultrasound combined with methylene blue method has been demonstrated as a powerful tool to guide sentinel lymph node biopsy in breast cancer patients and improve the detection rate and number of sentinel lymph nodes.Operation time can also be shortened using this technique.However,the practical value of contrast-enhanced ultrasound in the identification of sentinel lymph nodes in clinical application is still limited and need to be further explored.