The Value Of Transdermal Injection Of Ultrasound Contrast Agent In Sentinel Lymph Node Localization Of Breast Cancer

Objective:To investigate the identification rate of sentinel lymph nodes in breast cancer patients by subcutaneous and intradermal injection of ultrasound contrast agent in areola and compare the results with those of intraoperative methylene blue tracking sentinel lymph nodes.Methods:390 cases of breast cancer patients with planned sentinel lymph node biopsy were enrolled in this study at the department of breast surgery,sichuan provincial people's hospital between July 2017 and February 2019.All patients received contrast-enhanced ultrasound examination before operation,intradermal injection ultrasonic contrast agent 1ml at 3,6 o 'clock and subcutaneous injection ultrasonic contrast agent 1 ml at 9,12 o 'clock in the areola respectively after routine disinfection of mammary areola.Gently massage at the injection site and do 360-degree scanning around areola for enhanced lymphatic vessels,dynamically tracing the enhanced lymph nodes along the lymphatic vessels in real-time.The number of enhanced lymph nodes observed on contrast-enhanced ultrasound was recorded and ultrasound-guided injection of 1:10 diluted carbon nanoparticles were used to mark all first site enhanced lymph nodes(i.e.,sentinel lymph nodes)that were traced through lymphatic drainage.Intraoperative blue dye(methylene blue)was used to trace the sentinel lymph nodes and compared with the results of contrast-enhanced ultrasound.The lymph nodes which were marked by ultrasound-guided carbon nanoparticles,intraoperative blue-stained and the surrounding enlarged lymph nodes were removed and sent to pathological biopsy.Results: After 390 breast cancer patients were injected with ultrasonic contrast agent,373 cases were traced enhanced sentinel lymph nodes,with a identification rate of 95.64%(373/390).Intraoperative methylene blue injection had a identification rate of 92.05%(359/390),with a statistically significant difference(P=0.016).Of the 373 patients whosesentinel lymph nodes were traced by contrast-enhanced ultrasound,351 were traced blue-stained sentinel lymph nodes along the blue-stained lymphatic vessels by intraoperatively injection of methylene blue,while the other 22 cases,no blue-stained sentinel lymph nodes were traced due to the interruption of lymphatic staining.There were17 patients who were found interrupted lymphatic vessels and no enhanced sentinel lymph node in the process of tracing enhanced lymphatic vessel after injecting the ultrasonic contrast agents,no blue-stained sentinel lymph node were traced by intraoperatively injection of methylene blue in 9 of the 17 patients,the other 8 patients were traced the sentinel lymph nodes along the blue-stained lymphatic vessels.Among the 390 patients,a total of 808 enhanced lymph nodes were traced by preoperative contrast-enhanced ultrasound,with a median of 2(1,3),and a total of 971 blue-stained lymph nodes were traced by intraoperative dye method,with a median of 2(2,3),indicating a statistically significant difference(P<0.001).Conclusion: Intradermal and subcutaneous injection of ultrasonic contrast agent in areola has clinical application value for the identification and localization of sentinel lymph nodes in breast cancer patients,and its identification rate is higher than that of blue dye method,which can be used as a new tracer of sentinel lymph node biopsy and complement with other staining methods to improve the success rate.