title: Intradermal microbubbles and contrast-enhanced ultrasound (CEUS) is a feasible approach for sentinel lymph node identification in early-stage breast cancer.
abstract: BACKGROUND
  Microbubbles and contrast-enhanced ultrasound (CEUS) is a new technique for locating sentinel lymph node (SLN). The aim of this study is to explore the feasibility of SLNs tracing by CEUS using microbubbles in breast cancer patients and the value of enhancing patterns in diagnosing lymph nodes metastases.
  
  
  METHODS
  A clinical trial was registered (trial registration: ChiCTR-DDT-13003778). One hundred and one consecutive consenting patients with breast cancer undergoing SLN biopsy were enrolled. Before the surgery, microbubble was injected periareolarly. Lymphatic drainage pathway was detected by CEUS, and guidewire was deployed to locate the SLN before the operation. Blue dye was also used to help in tracing sentinel lymph node during the operation. The identification rate and the accuracy rate were recorded. Enhancing patterns of lymph nodes were recorded and compared with the pathological diagnosis.
  
  
  RESULTS
  Of the 101 cases, SLNs in 99 cases were successfully identified by at least one tracer, including 98 cases identified by CEUS and 97 cases by blue dye. There was no significant difference between the two methods (P = 0.705). Guidewires were deployed successfully in all 98 cases, and the localized SLNs were all isolated successfully in the following operations. The status of SLNs isolated by CEUS was completely identical to that of the whole axillary lymph node while 7.1 % cases were misdiagnosed as negative by blue dye method. The sensitivity of predicting SLNs metastases by CEUS enhancing pattern was 81.8 %, the specificity was 86.2 %, and the positive and negative predictive values were 75.0 and 90.3 %, respectively.
  
  
  CONCLUSIONS
  Microbubbles and CEUS are feasible approaches for SLN identification. The enhancing patterns on CEUS may be helpful to recognize the metastasizing SLNs. This novel method may be a promising technique for the clinical application.
authors.affiliation: Department of Breast Disease, Peking University People's Hospital, Beijing, China. fayxie@163.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Xie
authors.affiliation: Department of Breast Disease, Peking University People's Hospital, Beijing, China. snow_white_girl@163.com.
authors.forename: Dongjie
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Breast Disease, Peking University People's Hospital, Beijing, China. chenglin@pkuph.edu.cn.
authors.forename: Lin
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Department of Ultrasound Diagnosis, Peking University People's Hospital, Beijing, China. yulei@pkuph.edu.cn.
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
authors.affiliation: Department of Ultrasound Diagnosis, Peking University People's Hospital, Beijing, China. yangli@pkuph.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Breast Disease, Peking University People's Hospital, Beijing, China. tongfuzhong@pkuph.edu.cn.
authors.forename: Fuzhong
authors.initials: F
authors.lastname: Tong
authors.affiliation: Department of Breast Disease, Peking University People's Hospital, Beijing, China. liuhongjun@pkuph.edu.cn.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Ultrasound Diagnosis, Peking University People's Hospital, Beijing, China. shuwang@pkuph.edu.cn.
authors.forename: Shu
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Gastrointestinal Surgery, Peking University People's Hospital, Beijing, China. wangshan@pkuph.edu.cn.
authors.forename: Shan
authors.initials: S
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D018275:Carcinoma, Lobular / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D003287:Contrast Media; D055088:Early Detection of Cancer; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D045423:Microbubbles; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011300:Preoperative Care; D011379:Prognosis; D021701:Sentinel Lymph Node Biopsy; D016217:Ultrasonography, Mammary; D055815:Young Adult
chemical_list: D003287:Contrast Media