title: Clinical Evaluation of 99mTc-Rituximab for Sentinel Lymph Node Mapping in Breast Cancer Patients.
abstract: The metastatic status of sentinel lymph nodes (SLNs) might be the most important prognostic factor in breast cancer. In this paper, we report to our knowledge the first study of (99m)Tc-rituximab as a radiotracer for imaging of SLNs using lymphoscintigraphy in both preoperative and intraoperative breast cancer patients.
  
  
  METHODS
  (99m)Tc-rituximab was designed as an SLN tracer targeting the CD20 antigen, which expresses extensively in LNs. A retrospective study was performed on 2,317 patients with primary breast cancer who underwent lymphoscintigraphy and sentinel lymph node biopsy (SLNB). Before imaging, all patients were administered a preoperative peritumoral injection of 37 MBq of (99m)Tc-rituximab.
  
  
  RESULTS
  (99m)Tc-rituximab was synthesized in both high radiolabeling yield and high radiochemical purity (>95%), with molecular integrity and immune activity well maintained. The initial study of 100 breast cancer patients showed that the success rate of SLN lymphoscintigraphy by injection of (99m)Tc-rituximab, as compared with SLNB, was 100%, and the sensitivity, specificity, accuracy, and false negative rate were 97.4%, 100%, 98.0%, and 2.60%, respectively. Of the following 2,217 patients studied, the success rate of lymphoscintigraphy and SLNB was 98.8% and 99.9%, and the average number of SLN was 1.78 (range, 1-10) and 2.85 (range, 1-15). Age was an independent predictor of the number of SLNs identified by lymphoscintigraphy and intraoperative handheld γ-probe (P < 0.05), and other factors-such as sex, imaging time, primary tumor site, histopathologic subtype, clinical T stage, and immunochemistry-were not (P > 0.05). However, the SLN metastatic rates were different in patients with different histopathologic subtype, clinical T stage, and immunochemistry (P < 0.05).
  
  
  CONCLUSIONS
  Here we report the first study of the new radiotracer (99m)Tc-rituximab for breast cancer lymphoscintigraphy. This tracer showed great feasibility, safety, and effectiveness for SLN mapping in breast cancer patients.
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, China; and rainbow6238@sina.com pekyz@163.com.
authors.forename: Nan
authors.initials: N
authors.lastname: Li
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, China; and.
authors.forename: Xuejuan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, China; and.
authors.forename: Baohe
authors.initials: B
authors.lastname: Lin
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, China; and.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, China; and.
authors.forename: Cheng
authors.initials: C
authors.lastname: Liu
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, China; and.
authors.forename: Xiaobao
authors.initials: X
authors.lastname: Xu
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, China; and.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, China; and.
authors.forename: Shizhen
authors.initials: S
authors.lastname: Zhai
authors.affiliation: Breast Center, Peking University Cancer Hospital & Institute, Beijing, China.
authors.forename: Tao
authors.initials: T
authors.lastname: OuYang
authors.affiliation: Breast Center, Peking University Cancer Hospital & Institute, Beijing, China.
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, China; and rainbow6238@sina.com pekyz@163.com.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000328:Adult; D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology*; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D061305:Lymphoscintigraphy / Q000706:statistics & numerical data*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D015588:Observer Variation; D015609:Organotechnetium Compounds; D015995:Prevalence; D019275:Radiopharmaceuticals; D012307:Risk Factors; D000069283:Rituximab; D000071036:Sentinel Lymph Node / Q000000981:diagnostic imaging* / Q000473:pathology*; D021701:Sentinel Lymph Node Biopsy / Q000706:statistics & numerical data
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C509712:technetium 99m rituximab; D000069283:Rituximab
keywords: 99mTc-rituximab; breast cancer; lymphoscintigraphy; sentinel lymph node mapping