title: Optical imaging for monitoring tumor oxygenation response after initiation of single-agent bevacizumab followed by cytotoxic chemotherapy in breast cancer patients.
abstract: OBJECTIVE
  Optical imaging techniques for measuring tissue hemoglobin concentration have been recently accepted as a way to assess tumor vascularity and oxygenation. We investigated the correlation between early optical response to single-agent bevacizumab and treatment outcome.
  
  
  METHODS
  Seven patients with advanced or metastatic breast cancer were treated with single-agent bevacizumab followed by addition of weekly paclitaxel. Optical imaging of patient's breasts was performed to measure tumor total hemoglobin concentration (tHb) and oxygen saturation (stO2) at baseline and on days 1, 3, 6, 8, and 13 after the first infusion of bevacizumab. To assess early metabolic response, 2-deoxy-2-(18F)-fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT), 18F-fluoromisonidazole (FMISO)-PET/CT, and magnetic resonance imaging were performed at baseline and after two cycles of the regimen.
  
  
  RESULTS
  Seven patients were grouped as responders (n = 4) and nonresponders (n = 3) on the basis of metabolic response measured by FDG-PET/CT. The responders showed remarkable tumor shrinkage and low accumulations of FMISO tracer relative to those of the nonresponders at the completion of two cycles of chemotherapy. Tumors of both groups showed remarkable attenuation of mean tHb as early as day 1 after therapy initiation. The nonresponders had lower baseline stO2 levels compared with adjacent breast tissue stO2 levels along with a pattern of steadily low stO2 levels during the observation window. On the other hand, the responders appeared to sustain high stO2 levels with temporal fluctuation.
  
  
  CONCLUSIONS
  Low tumor stO2 level after single-agent bevacizumab treatment was characteristic of the nonresponders. Tumor stO2 level could be a predictor of an additional benefit of bevacizumab over that provided by paclitaxel.
authors.affiliation: Department of Breast Oncology, International Medical Center, Saitama Medical University, Hidaka, Saitama, Japan.
authors.forename: Shigeto
authors.initials: S
authors.lastname: Ueda
authors.affiliation: Department of Nuclear Medicine, International Medical Center, Saitama Medical University, Hidaka, Saitama, Japan.
authors.forename: Ichiei
authors.initials: I
authors.lastname: Kuji
authors.affiliation: Department of Breast Oncology, International Medical Center, Saitama Medical University, Hidaka, Saitama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Shigekawa
authors.affiliation: Department of Breast Oncology, International Medical Center, Saitama Medical University, Hidaka, Saitama, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Takeuchi
authors.affiliation: Department of Breast Oncology, International Medical Center, Saitama Medical University, Hidaka, Saitama, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sano
authors.affiliation: Department of Breast Oncology, International Medical Center, Saitama Medical University, Hidaka, Saitama, Japan.
authors.forename: Eiko
authors.initials: E
authors.lastname: Hirokawa
authors.affiliation: Department of Breast Oncology, International Medical Center, Saitama Medical University, Hidaka, Saitama, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Shimada
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamakita-ku, Hamamatsu, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamakita-ku, Hamamatsu, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Oda
authors.affiliation: Department of Breast Oncology, International Medical Center, Saitama Medical University, Hidaka, Saitama, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Osaki
authors.affiliation: Department of Breast Oncology, International Medical Center, Saitama Medical University, Hidaka, Saitama, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Saeki
mesh_terms: D000328:Adult; D061067:Antibodies, Monoclonal, Humanized / Q000494:pharmacology* / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D000068258:Bevacizumab; D001943:Breast Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism* / Q000503:physiopathology; D003603:Cytotoxins / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D019788:Fluorodeoxyglucose F18; D006439:Hemodynamics / Q000187:drug effects; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D064847:Multimodal Imaging; D061848:Optical Imaging; D010100:Oxygen / Q000378:metabolism*; D016896:Treatment Outcome
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D003603:Cytotoxins; D006454:Hemoglobins; D019788:Fluorodeoxyglucose F18; D000068258:Bevacizumab; D010100:Oxygen