title: Photoacoustic mammography: initial clinical results.
abstract: OBJECTIVE
  Photoacoustic tomography can image the hemoglobin distribution and oxygenation state inside tissue with high spatial resolution. The purpose of this study is to investigate its clinical usefulness for diagnosis of breast cancer and evaluation of therapeutic response in relation to other diagnostic modalities.
  
  
  METHODS
  Using a prototype machine for photoacoustic mammography (PAM), 27 breast tumor lesions, including 21 invasive breast cancer (IBC), five ductal carcinoma in situ (DCIS), and one phyllodes tumor, were measured. Nine out of twenty-one IBC patients had received primary systemic therapy (PST).
  
  
  RESULTS
  Eight out of twelve IBC without PST were visible. Notably, detection was possible in all five cases with DCIS, whereas it was not in one case with phyllodes tumor. Seven out of nine IBC with PST were assigned as visible in spite of decreased size of tumor after PST. The mean value of hemoglobin saturation in the visible lesions was 78.6 %, and hemoglobin concentration was 207 μM. The tumor images of PAM were comparable to those of magnetic resonance imaging (MRI).
  
  
  CONCLUSIONS
  It is suggested that PAM can image tumor vascularity and oxygenation, which may be useful for diagnosis and characterization of breast cancer.
authors.affiliation: Department of Breast Surgery, Graduate School of Medicine, Kyoto University, 54 Kawaracho Shogoin Sakyoku, Kyoto, 6068507, Japan, kitait@kuhp.kyoto-u.ac.jp.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kitai
authors.forename: Masae
authors.initials: M
authors.lastname: Torii
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Sugie
authors.forename: Shotaro
authors.initials: S
authors.lastname: Kanao
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Mikami
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Shiina
authors.forename: Masakazu
authors.initials: M
authors.lastname: Toi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000000981:diagnostic imaging / Q000473:pathology; D004867:Equipment Design; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008327:Mammography / Q000295:instrumentation / Q000379:methods*; D008875:Middle Aged; D061088:Photoacoustic Techniques / Q000295:instrumentation / Q000379:methods*
chemical_list: D006454:Hemoglobins