title: Monitoring of hepatocellular carcinoma, following proton radiotherapy, with contrast-enhanced color Doppler ultrasonography.
abstract: BACKGROUND
  We have reported that proton radiotherapy for hepatocellular carcinoma (HCC) is a safe and effective therapeutic option. However, it is difficult to evaluate its effect in certain cases. Recently, it has been reported that the usage of contrast-enhanced color Doppler ultrasonography (CECDU) can improve diagnostic accuracy, both in terms of the presence of hepatic tumor and in the evaluation of treatment. The aim of this study was to determine the usefulness of CECDU in assessing the therapeutic response of HCC treated with proton radiotherapy.
  
  
  METHODS
  Twenty-two patients treated with the proton radiotherapy were studied. We inspected HCC lesions by CECDU, before and after the irradiation, over time. The magnitude of blood flow in the HCC was quantified on still images by CECDU. The ratio of the number of color pixels against that of the total number of pixels in the tumor area was defined as the tumor blood flow ratio (TBFR).
  
  
  RESULTS
  Immediately after the proton treatment, a transient increase of blood flow in the tumor was recognized in more than half of the patients, while the TBFR was unchanged or decreased in the remaining patients. At longer periods after irradiation, the TBFR in all HCCs gradually decreased, and this reduction of TBFR was statistically significant from 9 months after irradiation. These findings are consistent with those obtained previously by computed tomography (CT) as well as magnetic resonance imaging (MRI).
  
  
  CONCLUSIONS
  We propose CECDU as a useful diagnostic option for the evaluation of HCC treated with proton radiotherapy.
authors.affiliation: Division of Gastroenterology and Hepatology, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences and University Hospital, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, 305-8575, Japan.
authors.forename: Gaku
authors.initials: G
authors.lastname: Niizawa
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ikegami
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Matsuzaki
authors.forename: Yukihisa
authors.initials: Y
authors.lastname: Saida
authors.forename: Eriko
authors.initials: E
authors.lastname: Tohno
authors.forename: Takashi
authors.initials: T
authors.lastname: Kurosawa
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Saito
authors.forename: Toshiya
authors.initials: T
authors.lastname: Chiba
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Kita
authors.forename: Koichi
authors.initials: K
authors.lastname: Tokuuye
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Akine
authors.forename: Naomi
authors.initials: N
authors.lastname: Tanaka
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000532:radiotherapy; D003287:Contrast Media / Q000008:administration & dosage*; D017357:Cyclotrons; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007275:Injections, Intravenous; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D011134:Polysaccharides / Q000008:administration & dosage; D011522:Protons; D011882:Radiotherapy, High-Energy / Q000379:methods*; D015203:Reproducibility of Results; D018615:Ultrasonography, Doppler, Color / Q000379:methods*
chemical_list: D003287:Contrast Media; D011134:Polysaccharides; D011522:Protons; C059891:SHU 508