title: Liver function after irradiation based on computed tomographic portal vein perfusion imaging.
abstract: OBJECTIVE
  To determine whether individual and regional liver sensitivity to radiation could be assessed by measuring liver perfusion during a course of treatment using dynamic contrast-enhanced computed tomography scanning.
  
  
  METHODS
  Patients with intrahepatic cancer undergoing conformal radiotherapy underwent dynamic contrast-enhanced computed tomography (to measure perfusion distribution) and an indocyanine extraction study (to measure liver function) before, during, and 1 month after treatment. We hoped to determine whether the residual functioning liver (i.e., those regions showing portal vein perfusion) could be used to predict overall liver function after irradiation.
  
  
  RESULTS
  Radiation doses from 45 to 84 Gy resulted in undetectable regional portal vein perfusion 1 month after treatment. The volume of each liver with undetectable portal vein perfusion ranged from 0 to 39% and depended both on the patient's sensitivity and on dose distribution. There was a significant correlation between indocyanine green clearance and the mean of the estimated portal vein perfusion in the functional liver parenchyma (p < 0.001).
  
  
  CONCLUSIONS
  This study reveals substantial individual variability in the sensitivity of the liver to irradiation. In addition, these findings suggest that hepatic perfusion imaging may be a marker for liver function and has the potential to be a tool for individualizing therapy.
authors.affiliation: Department of Radiation Oncology, University of Michigan, UH-B2C432, Box 0010, Ann Arbor, MI 48109-0010, USA. yuecao@umich.edu
authors.forename: Yue
authors.initials: Y
authors.lastname: Cao
authors.forename: Charlie
authors.initials: C
authors.lastname: Pan
authors.forename: James M
authors.initials: JM
authors.lastname: Balter
authors.forename: Joel F
authors.initials: JF
authors.lastname: Platt
authors.forename: Isaac R
authors.initials: IR
authors.lastname: Francis
authors.forename: James A
authors.initials: JA
authors.lastname: Knol
authors.forename: Daniel
authors.initials: D
authors.lastname: Normolle
authors.forename: Edgar
authors.initials: E
authors.lastname: Ben-Josef
authors.forename: Randall K
authors.initials: RK
authors.lastname: Ten Haken
authors.forename: Theodore S
authors.initials: TS
authors.lastname: Lawrence
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007208:Indocyanine Green; D008099:Liver / Q000098:blood supply* / Q000503:physiopathology / Q000528:radiation effects*; D008111:Liver Function Tests / Q000379:methods; D008113:Liver Neoplasms / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011169:Portal Vein / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011836:Radiation Tolerance; D011879:Radiotherapy Dosage; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D007208:Indocyanine Green