title: Prediction of liver function by using magnetic resonance-based portal venous perfusion imaging.
abstract: OBJECTIVE
  To evaluate whether liver function can be assessed globally and spatially by using volumetric dynamic contrast-enhanced magnetic resonance imaging MRI (DCE-MRI) to potentially aid in adaptive treatment planning.
  
  
  METHODS
  Seventeen patients with intrahepatic cancer undergoing focal radiation therapy (RT) were enrolled in institution review board-approved prospective studies to obtain DCE-MRI (to measure regional perfusion) and indocyanine green (ICG) clearance rates (to measure overall liver function) prior to, during, and at 1 and 2 months after treatment. The volumetric distribution of portal venous perfusion in the whole liver was estimated for each scan. We assessed the correlation between mean portal venous perfusion in the nontumor volume of the liver and overall liver function measured by ICG before, during, and after RT. The dose response for regional portal venous perfusion to RT was determined using a linear mixed effects model.
  
  
  RESULTS
  There was a significant correlation between the ICG clearance rate and mean portal venous perfusion in the functioning liver parenchyma, suggesting that portal venous perfusion could be used as a surrogate for function. Reduction in regional venous perfusion 1 month after RT was predicted by the locally accumulated biologically corrected dose at the end of RT (P<.0007). Regional portal venous perfusion measured during RT was a significant predictor for regional venous perfusion assessed 1 month after RT (P<.00001). Global hypovenous perfusion pre-RT was observed in 4 patients (3 patients with hepatocellular carcinoma and cirrhosis), 3 of whom had recovered from hypoperfusion, except in the highest dose regions, post-RT. In addition, 3 patients who had normal perfusion pre-RT had marked hypervenous perfusion or reperfusion in low-dose regions post-RT.
  
  
  CONCLUSIONS
  This study suggests that MR-based volumetric hepatic perfusion imaging may be a biomarker for spatial distribution of liver function, which could aid in individualizing therapy, particularly for patients at risk for liver injury after RT.
authors.affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109, USA. yuecao@umich.edu
authors.forename: Yue
authors.initials: Y
authors.lastname: Cao
authors.forename: Hesheng
authors.initials: H
authors.lastname: Wang
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Johnson
authors.forename: Charlie
authors.initials: C
authors.lastname: Pan
authors.forename: Hero
authors.initials: H
authors.lastname: Hussain
authors.forename: James M
authors.initials: JM
authors.lastname: Balter
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
authors.forename: Mary
authors.initials: M
authors.lastname: Feng
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000532:radiotherapy; D003287:Contrast Media; D005260:Female; D006801:Humans; D007208:Indocyanine Green / Q000493:pharmacokinetics; D008099:Liver / Q000098:blood supply* / Q000528:radiation effects*; D008103:Liver Cirrhosis / Q000503:physiopathology / Q000532:radiotherapy; D008113:Liver Neoplasms / Q000098:blood supply* / Q000532:radiotherapy*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D011169:Portal Vein / Q000502:physiology / Q000528:radiation effects*; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D003287:Contrast Media; D007208:Indocyanine Green