title: CT appearances of post-radiation livers in patients with unresectable cholangiocarcinoma.
abstract: OBJECTIVE
  To characterize the computed tomographic (CT) findings of post-radiation livers and the interval changes in patients with unresectable cholangiocarcinoma.
  
  
  METHODS
  Thirteen patients with unresectable cholangiocarcinoma who received concurrent chemoradiation with conformal radiotherapy technique (50 to 66 Gy, 2 Gy/fraction) were included in the present study. CT at pre-radiation and sequential follow-up at 1, 3, 6, 9 and 12 months were retrospectively reviewed by two abdominal radiologists to identify CT characteristics of post-radiation liver and the interval changes.
  
  
  RESULTS
  CT at pre-radiation and sequential follow-up at 1, 3, 6, 9 and 12 months were available in 92.3%, 100%, 76.9%, 53.8%, 30.8% and 23.1%, respectively. Post-radiation livers showed sharply-delineated, hypodense radiation areas, which were well related with the isodose line of 35 to 56 Gy (mean = 44.4 +/- 6.55 Gy). These radiation areas were mostly appreciated on portal venous phase at 1-month follow-up study in 12 of 13 (92.3%) patients and these were gradually less defined in subsequent studies. Progressive decrease size of radiation areas with persistent enhancement on delayed phase images were recognized. Progression of hepatic cortical irregularity was seen in four (30.8%) patients, as well as pulmonary fibrosis of lung bases.
  
  
  CONCLUSIONS
  Post-radiation liver in patients with unresectable cholangiocarcinoma showed a sharply-defined, hypodense radiation area, which was mostly appreciated in 1-month follow-up CT and was gradually less defined in subsequent studies with evidence of progressive atrophic change.
authors.affiliation: Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. punpae@yahoo.com
authors.forename: Piyaporn
authors.initials: P
authors.lastname: Apisarnthanarak
authors.forename: Krongkan
authors.initials: K
authors.lastname: Kanchanarat
authors.forename: Kobkun
authors.initials: K
authors.lastname: Muangsomboon
authors.forename: Walailak
authors.initials: W
authors.lastname: Chaiyasoot
authors.forename: Nantakan
authors.initials: N
authors.lastname: Ieumwananonthachai
authors.forename: Pittayapoom
authors.initials: P
authors.lastname: Pattaranutaporn
mesh_terms: D000328:Adult; D000368:Aged; D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy; D001653:Bile Ducts, Intrahepatic / Q000000981:diagnostic imaging*; D059248:Chemoradiotherapy; D018281:Cholangiocarcinoma / Q000000981:diagnostic imaging* / Q000628:therapy; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging* / Q000293:injuries*; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000000981:diagnostic imaging*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed