title: Intrahepatic cholangiocarcinoma treated with local-regional therapy: quantitative volumetric apparent diffusion coefficient maps for assessment of tumor response.
abstract: OBJECTIVE
  To evaluate volumetric changes in apparent diffusion coefficient (ADC) and contrast material enhancement on contrast-enhanced (CE) magnetic resonance (MR) images in hepatic arterial and portal venous phases for assessing early response in cholangiocarcinoma treated with transcatheter arterial chemoembolization (TACE).
  
  
  METHODS
  Twenty-nine patients with unresectable cholangiocarcinoma, including 11 men (mean age, 60 years; standard deviation, 16.8) and 18 women (mean age, 63 years; standard deviation, 11.5) were included in this retrospective institutional review board-approved, HIPAA-compliant study; informed consent was waived. Sixty-nine TACE procedures were performed during the observational time (range, one to five TACE sessions). No patients received another form of therapy after treatment with TACE. MR Imaging was performed before and 3-4 weeks after TACE, and images were analyzed with a semiautomatic volumetric software package. Patients were stratified as responders and nonresponders on the basis of overall survival (OS) as the primary end point. Differences between responders and nonresponders were analyzed with paired t tests, and OS was calculated with the Kaplan-Meier method. Significant differences were analyzed with the log-rank test.
  
  
  RESULTS
  Mean volumetric ADC increased from 1.54×10(-3) mm2/sec to 1.92×10(-3) mm2/sec (P<.0001), with no significant decrease in mean volumetric enhancement in hepatic arterial (40.6% vs 37.5%, P=.546) and portal venous (79.0% vs 70.0%, P=.105) phases. Patients who demonstrated improved survival of 10 months or more had a significant increase in mean volumetric ADC and volumetric ADC above the threshold level of 1.60×10(-3) mm2/sec (P<.002). Patients with 45% or greater (n=21; log-rank test, P<.02) and 60% or greater (n=12; log-rank test, P<.009) ADC changes for the whole tumor volume demonstrated better OS compared with patients in whom these ADC changes were not achieved.
  
  
  CONCLUSIONS
  Patients with percentage tumor volume increase in ADC of 45% or greater and 60% or greater above the threshold level of 1.60×10(-3) mm2/sec had favorable response to therapy and improved survival.
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, 600 N Wolfe St, Room 143, Baltimore, MD 21287, USA.
authors.forename: Vivek Gowdra
authors.initials: VG
authors.lastname: Halappa
authors.forename: Susanne
authors.initials: S
authors.lastname: Bonekamp
authors.forename: Celia Pamela
authors.initials: CP
authors.lastname: Corona-Villalobos
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.forename: Margaret
authors.initials: M
authors.lastname: Mensa
authors.forename: Diane
authors.initials: D
authors.lastname: Reyes
authors.forename: John
authors.initials: J
authors.lastname: Eng
authors.forename: Nikhil
authors.initials: N
authors.lastname: Bhagat
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Pawlik
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Geschwind
authors.forename: Ihab R
authors.initials: IR
authors.lastname: Kamel
mesh_terms: D000180:Acrylic Resins / Q000008:administration & dosage; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms; D001653:Bile Ducts, Intrahepatic; D016461:Chemoembolization, Therapeutic; D018281:Cholangiocarcinoma / Q000473:pathology* / Q000628:therapy*; D003287:Contrast Media; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D005780:Gelatin / Q000008:administration & dosage; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology* / Q000628:therapy*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011145:Polyvinyls / Q000008:administration & dosage; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D000180:Acrylic Resins; D003287:Contrast Media; D011145:Polyvinyls; C026699:ivalon sponge; C496735:trisacryl gelatin microspheres; D004317:Doxorubicin; D005780:Gelatin