title: Parametric response mapping of dynamic CT as an imaging biomarker to distinguish viability of hepatocellular carcinoma treated with transcatheter arterial chemoembolization.
abstract: OBJECTIVE
  Accurate assessment of viability of hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE) is important for therapy planning. The purpose of this study is to determine the diagnostic value of a novel image analysis method called parametric response mapping (PRM) in predicting viability of tumor in HCC treated with TACE for dynamic CT images.
  
  
  METHODS
  35 patients who had 35 iodized-oil defect areas (IODAs) in HCCs treated with TACE were included in our study. These patients were divided into two groups, one group with viable tumors (n = 22) and the other group with non-viable tumors (n = 13) in the IODA. All patients were followed up using triple-phase dynamic CT after the treatment. We compared (a) manual analysis, (b) using PRM results, and (c) using PRM results with automatic classifier to distinguish between two tumor groups based on dynamic CT images from two longitudinal exams. Two radiologists performed the manual analysis. The PRM approach was implemented using prototype software. We adopted an off-the-shelf k nearest neighbor (kNN) classifier and leave-one-out cross-validation for the third approach. The area under the curve (AUC) values were compared for three approaches.
  
  
  RESULTS
  Manual analysis yielded AUC of 0.74, using PRM results yielded AUC of 0.84, and using PRM results with an automatic classifier yielded AUC of 0.87.
  
  
  CONCLUSIONS
  We improved upon the standard manual analysis approach by adopting a novel image analysis method of PRM combined with an automatic classifier.
authors: Department of Radiology, Gachon University Gil Hospital, Incheon, Korea.
authors: Seung Joon
authors: SJ
authors: Choi
authors: Jonghoon
authors: J
authors: Kim
authors: Jongbum
authors: J
authors: Seo
authors: Hyung Sik
authors: HS
authors: Kim
authors: Jong-min
authors: JM
authors: Lee
authors: Hyunjin
authors: H
authors: Park
mesh_terms: D000368:Aged; D019540:Area Under Curve; D014408:Biomarkers, Tumor; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000628:therapy*; D016461:Chemoembolization, Therapeutic / Q000379:methods; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012372:ROC Curve; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D014408:Biomarkers, Tumor; D003287:Contrast Media; D007472:Iohexol; C038192:iopromide