title: Maximum number of target lesions required to measure responses to transarterial chemoembolization using the enhancement criteria in patients with intrahepatic hepatocellular carcinoma.
abstract: OBJECTIVE
  The European Association for the Study of the Liver (EASL) criteria and, more recently, the modified Response Evaluation Criteria in Solid Tumors (mRECIST), have been widely adopted for evaluating responses to locoregional therapies for hepatocellular carcinoma (HCC). We wished to establish the optimum maximum number of target lesions that need to be measured in enhancement estimations.
  
  
  METHODS
  From a prospective registry in our institution we identified 160 consecutive patients who had at least two measurable HCCs of nodular type exceeding 10mm in diameter, and who initially underwent transarterial chemoembolization (TACE). Intra-patient and inter-method agreement on confirmed response status were evaluated based on a maximum of one, two, or three target lesions selected among the measurable lesions according to size, versus all baseline lesions.
  
  
  RESULTS
  Per patient analyses showed that the most consistent response distribution under both EASL and mRECIST was obtained using two or three targets versus all measurable lesions. These features were maintained even in analyses of subgroups stratified according to size, distribution, and number of tumors. The kappa values of comparisons between using a maximum of two or three targets versus using all the lesions were near 1.0, significantly higher than those obtained under both criteria using just the largest tumor. Similar conclusions were obtained when either two or three targets were measured.
  
  
  CONCLUSIONS
  Our data indicate that evaluating the largest two lesions is generally the most useful procedure for measuring TACE responses under both EASL and mRECIST.
authors.affiliation: Department of Internal Medicine, Asan Liver Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Ju Hyun
authors.initials: JH
authors.lastname: Shim
authors.forename: Han Chu
authors.initials: HC
authors.lastname: Lee
authors.forename: Hyung Jin
authors.initials: HJ
authors.lastname: Won
authors.forename: Yong Moon
authors.initials: YM
authors.lastname: Shin
authors.forename: Kang Mo
authors.initials: KM
authors.lastname: Kim
authors.forename: Young-Suk
authors.initials: YS
authors.lastname: Lim
authors.forename: Dong Jin
authors.initials: DJ
authors.lastname: Suh
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D016461:Chemoembolization, Therapeutic; D023381:Endpoint Determination / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012042:Registries; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome