title: Inter-observer variability of response evaluation criteria for hepatocellular carcinoma treated with chemoembolization.
abstract: BACKGROUND
  Data comparing EASL and mRECIST criteria for response evaluation in treatment of hepatocellular carcinoma are rare. We evaluated inter-observer variability by these two response evaluation criteria in treatment-naïve patients undergoing chemoembolization.
  
  
  METHODS
  For 133 patients undergoing chemoembolization, two radiologists independently measured sum of bi-dimensional and uni-dimensional diameters at baseline using both EASL criteria and mRECIST, and their changes on first follow-up for up to 5 target lesions.
  
  
  RESULTS
  Concordance correlation coefficients for sum of bi-dimensional and uni-dimensional diameters at baseline between two observers were 0.992 and 0.988, respectively. However, those for their changes on follow-up were 0.865 and 0.877, respectively. Similarly, mean differences in sum of bi-dimensional and uni-dimensional diameters at baseline between two observers were small; -0.455 and 0.079 cm, respectively. However, mean differences in changes (%) in sum of bi-dimensional and uni-dimensional diameters on first follow-up between observers increased by -9.715% and -9.320%, respectively. Regarding tumour numbers, kappa-value between observers was 0.942. For treatment response (complete or partial response, stable disease and progression), kappa-value was 0.941 by both criteria. When only up to two target lesions were assessed, kappa-value was 1.000 by both criteria.
  
  
  CONCLUSIONS
  Inter-observer agreements using both response evaluation criteria were excellent, especially when up to two targets were assessed.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Republic of Korea; Liver Cirrhosis Clinical Research Center, Republic of Korea.
authors.forename: Beom Kyung
authors.initials: BK
authors.lastname: Kim
authors.affiliation: Department of Radiology, St. Vincent's Hospital, The Catholic University of Korea, Gyeonggi-do, Republic of Korea.
authors.forename: Kyung Ah
authors.initials: KA
authors.lastname: Kim
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Republic of Korea.
authors.forename: Myeong-Jin
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Republic of Korea; Institute of Gastroenterology, Yonsei University College of Medicine, Republic of Korea; Liver Cirrhosis Clinical Research Center, Republic of Korea.
authors.forename: Jun Yong
authors.initials: JY
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Republic of Korea; Institute of Gastroenterology, Yonsei University College of Medicine, Republic of Korea; Liver Cirrhosis Clinical Research Center, Republic of Korea.
authors.forename: Do Young
authors.initials: DY
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Republic of Korea; Institute of Gastroenterology, Yonsei University College of Medicine, Republic of Korea; Liver Cirrhosis Clinical Research Center, Republic of Korea; Brain Korea 21 Project for Medical Science, Seoul, Republic of Korea.
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Ahn
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Republic of Korea; Institute of Gastroenterology, Yonsei University College of Medicine, Republic of Korea; Liver Cirrhosis Clinical Research Center, Republic of Korea; Brain Korea 21 Project for Medical Science, Seoul, Republic of Korea.
authors.forename: Kwang-Hyub
authors.initials: KH
authors.lastname: Han
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Republic of Korea; Institute of Gastroenterology, Yonsei University College of Medicine, Republic of Korea; Liver Cirrhosis Clinical Research Center, Republic of Korea. Electronic address: ksukorea@yuhs.ac.
authors.forename: Seung Up
authors.initials: SU
authors.lastname: Kim
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Republic of Korea. Electronic address: radpms@yuhs.ac.
authors.forename: Mi-Suk
authors.initials: MS
authors.lastname: Park
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*; D016461:Chemoembolization, Therapeutic; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011859:Radiography; D066066:Response Evaluation Criteria in Solid Tumors; D047368:Tumor Burden / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D004317:Doxorubicin
keywords: EASL; Hepatocellular carcinoma; Inter-observer variability; Treatment response; mRECIST