title: Long-term Therapeutic Outcomes of Radiofrequency Ablation for Subcapsular versus Nonsubcapsular Hepatocellular Carcinoma: A Propensity Score Matched Study.
abstract: Purpose To compare the long-term therapeutic outcomes of radiofrequency (RF) ablation for hepatocellular carcinoma (HCC) in subcapsular versus nonsubcapsular locations by using propensity score matching. Materials and Methods RF ablation for subcapsular HCC is controversial because of a high risk of incomplete ablation or major complications. This retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Between April 2006 and December 2011, 508 consecutive patients (396 men, 112 women; age range, 30-80 years) with a single HCC (Barcelona Clinic Liver Cancer stage 0 or A) underwent ultrasonography-guided percutaneous RF ablation as a first-line treatment. The patients were divided into two groups according to tumor location: subcapsular (n = 227) and nonsubcapsular (n = 281). Subcapsular HCC was defined as an index tumor located within 0.1 cm of the liver capsule. The association of subcapsular location and therapeutic outcomes of RF ablation was evaluated, including (a) local tumor progression (LTP) by using a competing risk regression model and (b) overall survival (OS) by using a Cox proportional hazards model according to propensity score matched data. The major complication rates from both overall data and matched data were assessed. Results Matching yielded 163 matched pairs of patients. In the two matched groups, cumulative LTP rates were 18.8% and 20.9% at 3 and 5 years, respectively, in the subcapsular group and 13.2% and 16.0% in the nonsubcapsular group. Corresponding OS rates were 90.7% for 3 years and 83.2% for 5 years in the subcapsular group and 91.4% and 79.1%, respectively, in the nonsubcapsular group. Hazard ratios (HRs) for LTP (HR = 1.37, P = .244) and OS (HR = 0.86, P = .604) were not significantly different between the two matched groups. Additionally, differences in major complication rates were not significant between groups for the two sets of data (P > .05). Conclusion The differences in LTP, OS, and major complication rates of RF ablation for HCC were not significant between subcapsular and nonsubcapsular groups. (©) RSNA, 2016.
authors.affiliation: From the Department of Radiology and Center for Imaging Science (T.W.K., H.K.L., M.W.L., Y.S.K., H.R., W.J.L.) and Division of Hepatology, Department of Medicine (Y.H.P.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-ro 81, Gangnam-gu, Seoul 135-710, Republic of Korea; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea (H.K.L., W.J.L., Y.H.P.); and Biostatistics Team, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea (M.J.K., J.H.A.).
authors.forename: Tae Wook
authors.initials: TW
authors.lastname: Kang
authors.affiliation: From the Department of Radiology and Center for Imaging Science (T.W.K., H.K.L., M.W.L., Y.S.K., H.R., W.J.L.) and Division of Hepatology, Department of Medicine (Y.H.P.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-ro 81, Gangnam-gu, Seoul 135-710, Republic of Korea; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea (H.K.L., W.J.L., Y.H.P.); and Biostatistics Team, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea (M.J.K., J.H.A.).
authors.forename: Hyo Keun
authors.initials: HK
authors.lastname: Lim
authors.affiliation: From the Department of Radiology and Center for Imaging Science (T.W.K., H.K.L., M.W.L., Y.S.K., H.R., W.J.L.) and Division of Hepatology, Department of Medicine (Y.H.P.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-ro 81, Gangnam-gu, Seoul 135-710, Republic of Korea; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea (H.K.L., W.J.L., Y.H.P.); and Biostatistics Team, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea (M.J.K., J.H.A.).
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Lee
authors.affiliation: From the Department of Radiology and Center for Imaging Science (T.W.K., H.K.L., M.W.L., Y.S.K., H.R., W.J.L.) and Division of Hepatology, Department of Medicine (Y.H.P.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-ro 81, Gangnam-gu, Seoul 135-710, Republic of Korea; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea (H.K.L., W.J.L., Y.H.P.); and Biostatistics Team, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea (M.J.K., J.H.A.).
authors.forename: Young-Sun
authors.initials: YS
authors.lastname: Kim
authors.affiliation: From the Department of Radiology and Center for Imaging Science (T.W.K., H.K.L., M.W.L., Y.S.K., H.R., W.J.L.) and Division of Hepatology, Department of Medicine (Y.H.P.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-ro 81, Gangnam-gu, Seoul 135-710, Republic of Korea; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea (H.K.L., W.J.L., Y.H.P.); and Biostatistics Team, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea (M.J.K., J.H.A.).
authors.forename: Hyunchul
authors.initials: H
authors.lastname: Rhim
authors.affiliation: From the Department of Radiology and Center for Imaging Science (T.W.K., H.K.L., M.W.L., Y.S.K., H.R., W.J.L.) and Division of Hepatology, Department of Medicine (Y.H.P.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-ro 81, Gangnam-gu, Seoul 135-710, Republic of Korea; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea (H.K.L., W.J.L., Y.H.P.); and Biostatistics Team, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea (M.J.K., J.H.A.).
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Lee
authors.affiliation: From the Department of Radiology and Center for Imaging Science (T.W.K., H.K.L., M.W.L., Y.S.K., H.R., W.J.L.) and Division of Hepatology, Department of Medicine (Y.H.P.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-ro 81, Gangnam-gu, Seoul 135-710, Republic of Korea; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea (H.K.L., W.J.L., Y.H.P.); and Biostatistics Team, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea (M.J.K., J.H.A.).
authors.forename: Yong Han
authors.initials: YH
authors.lastname: Paik
authors.affiliation: From the Department of Radiology and Center for Imaging Science (T.W.K., H.K.L., M.W.L., Y.S.K., H.R., W.J.L.) and Division of Hepatology, Department of Medicine (Y.H.P.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-ro 81, Gangnam-gu, Seoul 135-710, Republic of Korea; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea (H.K.L., W.J.L., Y.H.P.); and Biostatistics Team, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea (M.J.K., J.H.A.).
authors.forename: Min Ji
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: From the Department of Radiology and Center for Imaging Science (T.W.K., H.K.L., M.W.L., Y.S.K., H.R., W.J.L.) and Division of Hepatology, Department of Medicine (Y.H.P.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-ro 81, Gangnam-gu, Seoul 135-710, Republic of Korea; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea (H.K.L., W.J.L., Y.H.P.); and Biostatistics Team, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea (M.J.K., J.H.A.).
authors.forename: Joong Hyun
authors.initials: JH
authors.lastname: Ahn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000601:surgery; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D057216:Propensity Score; D012189:Retrospective Studies; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional