title: Clinical usefulness of the ablative margin assessed by magnetic resonance imaging with Gd-EOB-DTPA for radiofrequency ablation of hepatocellular carcinoma.
abstract: OBJECTIVE
  The aim of this study was to investigate the feasibility of ablative margin (AM) grading by magnetic resonance imaging (MRI) with Gd-EOB-DTPA administered prior to radiofrequency ablation (RFA), and to identify factors for achieving a sufficient AM and predictors for local tumor progression.
  
  
  METHODS
  A total of 124 hepatocellular carcinomas (HCCs) were treated by RFA after Gd-EOB-DTPA administration. MRI and enhanced CT were performed within seven hours and one month after RFA. The AM assessment was categorized using three grades: AM (+), low-intensity area with continuous high-intensity rim; AM zero, low-intensity area with discontinuous high-intensity rim; and AM (-), low-intensity area extends beyond the high-intensity rim. Patients were followed and local tumor progression was observed.
  
  
  RESULTS
  AM (+), AM zero, AM (-), and indeterminate were found in 34, 33, 26, and 31 nodules, respectively. The overall agreement rate between MRI and enhanced CT for the diagnosis of AM was 56.8%. The κ coefficient was 0.326 (p<0.001), indicating moderate agreement. Multivariate logistic regression analysis showed that a significant factor for the achievement of AM (+) on MRI was no contiguous vessels. The cumulative local tumor progression rates (0% at 1, 2, and 3 years) in 33 AM (+) nodules were significantly lower than those (3.6%, 11.5%, and 18.3% at 1, 2, and 3 years respectively) in 32 AM zero nodules. A multivariate Cox proportional hazards model identified tumor size as an independent predictor for local tumor progression.
  
  
  CONCLUSIONS
  Gd-EOB-DTPA-MRI enabled an early assessment of RFA effectiveness in the majority ofHCC nodules. Local tumor progression was not detected in AM (+) nodules during the follow-up.
authors.affiliation: Second Department of Internal Medicine, Tottori University, Yonago, Tottori, Japan. Electronic address: masakoda@grape.med.tottori-u.ac.jp.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Koda
authors.affiliation: Second Department of Internal Medicine, Tottori University, Yonago, Tottori, Japan.
authors.forename: Shiho
authors.initials: S
authors.lastname: Tokunaga
authors.affiliation: Second Department of Internal Medicine, Tottori University, Yonago, Tottori, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Okamoto
authors.affiliation: Second Department of Internal Medicine, Tottori University, Yonago, Tottori, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Hodozuka
authors.affiliation: Second Department of Internal Medicine, Tottori University, Yonago, Tottori, Japan.
authors.forename: Kennichi
authors.initials: K
authors.lastname: Miyoshi
authors.affiliation: Second Department of Internal Medicine, Tottori University, Yonago, Tottori, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kishina
authors.affiliation: Second Department of Internal Medicine, Tottori University, Yonago, Tottori, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Fujise
authors.affiliation: Second Department of Internal Medicine, Tottori University, Yonago, Tottori, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Kato
authors.affiliation: Second Department of Internal Medicine, Tottori University, Yonago, Tottori, Japan.
authors.forename: Tomomitsu
authors.initials: T
authors.lastname: Matono
authors.affiliation: Division of Radiology, Department of Pathophysiological and Therapeutic Science, Tottori University School of Medicine, Yonago 683-8504, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Sugihara
authors.affiliation: Division of Radiology, Department of Pathophysiological and Therapeutic Science, Tottori University School of Medicine, Yonago 683-8504, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Oyama
authors.affiliation: Division of Radiology, Department of Pathophysiological and Therapeutic Science, Tottori University School of Medicine, Yonago 683-8504, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Hosho
authors.affiliation: Division of Radiology, Department of Pathophysiological and Therapeutic Science, Tottori University School of Medicine, Yonago 683-8504, Japan.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Okano
authors.affiliation: Second Department of Internal Medicine, Tottori University, Yonago, Tottori, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Murawaki
authors.affiliation: Division of Radiology, Department of Pathophysiological and Therapeutic Science, Tottori University School of Medicine, Yonago 683-8504, Japan.
authors.forename: Suguru
authors.initials: S
authors.lastname: Kakite
authors.affiliation: Division of Radiology, Department of Pathophysiological and Therapeutic Science, Tottori University School of Medicine, Yonago 683-8504, Japan.
authors.forename: Eijiro
authors.initials: E
authors.lastname: Yamashita
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation; D003287:Contrast Media; D018450:Disease Progression; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: Ablative margin; Gadoxetic acid; Gd-EOB-DTPA; Hepatocellular carcinoma; Local tumor progression; Prognosis; Radiofrequency ablation