title: Imaging prediction of residual hepatocellular carcinoma after locoregional therapy in patients undergoing liver transplantation or partial hepatectomy.
abstract: Locoregional therapies for hepatocellular carcinoma (HCC) offer alternatives for patients unable to undergo resection or awaiting transplant. We sought to evaluate the prevalence and interobserver agreement of imaging features suggestive of viable tumor at posttherapy CT/MRI and to determine a size threshold for tumor detection.
  
  
  
  Patients having undergone liver transplant or hepatectomy between 2012 and 2014 with presurgical embolization or ablation of HCC were identified. Imaging was retrospectively reviewed, and enhancement characteristics of each lesion were noted by two radiologists. Original pathology slides were reviewed, and the size of nodular viable tumor was noted, if present. Cohen's kappa was used to evaluate interobserver agreement.
  
  
  
  87 patients with 129 HCCs were reviewed retrospectively following IRB approval. 50% (65/129) of lesions showed viable tumor at pathology. 86 lesions (67%) were imaged with CT and 43 (33%) with MR. Of viable lesions, 25 (38%) showed nodular arterial enhancement and 18 (28%) demonstrated washout. One lesion had capsule appearance. Sensitivity/specificity for nodular enhancement, washout, and capsule were 0.38/0.83, 0.28/0.89, and 0.02/1.00, respectively. Overall detection rate was 41% of <1 cm, 54% of 1-2 cm, and 57% of >2 cm viable lesions.
  
  
  
  Nodular arterial enhancement was most frequently observed, followed by washout. Both showed moderate interobserver agreement. Sensitivity of any imaging feature was less than 50%, though findings were specific for viable disease. There is limited detection of nodules of viable tumor <1 cm and only marginal detection of larger lesions, though MRI outperformed CT for the detection of subcentimeter viable tumor.
authors.affiliation: Department of Radiology and Biomedical Imaging, UCSF, 505 Parnassus Ave., San Francisco, CA, 94143-0628, USA. eric.ehman@ucsf.edu.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Ehman
authors.affiliation: Department of Pathology, UCSF, 505 Parnassus Ave., Room 580, San Francisco, CA, 94143, USA.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Umetsu
authors.affiliation: Department of Radiology, ZSFG, 1001 Potrero Ave, ZSFG Bldg 5, San Francisco, CA, 94110, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Ohliger
authors.affiliation: Department of Radiology and Biomedical Imaging, UCSF, 505 Parnassus Ave., San Francisco, CA, 94143-0628, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Fidelman
authors.affiliation: Department of Pathology, UCSF, 505 Parnassus Ave., Moffitt Rm 590A, San Francisco, CA, 94143, USA.
authors.forename: Linda D
authors.initials: LD
authors.lastname: Ferrell
authors.affiliation: Department of Radiology and Biomedical Imaging, UCSF, 513 Parnassus Ave., Med Sci M372, San Francisco, CA, 94143, USA.
authors.forename: Ben M
authors.initials: BM
authors.lastname: Yeh
authors.affiliation: Department of Radiology, VAMC San Francisco, 3333 California St, San Francisco, CA, 94118, USA.
authors.forename: Judy
authors.initials: J
authors.lastname: Yee
authors.affiliation: Department of Radiology, VAMC San Francisco, 4150 Clement St., Room 2D007, San Francisco, CA, 94121, USA.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Hope
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D005260:Female; D006498:Hepatectomy / Q000379:methods*; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D016031:Liver Transplantation; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: CT; Hepatocellular carcinoma; Liver; MRI; Treatment