title: Pattern of retained contrast on immediate postprocedure computed tomography (CT) after particle embolization of liver tumors predicts subsequent treatment response.
abstract: OBJECTIVE
  To determine if the pattern of retained contrast on immediate postprocedure computed tomography (CT) after particle embolization of hepatic tumors predicts modified Response Evaluation Criteria in Solid Tumors (mRECIST) response.
  
  
  METHODS
  This study was approved by the Institutional Review Board with a waiver of authorization. One hundred four liver tumors were embolized with spherical embolic agents (Embospheres, Bead Block, LC Bead) and polyvinyl alcohol. Noncontrast CT was performed immediately after embolization to assess contrast retention in the targeted tumors, and treatment response was assessed by mRECIST criteria on follow-up CT (average time 9.0 ± 7.7 weeks after embolization). Tumor contrast retention (TCR) was determined based on change in Hounsfield units (HUs) of the index tumors between the preprocedure and immediate postprocedure scans; vascular contrast retention (VCR) was rated; and defects in contrast retention (DCR) were also documented. The morphology of residual enhancing tumor on follow-up CT was described as partial, circumferential, or total. Association between TCR variables and tumor response were assessed using multivariate logistic regression.
  
  
  RESULTS
  Of 104 hepatic tumors, 51 (49%) tumors had complete response (CR) by mRECIST criteria; 23 (22.1%) had partial response (PR); 21 (20.2%) had stable disease (SD); and 9 (8.7%) had progressive disease (PD). By multivariate analysis, TCR, VCR, and tumor size are independent predictors of CR (p = 0.02, 0.05, and 0.005 respectively). In 75 tumors, DCR was found to be an independent predictor of failure to achieve complete response (p < 0.0001) by imaging criteria.
  
  
  CONCLUSIONS
  TCR, VCR, and DCR on immediate posttreatment CT are independent predictors of CR by mRECIST criteria.
authors.affiliation: Interventional Radiology Service, Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, Room H118, New York, NY 10065, USA. wangxde@gmail.com
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Wang
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Erinjeri
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Jia
authors.forename: Mithat
authors.initials: M
authors.lastname: Gonen
authors.forename: Karen T
authors.initials: KT
authors.lastname: Brown
authors.forename: Constantinos T
authors.initials: CT
authors.lastname: Sofocleous
authors.forename: George I
authors.initials: GI
authors.lastname: Getrajdman
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Brody
authors.forename: Raymond H
authors.initials: RH
authors.lastname: Thornton
authors.forename: Majid
authors.initials: M
authors.lastname: Maybody
authors.forename: Ann M
authors.initials: AM
authors.lastname: Covey
authors.forename: Robert H
authors.initials: RH
authors.lastname: Siegelbaum
authors.forename: William
authors.initials: W
authors.lastname: Alago
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Solomon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy*; D016461:Chemoembolization, Therapeutic / Q000379:methods*; D015331:Cohort Studies; D003287:Contrast Media; D018450:Disease Progression; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D010316:Particle Size; D011237:Predictive Value of Tests; D011379:Prognosis; D011856:Radiographic Image Enhancement; D012074:Remission Induction; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003287:Contrast Media