title: ADCtotalratio and D ratio derived from intravoxel incoherent motion early after TACE are independent predictors for survival in hepatocellular carcinoma.
abstract: To explore the threshold of intravoxel incoherent motion (IVIM) parameters, apparent diffusion coefficient [ADCtotaland ADC(0,500)] ratios 24-48 hours after transarterial chemoembolization (TACE) to assess early response in patients with unresectable hepatocellular carcinoma (HCC) and to compare the association between diffusion-weighted imaging with the intravoxel incoherent motion (IVIM-DWI) and mRECIST with survival.
  
  
  
  Institutional Review Board approval and informed consent were obtained for this prospective study. There were 30 patients undergoing 1.5T magnetic resonance imaging (MRI) with IVIM-DWI of 12 b values (0, 10, 20, 30, 40, 50, 70, 100, 200, 300, 500, 800 s/mm2) 1 week before and 24-48 hours after TACE. Response was assessed with the change of true diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (PF), ADCtotal, and ADC(0,500)values relative to baseline and with mRECIST. Receiver operating characteristic (ROC) curve analysis was used to explore the threshold of these parameters ratios. Kaplan-Meier, log-rank tests, and the Cox hazard model were used to correlate the response variables with progression-free survival (PFS) and to assess the incidence and potential clinical risk factors for PFS. Mann-Whitney U-test was used to compare the difference in parameters between different groups with progression within and beyond median PFS prior to TACE.
  
  
  
  Median PFS was 99 days, within which 16 patients progressed. The threshold of ADCtotalratio, D ratio, and ADC(0,500)ratio were 13.1% (P = 0.001), 7.0% (P = 0.011), and 3.6% (P = 0.018) with sensitivity and specificity of 78.6% and 87.5%, 85.7% and 62.5%, 78.6% and 75%, respectively. The predictive utility of ADCtotalratio, D ratio, and ADC(0,500)ratio for PFS were 0.848, 0.772, and 0.754, respectively. Survival analyses showed ADCtotalratio, D ratio, ADC(0,500)ratio, liver cirrhosis, and mRECIST had a significant effect on PFS (P < 0.05). ADCtotalratio and D ratio were independent predictors for 99-day PFS (P = 0.025, P = 0.036). There were no significant differences in pretreatment IVIM-DWI parameters between PFS > 99-day group and PFS ≤ 99-day group with P values of 0.547 for D, 0.394 for D*, 0.575 for PF, 0.901 for ADC(0,500), and 0.506 for ADCtotal, respectively.
  
  
  
  The ADCtotalratio and D ratio 24-48 hours after TACE were independent predictors for response to TACE for HCC, and showed stronger association with PFS than mRECIST.
  
  
  
  1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:820-830.
authors.affiliation: Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Medical Imaging, Shanghai, P.R. China.
authors.forename: Lifang
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Medical Imaging, Shanghai, P.R. China.|Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China.
authors.forename: Pengju
authors.initials: P
authors.lastname: Xu
authors.affiliation: Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Medical Imaging, Shanghai, P.R. China.|Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China.
authors.forename: Shengxiang
authors.initials: S
authors.lastname: Rao
authors.affiliation: Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Medical Imaging, Shanghai, P.R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China.
authors.forename: Caizhong
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Siemens Healthcare, Shanghai, P.R. China.
authors.forename: Caixia
authors.initials: C
authors.lastname: Fu
authors.affiliation: Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Medical Imaging, Shanghai, P.R. China.|Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China.
authors.forename: Mengsu
authors.initials: M
authors.lastname: Zeng
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000628:therapy*; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008099:Liver / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009038:Motion; D012680:Sensitivity and Specificity; D016019:Survival Analysis
keywords: ADC; HCC; IVIM; TACE; mRECIST; response prediction and assessment