title: Renal Cell Carcinoma Metastatic to the Liver: Early Response Assessment after Intraarterial Therapy Using 3D Quantitative Tumor Enhancement Analysis.
abstract: OBJECTIVE
  Liver metastases from renal cell carcinoma (RCC) are not uncommon in the course of disease. However, data about tumor response to intraarterial therapy (IAT) are scarce. This study assessed whether changes of enhancing tumor volume using quantitative European Association for the Study of the Liver (qEASL) on magnetic resonance imaging (MRI) and computed tomography (CT) can evaluate tumor response and predict overall survival (OS) early after therapy.
  
  
  METHODS
  Fourteen patients with liver metastatic RCC treated with IAT (transarterial chemoembolization: n= 9 and yttrium-90: n= 5) were retrospectively included. All patients underwent contrast-enhanced imaging (MRI: n= 10 and CT: n= 4) 3 to 4 weeks pre- and posttreatment. Response to treatment was evaluated on the arterial phase using Response Evaluation Criteria in Solid Tumors (RECIST), World Health Organization, modified RECIST, EASL, tumor volume, and qEASL. Paired t test was used to compare measurements pre- and post-IAT. Patients were stratified into responders (≥65% decrease in qEASL) and nonresponders (<65% decrease in qEASL). OS was evaluated using Kaplan-Meier curves with log-rank test and the Cox proportional hazard model.
  
  
  RESULTS
  Mean qEASL (cm3) decreased from 93.5 to 67.2 cm3(P= .004) and mean qEASL (%) from 63.1% to 35.6% (P= .001). No significant changes were observed using other response criteria. qEASL was the only significant predictor of OS when used to stratify patients into responders and nonresponders with median OS of 31.9 versus 11.1 months (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.19-0.97; P= .042) for qEASL (cm3) and 29.9 versus 10.2 months (HR, 0.09; 95% CI, 0.01-0.74; P= .025) for qEASL (%).
  
  
  CONCLUSIONS
  Three-dimensional (3D) quantitative tumor analysis is a reliable predictor of OS when assessing treatment response after IAT in patients with RCC metastatic to the liver. qEASL outperforms conventional non-3D methods and can be used as a surrogate marker for OS early after therapy.
authors.affiliation: Yale University School of Medicine, Yale New Haven Hospital, New Haven, CT, USA; Department of Diagnostic and Interventional Radiology, Charité Universitätsmedizin, Campus Virchow Klinikum, Berlin, Germany.
authors.forename: Florian Nima
authors.initials: FN
authors.lastname: Fleckenstein
authors.affiliation: Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Vienna, Austria.
authors.forename: Rüdiger Egbert
authors.initials: RE
authors.lastname: Schernthaner
authors.affiliation: Centre Hospitalier Universitaire Vaudois and University of Lausanne, Department of Radiology, Lausanne, Switzerland.
authors.forename: Rafael
authors.initials: R
authors.lastname: Duran
authors.affiliation: The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins Hospital, Baltimore, MD, USA.
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Sohn
authors.affiliation: The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins Hospital, Baltimore, MD, USA.
authors.forename: Sonia
authors.initials: S
authors.lastname: Sahu
authors.affiliation: Vascular and Interventional Radiology, Northwestern University Feinberg School of Medicine.
authors.forename: Karen
authors.initials: K
authors.lastname: Marshall
authors.affiliation: Yale University School of Medicine, Yale New Haven Hospital, New Haven, CT, USA; U/S Imaging and Interventions, Philips Research North America, Cambridge, MA, USA.
authors.forename: MingDe
authors.initials: M
authors.lastname: Lin
authors.affiliation: Department of Diagnostic and Interventional Radiology, Charité Universitätsmedizin, Campus Virchow Klinikum, Berlin, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Gebauer
authors.affiliation: Yale University School of Medicine, Yale New Haven Hospital, New Haven, CT, USA.
authors.forename: Julius
authors.initials: J
authors.lastname: Chapiro
authors.affiliation: Vascular and Interventional Radiology, Northwestern University Feinberg School of Medicine.
authors.forename: Riad
authors.initials: R
authors.lastname: Salem
authors.affiliation: Yale University School of Medicine, Yale New Haven Hospital, New Haven, CT, USA. Electronic address: jeff.geschwind@yale.edu.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Geschwind