title: Perfusion CT best predicts outcome after radioembolization of liver metastases: a comparison of radionuclide and CT imaging techniques.
abstract: OBJECTIVE
  To determine the best predictor for the response to and survival with transarterial radioembolisation (RE) with (90)yttrium microspheres in patients with liver metastases.
  
  
  METHODS
  Forty consecutive patients with liver metastases undergoing RE were evaluated with multiphase CT, perfusion CT and (99m)Tc-MAA SPECT. Arterial perfusion (AP) from perfusion CT, HU values from the arterial (aHU) and portal venous phase (pvHU) CT, and (99m)Tc-MAA uptake ratio of metastases were determined. Morphologic response was evaluated after 4 months and available in 30 patients. One-year survival was calculated with Kaplan-Meier curves.
  
  
  RESULTS
  We found significant differences between responders and non-responders for AP (P < 0.001) and aHU (P = 0.001) of metastases, while no differences were found for pvHU (P = 0.07) and the (99m)Tc-MAA uptake ratio (P = 0.40). AP had a significantly higher specificity than aHU (P = 0.003) for determining responders to RE. Patients with an AP >20 ml/100 ml/min had a significantly (P = 0.01) higher 1-year survival, whereas an aHU value >55 HU did not discriminate survival (P = 0.12). The Cox proportional hazard model revealed AP as the only significant (P = 0.02) independent predictor of survival.
  
  
  CONCLUSIONS
  Compared to arterial and portal venous enhancement and the (99m)Tc-MAA uptake ratio of liver metastases, the AP from perfusion CT is the best predictor of morphologic response to and 1-year survival with RE.
  
  
  CONCLUSIONS
  • Perfusion CT allows for calculation of the liver arterial perfusion. • Arterial perfusion of liver metastases differs between responders and non-responders to RE. • Arterial perfusion can be used to select patients responding to RE.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Fabian
authors.initials: F
authors.lastname: Morsbach
authors.forename: Bert-Ram
authors.initials: BR
authors.lastname: Sah
authors.forename: Lea
authors.initials: L
authors.lastname: Spring
authors.forename: Gilbert
authors.initials: G
authors.lastname: Puippe
authors.forename: Sonja
authors.initials: S
authors.lastname: Gordic
authors.forename: Burkhardt
authors.initials: B
authors.lastname: Seifert
authors.forename: Niklaus
authors.initials: N
authors.lastname: Schaefer
authors.forename: Thomas
authors.initials: T
authors.lastname: Pfammatter
authors.forename: Hatem
authors.initials: H
authors.lastname: Alkadhi
authors.forename: Caecilia S
authors.initials: CS
authors.lastname: Reiner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007269:Injections, Intra-Arterial; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy / Q000556:secondary; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000627:therapeutic use; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D015021:Yttrium Radioisotopes / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D019275:Radiopharmaceuticals; D015021:Yttrium Radioisotopes