title: Intermodality comparison between 3D perfusion CT and 18F-FDG PET/CT imaging for predicting early tumor response in patients with liver metastasis after chemotherapy: preliminary results of a prospective study.
abstract: OBJECTIVE
  To evaluate the feasibility of 3D perfusion CT for predicting early treatment response in patients with liver metastasis from colorectal cancer.
  
  
  METHODS
  Seventeen patients with colon cancer and liver metastasis were prospectively enroled to undergo perfusion CT and 18F-FDG-PET/CT before and after one-cycle of chemotherapy. Two radiologists and three nuclear medicine physicians measured various perfusion CT and PET/CT parameters, respectively from the largest hepatic metastasis. Baseline values and reduction rates of the parameters were compared between responders and nonresponders. Spearman correlation test was used to correlate perfusion CT and PET/CT parameters, using RECIST criteria as reference standard.
  
  
  RESULTS
  Nine patients responded to treatment, eight patients were nonresponders. Baseline SUVmean30 on PET/CT, reduction rates of 30% metabolic volume and 30% lesion glycolysis (LG30) on PET/CT and blood flow (BF) and flow extraction product (FEP) on perfusion CT after chemotherapy were significantly different between responders and nonresponders (P=0.008-0.046). Reduction rates of BF (correlation coefficient=0.630) and FEP (correlation coefficient=0.578) significantly correlated with that of LG30 on PET/CT (P<0.05).
  
  
  CONCLUSIONS
  CT perfusion parameters including BF and FEP may be used as early predictors of tumor response in patients with liver metastasis from colorectal cancer.
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Kim
authors.forename: Se Hyung
authors.initials: SH
authors.lastname: Kim
authors.forename: Seock-Ah
authors.initials: SA
authors.lastname: Im
authors.forename: Sae-Won
authors.initials: SW
authors.lastname: Han
authors.forename: Jin Mo
authors.initials: JM
authors.lastname: Goo
authors.forename: Jürgen K
authors.initials: JK
authors.lastname: Willmann
authors.forename: Eun Seong
authors.initials: ES
authors.lastname: Lee
authors.forename: Jae Seon
authors.initials: JS
authors.lastname: Eo
authors.forename: Jin Chul
authors.initials: JC
authors.lastname: Paeng
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
authors.forename: Byung Ihn
authors.initials: BI
authors.lastname: Choi
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D019788:Fluorodeoxyglucose F18; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D002955:Leucovorin / Q000008:administration & dosage; D008113:Liver Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D055420:Perfusion Imaging / Q000379:methods*; D010865:Pilot Projects; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D009944:Organoplatinum Compounds; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D002955:Leucovorin; D005472:Fluorouracil; D002166:Camptothecin