title: Value of DCE-MRI and FDG-PET/CT in the prediction of response to preoperative chemotherapy with bevacizumab for colorectal liver metastases.
abstract: BACKGROUND
  The purpose of this study was to assess the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and (18)F-fluorodeoxyglucose positron emission tomography computed tomography (FDG-PET/CT) for evaluation of response to chemotherapy and bevacizumab and for prediction of progression-free survival (PFS) in patients with metastatic colorectal cancer (mCRC) with potentially resectable liver lesions.
  
  
  METHODS
  A total of 19 mCRC patients were treated with FOLFOX/FOLFIRI and bevacizumab followed by surgery. Dynamic contrast-enhanced magnetic resonance imaging and FDG-PET/CT were performed before treatment and after cycle 5. PET results were quantified by calculating maximum standardised uptake value (SUV(max)) whereas area under the enhancement curve (AUC), initial AUC (iAUC) and the endothelial transfer constant (K(trans)) were used to quantify DCE-MRI. Pathological analysis of the resection specimen was performed, including measurement of microvessel density (MVD) and proliferation index.
  
  
  RESULTS
  Both AUC and iAUC were significantly decreased following bevacizumab therapy (median change of 22% (P=0.002) and 40% (P=0.001) for AUC and iAUC, respectively). Progression-free survival benefit was shown for patients with >40% reduction in K(trans) (P=0.019). In the group of radiological responders, the median baseline SUV(max) was 3.77 (IQR: 2.88-5.60) compared with 7.20 (IQR: 4.67-8.73) in nonresponders (P=0.021). A higher follow-up SUV(max) was correlated with worse PFS (P=0.012). Median MVD was 10.9. Progression-free survival was significantly shorter in patients with an MVD greater than 10, compared with patients with lower MVD (10 months compared with 16 months, P=0.016).
  
  
  CONCLUSIONS
  High relative decrease in K(trans), low follow-up SUV(max) and low MVD are favourable prognostic factors for mCRC patients treated with bevacizumab before surgery.
authors.affiliation: Department of Respiratory Medicine, Ghent University Hospital, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: De Bruyne
authors.forename: N
authors.initials: N
authors.lastname: Van Damme
authors.forename: P
authors.initials: P
authors.lastname: Smeets
authors.forename: L
authors.initials: L
authors.lastname: Ferdinande
authors.forename: W
authors.initials: W
authors.lastname: Ceelen
authors.forename: J
authors.initials: J
authors.lastname: Mertens
authors.forename: C
authors.initials: C
authors.lastname: Van de Wiele
authors.forename: R
authors.initials: R
authors.lastname: Troisi
authors.forename: L
authors.initials: L
authors.lastname: Libbrecht
authors.forename: S
authors.initials: S
authors.lastname: Laurent
authors.forename: K
authors.initials: K
authors.lastname: Geboes
authors.forename: M
authors.initials: M
authors.lastname: Peeters
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D000068258:Bevacizumab; D002166:Camptothecin / Q000031:analogs & derivatives / Q000627:therapeutic use; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D002955:Leucovorin / Q000627:therapeutic use; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000556:secondary*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D020360:Neoadjuvant Therapy; D009944:Organoplatinum Compounds / Q000627:therapeutic use; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D009944:Organoplatinum Compounds; D019788:Fluorodeoxyglucose F18; D000068258:Bevacizumab; D002955:Leucovorin; D005472:Fluorouracil; D002166:Camptothecin