title: Response assessment in patients with multiple myeloma during antiangiogenic therapy using arterial spin labeling and diffusion-weighted imaging: a feasibility study.
abstract: OBJECTIVE
  To determine whether response to anti-angiogenic therapy in patients with multiple myeloma can be assessed by noncontrast perfusion magnetic resonance imaging (MRI) (ie, arterial-spin-labeling [ASL]), and diffusion-weighted [DWI] MRI.
  
  
  METHODS
  The study protocol was approved by the local institutional ethic board. Ten consecutive patients (eight men, two women; mean age 60.5 ± 8.5 years) with Stage III multiple myeloma were prospectively included. MRI was performed at baseline, as well as 3 and 8 weeks after onset of antiangiogenic therapy. Functional MRI data were compared with clinical outcome and conventional lesion size and signal-intensity measurements. Differences between baseline and follow-up values for ASL-MRI and DWI-MRI were assessed using a paired Student t-test.
  
  
  RESULTS
  Nine patients responded well to therapy, whereas one patient was classified a nonresponder. Temporary changes in signal intensity between baseline and follow-up examinations were inconsistent on T1-weighted (w) and T2w images. Likewise, determination of lesion size at follow-up proved unreliable. ASL showed a marked decrease in perfusion from baseline (251 ± 159 mL/(min*100g)) to follow-up at 3 weeks (115 ± 85 mL/(min*100g), P = .01) and 8 weeks (101 ± 90 mL/(min*100g, P = .01), respectively. Relative to the baseline examination, mean diffusion increased from 0.68 ± 0.19 × 10(-3) s/mm(2) at baseline to 0.94 ± 0.24 × 10(-3) s/mm(2) after 3 weeks (P = .04), and 0.96 ± 0.40 × 10(-3) s/mm(2) after 8 weeks (P = .049). Both methods were able to correctly classify 9/10 patients as responder or nonresponder.
  
  
  CONCLUSIONS
  ASL perfusion as well as DWI-MRI provide accurate, clinically relevant information regarding tumor viability and can predict response already early after therapy onset, as opposed to classical lesion size and MRI signal-intensity measurements.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str.3, 72076 Tuebingen, Germany. michael.fenchel@med.uni-tuebingen.de
authors.forename: Michael
authors.initials: M
authors.lastname: Fenchel
authors.forename: Marina
authors.initials: M
authors.lastname: Konaktchieva
authors.forename: Katja
authors.initials: K
authors.lastname: Weisel
authors.forename: Sabina
authors.initials: S
authors.lastname: Kraus
authors.forename: Claus D
authors.initials: CD
authors.lastname: Claussen
authors.forename: Marius
authors.initials: M
authors.lastname: Horger
mesh_terms: D020533:Angiogenesis Inhibitors / Q000008:administration & dosage*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000150:complications / Q000188:drug therapy* / Q000473:pathology*; D009389:Neovascularization, Pathologic / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology*; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels; D016896:Treatment Outcome
chemical_list: D020533:Angiogenesis Inhibitors; D013113:Spin Labels