title: Diagnostic precision of nanoparticle-enhanced MRI for lymph-node metastases: a meta-analysis.
abstract: BACKGROUND
  At present, there is no accepted, ideal imaging modality or technique for diagnosis of lymph-node metastases. We aimed to assess the diagnostic precision of MRI with ferumoxtran-10-an ultrasmall superparamagnetic iron-oxide nanoparticle used as a contrast agent for diagnosis of lymph-node metastases, compared with that of unenhanced MRI and final histological diagnosis.
  
  
  METHODS
  We did a meta-analysis of prospective studies that compared MRI, with and without ferumoxtran-10, with histological diagnosis after surgery or biopsy. Sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated for every study; summary receiver operating characteristic (ROC) and subgroup analyses were done; and study quality and heterogeneity were assessed. Metaregression analysis was used to analyse the effect of ferumoxtran-10 in diagnostic precision of MRI.
  
  
  RESULTS
  Summary ROC curve analysis for per-lymph-node data showed an overall sensitivity of 0.88 (95% CI 0.85-0.91) and overall specificity of 0.96 (0.95-0.97) for ferumoxtran-10-enhanced MRI. Overall weighted area under the curve for ferumoxtran-10-enhanced MRI was 0.96 (SE 0.01), DOR 123.05 (95% CI 5.93-256.93). Unenhanced MRI had less overall sensitivity (0.63 [0.57-0.69]) and specificity (0.93 [0.91-0.94]), with an overall weighted area under the ROC curve of 0.84 (SE 0.11) and DOR of 26.75 (95% CI 8.48-84.42). Significant heterogeneity was noted for studies reporting enhanced MRI and unenhanced MRI. Metaregression analysis confirmed the significant effect of ferumoxtran-10 in the diagnostic precision of MRI (p=0.001).
  
  
  CONCLUSIONS
  Ferumoxtran-10-enhanced MRI is sensitive and specific in detection of lymph-node metastases for various tumours. It offers higher diagnostic precision than does unenhanced MRI for detection of lymph-node metastases, and allows functional and anatomical definition when used as an imaging modality.
authors.affiliation: Centre for Academic Surgery, Barts and The London, Queen Mary's School of Medicine and Dentistry, Whitechapel, London, UK.
authors.forename: Olivia
authors.initials: O
authors.lastname: Will
authors.forename: Sanjay
authors.initials: S
authors.lastname: Purkayastha
authors.forename: Christopher
authors.initials: C
authors.lastname: Chan
authors.forename: Thanos
authors.initials: T
authors.lastname: Athanasiou
authors.forename: Ara W
authors.initials: AW
authors.lastname: Darzi
authors.forename: Wady
authors.initials: W
authors.lastname: Gedroyc
authors.forename: Paris P
authors.initials: PP
authors.lastname: Tekkis
mesh_terms: D003287:Contrast Media / Q000008:administration & dosage; D003911:Dextrans; D003937:Diagnosis, Differential; D052203:Ferrosoferric Oxide; D006801:Humans; D007501:Iron / Q000008:administration & dosage; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D049329:Nanostructures; D010087:Oxides / Q000008:administration & dosage; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; C097921:ferumoxtran-10; D007501:Iron; D052203:Ferrosoferric Oxide