title: Diagnostic accuracy of integrated (18)F-FDG PET/CT for restaging patients with malignant germ cell tumours.
abstract: OBJECTIVE
  Evaluation of utility of fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography/CT (PET/CT) for restaging patients with primary malignant germ cell tumours (GCTs).
  
  
  METHODS
  Data of 92 patients (age, 31.94 ± 10.1 years; male/female, 86/6) with histopathologically confirmed malignant GCTs (gonadal, 88; mediastinal, 4; seminomatous, 47 and non-seminomatous, 45) who underwent (18)F-FDG PET/CT for restaging (suspected recurrence/post-therapy evaluation) were retrospectively analysed. Two experienced nuclear medicine physicians reviewed the PET/CT images in consensus, qualitatively and semi-quantitatively [maximum standardized uptake value (SUVmax)]. Histopathology (if available) and clinical/imaging/biochemical follow-up (minimum of 6 months) were employed as the reference standard.
  
  
  RESULTS
  (18)F-FDG PET/CT was interpreted as positive in 59 and negative in 33 patients. Local disease was seen in 5, nodal disease in 50 and distant metastasis in 22 patients. PET/CT was true positive in 49, false positive in 10, true negative in 30 and false negative in 3 patients. (18)F-FDG PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 94.2%, 75.0%, 83.0%, 90.9% and 85.8% overall; 90.0%, 74.0%, 72.0%, 90.9% and 80.8% in seminomatous GCT; and 96.8%, 76.9%, 91.1%, 90.9% and 91.1% in non-seminomatous GCT, respectively. Difference in PET/CT accuracy for seminomatous and non-seminomatous GCTs was not significant (p = 0.263). PET/CT demonstrated disease in 13 patients with negative/equivocal conventional imaging findings and in 9 patients with normal tumour markers. No site- or histology-based difference was seen in SUVmax.
  
  
  CONCLUSIONS
  (18)F-FDG PET/CT demonstrates high diagnostic accuracy for restaging patients with malignant GCTs. It has comparable diagnostic performance in both seminomatous and non-seminomatous malignant GCTs.
  
  
  CONCLUSIONS
  The present article demonstrates high diagnostic accuracy of (18)F-FDG PET/CT for restaging both seminomatous and non-seminomatous malignant GCTs in a large patient population.
authors.affiliation: 1 Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: P
authors.initials: P
authors.lastname: Sharma
authors.forename: T K
authors.initials: TK
authors.lastname: Jain
authors.forename: G K
authors.initials: GK
authors.lastname: Parida
authors.forename: S
authors.initials: S
authors.lastname: Karunanithi
authors.forename: C
authors.initials: C
authors.lastname: Patel
authors.forename: A
authors.initials: A
authors.lastname: Sharma
authors.forename: S
authors.initials: S
authors.lastname: Thulkar
authors.forename: P K
authors.initials: PK
authors.lastname: Julka
authors.forename: C
authors.initials: C
authors.lastname: Bal
authors.forename: R
authors.initials: R
authors.lastname: Kumar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007223:Infant; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D009367:Neoplasm Staging / Q000379:methods; D009373:Neoplasms, Germ Cell and Embryonal / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D014408:Biomarkers, Tumor; D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D007472:Iohexol; C038192:iopromide