title: Prospective observational study on diagnostic accuracy of whole-body MRI in solid small round cell tumours.
abstract: OBJECTIVE
  To assess the diagnostic accuracy of whole-body magnetic resonance imaging (WB-MRI) for metastatic disease in patients with solid small round cell tumours (SRCT) by comparing it with routine staging procedures (standard of care).
  
  
  METHODS
  Eligible cases of neuroblastoma, primitive neuroectodermal tumour, and rhabdomyosarcoma were enrolled in the study after obtaining informed consent. WB-MRI was undertaken using overlapping coronal T1 and short-tau inversion recovery (STIR) sequences. Lesions were classified into skeletal, pulmonary, and soft-tissue types. Conventional staging, which consisted of combined positron-emission tomography & computed tomography (PET-CT), bone scintigraphy & bone marrow biopsy for bone metastases, CT thorax for lung metastases, combined PET-CT, metaiodobenzylguanidine (MIBG) scintigraphy (in neuroblastoma) for soft tissue metastases and clinical evaluation was used as the reference standard. Parameters for diagnostic accuracy were calculated.
  
  
  RESULTS
  Thirty-four out of forty patients enrolled were included in final analysis, half of them having metastatic disease. The sensitivity, specificity, positive and negative predictive value, and the diagnostic accuracy of WB-MRI and PET-CT for skeletal metastases as compared to reference standard were 91.9%, 99.8%, 97.4%, 99.6%, and 95.5% and 99.1%, 99.9%, 99.1%, 99.9%, and 99.9%, respectively. The sensitivity of MRI, only PET and PET-CT with plain CT thorax was 30%, 40%, and 100%, respectively, for lung metastases. The sensitivity of MRI for soft-tissue lesions was 76.9%.
  
  
  CONCLUSIONS
  WB-MRI is a radiation-free tool with high diagnostic accuracy for the evaluation of metastatic disease to the marrow. The rate of detection of soft-tissue metastases, such as nodal metastases, is less when WB-MRI is compared with conventional staging using coronal STIR images. CT thorax is essential for accurate evaluation of lung metastases.
authors.affiliation: Department of Radiodiagnosis, Tata Memorial Centre, Parel, Mumbai, India. Electronic address: seema.kembhavi@gmail.com.
authors.forename: S A
authors.initials: SA
authors.lastname: Kembhavi
authors.affiliation: Bio-Imaging Unit, Tata Memorial Centre, Parel, Mumbai, India.
authors.forename: V
authors.initials: V
authors.lastname: Rangarajan
authors.affiliation: Bio-Imaging Unit, Tata Memorial Centre, Parel, Mumbai, India.
authors.forename: S
authors.initials: S
authors.lastname: Shah
authors.affiliation: Department of Surgery, Tata Memorial Centre, Parel, Mumbai, India.
authors.forename: S
authors.initials: S
authors.lastname: Qureshi
authors.affiliation: Department of Medical Oncology, Tata Memorial Centre, Parel, Mumbai, India.
authors.forename: B
authors.initials: B
authors.lastname: Arora
authors.affiliation: Department of Radiodiagnosis, Tata Memorial Centre, Parel, Mumbai, India.
authors.forename: S
authors.initials: S
authors.lastname: Juvekar
authors.affiliation: Department of Radiotherapy, Tata Memorial Centre, Parel, Mumbai, India.
authors.forename: S
authors.initials: S
authors.lastname: Laskar
authors.affiliation: Department of Medical Oncology, Tata Memorial Centre, Parel, Mumbai, India.
authors.forename: T
authors.initials: T
authors.lastname: Vora
authors.affiliation: Department of Medical Oncology, Tata Memorial Centre, Parel, Mumbai, India.
authors.forename: G
authors.initials: G
authors.lastname: Chinnaswamy
authors.affiliation: Department of Pathology, Tata Memorial Centre, Parel, Mumbai, India.
authors.forename: M
authors.initials: M
authors.lastname: Ramadwar
authors.affiliation: Department of Medical Oncology, Tata Memorial Centre, Parel, Mumbai, India.
authors.forename: P
authors.initials: P
authors.lastname: Kurkure
mesh_terms: D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009367:Neoplasm Staging; D009447:Neuroblastoma / Q000473:pathology*; D017599:Neuroectodermal Tumors / Q000473:pathology*; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D013902:Radiography, Thoracic; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012015:Reference Standards; D015203:Reproducibility of Results; D012208:Rhabdomyosarcoma / Q000473:pathology*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D018084:Ultrasonography, Interventional; D051598:Whole Body Imaging
chemical_list: D019275:Radiopharmaceuticals