title: Diagnostic importance of contrast enhanced (18)F-fluorodeoxyglucose positron emission computed tomography in patients with tumor induced osteomalacia: Our experience.
abstract: OBJECTIVE
  To assess the diagnostic utility of contrast-enhanced (18)F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-ceCT) in localization of tumors in patients with clinical diagnosis of tumor-induced osteomalacia (TIO), in correlation with histopathological results.
  
  
  METHODS
  Eight patients (five male and three female) aged 24-60 (mean 42) years with a clinical diagnosis of TIO were included in this prospective study. They underwent whole body (head to toe) FDG PET-ceCT following a standard protocol on Philips GEMINI TF PET-CT scanner. The FDG PET-ceCT results were correlated with postoperative histology findings and clinical follow-up.
  
  
  RESULTS
  All the patients had an abnormal PET-ceCT study. The sensitivity of PET-ceCT was 87.5%, and positive predictive value was 100%. The tumor was located in the craniofacial region in 6/8 patients and in bone in 2/8 patients. Hemangiopericytoma was the most common reported histology. All patients underwent surgery, following which they demonstrated clinical improvement. However, one patient with atypical findings on histology did not show any clinical improvement, hence, underwent (68)Gallium-DOTANOC PET-ceCT scan for relocalization of the site of the tumor.
  
  
  CONCLUSIONS
  The tumors causing TIO are small in size and usually located in obscure sites in the body. Hence, head to toe protocol should be followed for FDG PET-ceCT scans with the inclusion of upper limbs. Once the tumor is localized, regional magnetic resonance imaging can be performed for better characterization of soft tissue lesion. Imaging with FDG PET-ceCT plays an important role in detecting the site of the tumor and thereby facilitating timely management.
authors.affiliation: Department of Nuclear Medicine and PET-CT, Apollo Hospitals, Chennai, Tamil Nadu, India.
authors.forename: Avani S
authors.initials: AS
authors.lastname: Jain
authors.affiliation: Department of Nuclear Medicine and PET-CT, Apollo Hospitals, Chennai, Tamil Nadu, India.
authors.forename: Simon
authors.initials: S
authors.lastname: Shelley
authors.affiliation: Department of Nuclear Medicine and PET-CT, Apollo Hospitals, Chennai, Tamil Nadu, India.
authors.forename: Indirani
authors.initials: I
authors.lastname: Muthukrishnan
authors.affiliation: Department of Nuclear Medicine and PET-CT, Apollo Hospitals, Chennai, Tamil Nadu, India.
authors.forename: Shilpa
authors.initials: S
authors.lastname: Kalal
authors.affiliation: Department of Nuclear Medicine and PET-CT, Apollo Hospitals, Chennai, Tamil Nadu, India.
authors.forename: Jaykanth
authors.initials: J
authors.lastname: Amalachandran
authors.affiliation: Department of Nuclear Medicine and PET-CT, Apollo Hospitals, Chennai, Tamil Nadu, India.
authors.forename: Sureshkumar
authors.initials: S
authors.lastname: Chandran
keywords: Contrast-enhanced 18F-fluorodeoxyglucose positron emission tomography-computed tomography; fibroblast growth factor-23; hemangiopericytoma; phosphaturic mesenchymal tumors; tumor-induced osteomalacia