title: Effective detection of the tumors causing osteomalacia using [Tc-99m]-HYNIC-octreotide (99mTc-HYNIC-TOC) whole body scan.
abstract: OBJECTIVE
  Tumor-induced osteomalacia (TIO) is an endocrine disorder caused by tumors producing excessive fibroblast growth factor-23 (FGF-23). The causative tumors are generally small, slow-growing benign mesenchymal tumors. The only cure of the disease depends on resection of the tumors, which are extremely difficult to localize due to their small sizes and rare locations. Since these tumors are known to express somatostatin receptors, this research was undertaken to evaluate efficacy of [Tc-99m]-HYNIC-octreotide (99mTc-HYNIC-TOC) whole body imaging in this clinical setting
  
  
  METHODS
  Images of 99mTc-HYNIC-TOC scans and clinical chart from 183 patients with hypophosphatemia and clinically suspected TIO were retrospectively reviewed. The scan findings were compared to the results of histopathological examinations and clinical follow-ups.
  
  
  RESULTS
  Among 183 patients, 72 were confirmed to have TIO while 103 patients were found to have other causes of hypophosphatemia. The possibility of TIO could not be either diagnosed or excluded in the remaining 8 patients. For analytical purposes, these 8 patients who could neither be diagnosed nor excluded as having TIO were regarded as having the disease, bringing the total of TIO patients to 80. The 99mTc-HYNIC-TOC scan identified 69 tumors in 80 patients with TIO, which rendered a sensitivity of 86.3% (69/80). 99mTc-HYNIC-TOC scintigraphy excluded 102 patients without TIO with a specificity of 99.1% (102/103). The overall accuracy of 99mTc-HYNIC-TOC whole body scan in the localization of tumors responsible for osteomalacia is 93.4% (171/183).
  
  
  CONCLUSIONS
  Whole body 99mTc-HYNIC-TOC imaging is effective in the localization of occult tumors causing TIO.
authors.affiliation: Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PR China. Electronic address: annsmile1976@sina.com.
authors.forename: Hongli
authors.initials: H
authors.lastname: Jing
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Hongming
authors.initials: H
authors.lastname: Zhuang
authors.forename: Zhenghua
authors.initials: Z
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Tian
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Xing
authors.forename: Jin
authors.initials: J
authors.lastname: Jin
authors.forename: Dingrong
authors.initials: D
authors.lastname: Zhong
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D000089703:Fibroblast Growth Factor-23; D006801:Humans; D008297:Male; D008875:Middle Aged; D009372:Neoplasms, Connective Tissue / Q000000981:diagnostic imaging*; D015282:Octreotide / Q000031:analogs & derivatives*; D015609:Organotechnetium Compounds; D010018:Osteomalacia; D010257:Paraneoplastic Syndromes; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D051598:Whole Body Imaging / Q000379:methods*; D055815:Young Adult
chemical_list: C000717427:FGF23 protein, human; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C410263:technetium Tc 99m hydrazinonicotinyl-Tyr(3)-octreotide; D000089703:Fibroblast Growth Factor-23; D015282:Octreotide
keywords: 99mTc-HYNIC-TOC; Hypophosphatemia; Oncogenic osteomalacia; Ostreoscan; Tumor-induced osteomalacia (TIO)