title: 13N-NH3 versus F-18 FDG in detection of intracranial meningioma: initial report.
abstract: OBJECTIVE
  Relatively high Tl-201 uptakes have been reported in all types of meningiomas, and it have been proposed that (201)TlCl SPECT could predict histologic types of meningiomas and differentiate the benign and aggressive meningiomas. Similar to Tl-201, (13)N-(13)NH(4)(+) is an analog of K(+) and could substitute K(+) in some cases. The aim of this study was to evaluate the capacity of PET with (13)N-NH(3) to discriminate meningioma from healthy tissue, and compare with F-18 FDG.
  
  
  METHODS
  Eleven patients with the neuroradiologic diagnosis of meningiomas were studied with (13)N-NH(3), and 10 of them were performed with F-18 FDG PET within 3 days. Ten of them were histologically confirmed (6 grade I, 4 grade II), and another one was proved by radiologic (computed tomography and magnetic resonance imaging) and clinical investigation.The PET images were evaluated by semiquantitative analysis using tumor-to-white matter ratio (T/W).
  
  
  RESULTS
  (13)N-NH(3) uptake was obviously increased in all 11 meningiomas with a good contrast to the surrounding normal brain tissues. Conversely, F-18 FDG uptake was decreased in comparison with the contralateral side in all 7 patients with grade I meningiomas and moderately increased in the remaining patient with grade II meningioma. The T/W ratio of (13)N-NH(3) was higher than that of F-18 FDG (7.03 ± 1.62 vs. 1.44 ± 0.57, P < 0.005). T/W of (13)N-NH(3) uptake was not useful for differentiating benign (Grade I) from atypical (Grade II) meningiomas (P = 0.88), whereas the T/W ratio of F-18 FDG uptake was better than that of N-NH3 for differentiating benign from malignant meningiomas (P = 0.037).
  
  
  CONCLUSIONS
  These preliminary results suggest that (13)N-NH(3) has relatively greater uptake in meningiomas in comparison with F-18 FDG. Clinical applications of (13)N-NH(3) PET for grading and follow-up of meningiomas need to be assessed in further studies.
authors: Department of Nuclear Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
authors: Zhang
authors: Z
authors: Xiangsong
authors: Shi
authors: S
authors: Xingchong
authors: Yi
authors: Y
authors: Chang
authors: Wang
authors: W
authors: Xiaoyan
authors: Chen
authors: C
authors: Zhifeng
mesh_terms: D000328:Adult; D000368:Aged; D000641:Ammonia; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D008579:Meningioma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D009590:Nitrogen Radioisotopes; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed
chemical_list: D009590:Nitrogen Radioisotopes; D019788:Fluorodeoxyglucose F18; D000641:Ammonia