title: Usefulness and limitations of fluorine-18-fluorodeoxyglucose positron emission tomography for the detection of malignancy of orbital tumors.
abstract: Fluorine-18-fluorodeoxyglucose positron emission tomography ([18F]FDG PET) was assessed as a method for providing information about the malignancy of orbital tumors. Twelve patients with 13 orbital tumors underwent [18F]FDG PET followed by biopsy or tumor removal via a transcranial approach. The accumulation ratio between the tumor and the contralateral normal tissue (T/N ratio) was calculated for 10 of the 13 lesions. The T/N ratio in benign lesions was compared with that in malignant tumors. Histological examination identified 7 lesions as malignant: anaplastic astrocytoma of the optic nerve in 1 patient, which recurred as glioblastoma of the optic nerve, malignant lymphoma of mucosa-associated lymphoid tissue type in 1 patient, malignant melanoma in 1 patient, adenoid cystic carcinoma in 2 patients, and adenocarcinoma (unknown origin) in 1 patient. The T/N ratio was 1.06 +/- 0.03 (mean +/- standard deviation) in benign tumors, and significantly higher at 1.81 +/- 0.27 in malignant tumors (p = 0.0027). Both patterns of high and iso uptake of [18F]FDG were found in orbital pseudotumor. [18F]FDG PET can determine the malignancy of orbital tumors, but cannot distinguish malignant tumor from inflammatory disease such as pseudotumor.
authors.affiliation: Department of Neurosurgery, Kyoto Prefectural University Graduate School of Medicine, Kyoto, Japan. miyapoo850@yahoo.co.jp
authors.forename: Junichi
authors.initials: J
authors.lastname: Miyamoto
authors.forename: Kazunori
authors.initials: K
authors.lastname: Tatsuzawa
authors.forename: Kei
authors.initials: K
authors.lastname: Owada
authors.forename: Takuya
authors.initials: T
authors.lastname: Kawabe
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Sasajima
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Mineura
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000000981:diagnostic imaging; D003528:Carcinoma, Adenoid Cystic / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D005909:Glioblastoma / Q000000981:diagnostic imaging; D020786:Hemangioma, Cavernous, Central Nervous System / Q000000981:diagnostic imaging; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000000981:diagnostic imaging; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging; D008875:Middle Aged; D009442:Neurilemmoma / Q000000981:diagnostic imaging; D019574:Optic Nerve Neoplasms / Q000000981:diagnostic imaging*; D009918:Orbital Neoplasms / Q000000981:diagnostic imaging*; D016727:Orbital Pseudotumor / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D055815:Young Adult
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18