Artikel
Predictive value of 18F-FET PET in 169 newly diagnosed glioma suspective cerebral lesions
Suche in Medline nach
Autoren
Veröffentlicht: | 28. April 2011 |
---|
Gliederung
Text
Objective: The study aimed to investigate the clinical value of preoperative O-(2-[18F] fluoroethyl)-L-tyrosine (18F-FET) positron emission tomography (PET) in patients with untreated intracerebral lesions suspicious for glioma.
Methods: We retrospectively evaluated the biological, clinical, radiological and neuropathological data of 169 patients (91 men, 78 women, median age 44.6 years) admitted to the department of neurosurgery for assessment of histological diagnosis of a cerebral mass or lesion detected by MRI between 2001 and 2010. Special attention was given to suspected grade II and III glioma. FET PET and Gd enhanced MRI was obtained in all patients within 6 weeks before surgery (n=79) or biopsy (n=90) was performed. In reference to the literature a FETmax uptake with a lesion to brain ratio of 1.6 or higher was considered positive in PET.
Results: Histology revealed a tumorous lesion in 150 and a non-tumorous lesion in 19 patients. FET PET was positive in 134 patients (sensitivity 84%, positive predictive value 0.9) and negative in 35 patients (specificity 43%, negative predictive value 0.3). Depending on the tumor entity the sensitivity was as follows: Gliomas WHO grade I (n=4) 50%, diffuse gliomas WHO grade II (n=73) 78%, anaplastic gliomas WHO grade III (n=47) 89%, glioblastomas WHO grade IV (n=20) 100% and lymphomas (n=2) 100%. Four patients with an initially unspecific histology developed a glioma WHO grade III or IV later and initial FET PET was positive in three. Depending on the non-tumorous entity the specificity was as follows: Unspecific gliotic lesions (n=9) 55%, demyelinating-inflammatory lesions (n=4) 25%, abscesses (n=2) 0%, vascular lesions (n=4) 75%.
Conclusions: The sensitivity of FET PET for detection of tumor tissue in glioma is high and increases with the WHO grade: While a subset of grade II gliomas shows low or absent FET-uptake nearly all grade III and IV gliomas are FET-positive. In contrast the specificity of FET-PET for tumor detection is moderate, because especially acute inflammatory or infectious lesions show moderate to high FET-uptake.