Diagnostic accuracy of F-18-fluoroethyltyrosine PET and PET/CT in patients with brain tumor

Abstract

Positron emission tomography with 18F-fluoroethyltyrosine (FET-PET) is increasingly used for the initial evaluation of patients with primary brain tumors (PBTs). This article provides an up-to-date systematic review and meta-analysis of FET-PET diagnostic performances in patients with suspected PBTs. The PubMed and EMBASE databases were searched for studies published in the period January 1977-September 2012. Inclusion criteria were: (1) use of FET-PET for assessment of newly diagnosed brain lesions; (2) no radiotherapy, surgery or chemotherapy prior to FET-PET and (3) use of histology as gold standard. A per-patient meta-analysis was performed, as well as a receiver operating characteristics (ROC) analysis of pooled patients to determine optimal tumor-to-background ratio (TBR) of FET uptake. In total, 16 studies (641 patients) were included. For the diagnosis of tumoral vs non-tumoral brain lesions, FET-PET demonstrated a pooled sensitivity of 0.80 (95 % CI 0.74-0.85), specificity of 0.67 (0.44-0.84), area under the curve of 0.81 (0.78-0.85), positive likelihood ratio of 2.4 (1.3-4.7), and negative likelihood ratio of 0.29 (0.19-0.45). ROC analysis showed a meanTBR threshold ≥1.6 and a maxTBR ≥2.2 to have the best diagnostic value for differentiating PBTs from non-tumoral lesions. This meta-analysis confirms the excellent performances of FET-PET used for the diagnosis of PBTs. For FET-PET to become a relevant tool for improving patient management, prospective multicenter studies with standardized acquisition protocols should investigate its added value over current magnetic resonance imaging and the optimal combination of FET-PET and MRI. © 2013 Italian Association of Nuclear Medicine and Molecular Imaging.