Comparison between18F-Dopa and 18F-Fet PET/CT in patients with suspicious recurrent high grade glioma: A literature review and our experience

Purposes: The aims of the present study were to: 1-critically assess the utility of L-3,4-dihydroxy-6-18Ffluoro-phenyl-alanine (18F-DOPA) and O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) Positron Emission Tomography (PET)/Computed Tomography (CT) in patients with high grade glioma (HGG) and 2-describe the results of18F-DOPA and18F-FET PET/CT in a case series of patients with recurrent HGG. Methods: We searched for studies using the following databases: PubMed, Web of Science and Scopus. The search terms were: glioma OR brain neoplasm and DOPA OR DOPA PET OR DOPA PET/CT and FET OR FET PET OR FET PET/CT. From a mono-institutional database, we retrospectively analyzed the18F-DOPA and18F-FET PET/CT of 29 patients (age: 56 ± 12 years) with suspicious for recurrent HGG. All patients underwent18F-DOPA or18F-FET PET/CT for a multidisciplinary decision. The final definition of recurrence was made by magnetic resonance imaging (MRI) and/or multidisciplinary decision, mainly based on the clinical data. Results: Fifty-one articles were found, of which 49 were discarded, therefore 2 studies were finally selected. In both the studies,18F-DOPA and18F-FET as exchangeable in clinical practice particularly for HGG patients. From our institutional experience, in 29 patients, we found that sensitivity, specificity and accuracy of18F-DOPA PET/CT in HGG were 100% (95% confidence interval-95%CI-81-100%), 63% (95%CI: 39-82%) and 62% (95%CI: 39-81%), respectively.18F-FET PET/CT was true positive in 4 and true negative in 4 patients. Sensitivity, specificity and accuracy for18F-FET PET/CT in HGG were 100%. Conclusion:18F-DOPA and18F-FET PET/CT have a similar diagnostic accuracy in patients with recurrent HGG. However,18F-DOPA PET/CT could be affected by inflammation conditions (false positive) that can alter the final results. Large comparative trials are warranted in order to better understand the utility of18F-DOPA or18F-FET PET/CT in patients with HGG