Preliminary evaluation of cerebral 18F-DOPA PET/CT in the differential diagnosis of brain lesions in inconclusive MR

Abstract

AimTo evaluate the utility of brain 18F-DOPA PET/CT in the differential diagnosis of brain lesions with inconclusive MRI. Material and methodsTwelve patients were studied, with a total of 16 lesions, without definitive diagnosis after brain MRI. A double acquisition PET/CT brain scan was acquired at 20 and 90min. Visual and semiquantitative assessment was performed with SUVmax calculation of the lesions and calculation of the T/S Ratio (tumor/contralateral striatum) and T/N Ratio (contralateral healthy tumor/parenchyma) for each time. ResultsBased on the visual assessment scale and using T/S ratio ≥1 and T/N ratio ≥1.3 to determine malignancy, the values of sensitivity (S), specificity (E) and positive predictive value (PPV) were: visual assessment (S 100%, E 33.3%, VPP 71.4%), T/S Ratio (S 90%, E 100%, VPP 100%) and T/N Ratio (S 100%, E 16.6%, VPP 66.6 %). No lesion showed an increase in SUVmax in late acquisition. 18F-DOPA PET/CT modified treatment in 75% of the patients. Conclusion18F-DOPA PET/CT is a useful tool in the study of brain lesions with inconclusive MRI. Late imaging (dual-point) has no added value in the final diagnosis. FDOPA has an impact on patient management modifying therapeutic behavior.