Imaging of glial tumor recurrence using [68Ga]Ga-PSMA-11 PET/CT
Abstract Background and PurposeLimited data is available on the possible use of [68Ga]Ga-PSMA-11 PET/CT for the diagnosis of glioma recurrence. The aim of this paper was to assess the use of [68Ga]Ga-PSMA-11 PET/CT for the detection of recurrence in different glial tumors.Materials and Methods34 patients (pts.) aged 44.5±10.3 years with suspicion of recurrence of histologically confirmed glioma grade III (6 pts.) and grade IV (28 pts.) were included in the study. All patients underwent contrast-enhanced MR and [68Ga]Ga-PSMA-11 PET/CT.ResultsNo radiopharmaceutical-related adverse events were noted. PET/CT was positive in all the areas suspected for recurrence at MR in all the patients. The recurrence was confirmed by histopathological examinations or follow-up imaging in all cases. The images showed a very low background activity of the normal brain. Median maximal standard uptake value (SUVmax) of the tumors was 6.5 (range: 0.9–15.6) and mean standard uptake value (SUVmean) was 3.5 (range: 0.9–7.5). Target-to-background (TBR) ratios varied between 15 and 1400 with a median of 152. Target-to-liver background ratios (TLR) ranged from 0.2 to 2.6, the median TLR was 1.3. No significant difference of the measured parameters was found between the subgroups according to the glioma grade.Conclusion[68Ga]Ga-PSMA-11 PET/CT shows excellent results in the diagnosis of glioma recurrence of various grades. Due to the very low background activity, this method provides high-quality images and allows for the detection of well-defined recurrence lesions.