Zhurnal voprosy neirokhirurgii imeni N. N. Burdenko | 2019

[C-methionine PET in assessment of brain lesions in patients with glial tumors after combined treatment].



Positron emission tomography (PET) with amino acid-based radiopharmaceuticals is considered as an effective method to diagnose continued growth of cerebral gliomas, but the variability of 11C-methionine uptake by brain lesions of different genesis after combined treatment still remains poorly understood. The aim of this study was to explore the information value of 11C-methionine PET in delimitating progression of cerebral gliomas and stable disease and to assess the risk of tumor recurrence at different values of the 11C-methionine uptake index. MATERIAL AND METHODS: We performed a retrospective analysis of the results of 11C-methionine PET or PET/CT in 324 patients suspected for continued growth of cerebral tumor based on magnetic resonance imaging (MRI) findings. A quantitative analysis of the results included calculation of the 11C-methionine uptake index (UI). RESULTS: A ROC analysis revealed that the specificity of PET in the diagnosis of continued tumor growth (CTG) was 98%, and the sensitivity was 71% for a UI of more than 1.9. We found that 98% of lesions with a negative level of RP uptake were related to radiation brain lesions (RBLs) or residual tumors combined with radiation pathomorphims. The UI in a range of 1.2-1.6 in 75% of lesions characterized a stable disease, but 25.5% of the lesions represented continued glioma growth. The proportion of recurrences increased to 40% in a UI range of 1.6-1.9, and 95.5% of brain lesions with a UI of more than 1.9 were tumor recurrences. Therefore, high 11C-methionine uptake with the UI above 1.9 in brain lesions characterized by radiological signs of disease progression is a highly specific indicator of CTG; however, the UI may significantly vary during tumor growth, and a substantial fraction of recurrent gliomas may have lower radiopharmaceutical uptake. In the case of borderline UI values, early dynamic control or complementary additional MRI or CT techniques should be used.

Volume 83 2
Pages \n 27-36\n
DOI 10.17116/neiro20198302127
Language English
Journal Zhurnal voprosy neirokhirurgii imeni N. N. Burdenko

Full Text