Positron Emission Tomography Applications in Neuro-Oncology

Positron emission tomography (PET) has emerged as a pivotal imaging modality in neuro-oncology, enabling non-invasive characterisation of tumour metabolism, proliferative activity and molecular phenotype. By administering radiolabelled tracers that target specific biochemical pathways, PET delineates viable tumour margins beyond those visible on conventional magnetic resonance imaging (MRI), thus refining biopsy guidance, surgical planning and radiotherapy target definition. Amino acid tracers such as O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) capitalise on upregulated amino acid transport in gliomas, while other ligands assess proliferation, hypoxia or inflammatory processes. Integration with MRI in hybrid PET/MR scanners affords simultaneous acquisition of structural and functional data, enhancing spatial accuracy. Advanced quantitative approaches, including kinetic modelling and radiomics, derive textural and dynamic parameters that correlate with tumour grade, genetic mutations (notably isocitrate dehydrogenase (IDH) status) and treatment response. Recent advances extend applications to differentiation of pseudoprogression versus true relapse, prognostic stratification and adaptive therapy planning. Standardisation efforts seek reproducible methods for background activity assessment and tumour-to-background ratio calculation, ensuring robust multicentre comparability. Collectively, PET applications in neuro-oncology are driving a more precise, personalised management of primary and recurrent brain tumours.

Research from Nature Portfolio

Combining amino acid PET and MRI imaging has demonstrated superior accuracy in mapping malignant foci within contrast-enhancing gliomas. By prospectively analysing serial biopsies, early FET uptake outside MRI-defined enhancement consistently indicated higher tumour grade and altered biopsy classification in a significant proportion of cases, underscoring the impact on diagnostic yield and treatment planning. Separately, high-resolution PET/MR radiomics has achieved non-invasive prediction of IDH mutation status in newly diagnosed gliomas. The amalgamation of static and dynamic FET uptake metrics with textural features yielded diagnostic accuracies exceeding conventional parameters, offering a preoperative biomarker for molecular stratification and guiding personalised therapeutic decisions.

Positron Emission Tomography Applications in Neuro-Oncology publication trend

The graph below shows the total number of articles in positron emission tomography applications in neuro-oncology across all publications each year (not limited to Nature Index journals).

Technical terms

Positron emission tomography (PET): A nuclear imaging technique that detects pairs of gamma rays emitted indirectly by positron-emitting radiotracers to visualise physiological processes.

Radiotracer: A radioactively labelled molecule administered to patients to probe specific metabolic or molecular targets.

O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET): An amino acid analogue taken up selectively by tumour cells, enabling enhanced contrast in glioma imaging.

Tumour-to-background ratio (TBR): A semiquantitative measure comparing radiotracer uptake in tumour tissue to reference normal tissue.

Radiomics: Extraction of high-dimensional quantitative features from imaging data to characterise tumour heterogeneity and predict outcomes.

Isocitrate dehydrogenase (IDH) mutation: A molecular alteration in gliomas with prognostic and therapeutic implications, detectable via imaging biomarkers.

Translocator protein (TSPO): A mitochondrial protein whose upregulation in neuroinflammation and tumour microenvironment can be targeted by specific PET ligands.

References

1. Combining amino acid PET and MRI imaging increases accuracy to define malignant areas in adult glioma. Nature Communications (2023).
2. Enhancing predictability of IDH mutation status in glioma patients at initial diagnosis: a comparative analysis of radiomics from MRI, [18F]FET PET, and TSPO PET. European Journal of Nuclear Medicine and Molecular Imaging (2024).
3. The role of amino acid PET in radiotherapy target volume delineation for adult-type diffuse gliomas: A review of the literature. Critical Reviews in Oncology/Hematology (2024).
4. Towards standardization of 18F-FET PET imaging: do we need a consistent method of background activity assessment?. EJNMMI Research (2017).
5. Predicting IDH genotype in gliomas using FET PET radiomics. Scientific Reports (2018).
6. Simultaneous FET-PET and contrast-enhanced MRI based on hybrid PET/MR improves delineation of tumor spatial biodistribution in gliomas: a biopsy validation study. European Journal of Nuclear Medicine and Molecular Imaging (2020).
7. Unsupervised consensus cluster analysis of [18F]-fluoroethyl-L-tyrosine positron emission tomography identified textural features for the diagnosis of pseudoprogression in high-grade glioma. Oncotarget (2016).