Purpose of Review: This review will explore the latest in advanced imaging techniques, with a focus on the complementary nature of multiparametric, multimodality imaging using magnetic resonance imaging (MRI) and positron emission tomography (PET). Recent Findings: Advanced MRI techniques including perfusion-weighted imaging (PWI), MR spectroscopy (MRS), diffusion-weighted imaging (DWI), and MR chemical exchange saturation transfer (CEST) offer significant advantages over conventional MR imaging when evaluating tumor extent, predicting grade, and assessing treatment response. PET performed in addition to advanced MRI provides complementary information regarding tumor metabolic properties, particularly when performed simultaneously. ¹⁸F-fluoroethyltyrosine (FET) PET improves the specificity of tumor diagnosis and evaluation of post-treatment changes. Incorporation of radiogenomics and machine learning methods further improve advanced imaging. Summary: The complementary nature of combining advanced imaging techniques across modalities for brain tumor imaging and incorporating technologies such as radiogenomics has the potential to reshape the landscape in neuro-oncology.

This Policy Review provides recommendations for the use of PET imaging in patients with gliomas and represents a joint effort of the Response Assessment in Neuro-Oncology (RANO) working group for PET and the European Association for Neuro-Oncology. The initial guideline was published in 2016, and summarised the previously established clinical benefit of PET with radiolabelled glucose and amino acid tracers in patients with gliomas. Since then, numerous additional studies have been published on this topic, focusing on differential diagnosis, prediction of molecular information, and prognostication. Further studies evaluated PET for biopsy guidance and delineation of glioma extent for local therapy planning, including resection and radiotherapy. In patients undergoing treatment, PET was studied for the assessment of response to local and systemic treatments and PET-based standardised response criteria (PET RANO 1.0) were proposed. In this Policy Review, the updated recommendations are based on evidence generated from studies that validated PET findings by histomolecular findings or clinical course. This guideline further underscores the previously reported clinical value of PET imaging and the superiority of amino acid PET over glucose PET, providing a framework for the use of PET in the management of patients with gliomas. The guideline also underscores the scarcity of class 1 evidence showing that incorporating PET imaging into clinical workflows improves patient outcomes, highlighting priority areas for future clinical studies designed to address this gap.

The fate of intranasal aerosolized radiolabeled polymeric micellar nanoparticles (LPNPs) was tracked with positron emission tomography/computer tomography (PET/CT) imaging in a rat model to measure nose-to-brain delivery. A quantitative temporal and spatial testing protocol for new radio-nanotheranostic agents was sought in vivo. LPNPs labeled with a zirconium 89 (⁸⁹Zr) PET tracer were administered via intranasal or intravenous delivery, followed by serial PET/CT imaging. After 2 h of continuous imaging, the animals were sacrificed, and the brain substructures (olfactory bulb, forebrain, and brainstem) were isolated. The activity in each brain region was measured for comparison with the corresponding PET/CT region of interest via activity measurements. Serial imaging of the LPNPs (100 nm PLA–PEG–DSPE+⁸⁹Zr) delivered intranasally via nasal tubing demonstrated increased activity in the brain after 1 and 2 h following intranasal drug delivery (INDD) compared to intravenous administration, which correlated with ex vivo gamma counting and autoradiography. Although assessment of delivery from nose to brain is a promising approach, the technology has several limitations that require further development. An experimental protocol for aerosolized intranasal delivery is presented herein, which may provide a platform for better targeting the olfactory epithelium.

Glioblastoma (GBM) is a deadly malignancy with a poor prognosis. An important factor contributing to GBM recurrence is high resistance of GBM cancer stem cells (GSCs). While temozolomide (TMZ), has...