CXCR4 PET/MRI Targeted Imaging for Grading Diagnosis, Molecular Typing, and Prognostic Evaluation of Brain Glioma

This project intends to evaluate the role of C-X-C chemokine receptor type 4 (CXCR4) targeted PET/MRI integrated imaging in the grading and molecular typing of brain gliomas, using primary glioma patients as the research subjects and post-operative histopathological analysis as the reference, and to establish an evaluation model for the prognosis of primary glioma patients.

1. PET/MRI Scan: Image acquisition was completed 15 days before surgery. CXCR4 contrast agent was injected at 6.5 MBq/kg based on body mass, with no drug extravasation, and imaging was performed after 60 minutes of quiet rest. All subjects were scanned in a supine position on a single bed of the Signa™ 3.0T scanner (GE Healthcare Systems), using a 3.0T gem HNU head coil with a scanning field of view focused on the head. PET acquisition lasted for 20 minutes and was reconstructed using OSEM. Simultaneous MRI acquisition included MR-based attenuation correction (MRAC) - zero echo time pulse sequence (ZTE), as well as structural and functional MRI sequences (T1WI, T2WI, FLAIR, DWI, MRS, DSC, T1-CE). Image fusion was performed on a GE post-processing workstation. 2. Image Analysis and Observation Indicators: PET/MRI images were independently reviewed and processed by two experienced neuroradiologists. Using IKT-SNAP software, target lesion VOIs were outlined based on FLAIR and T1-CE sequences. VOI delineation on the FLAIR sequence included solid tumor components, necrotic areas, and surrounding abnormal FLAIR signal regions. VOI delineation on the T1-CE sequence included enhanced solid components, non-enhanced solid components, and necrotic areas. MRI parameters (diffusion-weighted imaging parameters: ADC; perfusion imaging parameters: CBF, CBV, MTT, TTP; spectroscopic parameters: NAA, Cho, Cr, Lac, NAA/Cr, Cho/Cr) and PET parameters (SUVmax, SUVmean, SUVpeak, CXCR4 metabolic volume, TBR) were measured throughout the tumor and corresponding regions. 3. Pathological Analysis: Slices containing no less than 25% tumor tissue were used, with each slice having a thickness of 4um. HE, CD34, and CXCR4 immunohistochemical staining were performed separately. Two senior pathologists reviewed the slides using a double-blind method. IDH mutation status and 1p/19q deletion status were determined by the pathology department.