Related Experiment Video
Updated: Jul 17, 2025
05:45
Quantitative Immunohistochemistry of the Cellular Microenvironment in Patient Glioblastoma Resections
Published on: July 31, 2017
9.7K
PET Imaging and Protein Expression of Prostate-Specific Membrane Antigen in Glioblastoma: A Multicenter Inventory
Sanne A M van Lith1, Ilanah J Pruis2, Nelleke Tolboom3
1Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands.
Summary
This study investigated prostate-specific membrane antigen (PSMA) tracer uptake in glioblastoma multiforme (GBM). While tracers showed uptake, no correlation was found between PSMA expression and PET imaging results.
Area of Science:
- Neuro-oncology
- Radiopharmaceuticals
- Molecular Imaging
Background:
- Prostate-specific membrane antigen (PSMA) is upregulated in glioblastoma multiforme (GBM) neovasculature.
- The basis for PSMA-targeting tracer uptake in GBM (specific binding vs. non-specific uptake) remains unclear.
Purpose of the Study:
- To quantify PSMA-targeting tracer uptake in GBM using PET.
- To correlate in vivo tracer uptake with PSMA expression in tumor biopsy samples.
Main Methods:
- Fourteen patients with de novo or recurrent GBM underwent PET scans with [68Ga]Ga-PSMA-11, [18F]DCFpyl, or [18F]PSMA-1007.
- Tumor and tumor-to-background ratios were determined.
- PSMA expression was assessed via immunohistochemistry and RNA sequencing in tumor samples and correlated with PET uptake.
Main Results:
- All GBMs showed moderate to high heterogeneous tracer uptake, regardless of tracer type, yielding high tumor-to-background ratios.
- Immunohistochemistry revealed variable PSMA expression on tumor microvasculature and other cellular components.
- No significant correlation was found between in vivo tracer uptake and PSMA expression levels (IHC: r = -0.173, P = 0.320; RNA: r = -0.033, P = 0.915).
Conclusions:
- Various PSMA-targeting tracers show potential for GBM imaging.
- The lack of correlation between PSMA expression and PET uptake warrants further investigation into methodological factors, tracer pharmacokinetics, and blood-brain barrier effects.
