68Ga-P16-093 PET/CT Imaging in Glioma Patients

PSMA is highly expressed on the cell surface of the microvasculature of several solid tumors, including glioma. This makes it a potentially imaging target for the detection and grading of gliomas. This pilot study was designed to evaluate the diagnostic performance of 68Ga-P16-093, a novel radiopharmaceutical targeting PSMA, which was compared with MRI in the same group of glioma patients.

Glioma is the most common primary malignant brain tumor which can be divided into four grades according to different histopathological and molecular biological characteristics.Among them, glioblastoma is one of the most common types of glioma in adults (about 55%). It belongs to WHO Grade IV high-grade glioma, with a high recurrence rate, poor prognosis, and a 5-year survival rate of less than 10%. Prostate-specific membrane antigen (PSMA), as known as folate hydrolase I or glutamate carboxypeptidase II, is overexpressed on the cells of prostatic adenocarcinoma. However, PSMA is also expressed by tumor cells or neovascular endothelial cells of various solid neoplasms, such as glioma. Therefore, PSMA may be an ideal target for the diagnosis of glioma. 68Ga-P16-093, a novel radiopharmaceutical targeting PSMA, with the urea fragment of a conjugate that employs the HBED-CC chelator for labeling with 68Ga(III). The HBED-based chelating ligand binds the 68Ga3+ ion with high affinity in a pseudo-octahedral N2O4 coordination sphere by its two phenolate O, two amino-acetate carboxylate O, and two amino N donor atoms. This pilot study was designed to evaluate the diagnostic performance of 68Ga-P16-093 in the same group of glioma patients, compared with MRI.

Within 1 week, each patient underwent MRI scan and PET/CT scan after intravenous administration of 68Ga-P16-093, respectively.

Intravenous injection of 68Ga-P16-093 with the dosage of 1.5-1.8 MBq (0.04-0.05 mCi)/kg. Tracer doses of 68Ga-P16-093 will be used to image lesions of glioma by PET/CT.

Inclusion Criteria: glioma patients highly suggested by MRI or histologically confirmed; 68Ga-P16-093 PET/CT and MRI within two weeks; signed written consent. Exclusion Criteria: known allergy against PSMA; any medical condition that in the opinion of the investigator may significantly interfere with study compliance.