PET Imaging and Protein Expression of Prostate-Specific Membrane Antigen in Glioblastoma: A Multicenter Inventory Study

• DOI: 10.2967/jnumed.123.265738
• Publication Date: 2023-10-03T12:30:29Z
• Authors: Sanne A.M. van Lith; Ilanah J. Pruis; Nelleke Tolboom; Tom J. Snijders; Dylan Henssen; Mark ter Laan; Maarten te Dorsth...; William P.J. Leen...; Martin Gotthardt; James Nagarajah; Pierre A. Robe; Philip De Witt Hamer; Harry Hendrikse; Daniela E. Oprea-...; Maqsood Yaqub; Ronald Boellaard; Pieter Wesseling; Rutger K. Balvers; Frederik A. Verburg; Anita A. Harteveld; Marion Smits; Martin van den Bent; Sophie E.M. Veldh...; Elsmarieke van de...
• Keywords: Glutamate carboxypeptidase II; Brain tumor; Tumor progression

Upregulation of prostate-specific membrane antigen (PSMA) in neovasculature has been described glioblastoma multiforme (GBM), whereas vasculature nonaffected brain shows hardly any expression PSMA. It is unclear whether PSMA-targeting tracer uptake on PET based PSMA-specific binding to or aspecific tumor. Here, we quantified various tracers GBM and correlated this with PSMA tumor biopsy samples from the same patients. Methods: Fourteen patients diagnosed de novo (n = 8) recurrent 6) underwent a preoperative scan after injection 1.5 MBq/kg [68Ga]Ga-PSMA-11 7), 200 MBq [18F]DCFpyl 3), [18F]PSMA-1007 4). Uptake tumor-to-background ratios, contralateral as background, were determined. In subset patients, levels different regions tissue 40), determined using immunohistochemistry 35) RNA sequencing 13), PET. Results: Moderate high (SUVmax, 1.3-20.0) heterogeneous was found all tumors irrespective type used. low, resulting ratios (6.1-359.0) calculated by dividing SUVmax background. Immunohistochemistry showed variable endothelial cells microvasculature, well dispersed individual (of unknown origin), granular staining neuropil. No correlation between vivo (for immunohistochemistry, r -0.173, P 0.320; for RNA, -0.033, 0.915). Conclusion: Our results indicate potential use GBM. However, no intensity Whether may be explained methodologic reasons, such inability measure functionally active pharmacokinetics, contribution disturbed blood-brain barrier retention, should still investigated.