Can PSMA-Targeting Radiopharmaceuticals Be Useful for Detecting Brain Metastasis of Various Tumors Using Positron...

Area of Science:

• Nuclear Medicine
• Oncology
• Radiology

Background:

• Prostate-specific membrane antigen (PSMA) is highly expressed in neovascularization of non-prostatic tumors and metastases.
• PSMA imaging is increasingly used for glial tumor follow-up due to minimal background activity in brain tissue.
• Brain metastases (BM) present diagnostic challenges, necessitating advanced imaging techniques.

Purpose of the Study:

• To prospectively evaluate the diagnostic performance of 68Ga-PSMA-11 PET/CT in patients with brain metastases.
• To compare 68Ga-PSMA-11 PET/CT findings with 18F-FDG PET/CT and MRI in brain metastases detection.
• To assess the potential of 68Ga-PSMA-11 PET/CT for restaging and recurrence assessment of brain metastases.

Main Methods:

• Prospective study including 27 patients with diagnosed brain metastases.
• Patients underwent both 68Ga-PSMA-11 PET/CT and 18F-FDG PET/CT imaging.
• Comparison of PET/CT findings with MRI and histopathological data where available.

Main Results:

• 68Ga-PSMA-11 PET/CT detected PSMA-positive brain metastases in 26 out of 27 patients.
• 11 cases (42%) showed metastatic foci undetectable by 18F-FDG PET/CT but visible with 68Ga-PSMA-11 PET/CT.
• 68Ga-PSMA-11 PET/CT demonstrated excellent tumor-to-background contrast, with findings compatible with MRI.

Conclusions:

• 68Ga-PSMA-11 PET/CT is superior to 18F-FDG PET/CT for detecting brain metastases from various primary tumors.
• The high tumor-to-background contrast of 68Ga-PSMA-11 PET/CT is attributed to PSMA expression in neovascularization and absent uptake in normal brain parenchyma.
• Further large-scale studies integrating PSMA IHC are needed; findings may inform PSMA-targeted therapeutic strategies for brain metastases.