¹⁸F-Positron Emitting/Trimethine Cyanine-Fluorescent Contrast for Image-Guided Prostate Cancer Management

Area of Science:

• Radiochemistry
• Molecular Imaging
• Oncology

Background:

• Prostate cancer diagnosis and treatment rely on accurate imaging of tumor markers.
• Prostate-specific membrane antigen (PSMA) is a key biomarker for prostate cancer.
• Current imaging techniques have limitations in sensitivity and specificity.

Purpose of the Study:

• To develop and characterize a novel dual-modality imaging agent, [18/19F]-4, for PSMA-targeted prostate cancer imaging.
• To evaluate the efficacy of [18/19F]-4 in preclinical models.
• To assess the potential of [18/19F]-4 for image-guided intervention.

Main Methods:

• Radiolabeling of [19F]-4 using a one-step aqueous isotopic exchange reaction.
• In vitro characterization of PSMA binding affinity (EC50).
• In vivo imaging studies in mice bearing PSMA-positive and PSMA-negative prostate cancer xenografts using [18F]-PET and fluorescence imaging.

Main Results:

• [19F]-4 was efficiently radiolabeled with high radiochemical yield (≥27%) and molar activity (190 ± 50 mCi/μmol) in under 1 hour.
• The agent specifically delineated PSMA-positive (PC3-PIP) tumors in mice, showing high binding affinity (EC50 = 6.74 ± 1.33 nM).
• Co-localization of PET imaging, fluorescence, biodistribution, and PSMA expression confirmed targeted tumor uptake and imaging capability.

Conclusions:

• [18/19F]-4 is a promising anionic inhibitor of GCPII/PSMA with dual-modality imaging capabilities (fluorescence and PET).
• The agent demonstrates high specificity and sensitivity for PSMA-positive prostate cancer xenografts.
• [18/19F]-4 holds potential for image-guided intervention in prostate cancer management.