A Clinical Feasibility Study to Image Angiogenesis in Patients with Arteriovenous Malformations Using ⁶⁸Ga-RGD PET/CT

Area of Science:

• Vascular Biology
• Medical Imaging
• Oncology

Background:

• Arteriovenous malformations (AVMs) exhibit significant lesion growth driven by angiogenesis and angiogenic factors.
• Assessing the angiogenic status of AVMs is crucial for understanding disease progression and treatment response.

Purpose of the Study:

• To demonstrate the feasibility of using ⁶⁸Ga-labeled arginine-glycine-aspartate tripeptide sequence (RGD) Positron Emission Tomography/Computed Tomography (PET/CT) for quantitative assessment of angiogenesis in peripheral AVMs.
• To correlate imaging findings with immunohistochemical analysis of integrin α_vβ₃ expression.

Main Methods:

• Prospective inclusion of ten patients with peripheral AVMs scheduled for endovascular embolization.
• ⁶⁸Ga-RGD PET/CT imaging performed 60 minutes post-injection (mean dose, 207 ± 5 MBq).
• Quantification of tracer uptake (SUV_max, SUV_peak) in AVM lesions, blood pool, and muscle, alongside immunohistochemical analysis of biopsy samples for integrin α_vβ₃ expression.

Main Results:

• ⁶⁸Ga-RGD PET/CT demonstrated enhanced uptake in all AVM lesions (mean SUV_max, 3.0 ± 1.1; mean SUV_peak, 2.2 ± 0.9).
• Significantly higher lesion-to-blood (3.5 ± 2.2) and lesion-to-muscle (4.6 ± 2.8) ratios were observed compared to background tissues (P < 0.002).
• Immunohistochemistry confirmed cytoplasmatic and membranous integrin α_vβ₃ expression in AVM endothelial cells.

Conclusions:

• ⁶⁸Ga-RGD PET/CT imaging effectively visualizes and quantifies angiogenesis in peripheral AVMs.
• The imaging technique shows increased uptake in AVMs with angiogenic activity compared to normal tissues.
• This suggests ⁶⁸Ga-RGD PET/CT is a promising tool for assessing AVM angiogenesis and potentially guiding treatment decisions and response monitoring.