Biodistribution of the α_vβ₃-targeted tracer ¹⁸F-Alfatide in lung cancer patients

Objective: To study the biodistribution of ¹⁸F-Alfatide in lung cancer patients. Methods: Fifteen patients (12 males, 3 females, average age: (56 ± 9) years) with suspicious lung cancer underwent PET/CT imaging. Images were acquired for each patient 60 min after injection of ¹⁸F-Alfatide (3.7 MBq/kg), covering a field of view from the thigh to the skull. SUV_max and SUV_mean were calculated with ROI method. Immunohistochemistry test of tumor samples was performed to confirm the expression of integrin α_vβ₃. The relationship between the accumulation of ¹⁸F-Alfatide and the expression of α_vβ₃ was analyzed by Spear-son rank correlation. Results: There were 7 patients with squamous cell carcinoma, 7 patients with adenocarcinoma and 1 patient with small cell lung cancer. ¹⁸F-Alfatide was excreted by the kidneys. The radioactivity was quickly eliminated from plasma. The high accumulation of radioactivity was found in the liver, spleen and kidneys. ¹⁸F-Alfatide PET imaging identified all tumors. The SUV_max and SUV_mean of tumors were 4.27± 1.32 and 2.75 ± 0.77 respectively, T/NT ratio was 15.19 ± 9.33. The uptake of ¹⁸F-Aifatide in tumor tissues correlated with the expression level of integrin α_vβ₃(r_s = 0.765, P < 0.05). Conclusion: ¹⁸F-Alfatide has a favorable property of tissue biodistribution and can be effectively used for α_vβ₃-positive tumor imaging. (authors)