Abstract
Objective:
18F-albumin, a vascular imaging agent, may have potential to assess tumor responses to anti-angiogenic therapies. In these studies tumor distribution volume of 18F-albumin were first determined in various human tumor xenografts from biodistribtuion measurments and then one of the tumor type was used to evaluate changes in 18F-albumin uptake in anti-angiognic tumor model.
Method:
18F-albumin was synthesized via conjugation of 6-[18F]fluoronicotinic acid-2,3,5,6-tetrafluorophenyl ester, [18F]F-Py-TFP, with rat albumin. From the biodistribution of 18F-albumin in various human tumor xenografts tumor distribution volumes (DVs; tumor%ID/g:blood%ID/g) were first determined at various time points. Then, the ability of 18F-albumin to detect tumor angiogenic inhibition in one of these tumor types (U87MG) following treatment with sunitinib was evaluated by position emission tomography (PET) imaging at 0, 7, 14, and 21 days post treatment. Caliper measurements of tumor dimensions were also made at these same times. At Day 21, following imaging, biodistributions, autoradiography of tumor tissues and tumor blood vessel counts (CD31 IHC) were performed.
Results:
18F-albumin retention in various tumors steadily increased over time...Continue Reading