Imaging of tumor hypoxia with [124I]IAZA in comparison with [18F]FMISO and [18F]FAZA--first small animal PET results.

Abstract

PURPOSE: This study was performed to compare the 2-nitroimidazole derivatives [124I]IAZA, [18F] FAZA and well known [18F]FMISO in visualization of tumor hypoxia in a mouse model of human cancer using small animal PET. METHODS: PET imaging of female Balb/c nude mice bearing A431 tumors on a Phillips Mosaic small animal PET scanner was performed 3 h p.i. for all three tracers. Mice injected with [124I] IAZA were scanned again after 24 h and 48 h. In addition to the mice breathing air, in the case of [18F]FAZA and [124I] IAZA a second group of mice for each tracer was kept in an atmosphere of carbogen gas (5% of CO2 + 95 % of O2; from 1 h before to 3 h after injection) to evaluate the oxygenati..