Physicochemical Analysis According to Radiation Dose of Iodinated Contrast Agent

Abstract

The purpose of this study was to determine whether a high energy radiation dose used for radiation therapy might be one of environmental factors affecting physical and chemical changes of a contrast agent by identifying components of the contrast agent and analyzing its chemical structure.

Chemical structures of standard samples were analyzed using NMR Spectroscopy for Iopamidol preparation P contrast agent and Ioversol preparation O contrast agent. As one of environmental factors, radiation dose was 200 cGy (6 MV, 10 MV) and 300 cGy (6 MV, 10 MV) in the photon beam of an LINAC device. In an electron beam, 200 cGy (6 MeV, 9 MeV, 12 MeV, 16 MeV, 20 MeV) and 300 cGy (6 MeV, 9 MeV, 12 MeV, 16 MeV, 20 MeV) were irradiated. 1H-NMR spectra were obtained for stimulated sample through NMR analysis. Chemical shift value was compared with a standard.

With changes of radiation dose, physicochemical change was not observed for the Ioversol preparation O contrast agent. In the electron beam of the Iopamidol preparation P contrast agent, a singlet peak was clearly seen in all contrast agents irradiated at a dose of 300 cGy (6 MeV, 9 MeV, 12 MeV, 16 MeV) in the 2.5 ppm region. A quartet peak in the 3.6 ppm region was also clearly seen for the contrast agent irradiated at a dose of 300 cGy (20 MeV). There was no physical or chemical change depending on the radiation dose of the photon beam.

In ¹H-NMR analysis, the Iopamidol preparation P contrast agent showed a physicochemical change in the electron beam, but not in the photon beam. Thus, it can be concluded that Ioversol preparation O contrast agent has better physicochemical safety in than Iopamidol preparation P contrast agent.