Abstract
Near infrared photoimmunotherapy (NIR-PIT) is a new cancer treatment that combines the specificity of antibodies for targeting tumors with toxicity induced by photo-absorbers after irradiation with NIR light. A limitation of NIR-PIT is the inability to deliver NIR light to a tumor located deep inside the body. Cerenkov radiation (CR) is ultraviolet and blue light which is produced by a charged particle travelling through a dielectric medium faster than the speed of light in that medium and is commonly produced during radioactive decay. Here, we demonstrate the feasibility of using CR generated by 18F-FDG accumulated in tumors to induce photoimmunotherapy. Methods: Using A431-luc cells therapeutic effects of CR-photoimmunotherapy (CR-PIT) in vitro and in vivo were evaluated by bioluminescence imaging. Results: CR-PIT showed significant suppression of tumor size, but the decrease of bioluminescence after CR-PIT was not observed consistently over the entire time course. Conclusion: While CR-PIT can induce tumor killing deep within body, it is less effective than NIR-PIT. This may be related to the relatively lower efficiency of short wavelength light compared to NIR.
- Copyright © 2017 by the Society of Nuclear Medicine and Molecular Imaging, Inc.