Cherenkov Emissions Provide Real-Time Tool for Quality Assurance in Radiation Therapy

Using a simple camera and water tank, investigators from Dartmouth-Hitchcock's Norris Cotton Cancer Center, led by [Dartmouth engineering professor] Brian Pogue, PhD, and David J. Gladstone, ScD, demonstrated that induced Cherenkov light can be imaged and used to confirm that the complex spatial dose distribution imparted in dynamic treatment plans is being delivered correctly. Their paper "Video-rate optical dosimetry and dynamic visualization of IMRT and VMAT treatment plans in water using Cherenkov radiation," was recently published in Medical Physics.

"Cherenkov radiation is emitted and exists as a ‘free' optical signal that has not been previously utilized," explained Adam Glaser, lead [engineering] PhD student on the project. "By imaging the light, we can improve the quality and accuracy of delivered plans to prevent radiation mistakes. This will ultimately improve the overall outcome for patients being treated."

The Cherenkov Effect is responsible for the characteristic blue glow of nuclear reactors. Although the phenomenon has been constructively utilized for decades in high-energy particle physics and astrophysics, only recently has there been investigation into its utility in radiation therapy. In that context, it is the only current method that can reveal dosimetric information while remaining completely non-invasive. Essentially, the signal comes directly from the water phantom being irradiated rather than introducing detector arrays.