A recent study from researchers working at Dartmouth‘s Norris Cotton Cancer Center explored how the Cherenkov Effect, the blue light present in radiation therapy, can be measured and used in dosimetry (the measurement of the absorbed dose delivered by ionizing radiation) to create safer, more effective therapies. The study led by Dr. Brian W. Pogue and Dr. Adam K. Glaser was published in the Physics in Medicine and Biology journal.
“The beauty of using the light from the Cherenkov Effect for dosimetry is that it’s the only current method that can reveal dosimetric information completely non-invasively in water or tissue,” Dr. Glaser said in a press release.
This phenomenon has been effectively used for decades for high-energy particle and astrophysics purposes and only recently has been explored for radiation therapy use. In this study, the team separately measured emissions of x-ray protons, photons, and electrons, discovering a wide range of utilities.
Based on findings that link Cherenkov emission and dosage adjustment, researchers concluded that for x-ray photons the emission of light would be well suited for surgery confirmation studies and narrow beam stereotactic radiation therapy, verification of dynamic intensity-modulated and volumetric modulated arc therapy treatment plans in water tanks, and also for imaging dosimetry of both narrow and broad beams.
In terms of electron use, the Cherenkov emission is suitable only for surface dosimetry applications, while for proton dosimetry researchers concluded that there is a crucial lack of Cherenkov emission at the Bragg peak, negating the technique’s utility even though scientists think post-irradiation detection of radioisotopes’ light emission could be of use.
“By detecting this light, we can pursue novel applications of Cherenkov light emission during radiation therapy to help clinicians improve the overall treatment outcome for patients,”said Dr. Pogue.
This study was funded by the National Institutes of Health. Further investigation is necessary to find other applications where the technique can be used. Clinical studies will be ongoing, allowing Cherenkov light from x-ray beams to be imaged directly from the tissue surface of patients during radiation therapy.