Abstract: Radiotherapy is the controlled delivery of high energy MV and MeV radiation to human tissue, in a manner that maximizes damage to cancer tissues, while minimizing damage to normal tissues. The control of this delivery and visualization of it requires several advanced technologies for guidance. An example is the use of time-gated Cherenkov imaging as a tool for the therapists to see what is happening within the room where the treatment is occurring. The invention and development of this approach will be outlined, where single photon imaging is achieved with full ambient room lighting. Additionally, these cameras can be used for scintillator spot imaging as a way to achieve non-contact radiation dose measurement.
A recent offshoot of this work has been in the setting of ultra-high dose rate radiation delivery, which has been termed “FLASH’ radiotherapy. This technique uses dose rates >40 Gy/s and instantaneous dose rates of >105 Gy/s to deliver the radiation, and has an apparent normal tissue sparing effect. This technique has become intensely investigated in the last 5 years, because it holds potential for a revolutionary change in how radiation therapy is delivered. The hypothesized models of this ‘FLASH’ effect and the physio-chemical measurements to discern the mechanisms will be reviewed, along with the Cherenkov based dosimetry methods being developed.
Brian W. Pogue, PhD is Chair of the Department of Medical Physics at the University of Wisconsin-Madison, and Professor of Medical Physics, Radiology and Human Oncology, and Adjunct Professor of Engineering at Dartmouth. Dr Pogue’s work in the area of optical imaging devices to guide cancer therapies, has led to the invention of a unique system for imaging radiation dose with Cherenkov emission, and another unique approach to imaging hypoxia during surgical resection. Each of these is supported by NIH funding, and this translational work led to co-founding of three start-ups companies DoseOptics LLC, QUEL Imaging LLC and Hypoxia Surgical LLC. This work has led to US Patents, with 12 issued and 29 pending, and more than 450 peer-reviewed papers. Dr Pogue is a Fellow member of Optica, SPIE, AIMBE, and the National Academy of Inventors, and is the Editor-in-Chief of the Journal of Biomedical Optics.