Physics and Biology of FLASH Radiation

Radiotherapy is an effective tool in the treatment of cancer. However, the full potential of radiotherapy is limited by the fact that radiation also damage healthy tissues. To avoid causing severe damage and suffering for patients receiving treatment, the radiation dose delivered must be limited. Even though, for many patients, a higher treatment dose would be necessary for curing them. In cancer treatment with FLASH radiotherapy, all the radiation dose is delivered in parts of a second, more than 1 000 times quicker than in conventional radiotherapy. This new radiotherapy technique has great potential in improving cancer treatment, as it is less toxic to healthy tissues compared to standard radiotherapy but as effective at treating tumours. However, very little is known about the biological processes behind this highly beneficial FLASH effect. We have a powerful and flexible linear accelerator available for experiments. It is capable of delivering the intense radiation fields needed for FLASH radiotherapy. By performing different cell, tissue, and mice experiments, we aim to explain the effect and to find out how to best take advantage of this treatment technique when moving towards human trials in our cancer treatment centres.