Radiotherapy of cancer: slow or fast?

Synopsis

Radiotherapy, often used to treat cancer, is delivered in a number of fractions to spare healthy tissues. During each fraction, the tumor is typically irradiated for 1-5 minutes. In this talk, I will present two new radiotherapy techniques that are very different in terms of dose rate delivery. The first low dose rate technique called kilovoltage arc therapy (KVAT) delivers dose with lowenergy x-rays. It has a great potential to decrease the cost of radiotherapy and make it more accessible in developing countries. The second ultra-high dose rate technique called FLASH is often delivered with electron beams and shows promise in sparing of healthy tissues while providing the same tumor control. The history, principles, patient Monte Carlo dose distributions and some FLASH phantom, cell and animal experimental results will be presented. At the end of the presentation, I will outline possible Canadian contributions to the development of the two exciting cancer treatment techniques.