From imaging to treatment
From imaging to treatment
Diagnostic X-rays are used to form images, so their energy is just high enough to pass through tissue and produce contrast. They are typically about 20 keV20 \text{ keV}20 keV to 150 keV150 \text{ keV}150 keV, whereas external beam radiotherapy uses much higher-energy X-rays, typically about 1 MeV1 \text{ MeV}1 MeV to 20 MeV20 \text{ MeV}20 MeV.