Chemotherapy (or chemo) and radiation therapy are both cancer treatments, but there are key differences:
Chemotherapy is a medication that’s used to shrink or destroy cancer cells. It’s typically given through a needle in the vein, though some types of chemotherapy drugs can be taken as a pill. Chemotherapy works through your whole body to prevent the spread of cancer.
Radiation therapy shrinks or kills cancer cells with high-energy beams, usually from a machine outside of the body. It can also be delivered with an implant inside of the body or medication. Radiation therapy is a local treatment, which means it can be used to treat the area where your cancer is without affecting the rest of your body.
Sometimes these treatments are used together or in combination with other treatments, like surgery or immunotherapy. The type of cancer you have and how far along it is will help your doctor decide which treatment you need.