if radiation causes cancer, why does radiation therapy stop cancer and not give you more cancer?

Question

if radiation causes cancer, why does radiation therapy stop cancer and not give you more cancer?

In: 2

Answer 1

“The dose makes the poison”. If you chug 10 gallons of water that will also kill you.
Another factor to take into consideration is that radiation therapy is *focused* at the cancer and not the whole body. It does affect the cancer cells and it does kill them but since we didn’t want them anyways it’s no big deal that they die.