How can cancer cells survive radiation ?

How do normal human cells survive radiation? The premise behinde radiation treatment is that the cancer cells are LESS resistant to radiation than the other cells in the rest of the body.

If you apply enough radiation, you will be sure to kill all the cancer cells and the patient as well.

Cancer cells are not necessarily resistant to radiation. More specifically, they may be resistant to Radiation Treatment, which involves exposing a person with cancer to just enough radiation to possibly kill the cancer, but not the patient. It is not that cancer cells don’t die from the radiation, it is just that if enough radiation was applied to kill all the cancer cells, then the patient would be killed as well.

It is analogous to using the A-bomb to eradicate that roach problem in your house. No doubt, there is little chance those roaches will survive. But it is also obvious that the side effects produced by this proposed solution are far more devastating than the problem itself.