How does radiation permanently damage cancer cells but not normal cells?

[A furry]

Heard that radiation therapy will permanently damage the DNA structure of cancer cells in order to not reproduce, but normal cells will heal from this.

 

[Tarkarri]

It is linked to the rapid reproduction of the cancer cells.

 

[April]

Our cells are constantly reproducing and dying off, only to reproduce some more. When radiation kills off some healthy cells, the cells it doesn't kill start reproducing. And the process starts all over again. If the radiation misses one cancer cell, the cancer starts repairing itself and the process starts all over again.

 

[dENISE D]

It kills normal cells too. This is why it takes the entire first appointment to set up measurements and angles, to minimize damage to good tissue. It is also why radiation cannot be done near the heart.