Question: How does the effects of radiotherapy impact on the cancer cell, and is there a slight chance that the cancer cell may regrowth due to the emission of gamma rays from radiotherapy?

Charlotte Heaven answered on 23 Jun 2025:

Radiation such as gamma rays, damages DNA in the cell. When the cell tries to repair that DNA it may repair incorrectly causing mutations.
This is how harmful radiation from the sun can lead to skin cancer, small amounts of damage in the cells may be repaired incorrectly and over a long time the cells can change, a bit like a game of Chinese whispers when a small change in the sentence can become bigger over time.
Radiation in radiotherapy is usually a higher dose and uses gamma or x-ray rather than UV from the sun. This causes a higher level of damage to the DNA so the cell gets so damaged it dies.Because we are killing the cells, they don’t have the chance to mutate and regrow.
If we gave lots of very low doses of radiotherapy over a long time there is a chance we could cause mutations which could lead to changes in the cells and possibly cause new cancers but this is very tightly controlled by the doctors and there is a lot of research to try and stop any chances of this.