Describe how radiotherapy uses ionising radiation to destroy cancer cells.

Within Uses of nuclear radiation, this learning objective asks you to describe how radiotherapy uses ionising radiation to destroy cancer cells. Focus on the approved ideas radiotherapy and connect them clearly to Hazards and uses of radioactive emissions and of background radiation. A strong response should state the relevant particle, radiation, isotope, decay, half-life or nuclear-equation idea, then explain how it answers the exact command word. Avoid swapping nearby concepts such as atomic number and mass number, isotope and ion, alpha, beta and gamma radiation, or contamination and irradiation.