Women who underwent radiation therapy for cancer as children have an increased long-term risk for developing breast cancer.

However, when the childhood treatments included a high dose of radiation to the ovaries, women's risk of developing future breast tumors was "sharply reduced".

• cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis)


• curative or adjuvant cancer treatment


• palliative treatment (where cure is not possible and the aim is for local disease control or symptomatic relief) or as therapeutic treatment (where the therapy has survival benefit and it can be curative)


• Total body irradiation (TBI) is a radiotherapy technique used to prepare the body to receive a bone marrow transplant.


• 
  several applications in non-malignant conditions, such as the treatment of trigeminal neuralgia, severe thyroid eye disease, pterygium, pigmented villonodular synovitis, prevention of keloid scar growth, and prevention of heterotopic ossification. The use of radiotherapy in non-malignant conditions is limited partly by worries about the risk of radiation-induced cancers.


• treatment of malignant tumors (cancer), and may be used as the primary therapy.


• commonly applied to the cancerous tumour