Radiation therapy, aka XRT or radiotherapy, uses high doses of radiation to destroy, cure or slow the growth of cancer in a localized area. More than 60% of cancer patients need radiation and it may be combined with surgery or chemotherapy. Radiation can be administered two ways (external or internal):
- External radiation is delivered by a machine and is usually given on an outpatient basis. The radiotherapist will tell you how many treatments over a specific timeline to complete a total of certain number of Gy (gray or unit) of absorbed radiation
- Internal radiation is a container of radioactive material implanted directly into or next to the tumor. For internal radiation, the patient will need to stay in the hospital for a few days
Radiation does not kill cancer cells immediately. After treatment, it may take days, weeks or months for the cancer cells to die. While the radiation itself does not hurt, the side effects of treatment may cause pain or discomfort.