Radiation therapy uses high-energy particle waves of X-rays and gamma rays to destroy or damage cancer cells. It is estimated that 50-60 percent of cancer patients will receive radiation during their cancer treatment.
Radiation can be used at different stages of cancer treatment including:
- Early stages in an attempt to cure or control the cancer
- Before surgery to shrink the cancer
- During surgery using intraoperative radiation therapy
- After surgery to prevent cancer from coming back
- With surgery or chemotherapy for advanced cancer
Types of radiation
Ionizing radiation consists of:
- Electromagnetic radiation (X-rays and gamma rays)
- Particulate radiation (electrons, protons, neutrons, alpha and beta particles)
The most common type of radiation therapy uses high-energy photons from radioactive sources such as cobalt, cesium or a machine called linear accelerator.
How radiation is given
Intraoperative radiation therapy (via the Intrabeam radiation system) delivers low-energy radiation directly to the tumor site during breast conserving surgery. Intraoperative radiation can dramatically reduce or even eliminate the need for weeks of external radiation treatment following surgery for select patients with early stage breast cancers.
External beam radiation is the most common type of radiation therapy. The radiation is given from a machine outside the body much like an x-ray in daily fractions over several weeks.
Internal radiation, also known as brachytherapy, has two main types:
- Intersitial radiation is placed in the affected tissue using small pellets, wires, tubes or other containers.
- Intracavity uses a reactive source sealed in a container, which is then placed in the cavity of the body close to the affected area.
Radiopharmaceuticals uses unsealed sources of radiation that are then administered intravenously, orally or into a body cavity.
- Skin irritation
- Muscosal irritation
- Other effects related to the treatment site