Radiation therapy is used to treat many cancerous and non-cancerous conditions. When targeting tumors with radiation, doctors aim to destroy cancer cells and shrink tumors. Radiation therapy accomplishes this goal by delivering a focused dose of radiation that damages the DNA of cells, causing the cancer cells to die.
Radiation therapy may be performed in the following situations:
- Complementing surgery. Radiation therapy may be used before, during or after surgical intervention. It can be used to make the surgery more effective.
- Treating cancer and other conditions. In certain cases, radiation therapy may be the only therapy required to destroy cancer, benign tumors or affect other conditions.
- Reducing symptoms. Doctors can use radiation therapy to control conditions such as cancer that are causing adverse symptoms, such as pain or loss of function, and provide symptom relief.
Radiation therapy doesn’t just differ for the varying types of conditions, but the dosages and delivery methods can also vary. Based on the cancer being treated, a radiation therapy program is personalized for the patient and then administered in one of two ways. These are:
- Externally — Specialized machines that direct radiation beams at the target. Using precise technology, such as the Leksell Gamma Knife, which merges multiple scanning technologies to provide ultimate precision in radiation treatment, and linear accelerators with 3D and 4D imaging systems that dramatically lessen the likelihood that a patient will be out of position during treatment, doctors are able to control the radiation beam so limited healthy tissue is damaged.
- Internally (brachytherapy)— Radioactive substances are sealed within an implant, which is then placed either inside the tumor (intracavitary radiation) or inside the tumor site (interstitial radiation) using a catheter. Implants can be left in place permanently or removed when treatment is complete. High-dose-rate brachytherapy can be intense over a short period of time, while low-dose-rate brachytherapy involves lower doses over a longer period of time.
- Radiosurgery - High doses of radiation therapy given with high precision and image guidance in fewer treatments.