Radiation therapy uses high-energy radiation to shrink tumors and kill cancer cells. X-rays, gamma rays, and charged particles are types of radiation used for cancer treatment. Radiation therapy kills cancer cells by damaging their DNA (the molecules inside cells that carry genetic information and pass it from one generation to the next). Radiation therapy can either damage DNA directly or create charged particles (free radicals) within the cells that can in turn damage the DNA. Cancer cells whose DNA is damaged beyond repair stop dividing or die. When the damaged cells die, they are broken down and eliminated by the body’s natural processes.
About half of all cancer patients receive some type of radiation therapy sometime during the course of their treatment. A patient may receive radiation therapy before, during, or after surgery. Some patients may receive radiation therapy alone, without surgery or other treatments. Some patients may receive radiation therapy and chemotherapy at the same time. The timing of radiation therapy depends on the type of cancer being treated and the goal of treatment. Using sophisticated treatment planning software, your radiation oncology treatment team plans the size and shape of the beam, as well as how it is directed at your body, to effectively treat your tumor while sparing the normal tissue surrounding the cancer cells.
Types of Radiation Therapy
Radiation can come from a machine outside the body (external-beam radiation therapy) or from radioactive material placed in the body near cancer cells (internal radiation therapy, more commonly called brachytherapy). Systemic radiation therapy uses a radioactive substance, given by mouth or into a vein, that travels in the blood to tissues throughout the body. The radiation oncologists at Compass Oncology specialize in a variety of radiation therapies, such as:
External Beam Radiation
External beam radiation therapy comes is a type of radiation that comes from a machine outside of your body that aims radiation at the location of your cancer. It does not touch you, but it can move around to position the radiation beams in the most effective places. It is a local treatment, which means it treats a specific part of your body.
3-Dimensional Conformal Radiation Therapy
3-Dimensional Conformal Radiation Therapy is a three-dimensional (3-D) conformal radiation is a technique that allows doctors to direct radiation beams to conform to the shape of the tumor. It is one of the most common forms of external radiation therapy treatment.
Intensity-Modulated Radiation Therapy (IMRT)
Intensity-Modulated Radiation Therapy (IMRT) is an advanced type of radiation therapy used to treat cancer tumors. The goal of IMRT is to precisely target the tumor while avoiding or reducing damage to healthy tissues and providing a better quality of life for the patient by limiting the side effects of treatment.
Volumetric-Modulated Arc Therapy (VMAT) is an advanced form of IMRT that allows a targeted, three-dimensional dose of radiation to be delivered directly to a tumor. The machine that delivers radiation can deliver the dose to the entire tumor in a 360-degree rotation, up to eight times faster than IMRT alone.
Image-Guided Radiation Therapy (IGRT)
Image-Guided Radiation Therapy (IGRT) is a method of radiation therapy that uses imaging techniques during cancer treatment sessions. The incorporation of imaging during therapy helps improve the precision and accuracy of treatment delivery.
Stereotactic Radiosurgery (SRS)
Stereotactic Radiosurgery (SRS) is a non-surgical radiation therapy that is typically used to treat cancerous tumors or other abnormalities in the brain. It can deliver precisely-targeted radiation in fewer high-dose treatments than traditional therapy, which can help preserve healthy tissue.
Stereotactic Body Radiotherapy (SBRT)
Stereotactic Body Radiotherapy (SBRT) is an advanced type of non-surgical radiation technology used to treat body tumors in locations such as the lung, liver, abdomen, spine, prostate, head and neck.
Stereotactic Radiation Therapy (SRT)
Stereotactic Radiation Therapy (SRT) is a type of external radiation therapy that uses special equipment to position the patient and precisely deliver radiation to a tumor. The total dose of radiation is divided into several smaller doses given over several days. Stereotactic radiation therapy is used to treat brain tumors and other brain disorders.
Internal Radiation Therapy
Internal radiation therapy, also known as Brachytherapy, is a form of radiation therapy that involves placing a temporary or permanent radioactive implant is placed inside the patient to treat cancer. This makes it possible to position a higher total dose of radiation in a smaller area than what can be achieved with external beam radiation. This reduces radiation exposure to surrounding healthy tissue or tissues that could be very sensitive to radiation.
The radiation is inserted in an implant, which could be in the form of seeds, balloons, tubes, capsules, ribbons, wires, pellets, or needles. The amount of time the implants are in place varies by the patient and the type of cancer. There are some that are left in place for only a few minutes or a few days (high-dose-rate brachytherapy) and some are left in place to slowly break down on their own (low-dose-rate brachytherapy).
High-Dose Rate (HDR) Brachytherapy
High-Dose Rate (HDR) Brachytherapy is a radiation treatment that is delivered via radioactive “seeds” that are placed directly in or near the tumor. HDR allows doctors to use a higher total dose of radiation to treat a smaller area in less time than conventional external beam radiation therapy.
Breast Brachytherapy (Mammosite Radiation Therapy) is a breast cancer treatment that involves the temporary placement of radioactive materials within the breast to treat only certain parts of the breast. It is also sometimes administered to give an extra dose of radiation to the area of the excision site (called a "boost").
Endometrial Cancer HDR Brachytherapy is an endometrial cancer treatment that involves a source of radiation being placed into a cylinder and inserted into the vagina. The radiation mainly affects the area of the vagina in contact with the cylinder.
Skin Cancer HDR Brachytherapy can be an effective form of skin cancer treatment especially when the cancer would not be completely removed through surgery, when the cancer surgery would cause too much scarring, or where surgery was too difficult to perform.
Systemic Radiation Therapy
Systemic Radiation Therapy is a type of internal radiation therapy which treats cancer with radioactive drugs (called radiopharmaceuticals). These liquid, radioactive substances, which are administered orally or intravenously, travel in the blood to kill cancer cells.
Radioisotope (e.g. Radium-223) Administration - Xofigo® (radium Ra 223 dichloride) is an injection that releases radiation that targets and kills prostate cancer cells. This treatment is commonly used to treat prostate cancer that has spread to the bones, and no longer responds to hormonal or surgical treatments that lower testosterone.
The type of radiation therapy prescribed by a radiation oncologist depends on many factors, including:
- The type of cancer.
- The size of the cancer.
- The cancer’s location in the body.
- How close the cancer is to normal tissues that are sensitive to radiation.
- How far into the body the radiation needs to travel.
- The patient’s general health and medical history.
- Whether the patient will have other types of cancer treatment.
- Other factors, such as the patient’s age and other medical conditions.