External Beam
The use of an external machine to aim radiation at your cancer.
What is external beam radiation?.jpg)
External beam radiation sends high-energy X-ray beams from outside your body through your skin to the tumor, killing or slowing the growth of the cancerous cells.
How does it work?
Your radiation oncologist utilizes a machine called a linear accelerator (LINAC) to produce and precisely aim high-energy radiation beams at the tumor. Your radiation treatment team can adjust the size and shape of the beam, its intensity, and how it is directed at your body so that the radiation effectively destroys your cancer while avoiding damage to healthy tissue.
External beam radiation usually requires a series of treatments over a period of several weeks, depending on your cancer.
Cancer Care Northwest’s South Office, Deaconess Office, and North Office each have a linear accelerator, making radiation therapy easily accessible and convenient for patients throughout the area. The North Office is home to the new Varian Clinac ix Linear Accelerator, a state-of-the-art, digital linear accelerator that delivers some of the most advanced forms of radiation therapy in the region.
Simulation
Before treatment begins, your radiation oncologist will take CT images (CAT Scan) pictures of your body in a process called “simulation.” These three-dimensional images help your doctor pinpoint your cancer and determine how to position your body so that the beams can be accurately aimed at your cancer.
Your doctor may make a special mold so you can replicate that exact position during your actual treatment. Sometimes your doctor will also make a device called a “block” or use automatic blocking built right into the machine to shield your healthy cells from the radiation.
External Beam Radiation at Cancer Care Northwest
The type of external beam radiation therapy you receive depends on the size and shape of your tumor and where it is located in your body. Our radiation oncologists’ expertise and sophisticated techniques safely and effectively destroy the cancer, while causing as little damage to the healthy cells as possible.
Three-Dimensional Conformal Radiation Therapy (3D-CRT)
In three-dimensional conformal radiation therapy, your radiation oncologist uses imaging technologies, such as PET/CT, CT or ultrasound, to create 3-D pictures of the tumor so that the radiation beams can be formed to fit the size and shape of your tumor. Usually the treatment is delivered through several different angles.
Intensity Modulated Radiation Therapy
Intensity Modulated Radiation Therapy (IMRT) is an advanced form of 3D-CRT treatment in which radiation beams of various intensities are formed to fit the exact shape of the tumor. This approach precisely targets the cancer, while reducing the amount of radiation that affects healthy tissue. IMRT makes it possible to safely use radiation to treat tumors that are next to vital organs and body structures.
Cancer Care Northwest’s radiation oncologists have offered IMRT longer than any other cancer care provider in the region.
Image Guided Radiation Therapy
In Image Guided Radiation Therapy (IGRT), radiation oncologists use x-rays or ultrasound just before or during treatment to measure any changes in size and location of the cancer. They use specialized computer software to compare these images and to accurately adjust your treatment as needed.
Hypofractionated Radiotherapy (Stereotactic Body Radiotherapy)
Cancer Care Northwest’s radiation oncologists use hypofractionated radiotherapy (three-five large doses to small, focused areas) to treat early lung cancers that are not surgical candidates.
This treatment involves approximately 10 radiation beams, each 1/10 of the full dose of radiation, that are precisely aimed at the cancer from different angles. The computerized radiation plan is developed by taking 4-dimensional images that track the tumor’s movement while the patient breathes. This assures that the tumor is always within the small radiation field while the patient breathes normally during treatment.