What Happens During External Beam Radiation Treatment for Pancreatic Cancer

For this treatment, you’ll talk with a doctor who specializes in both cancer and radiation, called a radiation oncologist. This doctor will tell you what type of radiation you need, at what dose, and for how long. During your visit, ask what you can expect to feel during and after the treatment.

You can receive external beam radiation treatment (EBRT) as an outpatient. This means you’ll get the treatment at a hospital or clinic, but you will not have to spend the night. Usually, you’ll receive treatment five days a week. The treatment will continue for several weeks, depending on the type and dose of EBRT you need.

External radiation usually comes from a machine called a linear accelerator.

Types of EBRT

These are the three kinds of EBRT commonly used to treat pancreatic cancer:

• Standard EBRT. This type of EBRT directs radiation at your pancreas from one direction. You lie on a table while the machine is placed over you. The experience is much like that of getting an X-ray, only it lasts longer. It takes about 30 minutes for the whole process. You will actually get radiation for only about five minutes of this time.

• Three-dimensional conformal radiation therapy (3D-CRT). This type of EBRT directs radiation at your pancreas from several directions. Imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET), are used along with computers to develop a very specific location for aiming the radiation for treatment. 3D-CRT may be best for you if you have an advanced stage of cancer, meaning the cancer has spread. Some types of 3D-CRT use higher doses of radiation for shorter periods of time. Other types use protons instead of regular photon radiation. Both of these variations reduce the damage to healthy tissue. Each treatment only lasts a few minutes. 

• Intensity-modulated radiation therapy (IMRT). This is a high-precision type of radiation. It uses a computer to control the strength (intensity) and shape of X-rays to precisely deliver radiation to a tumor. This type of therapy minimizes the radiation exposure to surrounding normal tissues.

Preparing for External Radiation

Before your first radiation treatment, you’ll have an appointment to plan exactly where on your body the radiation beam needs to be directed. This process is called simulation. The appointment may take up to two hours. Here’s what you can expect to happen during simulation:

• You’ll lie still on a table while a radiation therapist uses a machine to define your treatment fields. These are also called treatment ports. The field is the exact area on your body where the radiation will be aimed. The therapist marks your skin with tiny dots of colored permanent ink tattoos. Radiation will be aimed at the exact same place each time.

• You may also have imaging scans, such as CT. These scans help the radiation oncologist know the exact location of your tumor to better aim the radiation.

• If you’re having 3D-CRT, you may need to have a plastic mold of your body made to help you lie still during the treatment.