Stereotactic Body Radiotherapy (SBRT) for Cancer

Radiation therapy is a treatment for cancer. SBRT is a form of radiation therapy. Your doctor may recommend SBRT if your cancer cannot be treated with surgery or other methods. SBRT may be used to help cure or control the growth of your cancer. Or, it may be used to help relieve pain and other symptoms caused by your cancer. This sheet tells you more about SBRT and what to expect. If you have further questions about the treatment, talk with your doctor.

How SBRT Works

SBRT uses radiation (high-energy X-rays) to destroy cancer cells. Imaging studies are used to create detailed pictures of the tumor. Then a machine called a linear accelerator (linac) is aimed at the tumor. It sends high doses of radiation into the tumor. This can help kill cancer cells or slow their growth. It can also shrink the size of the tumor. Each radiation dose is precisely focused so that normal tissue around the tumor receives little or no radiation. This helps reduce the risk of side effects.

Preparing for Your Treatment

SBRT is performed by a radiation therapy team. This team often includes a radiation doctor, nurse, therapist, physicist, and dosimetrist. Before your treatment begins, you will have one or more visits with your team to plan and prepare for your treatment. This may involve having other tests and procedures. Prior to your first treatment session:

• You may need to have tattoo markings placed in or near the tumor site or a body mold made for proper positioning and alignment. Your doctor will explain this procedure to you in more detail if it is needed.
• You may have CT scans or other imaging tests done. These are used to map out the exact sites in your body that will be treated with radiation.

Having SBRT Treatments

With SBRT, one to 5 radiation doses are given over the course of 1 to 2 weeks. You and your team will discuss the exact schedule for your treatment in advance. Each treatment session takes about 60-90 minutes. Here is what to expect during each session:

• You change into a patient gown. The radiation therapist positions you on the treatment table. If positioning devices were made, they are used at this time.
• The therapist leaves the room and turns on the linac from outside. He or she watches you on a TV monitor. You and the therapist can speak through an intercom.
• X-ray or CT images are used to confirm correct positioning and alignment of the beams from the linac with your body. The beams are then directed at the tumor. You will hear the machine, but you will not feel anything.
• You can go home shortly after the treatment is done. Your doctor or nurse will let you know if and when you need to return for your next session.

Possible Side Effects of SBRT

With any form of radiation therapy, healthy cells and tissue around the tumor can also be affected by the treatment. This can lead to side effects, such as fatigue and skin changes. Most side effects go away soon after treatment ends. Some side effects do not occur until months or even years after the treatment. The type of side effects you have and how severe they are will depend on the amount of radiation received and the part of your body being treated. Your doctor can tell you more about what side effects to expect and how to manage them. If needed, medications can be prescribed to treat some side effects. Your health care team can also teach you ways to help cope with side effects.

Follow-Up

You will have one or more follow-up visits with your doctor. These allow your doctor to check your health and the progress of your treatment. If more tests or treatments are needed, your doctor will discuss these with you.