Implanted Cardiac Devices and Radiation Therapy

What is an implanted cardiac device?

An implanted cardiac device is something put into your body to help your heart work. Some types of implanted cardiac devices are:

• Implanted cardioverter defibrillator (ICD) – a battery-powered device that tracks your heart rate. It can shock the heart and bring it back to a normal rhythm if it detects an abnormal heart rhythm. Wires attached to the ICD are implanted into the heart to deliver the shock.
• Pacemaker – a battery-powered device that helps the heart stay in a regular rhythm. It is small and has wires that are implanted into the heart to send electrical impulses that keep a regular rhythm.
• Left ventricular assist device – a battery-powered pump-like device that helps the heart pump effectively when it can’t on its own. Can be used for patients waiting for a heart transplant.

Your cardiology team will be able to tell you more specific information about your device, how it works, and any precautions you should take.

Does radiation therapy to treat cancer affect an implanted cardiac device?

Radiation therapy can permanently (never gets better) or temporarily (does go away) change or damage these devices. It is unknown how much damage radiation can cause, and in some cases, there is no damage at all. Some manufacturers of these devices provide information about the maximum (highest) dose of radiation your device should be exposed to. In cases where that information is not provided, your providers will use a conservative estimate - the dose that will likely not affect your device. Your radiation and cardiology teams will work closely together to create a treatment plan that is safe and will treat your cancer while managing its effects on your device.

What is considered when receiving radiation with an implanted cardiac device?

Your radiation and cardiology teams will plan the best way to deliver your treatment. The way your radiation is given will depend on many factors like:

• The type of device you have.
• If you are dependent or non-dependent on your device.
• The type of radiation therapy and the maximum radiation dose you will be receive.
• Where in your body you are receiving treatment and if the device is in the treatment field.

All of these factors will be considered when planning your treatment.

What can you expect during treatment?

In cases where radiation is a necessary part of your cancer treatment, precautions will need to be taken. Each radiation therapy center may have its own policy and procedures for taking care of patients with implanted devices. Some things you may experience are:

• You may be asked to bring in your device card and sign a consent for treatment.
• Have your implanted device interrogated before treatment, throughout treatment, and after treatment is done. An interrogation is a test that is used to check your device. A small box or wand is placed over the part of your body where your device is. It can check battery life, how the leads are working, and if you are having any changes in your heart rate or rhythm. It is painless and takes about 10 to 15 minutes.  
• Surgery to move the device away from the treatment field.
• A magnet may be used to change how your device works. If needed, it will be used before treatment starts and right after your treatment is done.
• Closely monitoring your vital signs, especially your heart rate, during treatment. You may also need EKGs done.
• You may be asked if you have felt your device shock you at all during or between treatments.
• If you are feeling different at all during or in between treatments, it is important to tell your providers right away.

Providers are still learning about how radiation treatment affects cardiac devices. Your care teams will work together to make sure you are receiving treatment safely.