Implanted Cardiac Devices and Radiation Therapy

What is an implanted cardiac device?

An implanted cardiac device is something that is 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 your heart and bring it back to a normal rhythm if it picks up an abnormal heart rhythm. Wires attached to the ICD are implanted into your heart to deliver the shock.
• Pacemaker– A battery-powered device that helps your heart stay in a regular rhythm. It is small and has wires that are implanted into your heart to send electrical impulses that keep a regular rhythm.
• Left ventricular assist device (LVAD)– A battery-powered pump-like device that helps your heart pump as it should, even when it can’t on its own. You may have an LVAD if you are waiting for a heart transplant.

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

Does radiation therapy affect implanted cardiac devices?

Radiation therapy can permanently (never gets better) or temporarily (will 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 companies who make these devices give information about the maximum (highest) dose of radiation your device should be exposed to. In cases where that information is not given, your providers will use the dose that will likely not affect your device (based on their best educated guess). Your radiation and cardiology teams will work closely together to make a treatment plan that is safe that will treat your cancer while managing its effects on your device.

What goes into the decision to receive radiation therapy 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 depends on many things 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 receive.
• Where the radiation will be aimed and if the device is in the treatment field.

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

What should I expect during treatment?

If radiation is 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.
• Your provider will keep an eye on 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.