Effects of scatter radiation on ICD and CRT function

Area of Science:

• Cardiology
• Radiation Oncology
• Biomedical Engineering

Background:

• Direct radiation effects on cardiac devices are known, but scatter radiation impacts remain unclear.
• Existing recommendations for radiotherapy in patients with cardiac devices are based on limited pacemaker studies.
• The effects of scatter radiation on implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT)-ICDs require further elucidation.

Purpose of the Study:

• To investigate the impact of scatter radiation on ICDs and CRT-ICDs.
• To assess device function and programmed parameters following exposure to scatter radiation.

Main Methods:

• Exposed 12 ICDs and 8 CRT-ICDs to 400 cGy scatter radiation from a 6-MV photon beam.
• Performed device interrogations before, during, and after radiation exposure, plus a 1-week follow-up.
• Retrospectively reviewed 13 patients with cardiac devices undergoing radiotherapy (device outside radiation field), with 12 interrogated pre- and post-radiation.

Main Results:

• No instances of device reset or malfunction were observed during or after scatter radiation exposure.
• Patient device interrogations revealed no episodes of reset, inappropriate sensing, or therapy changes.
• Programmed parameters remained stable throughout the study period for all tested devices and patients.

Conclusions:

• Scatter radiation is unlikely to cause device reset or malfunction in ICDs and CRT-ICDs.
• No clear contraindications exist for radiotherapy in patients with ICDs or CRT-ICDs.
• Precautions to avoid direct radiation and close patient monitoring before and after radiotherapy are recommended.