Ionizing Radiation
CAUTION:
It is not possible to specify a safe radiation dosage or guarantee proper pulse generator function
following exposure to ionizing radiation. Multiple factors collectively determine the impact of radiation therapy
on an implanted pulse generator, including proximity of the pulse generator to the radiation beam, type and
energy level of the radiation beam, dose rate, total dose delivered over the life of the pulse generator, and
shielding of the pulse generator. The impact of ionizing radiation will also vary from one pulse generator to
another and may range from no changes in function to a loss of pacing and de
fi
brillation therapy.
Sources of ionizing radiation vary signi
fi
cantly in their potential impact on an implanted pulse generator.
Several therapeutic radiation sources are capable of interfering with or damaging an implanted pulse generator,
including those used for the treatment of cancer, such as radioactive cobalt, linear accelerators, radioactive
seeds, and betatrons.
Prior to a course of therapeutic radiation treatment, the patient’s radiation oncologist and cardiologist or
electrophysiologist should consider all patient management options, including increased follow-up and device
replacement. Other considerations include:
•
Maximizing shielding of the pulse generator within the treatment
fi
eld
•
Determining the appropriate level of patient monitoring during treatment
Evaluate pulse generator operation during and following the course of radiation treatment to exercise as much
device functionality as possible ("Post-Therapy Pulse Generator Follow Up" on page 19). The extent, timing,
and frequency of this evaluation relative to the radiation therapy regimen are dependent upon current patient
health, and therefore should be determined by the attending cardiologist or electrophysiologist.
Many pulse generator diagnostics are performed automatically once per hour, so pulse generator evaluation
should not be concluded until pulse generator diagnostics have been updated and reviewed (at least one hour
after radiation exposure). The effects of radiation exposure on the implanted pulse generator may remain
undetected until some time following exposure. For this reason, continue to monitor pulse generator function
closely and use caution when programming a feature in the weeks or months following radiation therapy.
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