Clinical Implementation of TG-203 for Patients With Implanted Cardiac Devices at One Institution

Abstract

Patients with implantable cardiac devices present an additional safety concern when receiving radiation therapy. The interaction of the high-energy beams with the device increases the possibility of device failure. AAPM recently published TG-203 Management of radiotherapy patients with implanted cardiac pacemakers and defibrillators. The intent of this report was to provide up-to-date recommendations from TG-34, and to provide a more uniform approach for these types of patients. This work presents the experience, challenges and results at our clinic implementing the recommendations of the new report. An update to our existing implanted device policy was established at our clinic following the TG-203 guidelines. This policy clearly defined the roles and responsibilities of different Radiation Oncology personnel, including physicians, nurses, physicists and dosimetrists. Physics’ responsibilities include confirming the treatment plan meets TG-203 and vendor recommendations, completing a dose assessment for the device, and determining a risk categorization for the patient. Categorizing patients according to risk of device malfunction is an important part of the TG-203 report and should be a factor in determining what types of precautions should be taken. Approximately a dozen patients with cardiac devices have been assessed for risk following the implementation of the TG-203 recommendations. Categorization of patients by risk in accordance with TG-203 was determined by the patient’s device dependency, accumulated dose to the device, and presence of neutron contamination. No patient has had an accumulated dose to the device of more than 2 Gy. The patient’s device dependency is the main reason for categorizing the patient at the medium risk level. No patient has been categorized as high-risk. One of the biggest challenges in implementing TG-203 has been the communication with the patient’s cardiologist to determine if it’s safe to disable the device. For this reason, a template was created with standard wording explaining the risks associated with radiation therapy and requesting permission to safely disable the device. This template is faxed and sent to the Cardiologist office. This allowed us to streamline the process while still communicating the important information to the Cardiologist. It also decreased the amount of calls necessary to explain our intentions and the rationale. For a few cases, specifically for non-pacemaker dependent patients, cardiologists have not recommended putting the device in a constant pacing mode, against TG-203 recommendation. The implementation of TG-203 is still an evolving process. Optimization of the communication process remains an ongoing challenge. More so, the biggest challenge for physicists continues to be the need to educate other health professionals, in and outside Radiation Oncology, about the effects of radiation on implanted electronic devices.