Effects of Ionizing Radiation on Cardiac Implantable Electronic Devices (CIEDs) in Patients with Esophageal Cancer Undergoing Radiotherapy: A Pilot Study

Simple Summary The number of cancer patients who require an implantable electronic heart device due to their heart disease is steadily increasing. Radiotherapy is an important treatment option for esophageal cancer, in addition to surgery and chemotherapy. Ionizing radiation can lead to serious malfunctions of cardiac devices, including complete loss of function with life-threatening consequences. There is already data in the literature on other types of cancer and radiotherapy. Esophageal cancer is rare, so there is limited information on patients with this cancer who need radiotherapy and have an electronic heart device. We retrospectively analyzed the occurrence of cardiac device malfunction in patients with esophageal cancer in our study between 2012 and 2022. By applying our internal treatment protocol, serious cardiac device malfunctions during, and after radiotherapy could be prevented. It is important to carefully plan and select the energy of the photons. The manufacturer's recommended dose limits should be observed.Abstract (1) Background: The prevalence of cancer patients relying on cardiac implantable electronic device (CIED) is steadily rising. The aim of this study was to evaluate RT-related malfunctions of CIEDs. (2) Methods: We retrospectively analyze sixteen patients with esophageal cancer who were treated with radiotherapy between 2012 and 2022 at the University Hospital Heidelberg. All patients underwent systemic evaluation including pre-therapeutic cardiological examinations of the CIED functionality and after every single irradiation. (3) Results: Sixteen patients, predominantly male (14) with a mean age of 77 (range: 56-85) years were enrolled. All patients received 28 fractions of radiotherapy with a cumulative total dose 58.8 Gy. The mean maximum dose at the CIEDs was 1.8 Gy. Following radiotherapy and during the one-year post-radiation follow-up period, there were no registered events associated with the treatment in this evaluation. (4) Conclusion: The study did not observe any severe CIED malfunctions following each radiation fraction or after completion of RT. Strict selection of photon energy and alignment with manufacturer-recommended dose limits appear to be important. Our study showed no major differences in the measured values of the pacing threshold, sensing threshold and lead impedance after RT.