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

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.

Keywords: cardiac devices; esophageal cancer; radiotherapy; toxicity.

Figure 1

Radiation plan of a 62-year-old patient with esophageal cancer: distance and dose distribution to the cardiac implantable electronic device (CIED). The D95 in this patient was 1.84 Gy at the pacemaker. According to TPS, the uncertainty of the planned dose values for the PTV in this patient was 0.3%.