Radiotherapy in Patients with Cardiac Implantable Devices: A Single-Centre Retrospective Observational Analysis of...

Background: The aim of this study is to determine the safety of a locally implemented Standard of Practice (SOP) in patients with cardiac implantable electronic devices (CIEDs). With increasing use of radiotherapy in cancer treatment and the widespread adaptation of CIEDs, the British Heart Rhythm Society introduced new guidance in 2025. There remains ambiguity between various international, as well as manufacturer, guidelines on the management of these patients. Methods: This was a retrospective single-centre observational study analysing patients with CIEDs receiving radiotherapy after the implementation of our Standard of Practice in 2021. Patients were identified using the Cardiobase system. Patients were divided into non-pacemaker-dependent, pacemaker-dependent and implantable-cardioverter-defibrillator (ICD) groups. Lead sensing and impedance values were gathered pre- and post-treatment and analysed using a paired Student's T-test. Results: A total of 320 patients were included in this study. There were no statistically significant changes in lead sensing capabilities in any of the groups pre- and post-radiotherapy with a p value of >0.05. There were no statistically significant changes in lead impedance in the ICD and non-pacemaker-dependent groups. Although statistically significant (p = 0.039), there was no clinically significant reduction in atrial lead impedance in the pacemaker-dependent cohort. Conclusions: From the obtained results, we can conclude that our locally implemented SOP is a safe alternative to BHRS guidelines.