Cardio-oncology challenges: radiation therapy in patients with non-transvenous cardiac implantable devices

Abstract Background The expanding population of patients with non-transvenous implantable electronic devices (CIEDs), such as subcutaneous implantable cardioverter-defibrillators (S-ICDs) and leadless pacemakers (LPMs), has created new clinical challenges as more of these patients are exposed to radiation therapy during oncological treatment. These novel device technologies eliminate the risk of lead-related complications but introduce uncertainties regarding their safety and functionality in the radiation environment. Current evidence on device performance during RT remains limited, and formal recommendations for managing such patients are still lacking. Purpose The aim of this analysis was to summarize the clinical experience and safety data on radiation therapy in patients with non-transvenous cardiac implantable electronic devices (S-ICDs and LPMs) in a large tertiary cardio-oncology centre. Methods This retrospective analysis included all consecutive patients with non-transvenous cardiac implantable electronic devices (S-ICDs or LPMs) who underwent radiation therapy (RT) in our centre from 2016. Clinical, oncological, and device-related data were reviewed, including device type, manufacturer, RT cumulative dose and number of fractions, and device function before and after treatment. Device interrogation and remote monitoring reports were analyzed to identify any radiation-induced malfunctions or parameter changes. Results Among 388 patients who underwent radiation therapy (RT), six had non-transvenous cardiac implantable electronic devices. Two patients had subcutaneous implantable cardioverter-defibrillators (S-ICDs) and four had leadless pacemakers (LPMs). One patient with an LPM was intermittently pacing-dependent. In all cases, beam energies did not exceed 10 MV, and the estimated radiation doses delivered to the devices were below 2 Gy. Four patients completed RT without complications, whereas two patients died during treatment due to causes unrelated to the radiotherapy itself or device malfunction — one S-ICD recipient died from gastric ulcer perforation, and one patient with a LPM died from sepsis. No significant device-related malfunctions, resets, or inappropriate therapies were observed during treatment or follow-up. Conclusions Patients with non-transvenous devices constitute the population with multiple comorbidities and are concomitantly at an elevated risk of non-cardiac adverse events. Our analysis found no clinically significant changes in device parameters, indicating that radiotherapy in the presence of these devices can be considered safe if appropriate precautions are taken and proper supervision is provided.