https://doi.org/10.1007/s00392-025-02625-4
1Universitätsklinikum Regensburg Klinik und Poliklinik für Innere Med. II, Kardiologie Regensburg, Deutschland; 2Universitätsklinikum Regensburg Klinik und Poliklinik für Strahlentherapie Regensburg, Deutschland
Purpose: Ionizing radiation can cause significant malfunctions in cardiac implantable electronic devices (CIEDs). In the context of advanced intensity-modulated RT techniques and the prevalent use of 6 MV photons, CIED malfunctions are rarely observed. This study aimed to evaluate the necessity of daily CIED monitoring, hypothesizing that clinically significant device interactions would not occur.
Methods: From 2014 to 2022, we analyzed data from 106 patients (146 treatment courses), conducting daily CIED interrogations (n = 1830). Skin dose over the CIED was measured using semiconductor or ion chamber dosimetry at least once per RT course, with additional dose calculations performed in many cases.
Results: The prescribed dose to the planning target volume (PTV) ranged from 3 to 78.0 Gy. The median cumulative skin dose measured above the CIED was 0.76 Gy, while the median calculated dose was 1.00 Gy. No malfunctions were observed in patients treated with beam energies >10 MeV. Four minor events, with no clinical relevance, were noted in cases using intensity-modulated techniques with 6 MV. None of these devices were located directly within the PTV. There were no differences between the initial and last interrogation regarding pacing threshold, sensing, lead impedance or battery voltage (each p=n.s.).
Conclusion: CIED malfunctions during RT are infrequent. In our study, no CIED relocations were required, and clinically significant incidents were rare. Therefore, the results confirm the EHRA guidelines, demonstrating that strict device interrogation does not provide additional benefit. Selective daily monitoring may be safely omitted in certain cases, without compromising patient safety.