Malfunction of cardiac devices after radiotherapy without direct exposure to ionizing radiation: mechanisms and experimental data

Massimo Zecchin, Gaetano Morea, Mara Severgnini, Elisabetta Sergi, Anna Baratto Roldan, Elisabetta Bianco, Silvia Magnani, Antonio De Luca, Anna Zorzin Fantasia, Luca Salvatore, Vittorino Milan, Gianrossano Giannini (+1 others)
2015 Europace  
Aims Malfunctions of cardiac implantable electronical devices (CIED) have been described after high-energy radiation therapy even in the absence of direct exposure to ionizing radiation, due to diffusion of neutrons (n) causing soft errors in inner circuits. The purpose of the study was to analyse the effect of scattered radiation on different types and models of CIED and the possible sources of malfunctions. Methods and results Fifty-nine explanted CIED were placed on an anthropomorphous
more » ... hropomorphous phantom of tissue-equivalent material, and a high-energy photon (15 MV) radiotherapy course (total dose ¼ 70 Gy) for prostate treatment was performed. All devices were interrogated before and after radiation. Radiation dose, the electromagnetic field, and neutron fluence at the CIED site were measured. Thirty-four pacemakers (PM) and 25 implantable cardioverter-defibrillators (ICD) were analysed. No malfunctions were detected before radiation. After radiation a software malfunction was evident in 13 (52%) ICD and 6 (18%) PM; no significant electromagnetic field or photon radiations were detected in the thoracic region. Neutron capture was demonstrated by the presence of the 198 Au( 197 Au + n) or 192 Ir( 191 Ir + n) isotope activation; it was significantly greater in ICD than in PM and non-significantly greater in damaged devices. A greater effect in St Jude PM (2/2 damaged), Boston (9/11), and St Jude ICD (3/6) and in older ICD models was observed; the year of production was not relevant in PM. Conclusion High-energy radiation can cause different malfunctions on CIED, particularly ICD, even without direct exposure to ionizing radiation due to scattered radiation of neutrons produced by the linear accelerator. ---
doi:10.1093/europace/euv250 pmid:26333380 fatcat:m6trnr4c2nhtbfcrxewdcxdgpe