A review of implantable cardioverter defibrillator failures during radiation therapy in three Sydney hospitals

Abstract

Introduction: In recent years, using radiation energies greater than 10 MV in patients with implantable cardioverter defibrillators (ICDs) has been contraindicated due to the risk of a power on reset (POR) occurring. The ICD is often greater than 30 cm from the treatment field and subject to scatter radiation only. The aim of this study was to use recent patient cases to verify published failure rates and treatment recommendations. Method: Five patients with ICDs who experienced a device malfunction during radiation therapy treatments were identified in three Sydney hospitals between 2008 and 2012. The types of treatments delivered during these events were assessed. Further assessment of all ICD patients at one Sydney hospital during this time was carried out to assess the rate of ICD failure during high energy treatments using 18 MV. Results: All ICDs that suffered malfunctions were exposed to scatter radiation only. All were exposed to partial or exclusive irradiation using 18 MV photons. Accumulated doses to the ICDs were estimated to be well below accepted dose limits found in literature. One centre reported a 22.2% rate of POR during exposure to 18 MV radiation therapy during this time frame. Conclusions: Where possible, radiation therapy using energies greater than 10 MV should be avoided for ICD patients. While the use of these energies carries a risk of failure, it must be weighed against potential benefit to the patient requiring treatment if no alternatives are available. Stringent monitoring of these patients, including regular cardiac device checks and ECG monitoring is recommended if treatment is to proceed with energies greater than 10 MV.

CIED malfunction in patients receiving radiation is a rare event that could be detected by remote monitoring

“…In comparison, the literature reports on a variety of radiation related CIED malfunctions, which includes such events as inappropriate sensing due to noise, 5 runaway pacemaker resulting in rapid inappropriate pacing, 9 reset to back-up pacing resulting in AV dyssynchrony, 10 inappropriate ICD shocks due to noise, 11 and complete device failure. 12,13 This is the first study to look at different types of interrogations while following patients with CIEDs who are receiving radiation to their radiation treatments. The cause and significance of this finding is unclear as these patients may have also been exposed to systemic therapies for their cancer treatment and this is beyond the scope of this study.…”

Revisiting the impact of radiation therapy on cardiac implantable electronic device (CIED) function

“…In contrast to the above studies, other reports suggest high incidence of CIED malfunction during RT 9,10,15 or clinically significant CIED malfunctions, 11,24,25 some of which are potentially lifethreatening. Elders et al report high incidence of RT-induced CIED malfunction occurring in 5/15 (33%) patients undergoing RT.…”

“…10 Another study showed 16 cases of CIED malfunction out of a cohort of 230 patients undergoing RT, with a reset to backup pacing being the dominant one. 11,24 Notably, most of the above studies are single center studies incorporating small number of patients, which no doubt contributes to the difficulty in establishing consensus. These included a "runaway pacemaker" phenomenon, in which a potential lethal nonphysiological high rate pacing occurs, 25 or complete device failure.…”

“…These included a "runaway pacemaker" phenomenon, in which a potential lethal nonphysiological high rate pacing occurs, 25 or complete device failure. 11,24 Notably, most of the above studies are single center studies incorporating small number of patients, which no doubt contributes to the difficulty in establishing consensus. periopertaive management of patients with CIED 28 recommend strict avoidance of direct irradiation of CIED and maintaining a cumulative dose limit <5 Gy or as advised by each manufacturer recommendations.…”

Inevitable high-dose irradiation to lead of implantable cardioverter defibrillator in small cell lung cancer: a case report

“…According to their study, the maximum safe dose of ICD is uncertain; generally, 2 Gy is used as a reference [1]. Several studies have reported on the radiation dose needed to result in ICD damage [6–11]. A summary of in vivo studies of thoracic radiotherapy with ICD is presented in Table 1.…”