An analysis revealed that in a cohort of patients with cardiovascular implantable electronic devices (CIEDs) requiring radiotherapy (RT), all cases of single-event upset malfunction (device memory data loss or parameter reset) was 21% for neutron-producing RT and 0% for non-neutron- producing RT (178 courses).
Whenever feasible, the use on non-neutron-producing radiotherapy is recommended, according to a retrospective review published online ahead of print in JAMA Oncology.
Researchers included all patients with a functioning CIED who underwent RT between August 2005 and January 2014 with CIED interrogation data following RT in an academic cancer center.
The intent was to find clinical incidence, predict malfunction, and describe associated clinical consequences in a large cohort of patients treated with photon- and electron-based RT.
A total of 249 courses of photon- and electron-based RT were found in 215 patients (123 [57%] pacemakers; 92 implantable cardioverter defibrillators [43%]). Substantial neutron production was generated in 71 courses (29%).
Malfunction of CIED, characterized by single-event upset and delayed effects including signal interference, pacing threshold changes, and premature battery depletion that was attributed to RT occurred during 18 courses (7%).
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Those most likely to have a single-event upset were patients treated to the abdomen/pelvis region. Neutron-producing radiation (>10 MV) was the principal risk factor for device malfunction.
Six patients with a CIED parameter reset developed clinical symptoms: 3 hypotension and/or bradycardia, 2 abnormal chest ticking consistent with pacemaker syndrome, 1 congestive heart failure. The 3 episodes of signal interference did not result in clinical effects. No delayed malfunctions were directly linked to RT.
- Grant JD, Jensen GL, Tang C, et al. Radiotherapy-induced malfunction in contemporary cardiovascular implantable electronic devices: clinical incidence and predictors. JAMA Oncol. 2015. [epub ahead of print]. doi: 10.1001/jamaoncol.2015.1787.