Implantable cardiac pacemaker failure by cumulative dose effects of flattening filter free beams

Abstract

Cumulative dose effects, which are one of the main causes of errors that occur when an implantable cardiac pacemaker (ICP) is irradiated with ionizing radiation, induce permanent failure in ICPs. Although flattening filter free (FFF) beams, which are often used in stereotactic radiotherapy, are known to have different characteristics from conventional (with flattening filter [WFF]) beams, the cumulative dose effects on ICPs with FFF beams have been under-investigated. This study investigates ICP failure induced by cumulative dose effects of FFF beams. When the ICP placed in the center of the irradiation field was irradiated with 10 MV-FFF at 24 Gy/min, the cumulative dose at which failure occurred was evaluated on the basis of the failure criteria associated with high cumulative dose as described in the American Association of Physicists in Medicine Task Group 203. The ICP failures such as a mild battery depletion at a cumulative dose of 10 Gy, pacing-output voltage change >25% at a cumulative dose of 122 Gy, and the loss of telemetry capability at cumulative dose 134 Gy were induced by cumulative dose effects. The cumulative doses by which the cumulative dose effects of FFF beams induced ICP failure were not very different from those reported in previous studies with WFF beams. Therefore, radiotherapy with FFF beams (and WFF beams) for patients with ICP requires appropriate management for minimizing the cumulative dose effects.

Risk of cardiac implantable device malfunction in cancer patients receiving proton therapy: an overview

“…Previous studies on photon-EBRT expressed concerns about the influences of high dose rate and cumulative dose on CIED malfunctions ( 16 , 72 , 73 ). Matsubara et al ( 73 ) have categorised high dose rate and large cumulative dose as secondary and tertiary risk factors, respectively, while scattered neutrons are considered the primary cause.…”

“…Matsubara et al ( 73 ) have categorised high dose rate and large cumulative dose as secondary and tertiary risk factors, respectively, while scattered neutrons are considered the primary cause. Cumulative radiation dose can generate irreversible critical malfunctions in CIEDs such as battery depletion (classified as hardware malfunction) and altered telemetry capability due to the accumulation of aberrant charges in the battery and electronic circuitry ( 72 ). Moreover, high dose rates can charge the circuitry of CIEDs to a higher voltage, further introducing pseudo signals which can cause TEs during irradiation.…”