Interaction between CIEDs and modern radiotherapy techniques: Flattening filter free-VMAT, dose-rate effects, scatter radiation, and neutron-generating energies

doi:10.1016/j.radonc.2019.12.007

Radiotherapy and Oncology

Volume 152, November 2020, Pages 196-202

https://doi.org/10.1016/j.radonc.2019.12.007 Get rights and content

Highlights

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ICDs investigated with 6 and 10 MV FFF-VMAT.
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6 MV FFF-VMAT is safely applicable with ICDs in 2.5 cm or 35 cm distance.
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10 MV FFF-VMAT already causes ICD-failures.
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High dose-rates may be applied in the vicinity of ICDs.

Abstract

Background and purpose

Providing evidence for radiotherapy (RT)-induced effects on cardiac implantable electric devices (CIEDs) with focus on flattening filter free-volumetric modulated arc therapy (FFF-VMAT) at 6 and 10 MV as well as 3D-conformal radiotherapy (3D-CRT) at 18 MV.

Materials and methods

68 CIEDs (64 implantable cardioverter-defibrillators (ICDs) and 4 cardiac pacemakers (PMs)) were located on the left chest position on a slab phantom and irradiated under telemetrical surveillance either directly, or distant to 3D-CRT or FFF-VMAT, dose-rate 2500 cGy/min, and target dose of 150 Gy. Devices were placed within, close by (2.5 cm and 5 cm), and distant (35 cm) to the radiation field. Scatter radiation (SR) and photon neutrons (PN) were recorded. CIEDs were investigated in following groups: 1a) 18 MV 3D-CRT − 4 ICDs/4 PMs out of radiation field, 1b) 18 MV open field − 4 ICDs/4 PMs within radiation field, 2) 6 MV FFF-VMAT, 15 ICDs in 35 cm distance to VMAT, 3) 10 MV-FFF VMAT, 15 ICDs in 35 cm distance to VMAT, 4) 6 MV FFF-VMAT, 15 ICDs in 2.5 cm distance to VMAT, 5) 10 MV FFF-VMAT, 15 ICDs in 2.5 cm distance to VMAT.

Results

No incidents occurred at 6 MV FFF. 10 MV FFF-VMAT and 18 MV 3D-CRT resulted in data loss, reset, and erroneous sensing with inhibition of pacing (leading to inadequate defibrillation) in 8/34 ICDs and 2/4 PMs which were not located within radiation. Direct radiation triggered instantaneous defibrillation in 3/4 ICDs.

Conclusions

6 MV FFF-VMAT is safe even at high dose-rates of 2500 cGy/min, regardless whether CIEDs are located close (2.5 cm) or distant (35 cm) to the radiation beam. CIEDs should never be placed within radiation and energy should always be limited to 6 MV. At 6 MV, VMAT at high dose-rates can be used to treat tumors, which are located close to CIEDs.

Section snippets

Cardiac implantable electronic devices

After approval from the local ethics committee (Medizinische Ethik-Komission II, Medical Faculty Mannheim, University of Heidelberg), we used 64 explanted ICDs and 4 PMs. All CIEDs had sufficient battery capacity and were fully functional. All devices were interrogated prior to experiments and relevant data including history of previous CIED-therapies were registered. Detection parameters of ventricular tachyarrhythmias or pacing parameters were not reprogrammed even though shock delivery was

CIEDs were investigated within following groups (Fig. 1):

1a. 18 MV, 150 Gy thoracic 3D-CRT, 4 ICDs/4 PMs 5 cm distant to radiation field
1b. 18 MV, 50 Gy open field, 4 ICDs/4 PMs from group 1a within 40 × 40 cm radiation field
2. 6 MV FFF, 150 Gy PCA-VMAT, 15 ICDs 35 cm distant to VMAT
3. 10 MV FFF, 150 Gy PCA-VMAT, 15 ICDs 35 cm distant to VMAT
4. 6 MV FFF, 150 Gy TT-VMAT, 15 ICDs 2.5 cm distant to VMAT
5. 10 MV FFF, 150 Gy TT-VMAT, 15 ICDs 2.5 cm distant to VMAT

For proof-of-principle tests (groups 1a and 1b) an 18 MV thoracic vertebral column

Results

No immediate hard-errors were noted (Table 1). Two PMs had become permanently damaged due to loss in battery power at interrogation after 6 weeks. Following soft errors occurred: inadequate sensing of ventricular tachycardia (VT) leading to shock (defibrillation) therapy (ISofVT-ST, n = 5), reset (n = 2), loss of patient-related data (n = 3), inadequate sensing and inhibition of pacing (n = 5). Device malfunctions were noted only in CIEDs subjected to direct radiation or to scatter radiation of

Discussion

This is the first systematic mechanistic study investigating a large number of CIEDs and modern radiotherapy techniques. These results can modify current recommendations for safe radiotherapy of CIED-bearing patients [2], [3], [4], [5]. Additionally, with developing new therapeutic modalities like cardiac radioablation, an increasing number of patients will receive RT in close proximity to their CIEDs [11], [12]^.

Our data show (1) that PE >6 MV may inflict CIED damage and should therefore be

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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Cited by (10)

In-vitro investigation of cardiac implantable electronic device malfunction during and after direct photon exposure: A three-centres experience
2022, Physica Medica
Citation Excerpt :
The risk of device malfunctioning during radiotherapy treatment may depend on both treatment characteristics (photon energy, photon dose at the pocket site, dose rate and imaging dose) and patient characteristics (history of frequent appropriate shocks in ICDs rather than PM-dependency) [4–8,10–18,20–22,29,31–36]. In order to prevent secondary neutron scattering, which increases the risk of device malfunction, it is recommended to use photon beams lower than 10 MV [4–8,13–18,21,22,29,32]. However, literature reports malfunctions may even occur in 6-MV-linear accelerator environments [4–8,20], especially when direct radiation is delivered.
Radiotherapy may cause malfunction of implantable cardioverter-defibrillators (ICDs) and pacemakers (PMs). We carried-out a multicentre randomized in-vitro study on 65 ICDs and 145 PMs to evaluate malfunctions during and after direct irradiation to doses up to 10 Gy.
Three centres equipped with different linear accelerator and treatment-planning systems participated in the study. Computed Tomography (CT) acquisitions were performed to build the treatment plans. All devices were exposed to dose of 2, 5, or 10 Gy (6 MV). All devices underwent a baseline examination and 64 wireless real-time telemetry-transmissions (47 ICDs and 17 PMs) were monitored during photon exposures. All devices were interrogated after exposure and once monthly for six subsequent months.
Fifty-four of the 64 wireless-enabled CIEDs (84.4%) recorded noise-related interferences during exposure. In detail, 40/47 ICDs (85.1%) reported interference, of which 16 ICDs (34%) reported potentially clinically relevant pacing inhibition and inappropriate detections. Following exposure, a soft reset occurred in 1/145 PM (0.7%) while 7/145 PMs (4.8%) reported battery issues. During the six-month follow-up, 1/145 PM (0.7%) reported a soft reset, while 12/145 more PMs (8.3%) and 1/64 ICD (1.5%) showed abnormal battery depletion.
All reported issues occurred independently of exposure dose. Finally, irreversible effects on software and battery life occurred in only non-MRI-compatible devices.
ICDs mostly featured real-time transient sensing issues, while PMs mostly experienced long-term battery or software issues that were observed immediately following radiation exposure and during follow-up. Irreversible effects on battery life and software occurred in only non-MRI-compatible devices.
Radiotherapy for patient with cardiac implantable electronic device, consensus from French radiation oncology society
2022, Cancer/Radiotherapie
Radiotherapy in patients with cardiac implantable electronic device such as pacemakers or defibrillators, is a clinical situation that is becoming increasingly common. There is a risk of interaction between the magnetic field induced by accelerators and the cardiac implantable electronic device, but also a risk of device dysfunction due to direct and/or indirect irradiation if the cardiac implantable electronic device is in the field of treatment. The risk can be dose-dependent, but it is most often independent of the total dose and occurs randomly in case of neutron production (stochastic effect). The presence of this type of device is therefore described as a contraindication for radiotherapy by the French national agency for the safety of medicines and health products (Agence nationale de sécurité du médicament et des produits de santé, ANSM). Nevertheless, since radiotherapy is often possible, it is advisable to respect the recommendations of good practice, in particular the eligibility criteria, the monitoring modalities before, during and after irradiation according to the type of treatment, the dose and the characteristics of the cardiac implantable electronic device. It is sometimes necessary to discuss repositioning the device and/or modifying the treatment plan to minimize the risk of cardiac implantable electronic device dysfunction. We present the update of the recommendations of the French society of oncological radiotherapy on in patients with cardiac implantable electronic device.
La radiothérapie chez les patients porteurs de dispositifs rythmologiques implantables, de type stimulateur ou défibrillateur cardiaque, est une situation clinique qui devient de plus en plus fréquente. Il existe un risque d’interaction entre le champ magnétique induit par l’accélérateur et le boîtier du dispositif rythmologique implantable, mais surtout un risque de dysfonction du dispositif du fait de l’irradiation directe et/ou indirecte sur le boîtier. Le risque peut être dose-dépendant, mais il est le plus souvent indépendant de la dose totale et survenant de façon aléatoire en cas de production de neutrons secondaires (effet stochastique). La présence de ce type de dispositifs est donc décrite comme contre-indication relative à la radiothérapie par l’Agence nationale de sécurité du médicament et des produits de santé. Néanmoins, la radiothérapie est le plus souvent possible. Il convient de respecter les recommandations de bonnes pratiques notamment les critères d’éligibilité, les modalités de surveillance avant, pendant et après l’irradiation selon le type de traitement, la dose et les caractéristiques du dispositif rythmologique implantable. Il est parfois nécessaire de discuter un repositionnement du dispositif et/ou une modification du plan de traitement pour minimiser les risques de dysfonction du dispositif rythmologique implantable. Nous présentons la mise à jour des recommandations de la Société française de radiothérapie oncologique sur la mise en œuvre d’une radiothérapie chez un patient porteur d’un dispositif rythmologique implantable.
Photoneutron-induced damage reduction for cardiac implantable electronic devices using neutron-shielding sheets in high-energy X-ray radiotherapy: A phantom study
2021, Physica Medica
To evaluate damage reduction in cardiac implantable electronic devices (CIEDs) caused by photoneutrons in high-energy X-ray radiotherapy using a neutron-shielding sheet (NSS).
The NSS consists of a bolus with a thickness of 1 or 2 cm (Bls1 or Bls2) as a moderator and several absorbers (20%, 50%, or 80% B₄C silicone sheet [B₄C20, B₄C50, or B₄C80] or a 40% LiF silicone sheet [LiF40]). First, a linear accelerator (LINAC) with a water-equivalent phantom was modeled in the simulation and measured experimentally. Several NSSs were placed on the phantom, a Eu:LiCaAlF₆ scintillator was placed between the phantom and the NSS, and X-rays were irradiated. The relative counts (Cr = counts when placing the NSS or Bls2) were compared between the experiment and simulation. Second, CIED damage was evaluated in the simulation. The relative damage (Dr = damage when placing or not placing the NSS) was compared among all the NSSs. In addition, the γ-ray and leaking X-ray dose from B₄C was measured using a dosimetric film. After determining the optimal NSS combination, Dr value analysis was performed by changing the length of one side and the thickness.
The Cr values of the simulation and experiment agreed within a 30% percentage difference, except for Bare or LiF40-only. The Dr value was reduced by 43% when Bls2 + B₄C80 was applied. The photon dose was less than 5 cGy/1500 MU. The Dr values were smaller for the smaller lengths of one side of B₄C80 and decreased as the M-layer thickness increased.
The CIED damage induced by photoneutrons generated by a LINAC was effectively reduced by applying the optimal NSS.
Impact of different radiation techniques and doses on cardiac implantable electronic devices
2021, Zeitschrift fur Medizinische Physik
Citation Excerpt :
We put the devices directly into the radiation beam to simulate a “worst case” scenario as it might occur e.g. for planning of thoracic tumor radiotherapy. So far, there are few reports about effects of direct radiation on CIEDs in the literature [14,17–20]. If possible, devices should not be located in the direct beam during clinical radiation therapy as recommended through guidelines of the AAPM [5] and other national guidelines [6,21].
Purpose of this investigation was to get deeper insight into the impact of different radiation techniques and doses on cardiac implantable electric devices (CIEDs). We aimed to mimic a worst-case scenario with very high doses and external radiation being applied directly on the devices.
Radiation was applied on 21 CIEDs as photon or electron therapy with maximum dose of 150 Gy in fractions of 2 -20 Gy. CIEDS were put directly into the beam. Brachytherapy was applied with doses of 6 Gy to a maximum of 42 Gy. Check-ups took place after every fraction and one week after radiation. We calculated the estimated potential risk for the health and survival of patients as well as the risk for CIEDs’ loss of function.
28 life- or health-threatening errors occurred during photon therapy, 3/7 devices showed complete loss of function. During electron therapy, 31 potentially patient-threatening errors and 2 losses of function were detected. During brachytherapy, none of the devices showed loss of function but 8 patient-threatening errors occurred. Inadequate shock releases were mostly seen after photon and brachytherapy, random noises occurred more often during electron therapy. The earliest potentially serious error occurred during after 2 Gy photon radiation and 6 Gy brachytherapy. Losses of function occurred earliest at 80 Gy.
The results underline the warning for precaution concerning CIED patients derived from recommendations in the literature. Our study offers new information especially about the impact of electron radiation and brachytherapy on CIEDs. Risk for the devices to for loss of telemetry or battery capacity might be negligible with normafractionated therapy.
Safety of lung stereotactic ablative radiotherapy for the functioning of cardiac implantable electronic devices
2021, Radiotherapy and Oncology
The prevalence of patients with a cardiac implantable device (CIED) developing cancer and requiring a course of radiotherapy (RT) is increasing remarkably. Previously published reports agree that standard and conventionally fractionated RT is usually safe for CIEDs, but no “in-vivo” reports are available on the potential effects of thoracic stereotactic ablative radiotherapy (SABR) regimens to CIEDs functioning. The purpose of our study is therefore to evaluate the effects of SABR on CIEDs (pacemakers [PM] or implantable cardiac defibrillators [ICD]) in a cohort of patients affected by primary or metastatic lung lesions.
We retrospectively collected all CIED-bearing patients undergoing SABR between 2007 and 2019 at our Institution. All CIEDs were interrogated before and after the SABR course to check for any malfunction. Prescription dose, beam energy and maximum dose (Dmax) to CIEDs were retrieved for each patient. Electrical records of the CIEDs were reviewed by the medical records.
Thirty-four consecutive patients (24 with a PM and 10 with an ICD), who underwent 38 separate SABR courses, were included in the study. Eight patients (24%) were PM-dependent. Prescription dose of SABR ranged 26–60 Gy in 1–8 fractions, with a photon energy ranging 6-to-10 MV (76.3% and 23.7%, respectively) and a median Dmax to CIEDs of 0.17 Gy (range 0.04–1.97 Gy). Electrical parameters were stable in post-treatment device programming visits and no transient or persistent alteration of the CIED function was recorded in any patient. No inappropriate interventions were recorded in the 10 ICD-bearing patients during the treatment fractions.
Thoracic SABR proved to be safe for CIEDs when the dose is kept <2 Gy and the beam energy is ≤10 MV, irrespective of the pacing-dependency and of the CIED type.
Effect of simultaneous integrated boost concepts on photoneutron and distant out-of-field doses in VMAT for prostate cancer
2024, Strahlentherapie und Onkologie

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Original ArticleInteraction between CIEDs and modern radiotherapy techniques: Flattening filter free-VMAT, dose-rate effects, scatter radiation, and neutron-generating energies

Highlights

Abstract

Background and purpose

Materials and methods

Results

Conclusions

Section snippets

Cardiac implantable electronic devices

CIEDs were investigated within following groups (Fig. 1):

Results

Discussion

Declaration of Competing Interest

Int J Cardiol

Z Med Phys

Int J Radiat Oncol Biol Phys

Rep Pract Oncol Radiother

Int J Radiat Oncol Biol Phys

Radiotherapy-induced malfunction in contemporary cardiovascular implantable electronic devices: clinical incidence and predictors

JAMA Oncol

Management of radiotherapy patients with implanted cardiac pacemakers and defibrillators: a report of the AAPM TG-203

Med Phys

DEGRO/DGK guideline for radiotherapy in patients with cardiac implantable electronic devices

Strahlenther Onkol

Management of radiation oncology patients with a pacemaker or ICD: a new comprehensive practical guideline in The Netherlands. Dutch Society of Radiotherapy and Oncology (NVRO)

Radiat Oncol

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

Europace

The effect of radiotherapy beam energy on modern cardiac devices: an in vitro study

Europace

Interference detection in implantable defibrillators induced by therapeutic radiation therapy

Netherlands Heart J

Original Article
Interaction between CIEDs and modern radiotherapy techniques: Flattening filter free-VMAT, dose-rate effects, scatter radiation, and neutron-generating energies