Radiotherapy in patients with pacemakers and implantable cardioverter defibrillators: a literature review

Effects of Ionizing Radiation on Cardiac Implantable Electronic Devices (CIEDs) in Patients with Esophageal Cancer Undergoing Radiotherapy: A Pilot Study

(1) Background: The prevalence of cancer patients relying on cardiac implantable electronic device (CIED) is steadily rising. The aim of this study was to evaluate RT-related malfunctions of CIEDs. (2) Methods: We retrospectively analyze sixteen patients with esophageal cancer who were treated with radiotherapy between 2012 and 2022 at the University Hospital Heidelberg. All patients underwent systemic evaluation including pre-therapeutic cardiological examinations of the CIED functionality and after every single irradiation. (3) Results: Sixteen patients, predominantly male (14) with a mean age of 77 (range: 56-85) years were enrolled. All patients received 28 fractions of radiotherapy with a cumulative total dose 58.8 Gy. The mean maximum dose at the CIEDs was 1.8 Gy. Following radiotherapy and during the one-year post-radiation follow-up period, there were no registered events associated with the treatment in this evaluation. (4) Conclusion: The study did not observe any severe CIED malfunctions following each radiation fraction or after completion of RT. Strict selection of photon energy and alignment with manufacturer-recommended dose limits appear to be important. Our study showed no major differences in the measured values of the pacing threshold, sensing threshold and lead impedance after RT.

Stereotactic arrhythmia radioablation: A multicenter pre-post intervention safety evaluation of the implantable cardioverter-defibrillator function

BACKGROUND

Stereotactic arrhythmia radioablation (STAR) appears to be beneficial in selected patients with therapy-refractory ventricular tachycardia (VT). However, high-dose radiotherapy used for STAR-treatment may affect functioning of the patients' implantable cardioverter defibrillator (ICD) by direct effects of radiation on ICD components or cardiac tissue. Currently, the effect of STAR on ICD functioning remains unknown.

METHODS

A retrospective pre-post multicenter study evaluating ICD functioning in the 12-month before and after STAR was performed. Patients with (non)ischemic cardiomyopathies with therapy-refractory VT and ICD who underwent STAR were included and the occurrence of ICD-related adverse events was collected. Evaluated ICD parameters included sensing, capture threshold and impedance. A linear mixed-effects model was used to investigate the association between STAR, radiotherapy dose and changes in lead parameters over time.

RESULTS

In total, 43 patients (88% male) were included in this study. All patients had an ICD with an additional right atrial lead in 34 (79%) and a ventricular lead in 17 (40%) patients. Median ICD-generator dose was 0.1 Gy and lead tip dose ranged from 0-32 Gy. In one patient (2%), a reset occurred during treatment, but otherwise, STAR and radiotherapy dose were not associated with clinically relevant alterations in ICD leads parameters.

CONCLUSIONS

STAR treatment did not result in major ICD malfunction. Only one radiotherapy related adverse event occurred during the study follow-up without patient harm. No clinically relevant alterations in ICD functioning were observed after STAR in any of the leads. With the reported doses STAR appears to be safe.

Pacemaker Relocation for Radiation Against Overlapping Lung Cancer

We experienced a patient after pacemaker (PM) implantation who had lung cancer of the left upper lobe that developed just behind the PM. The patient was an 81-year-old man with many complications. Radiation was the only treatment option. The PM had to be moved to another place to avoid direct radiation exposure to it. An epicardial pacing lead was implanted on the right ventricular epicardium, and the new generator was implanted in the abdomen. The patient was treated with a total of 62 Gy of radiotherapy for lung cancer, achieving a temporary shrinkage of the tumor. During the radiotherapy period, the PM functioned well without harmful events. When radiation therapy is needed in cases where the tumor overlaps the PM, relocation surgery using an epicardial pacing lead may be a useful option.

Pacemaker Malfunction During Passive Proton Beam Therapy for Localized Prostate Cancer: Case Reports and a Literature Review

We report two cases of pacemaker malfunction occurring during proton beam therapy (PBT) for localized prostate cancer treatment. The first case involved mode changes in the pacemaker, while the second exhibited prolongation of the RR interval. Remarkably, both cases did not manifest significant clinical changes. Our findings indicate that careful consideration should be given to passive PBT in patients with localized prostate cancer who have pacemakers, like the considerations in patients with thoracic and abdominal cancers. Moreover, our report highlights the importance of recognizing potential cardiac implantable electronic devices malfunction in various PBT scenarios.

Cardiac pacing and lead devices management: 25 years of research at EP Europace journal

AIMS

Cardiac pacing represents a key element in the field of electrophysiology and the treatment of conduction diseases. Since the first issue published in 1999, EP Europace has significantly contributed to the development and dissemination of the research in this area.

METHODS

In the last 25 years, there has been a continuous improvement of technologies and a great expansion of clinical indications making the field of cardiac pacing a fertile ground for research still today. Pacemaker technology has rapidly evolved, from the first external devices with limited longevity, passing through conventional transvenous pacemakers to leadless devices. Constant innovations in pacemaker size, longevity, pacing mode, algorithms, and remote monitoring highlight that the fascinating and exciting journey of cardiac pacing is not over yet.

CONCLUSION

The aim of the present review is to provide the current 'state of the art' on cardiac pacing highlighting the most important contributions from the Journal in the field.

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

Age is a risk factor for both cardiovascular disease and cancer, and as such radiation oncologists frequently see a number of patients with cardiac implantable electronic devices (CIEDs) receiving proton therapy (PT). CIED malfunctions induced by PT are nonnegligible and can occur in both passive scattering and pencil beam scanning modes. In the absence of an evidence-based protocol, the authors emphasise that this patient cohort should be managed differently to electron- and photon- external beam radiation therapy (EBRT) patients due to distinct properties of proton beams. Given the lack of a PT-specific guideline for managing this cohort and limited studies on this important topic; the process was initiated by evaluating all PT-related CIED malfunctions to provide a baseline for future reporting and research. In this review, different modes of PT and their interactions with a variety of CIEDs and pacing leads are discussed. Effects of PT on CIEDs were classified into a variety of hardware and software malfunctions. Apart from secondary neutrons, cumulative radiation dose, dose rate, CIED model/manufacturer, distance from CIED to proton field, and materials used in CIEDs/pacing leads were all evaluated to determine the probability of malfunctions. The importance of proton beam arrangements is highlighted in this study. Manufacturers should specify recommended dose limits for patients undergoing PT. The establishment of an international multidisciplinary team dedicated to CIED-bearing patients receiving PT may be beneficial.

Evaluation and management of cancer patients presenting with acute cardiovascular disease: a Clinical Consensus Statement of the Acute CardioVascular Care Association (ACVC) and the ESC council of Cardio-Oncology—part 2: acute heart failure, acute myocardial diseases, acute venous thromboembolic diseases, and acute arrhythmias

Advances in treatment, common cardiovascular (CV) risk factors and the ageing of the population have led to an increasing number of cancer patients presenting with acute CV diseases. These events may be related to cancer itself or cancer treatment. Acute cardiac care specialists must be aware of these acute CV complications and be able to manage them. This may require an individualized and multidisciplinary approach. The management of acute coronary syndromes and acute pericardial diseases in cancer patients was covered in part 1 of a clinical consensus document. This second part focusses on acute heart failure, acute myocardial diseases, venous thromboembolic diseases and acute arrhythmias.

Radiotherapy for a Patient With Spinal Cord Stimulation: A Case Report

Cancer-related neuropathic pain is prevalent in up to 40% of patients with advanced disease. Spinal cord stimulation (SCS) is used to treat chronic pain when other treatments are ineffective. Radiotherapy is an established treatment modality for patients with oncological diseases. The ionizing radiation from radiotherapy can potentially damage electrical devices, including SCS devices. Additionally, all parts of SCS can potentially interfere with radiotherapy delivery. We present a case of successful administration of radiotherapy to a patient without damaging the SCS device implanted in proximity to the target lesion.

The impact of particle radiotherapy on the functioning of cardiac implantable electronic devices: a systematic review of in vitro and in vivo studies according to PICO criteria

The number of oncological patients who may benefit from proton beam radiotherapy (PBT) or carbon ion radiotherapy (CIRT), overall referred to as particle radiotherapy (RT), is expected to strongly increase in the next future, as well as the number of cardiological patients requiring cardiac implantable electronic devices (CIEDs). The management of patients with a CIED requiring particle RT deserves peculiar attention compared to those undergoing conventional photon beam RT, mostly due to the potential generation of secondary neutrons by particle beams interactions. Current consensus documents recommend managing these patients as being at intermediate/high risk of RT-induced device malfunctioning regardless of the dose on the CIED and the beam delivery method used, despite the last one significantly affects secondary neutrons generation (very limited neutrons production with active scanning as opposed to the passive scattering technique). The key issues for the current review were expressed in four questions according to the Population, Intervention, Control, Outcome criteria. Three in vitro and five in vivo studies were included. Based on the available data, PBT and CIRT with active scanning have a limited potential to interfere with CIED that has only emerged from in vitro study so far, while a significant potential for neutron-related, not severe, CIED malfunctions (resets) was consistently reported in both clinical and in vitro studies with passive scattering.

Case Report: Can Targeted Intraoperative Radiotherapy in Patients With Breast Cancer and Pacemakers be the New Standard of Care?

Background

Partial breast irradiation with Intra-operative radiotherapy (IORT) has become a popular management option as opposed to whole breast radiation using external beam radiotherapy for breast cancer patients. While previous studies have highlighted the use of IORT in breast cancer patients, there is a scarcity of literature on the use of IORT in those who also have ipsilateral pacemakers. Thus, the aim of our case report is to highlight the applicability of IORT in breast cancer patients who also have a pacemaker.

Case Reports

Two female patients with an implanted dual-chamber pacemaker presented with a diagnosis of left-sided invasive ductal carcinoma on mammogram. Mammography of the left breast revealed a 10 mm and 7 mm spiculated mass, respectively, further confirmed with an ultrasound-guided core biopsy that was conclusive of clinical Stage I T1 N0 grade 2, ER +, PR + Her2 – invasive ductal carcinoma. They met our eligibility criteria for IORT, which is being performed as a registry trial. These patients underwent a wide excision lumpectomy along with IORT.

Conclusion

Our findings underscore the successful use of targeted IORT for breast-conserving surgery in a patient with invasive ductal carcinoma and pacemaker, hence eliminating the necessity for relocating pacemaker surgeries in these patients. Furthermore, no device failure or malfunction for the pacemaker was recorded before, during, or after the surgery, demonstrating the safety of using IORT in patients with preinstalled pacemaker despite a lack of evidence on safe radiation dosage or manufacturer guidelines. Nonetheless, the effects of IORT on pacemaker < 10 cm were not studied in our patients and further clinical studies are recommended to reinforce the applicability and safe distance of IORT in breast cancer patients with pacemaker.

Cardiac Implantable Electronic Device Dysfunctions in Patients Undergoing Radiotherapy A Prospective Cohort Study

BACKGROUND

Increasing numbers of patients with cardiac implantable electronic devices (CIEDs) are undergoing radiotherapy for cancer. The aim of the study was to prospectively evaluate the incidence, characteristics, and associated factors of CIED dysfunctions related to radiotherapy.

METHODS

Between April 2013 and March 2020, all patients with a CIED who underwent ≥1 radiotherapy session were enrolled. Patients were monitored according to a systematic protocol, including device interrogation before the 1^st and after each radiotherapy session. The primary endpoint was CIED dysfunction, defined as oversensing, total or partial deprogramming, and/or unrecoverable reset.

RESULTS

We included a total of 92 CIED radiotherapy courses: 77 (83.7%) in patients with a pacemaker and 15 (16.3%) in those with an implantable cardioverter defibrillator. Overall, 13 dysfunctions (14.1%) were observed during 92 courses (1509 sessions), giving an incidence of 0.9 per 100 sessions. These included nine deprogramming (three total resets to back-up pacing mode and six partial deprogramming that were all successfully reprogrammed), three transient oversensing, and one unrecoverable oversensing requiring CIED and leads replacement. There were no adverse clinical events related to device dysfunction. In multivariable analysis, neutron-producing irradiation (odds ratio [OR], 5.59; 95% confidence interval [CI], 1.09-28.65; P=0.039) and cumulative tumor dose (OR, 1.05; 95% CI, 1.01-1.10; P=0.007) remained significantly associated with CIED dysfunction.

CONCLUSIONS

In this prospective study, transient or permanent subclinical CIED dysfunction occurred in 14.1% of radiotherapy courses. Our findings emphasize the importance of high-energy beams and neutron-producing irradiation in risk assessment. This article is protected by copyright. All rights reserved.

In-vitro investigation of cardiac implantable electronic device malfunction during and after direct photon exposure: A three-centres experience

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Safety verification of carbon-ion radiotherapy for patients with cardiac implantable electronic devices (CIEDs)

According to guidelines, carbon-ion beam therapy is considered to carry a high safety risk for patients with cardiac implantable electronic devices (CIEDs), although the actual impacts remain unclear. In this study, we investigated the safety of carbon-ion beam therapy in patients with CIEDs. Patients with CIEDs who underwent carbon-ion therapy at Gunma University Heavy Ion Medical Center between June 2010 and December 2019 were identified and investigated for abnormalities in the operation of their CIEDs, such as oversensing and resetting during irradiation, and abnormalities in operation after treatment. In addition, the risk of irradiation from carbon-ion beam therapy was evaluated by model simulations. Twenty patients (22 sites) with CIEDs were identified, 19 with pacemakers and one with an implantable cardioverter-defibrillator (ICD). Treatments were completed without any problems, except for one case in which the treatment was discontinued because of worsening of the primary disease. Monte Carlo simulation indicated that the carbon beam irradiation produced neutrons at a constant and high level in the irradiation field. Nevertheless, with the distances between the CIEDs and the irradiation fields in the analyzed cases, the quantity of neutrons at the CIEDs was lower than that within the irradiation. Although carbon-ion beam therapy can be safely administered to patients with CIEDs, it is advisable to perform the therapy with sufficient preparation and backup devices because of the risks involved.

Radiotherapy for patient with cardiac implantable electronic device, consensus from French radiation oncology society

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.

Management of IMRT in a gastric cancer patient with pacemaker: A case report and review of the literature

Due to the prolongation of a lifetime, more cancer patients with cardiac implantable electronic devices are treated by radiotherapy. However, radiation may cause permanent or temporary malfunctions on these devices, and new-generation devices are more sensitive to radiation. Besides, radiotherapy techniques and image guidance methods that may cause different interactions with the functions of the devices have been changed significantly recently. Here, we reported our clinical experience in a patient with a pacemaker who underwent radiotherapy with intensity-modulated radiation therapy (IMRT) due to gastric cancer and reviewed the literature.

Assessment of Radiation-Induced Malfunction in Cardiac Implantable Electronic Devices

Background

Radiation therapy (RT) is a standard cancer treatment modality, and an increasing number of patients with cardiac implantable electronic devices (CIEDs) are being referred for RT. The goals of this study were as follows: (i) to determine the incidence of CIED malfunction following RT; (ii) to characterize the various types of malfunctions that occur; and (iii) to identify risk factors associated with CIED malfunction following RT.

Methods

A retrospective study of patients with CIEDs who received RT between 2007 and 2018 at 4 Canadian centres (Sunnybrook Health Sciences Centre, Kingston General Hospital, Hamilton Health Sciences Centre, and University of Ottawa Heart Institute) was conducted. Patients underwent CIED interrogation after completion of RT, to assess for late damage to the CIEDs. Data on demographics, devices, and RT were compared for the primary outcome of device malfunction.

Results

Of 1041 patients with CIEDs who received RT, 811 patients with complete data were included. Device malfunctions occurred in 32 of 811 patients (4%). The most common device malfunctions were reduced ventricular/atrial sensing (in 13 of 32 [41%]), an increase in lead threshold (in 9 of 32 [22%]), lead noise (in 5 of 32 [16%]), and electrical reset (in 2 of 32 [6%]). Higher beam energy (≥ 10 MV) was associated with malfunction (P < 0.0001). Radiation dose was not significantly different between the malfunction and non-malfunction groups (58.3 cGy vs 65 cGy, respectively, P = 0.71).

Conclusions

Although RT-induced CIED malfunctions are rare (occurring in 4% of patients with a CIED who undergo RT), collaborative efforts between radiation oncologists and cardiac rhythm device clinics to optimize CIED monitoring are needed, to detect and manage CIED malfunctions. Malfunctions are more common in patients receiving higher–beam energy (≥10MV)RT.

A Review and Analysis of Managing Commonly Seen Implanted Devices for Patients Undergoing Radiation Therapy

Purpose

This review article aims to consolidate information regarding existing and emerging implanted devices used in patients undergoing radiation therapy and to categorize levels of attention needed for each device, including which devices require monitoring throughout treatment.

Methods and Materials

Based on the collective information from scholar searches, manufacturers' technical reports, and institutional experiences in the past years, commonly present devices in patients with cancer are compiled. This work summarizes cardiac pacemaker, implanted cardiac defibrillator, hepatic pump, intrathecal pain pump, neurostimulator, shunt, loop recorder, and mediport. Three different classifications of implanted devices can be made based on the potential effect of radiation: life-dependent, nonlife-dependent but with adverse effects if overdosed, and devices without electronic circuits. Implanted devices that contain electronic circuits that would be life-dependent or have adverse effects if overdosed, include cardiac pacemakers, implanted cardiac defibrillators, programmable hepatic pumps, pain pumps, neurostimulators, and loop recorders.

Results

Dose exposure to these devices need to be calculated or measured in vivo, especially for cardiac implanted devices, and they should be minimized to assure continued healthy functioning. Treatment planning techniques should be chosen to reduce entry, exit and internal scatter dose. Lower energy photon beams should be used to decrease potential neutron contamination. Implanted devices without electronic circuits are less of a concern. If a patient is life-dependent on the implanted device, it is not recommended to treat the patient with proton therapy.

Conclusions

This study reviewed the management of patients with commonly seen implanted devices and summarized a workflow for identifying and planning when a patient has implanted devices. Classifications of implanted devices could help clinicians make proper decisions in regard to patients with specific implanted devices. Lastly, the management of such devices in the era of the pandemic is also discussed in this review article.

Photoneutron-induced damage reduction for cardiac implantable electronic devices using neutron-shielding sheets in high-energy X-ray radiotherapy: A phantom study

PURPOSE

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

The CIED damage induced by photoneutrons generated by a LINAC was effectively reduced by applying the optimal NSS.

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

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.

Radiotherapy in patient with an automated implantable cardioverter defibrillator

Introduction:

An ever-growing number of patients with implantable cardiac rhythm devices are treated with radiation therapy for cancer and are therefore at risk of device failure. Several medical societies developed recommendations for the management of such patients.

We report the case of a 76-year-old patient with an implanted cardioverter defibrillator, treated with external radiotherapy for breast cancer, to test in practice the recommendations on the management of similar cases.

Breast Radiotherapy-Related Cardiotoxicity. When, How, Why. Risk Prevention and Control Strategies

In recent decades, improvements in breast cancer management have increased overall patient survival; however, many cancer therapies have been linked to an important risk of cardiovascular adverse events. Cardio-oncology has been proposed as an emerging specialty to coordinate preventive strategies that improve the cardiovascular health of oncologic patients. It employs the most suitable personalized multidisciplinary management approach for each patient to optimize their cardiovascular health and improve their survival and quality of life. Radiotherapy is an essential part of the therapeutic regimen in breast cancer patients but can also increase the risk of cardiovascular disease. Therefore, minimizing the negative impact of radiation therapy is an important challenge for radiotherapy oncologists and cardiologists specializing in this field. The aim of the present review is to update our knowledge about radiation-induced cardiotoxicity in breast cancer patients by undertaking a critical review of the relevant literature to determine risk prevention and control strategies currently available.

Usefulness of remote monitoring for the early detection of back-up mode in implantable cardioverter defibrillators

BACKGROUND

Reversion of an implantable cardioverter defibrillator (ICD) to back-up mode degrades the operating capabilities of the device, puts patients at risk and requires rapid intervention by a manufacturer's technician.

AIM

To illustrate the usefulness of remote monitoring of ICDs for the early detection of reversion to back-up mode.

METHODS

In our centre, all patients implanted with an ICD, with or without resynchronisation, were offered remote monitoring as soon as the technology became available. Alerts triggered by the remote monitoring system were included prospectively in a register. During a mean follow-up of 5.7±1.3 years, a total of 1594 patients with an ICD (441 with resynchronisation function) followed with remote monitoring were included in the register.

RESULTS

Among 15,874 alerts, only 10 were related to a reversion to back-up mode. Among those, seven reversions were caused by radiotherapy, two were fake events and one was caused by magnetic resonance imaging. Except for the two fake events, the eight other patients had an emergency admission for the resetting and reprogramming of their ICD. None of the reversion to back-up mode alerts was followed by a clinical alert (i.e. a shock alert) before the ICD problem was resolved.

CONCLUSIONS

Reversion to back-up mode is a very rare event, accounting for 0.06% of total alerts; remote monitoring facilitates the early detection of this critical event to resolve the problem faster than the next scheduled follow-up. Remote monitoring can prevent serious damage to the patient and avoids systematic ambulatory control of the ICD after each radiotherapy session.

Focus on stereotactic radiotherapy: A new way to treat severe ventricular arrhythmias?

Ventricular tachycardia has a significant recurrence rate after ablation for several reasons, including inaccessible substrate. A non-invasive technique to ablate any defined areas of myocardium involved in arrhythmogenesis would be a potentially important therapeutic improvement if shown to be safe and effective. Early feasibility studies of single-fraction stereotactic body radiotherapy have demonstrated encouraging results, but rigorous evaluation and follow-up are required. In this document, the basic concepts of stereotactic body radiotherapy are summarized, before focusing on stereotactic arrhythmia radioablation. We describe the effect of radioablation on cardiac tissue and its interaction with intracardiac devices, depending on the dose. The different clinical studies on ventricular tachycardia radioablation are analysed, with a focus on target identification, which is the key feature of this approach. Our document ends with the indications and requirements for practicing this type of procedure in 2020. Finally, because of the limited number of patients treated so far, we encourage multicentre registries with long-term follow-up.

Case Report: Complete heart block as a manifestation of cardiac metastasis of oral cancer

Metastatic tumors of the heart presenting with complete heart block (CHB) is an extremely uncommon case. There are no available guidelines in managing CHB in terminal cancer. Permanent pacemaker implantation in such cases is a challenge in terms of clinical utility and palliative care.

We report a case of a 24-year-old man suffering from tongue cancer presenting with CHB. An intracardiac mass and moderate pericardial effusion were present, presumed as the metastatic tumor of tongue cancer. We implanted a temporary pacemaker for his symptomatic heart block and cardiogenic shock, and pericardiocentesis for his massive pericardial effusion. We decided that a permanent pacemaker would not be implanted based on the low survival rate and significant comorbidities.

Multiple studies report a variable number of cardiac metastasis incidence ranging from 2.3% to 18.3%. It is rare for such malignancies to present with CHB. The decision to implant a permanent pacemaker is highly specific based on the risks and benefits of each patient. It needs to be tailored to the patient’s functional status, comorbid diseases, prognosis, and response to conservative management.

JASTRO/JCS Guidelines for radiotherapy in patients with cardiac implantable electronic devices

This publication is an English version of the Japanese Society for Radiation Oncology (JASTRO) and The Japanese Circulation Society official guidelines for patients with cardiac implantable electronic devices (CIEDs). Several radiotherapy-associated malfunctions have been reported for CIEDs such as pacemakers and implantable cardioverter-defibrillators. Accordingly, guidelines for radiotherapy in patients with CIEDs have been issued by other countries and societies. In August 2010, JASTRO published the ‘Radiotherapy Guidelines for Patients with Pacemakers and Implantable Defibrillators’ (hereafter referred to as the former guidelines). Given new findings in this decade, a multidisciplinary working group of radiation oncologists, medical physicists, radiation therapists and cardiologists jointly reviewed and revised the former guidelines.

Comparison of Measured Data between Pre- and Post-Radiotherapy in a Patient with Cardiac Resynchronization Therapy Defibrillator

Although some researches proved the influence of radiation therapy (RT) on pacemakers and implantable cardioverter defibrillators, little has been reported on cardiac resynchronization therapy defibrillators (CRTDs). We experienced a case of RT on CRTD and had a new finding.A patient with CRTD implanted for dilated cardiomyopathy was diagnosed with lung squamous cell carcinoma and started receiving RT. All the implanted devices, including the main body of CRTD, left ventricular lead (LV), right ventricular lead with high-voltage conductor, and right atrial lead, were from the same manufacturer. The radiation targeted the tumor of 67 mm in diameter in the right superior lobe for 5 min per session. The CRTD was outside the radiation field, which is 65 mm, but the leads were inside. Plan 1 used 2 Gy/fr with 8 megavolt photons, and Plan 1 was irradiated at 0° and 180° for 16 RT sessions. The dosage was increased to 3 Gy for Plan 2 for 4 sessions. Plan 3 used 2 Gy with 6 and 8 megavolt photons, and Plan 3 was irradiated at 27.7° and 200.7° for 11 RT sessions. Changes in measured parameters were assessed before and after RT.Changes in impedance of LV and high-voltage lead exceeded prespecified threshold. However, no significant errors were detected in the CRTD on the dosages and energy we used.We hypothesize that the lead insulator could have been affected by radiation.

Radiotherapy in Patients With a Cardiac Implantable Electronic Device

Recently, the Heart Rhythm Society published recommendations on management of patients with cardiac implantable electronic device (CIED) who require radiotherapy (RT). We aimed to report the experience of a teaching hospital, and discuss our practice in the context of recently published guidelines. We identified all consecutive CIED recipients (12,736 patients) who underwent RT between March 2006 and June 2017. Among them, 90 (1%) patients (78.2 ± 10 years, 73% male) had a CIED: 82 pacemakers and 8 implantable cardioverter-defibrillators. Two patients required CIED extraction prior to RT for ipsilateral breast cancer (no device replacement in 1 patient). Four patients (5%) were considered at high-risk, 35 (39%) at intermediate-risk, and the remaining 50 (56%) at low-risk for CIED dysfunction. Overall, only a minority of patients followed recommended local protocol during RT delivery (31%) and during follow-up (56%). CIED malfunction was detected in 5 patients (6%), mainly back-up mode resetting (80%), with 4 (including 3 pelvic cancer location) patients initially classified as being at intermediate-risk and 1 at low-risk. Four out of the 5 patients with CEID malfunction had received neutron producing beams. In conclusion, our findings underline the lack of rigorous monitoring of patients undergoing RT (though CIED malfunction appears to be rare and relatively benign in nature), and emphasize the interest of considering neutron producing beam for risk stratification as recommended in recent guidelines. Optimization of patient's management requires a close collaboration between both CIED clinicians and radiation oncologists, and more systematic remote CIED monitoring may be helpful.

A randomized in vitro evaluation of transient and permanent cardiac implantable electronic device malfunctions following direct exposure up to 10 Gy

BACKGROUND AND PURPOSE

High-dose 6‑MV radiotherapy may cause cardiac implantable electronic devices (CIEDs) to malfunction. To assess CIED malfunctions resulting from direct exposure up to 10 Gy, 100 pacemakers (PMs) and 40 implantable cardioverter-defibrillators (ICDs) were evaluated.

MATERIALS AND METHODS

CIEDs underwent baseline interrogation. In ICDs, antitachycardia therapies were disabled via the programmer while the detection windows were left enabled. A computed tomography (CT) scan was performed to build the corresponding treatment plan. CIEDs were "blinded" and randomized to receive single doses of either 2, 5, or, 10 Gy via a 6-MV linear accelerator (linac) in a water phantom. Twenty-two wireless telemetry-enabled CIEDs underwent a real-time session, and their function was recorded by the video camera in the bunker. The CIEDs were interrogated after exposure and once monthly for 6 months.

RESULTS

During exposure, regardless of dose, 90.9% of the CIEDs recorded electromagnetic interference, with 6 ICDs (27.3%) reporting pacing inhibition and inappropriate arrhythmia detections. After exposure, a backup reset was observed in 1 PM (0.7% overall, 1% among PMs), while 7 PMs (5% overall, 7% among PMs) reported battery issues (overall immediate malfunction rate was 5.7%). During follow-up, 4 PMs (2.9% overall; 4% among PMs) and 1 ICD (0.7% overall; 2.5% among ICDs) reported abnormal battery depletion, and 1 PM (0.7% overall; 1% among PMs) reported a backup reset (overall late malfunction rate was 4.3%).

CONCLUSION

Apart from transient electromagnetic interference, last-generation CIEDs withstood direct 6‑MV exposure up to 10 Gy. Permanent battery or software errors occurred immediately or later only in less recent CIEDs.

Targeted Intraoperative Radiotherapy Is a Safe Approach for Patients with Pacemakers: A Case Study and Literature Review

Case reports detailing the effects of targeted intraoperative radiation therapy (IORT) on patients with cardiac pacemakers (PMs) are rare. This growing population sub-group requiring IORT and lack of standardized guidelines necessitate more practical published research. An 81-year-old patient with clinical stage II, T1 N0 grade III, triple-negative invasive ductal carcinoma and an implanted single-lead chamber PM (VVIR mode, model: Biotronik, type Effecta SR) received targeted intraoperative radiotherapy at the time of wide local excision and sentinel lymph node biopsy. It presents the shortest distance between the outer diameter of the PM and IORT applicator in literature. Target IORT was performed utilizing an Intrabeam device (50 kV, Carl Zeiss Surgical, Oberkochen, Germany). This case elucidates the successful use of targeted IORT for breast-conserving surgery in a patient with a single ipsilateral chamber VVIR mode PM. No device failure or malfunction was reported for the PM before, during, or after the procedure. These findings support the use of targeted IORT for patients diagnosed with early-stage breast carcinomas who have a PM implanted. However, further research is needed to understand the safety of other methods and devices for IORT patients with cardiac implantable electronic devices.

Effects of high-energy photon beam radiation therapy on Jarvik 2000 LVAD: in vitro evaluation

PURPOSE

Left ventricular assist device (LVAD) is considered a standard care for patients with advanced heart failure. The aim of this work was to study in vitro the effects of direct exposure of the Jarvik 2000 LVAD to 10-MV photon beams.

METHODS

Jarvik 2000 pump was immersed in a siliconized box filled with deionized water. A 30 × 30 × 15 cm RW3 slabs were added forth and back to the box. A treatment plan consisting of a single direct 10 × 10 cm² field size beam was used to deliver 1000 MU at the center of the pump. During irradiation, the external Flow Maker controller and the lithium battery were positioned away from the beam. Pump parameter data (included voltage, current and frequency) were measured, recorded and analyzed for changes in pump function among baseline, pre-irradiation, during irradiation, post-irradiation and after 6 months. The whole session lasted 6 months. The Mann-Whitney U test was used to compare the repeated measurements. X-ray radiation attenuation was also studied.

RESULTS

The parameters investigated remained stable over the 6 months; that is, no pump stops, alarms, events, operational changes or abnormalities during the discharge rate of the connected power sources, were encountered, confirmed by the Mann-Whitney U test applied to all sessions (p > 0.1). The measured X-ray attenuation differed from the calculated one by TPS by 34%.

CONCLUSION

The Jarvik 2000 resulted stable under direct X-ray beam of 10-MV energy. Its strong attenuation, however, can affect dose deposition in the pump in TPS, and it must be taken into account.

Non-invasive Stereotactic Radioablation: A New Option for the Treatment of Ventricular Arrhythmias

Ventricular tachycardia (VT) is associated with significant morbidity and mortality. Radiofrequency catheter ablation can be effective for the treatment of VT but it carries a high rate of recurrence often attributable to insufficient depth of penetration for reaching critical arrhythmogenic substrates. Stereotactic body radioablation (SBRT) is a commonly used technology developed for the non-invasive treatment of solid tumours. Recent evidence suggests that it can also be effective for the treatment of VT. It is a non-invasive procedure and it has the unique advantage of delivering ablative energy to any desired volume within the body to reach sites that are inaccessible with catheter ablation. This article summarises the pre-clinical studies that have formed the evidence base for SBRT in the heart, describes the clinical approaches for SBRT VT ablation and provides perspective on next steps for this new treatment modality.

PAIDEIA: pacemaker and implanted cardioverter defibrillator management in radiation therapy-a survey by the Young Group of the Italian Association of Radiotherapy and Clinical Oncology (AIRO)

INTRODUCTION

The management of patients bearing a cardiac implantable electronic device and needing a radiotherapy treatment is an important clinical scenario. The aim of this survey was to evaluate the level of awareness within the Italian Radiation Oncologist community on this topic.

MATERIALS AND METHODS

A survey was promoted by the Young Group of Italian Association of Radiotherapy and Clinical Oncology (AIRO) with a questionnaire made up of 22 questions allowing for multiple answers, which was administered, both online and on paper version. It was addressed to Radiation Oncologists, AIRO members, participating in the National Congress held in 2015.

RESULTS

A total of 113 questionnaires were collected back and analyzed (survey online: 50 respondents; paper version: 63). The answers showed a good level of awareness on the issue, but with a nonhomogeneous adherence to the different published guidelines (GL). There is a general low rate of referral for a preliminary cardiological evaluation in patients bearing PM/ICDs, in line with some published surveys; nevertheless, a focused attention to certain specific treatment factors and patient-centered point of view emerged.

CONCLUSIONS

A generally good awareness of this topic was shown but homogeneous application of GL was not observed, possibly due to the multiplicity of available GL. A prospective data collection could help to better clarify the shadows on this topics.

Cardio-Oncology Fellowship Training and Education

PURPOSE OF REVIEW

With the rapid development of novel cancer therapeutics and the growing number of cancer survivors, there is significant demand for cardio-oncology experts to care for these patients. As such, it has become increasingly necessary to develop formalized training in the field of cardio-oncology. This review will focus on the current state of cardio-oncology education, with recommendations for the development of dedicated cardio-oncology fellowships.

RECENT FINDINGS

Cardio-oncology fellowships should be affiliated with high-volume centers that have established cardio-oncology clinical and research programs with dedicated cardio-oncology faculty. Several recent publications have proposed recommendations to develop uniform cardio-oncology training standards, core curricula, and evaluation metrics. With the rapid evolution of the field and the support of various profession organizations, the number and quality of dedicated cardio-oncology fellowship programs is expected to increase significantly. The adoption of defined training requirements and evaluation standards to measure competency will be essential to ensure the legitimacy and success of the field.

Radiotherapy for patients with cardiovascular implantable electronic devices: an 11-year experience

PURPOSE

As cardiovascular implantable electronic devices (CIEDs) are increasingly indicated in older patients, and the burden of cancer is rising with the aging population, the management of patients with CIEDs who require radiotherapy (RT) is a timely concern. The objective of the study was to evaluate the management of, and malfunctions in, patients with CIEDs undergoing RT.

METHODS

A retrospective study of patients with CIEDs receiving RT at Kingston Health Sciences Center from March 2007-April 2018 was conducted. Data on demographics, RT, devices, and management were compared for the primary outcome of device malfunction.

RESULTS

Of the 189 patients with CIEDs receiving a total of 297 courses of RT, 4 patients (2.1%) experienced device malfunctions. Higher beam energy was associated with a malfunction (p < 0.05). Patients with malfunctions received a lower dose of radiation per fraction (267 ± 93 cGy vs. 477 ± 282 cGy; p < 0.05) and were significantly younger (71.4 ± 2.2 years vs. 77.8 ± 9.8 years; p < 0.01) compared to patients without malfunctions.

CONCLUSION

RT-induced device malfunctions are rare, but given the potential complications, a better understanding of the potential predictors of malfunction and the development of evidence-based guidelines will help optimize patient safety.

Initial experience with a leadless pacemaker (Micra™) implantation in a low volume center in South East Asia

Aim:

The Micra™ Transcatheter Pacing System is a leadless pacemaker that has been introduced recently. We share our experience in a low volume center and the use of right ventricular angiography (RVA) during implantation.

Materials & methods:

Patients underwent Micra implantation and RVA was performed to predetermine the implant site.

Results:

Nine patients underwent Micra implantation. The most common indication was atrial fibrillation with bradycardia. The device was implanted at apical-septum in seven and mid-septum in two. The procedure time ranged from 30 to 100 min and fluoroscopic time 4–18 min. Pacing parameters remained stable after 1-month follow-up.

Conclusion:

The Micra implantation technique can be easily learnt. RVA was helpful in selecting an appropriate site for the Micra implant.

Dosimetric study to assess the feasibility of intraoperative radiotherapy with electrons (ELIOT) as partial breast irradiation for patients with cardiac implantable electronic device (CIED)

PURPOSE

To report in-vivo dosimetry in the infraclavicular region, a potential site of a cardiac implantable electronic device (CIED) and to evaluate the absorbed dose from intraoperative radiotherapy with electrons (ELIOT).

METHODS

27 non-cardiopathic breast cancer (BC) patients without CIED received quadrantectomy and ELIOT as partial breast irradiation. Before delivering ELIOT, two catheters, each containing eight thermoluminescent dosimeters (TLDs), were positioned in the infraclavicular region. TLDs internal catheter was located deep in the tumor bed while the external catheter was placed on patient's skin.

RESULTS

Data were available for 24/27 patients. The absorbed doses were referred to the dose of 21 Gy. Values measured by the external catheter were low, although statistically significant higher doses were found close to the applicator (mean values 0.26-0.49 Gy). External TLD doses in proximity of the applicator were lower than those detected by their internal counterparts. Values measured by the internal catheter TLDs varied according to the distance from the applicator while no correlation with tumor site and beam energy was found. The distance from the applicator to deliver < 2 Gy to a CIED was 2 cm, while from 2.5 cm the dose measured in all the patients became negligible.

CONCLUSIONS

This dosimetric study provided data to support the clinical use of ELIOT in BC patients having CIEDs as long as the suggested minimum safe distance of 2.5 cm is taken from the RT field in case of ELIOT single dose of 21 Gy, in the energy range of 6-10 MeV.

Approach to cardio-oncologic patients with special focus on patients with cardiac implantable electronic devices planned for radiotherapy: results of the European Heart Rhythm Association survey

The aim of this European Heart Rhythm Association (EHRA) survey was to evaluate clinical practice regarding cardio-oncologic patients, with special focus on patients with cardiac implantable electronic devices (CIEDs) planned for anticancer radiotherapy (RT), among members of the EHRA electrophysiology research network. Of the 36 responding centres, 89% managed patients who were diagnosed or treated oncologically, and this diagnosis affected 1-5% of cardiovascular patients in majority of centres (57%). The main side effects of anticancer therapy in patients treated by cardiologists were thromboembolic complications and left ventricular dysfunction (both reported as 'frequent' by 43% of the centres). The main agents associated with complications were anthracyclines, RT, and monoclonal antibodies. Echocardiography was the most common method of screening for cardiovascular complications (93%), and 10% of the centres did not routinely screen for treatment-induced cardiotoxicity. Opinions on the safe radiation dose, methods of device shielding, and risk calculation prior to RT in CIED patients differed among centres. Precaution measures in high-risk CIED patients were very heterogeneous among centres. Our survey has shown that the awareness of cardiac consequences of anticancer therapy is high, despite relatively low proportion of patients treated oncologically among all cardiovascular patients. There is a consensus of which screening methods should be used for cardiotoxicity of anticancer treatment, but the apprehension of screening necessity is low. Methods of risk assessment and safety measures in CIED patients undergoing RT are very heterogeneous among the European centres, underscoring the need for standardization of the approach to cardio-oncologic patients.

Radiotherapy for Patients with Cardiovascular Implantable Electronic Devices: A Review

Because cardiovascular implantable electronic devices are increasingly indicated in older patients, and the burden of cancer is rising with the growth and aging of the world population, the management of patients with cardiac devices who require radiotherapy for cancer treatment is a timely concern. Device malfunctions might occur in as high as 3% of radiotherapy courses, posing a substantial issue in clinical practice. A nonsystematic comprehensive review was undertaken. We searched PubMed and the MEDLINE database for randomized controlled trials, meta-analyses, systematic reviews, observational studies, in vitro/in vivo studies, and case reports. Articles were selected by 2 independent reviewers, and emphasis was given to information of interest to a general medical readership. The pathophysiology and predictors of cardiovascular implantable electronic device malfunction due to radiotherapy are reviewed, recommendations for the management of patients with such devices undergoing radiotherapy are summarized, and the clinical significance and future directions of this field are discussed. Radiotherapy-induced device malfunctions are rare, but because of the potential complications, the development of evidence-based guidelines for the management of patients with cardiovascular implantable electronic devices undergoing radiotherapy is a timely concern.