p.60 抽出テキスト

..................................................................................... with adequate tumour treatment or in very selected high-risk cases.757,761

According to published recommendations for CIED patients,745,759,762 the risk of malfunction (or adverse events) is higher in the following situations for pacemaker patients:

• With photon radiation applying energy >610 MV: the risk of malfunctions (usually soft errors) is due to secondary neutron production, is not associated with the target zone, and cannot be shielded. • With a cumulative dose reaching the device >2 Gy (moderate risk) or >10 Gy (high-risk): the dose reaching the pacemaker can be estimated before and measured during treatment, is correlated with the target zone, and can be shielded. • If the patient is pacemaker dependent.

Appropriate decision-making is suggested in Figure 15. Experience with proton radiation therapy in CIED patients is limited. However, compared with photon irradiation, this radiation modality produces more secondary neutrons, which may affect the risk of device errors or failure.763 Currently, no specific guidance can be given regarding proton radiation therapy in CIED patients. The specific recommendations of CIED manufacturers are reported in Supplementary Table 23.

11.3 Temporary pacing

Temporary pacing can provide electronic cardiac stimulation in patients with acute life-threatening bradycardia or can be placed prophylactically when the need for pacing is anticipated (e.g. after cardiac surgery).764,765 Modalities for emergency temporary pacing include transvenous, epicardial, and transcutaneous approaches. The transvenous approach often requires fluoroscopic guidance, although echo-guided placement is also feasible.766 Balloon-tipped floating catheters are easier to insert, more stable, and safer than semi-rigid catheters.767,768 Patients who undergo transvenous temporary cardiac pacing have a high risk for procedure-related complications (e.g. cardiac perforation, bleeding, malfunction, arrhythmias, and accidental electrode displacement) and complications related to immobilization (e.g. infection, delirium, and thrombotic events).764,765,769775 In addition, previous temporary pacing is associated with an increased risk of permanent pacemaker infection.639,641 A percutaneous transvenous active fixation lead connected to an external device is safer and more comfortable for patients requiring prolonged temporary pacing.776779 There are no good data that support either a jugular or axillar/subclavian access; however, intrathoracic subclavian puncture should be avoided to reduce the risk of pneumothorax. A jugular access should be preferred if implantation of a permanent ipsilateral device is planned. In selected cases where fast and efficient pacing is needed, a femoral access may be used. Owing to instability of passive leads placed through the femoral vein and immobilization of the patient, the duration of this approach should be as short as possible until bradycardia has resolved or a more permanent solution has been established. The epicardial approach is mostly used following cardiac surgery. Removal of these leads is associated with complications such as bleeding and tamponade.780782 Transcutaneous temporary pacing is a fast and effective non-invasive method, but is not as

Pacemaker management in patients undergoing radiation therapy

Avoid direct radiation Limit cumulative dose Reduce beam energy to minimize direct neutron radiation

Device-specific treatment planning considerations:a

N

Comprehensive PM evaluation before radiation therapy

Neutron-producing treatment ( > 10 MV)

Weekly comprehensive

PM evaluation Comprehensive PM evaluation

after end of radiation therapy

Y

Figure 15 Pacemaker management during radiation therapy ECG = electrocardiographic; PM = pacemaker. aRelocation of the device, continuous ECG monitoring, reprogramming, or magnet application are very rarely indicated. Downloaded from academic.oup.com/eurheartj/article/42/35/3427/6358547 by guest on 07 October 2026