How to Manage Implantable Cardiac Defibrillator Protection in an Implantable Cardiac Defibrillator-Dependent Patient Undergoing Palliative Radiotherapy?

Abstract

A 61-year-old female patient underwent left breast segmental mastectomy for invasive ductal carcinoma in 2011. Thereafter, trastuzumab therapy was initiated as an adjuvant chemotherapy. However, trastuzumab-related cardiotoxicity developed leading to a left ventricular ejection fraction (LVEF) value of 25% in the patient. Notably, LVEF did not improve with optimal medical treatment on follow-up. Therefore, decision-making for an implantable cardiac defibrillator (ICD) therapy (for primary prevention) was implemented. Implantable cardiac defibrillator was implanted in the right pectoral region due to left mastectomy and lymph node excision. On follow-up, positron emission computed tomography revealed metastatic lesions involving the anterior upper lobe of the right lung and right infraclavicular lymph nodes. The patient was referred to our clinics due to the fact that she had an ICD generator in the vicinity of the metastatic sites (Figure 1A). This might substantially reduce the effectiveness of planned radiotherapy on this region. Moreover, radiotherapy with a cumulative dose of >5 Gy might potentially hamper the ICD generator. Notably, the calculated dose was seemingly over this threshold according to the American Association of Physicists in Medicine Task Group 203. Based on the abovementioned challenges, temporary removal of the ICD generator, leaving the leads in place, and reimplantation of the generator in the same region following radiotherapy were considered. However, even though the patient was not dependent on cardiac pacing by the device, the patient might be