Functional Disorders of Heart Stimulating Systems in Patients Treated with Radiation Therapy ? Own Experiences

Objectives To analyze our experiences in irradiation of patients with implanted pacemakers and to draft guidelines regarding the therapy with ionizing radiation in this group. Methods We developed an algorithm of management of patients with implanted heart stimulator who were qualified to radiotherapy. These rules were applied to 50 patients treated at our center in 2009-2012. Results A total of 55 radiation therapy procedures were performed amongst 50 studied patients, including 31 (56 %) radical radiotherapies and 24 (44 %) palliative radiotherapies. The majority of heart stimulating systems in our group were pacemakers (47 radiation therapy procedures, 85 %), seven (13 %) patients were implanted with cardioverter-defibrillator, and one (2 %) had cardiac resynchronization device. In the majority of cases, the heart stimulating system was located outside the irradiated area (23 procedures, 42 %). However, the stimulator was placed in the therapeutic area in 10 (18 %) patients, and one of them required displacement of the device to the right infraclavicular area. In another 22 individuals (40 %) the stimulator was implanted in close proximity to the irradiated area. Mean dose received by a pulse generator was equal to 1.43 Gy (range 0-3 Gy). Only three patients (5.5 %) showed transient irradiation-related functional defects of heart stimulating system. Conclusions Irradiation of patients with heart stimulator is rarely associated with the functional disorders of the stimulating system. The presence of heart stimulating system does not constitute an absolute contraindication to radiation therapy. There is a need of tight cooperation between radiotherapist and cardiologist in the course of radiotherapeutic process.