There are no large clinical studies for the determination of the exact radiation level that causes failure of the cardiac pacemaker and ICD. Most radiotherapy departments are using the radiation dose constraints for implanted devices based on the sparse number of the case reports and in vitro studies which occasionally demonstrate different results [
1-
3]. The American Association of Physicists in Medicine (AAPM) defined the guidelines for the irradiation exposure of the cardiac pacemakers in 1994 [
4]. These guidelines are based on the first generation of Complementary-Metal-Oxide-Semiconductor (CMOS) pacemakers and do not take into account the newer radiation treatment technology. More recently, the Dutch guideline based on the newer data of in vitro experiments and several clinical studies was written [
5]. These guidelines cover the recommendations for the irradiation of ICDs and consider the modern radiotherapy techniques such as intensity modulated radiation therapy (IMRT) or arc technique. Some investigators demonstrated a predisposition of batteries in modern cardiac pacemakers to quicker or even sudden unloading by an accumulated dose over 5Gy [
3,
6,
7]
. Radiation exposure of more than 2Gy is rarely found when the location of the heart pacemaker is outside the radiation field [
8,
9]. According to the data of Mouton et al. the failure of actually used CMOS pacemaker seems to appear at lower doses, also < 2Gy, but in a high dose rate [
10]
. Last et al. and Wilm et al. recommended to keep the cumulative exposure dose on heart pacemaker if possible <2Gy and by all means <10Gy, with the lowest possible dose rate [
11,
12]. ICDs are more sensitive to radiation than pacemakers because of scattered radiation effect on the random access memory (RAM) [
13]. Manufacturers often provide the recommendations on radiation tolerance of their produced devices. However the recommended maximal dose tolerance differs considerably depending on the technical design of machines. For example, St.-Jude Medical GmbH® recommends the radiation dose limit for pacemaker by 20-30Gy and for ICD the dose tolerance was not stated [
7,
14]. The recommended dose limit for ICDs produced from Medtronic is variable from 1Gy to 5Gy depending on the model of ICD [
7,
15]. These recommendations do not take into consideration the recently used technical aspects and physical property of radiation treatment. In the literature we did not find any relevant information about radiation dose constraints or radiation resistance for the case of CPS device. We report here a possibility of the thoracic radiotherapy for central bronchial carcinoma patient with implanted cardiac pacemaker, ICD and assist device
. . This case of radiation therapy is considered to be complicated because the active ICD is partially located in the radiation field.