[The reaction of the heart to radiation. II. Clinical studies].

In a review the cardiac attendant reactions in tumor irradiation in thoracal area are represented by means of papers and experiences of our own. It is shown that the heart reacts differently on ionizing rays and in special cases it can become a critical organ for radiotherapy. The diagnostic practice and the phenomenon of pericardiac and myocardiac reactions are described in detail. Complications on coronary vessel system are not frequent but because of their clinical consequence always they have to take into consideration. Cardiac radioreactions can be transient or harmless but rarely can lead to vitally threatening situations. Therefore it is referred to symptoms, diagnostic proving and possible or necessary therapeutic measures. Because significant curative therapeutic results can be attained by radiotherapy in thoracal area and the chances for curing increase for many patients, a slight risk is justifiable for side-effects on healthy adjoining tissue. On the other hand undesirable side reactions can influence the life-quality of the tumor cured patients. Therefore a radiotherapy in intrathoracal tumors with the aim of healing without complications has to take into consideration the sensibility of heart in addition to those of lung and spinal marrow. Beside permanent development of physical-technical suppositions these biological aspects have a substantial influence on optimizing irradiation in thoracal area. Finally it is tried to formulate really existing possibilities reducing a risk for cardiac side-effects and to refer to prospective interesting problems.