[Comparison of neutron and photon irradiation of bronchial carcinoma]

Fast neutrons are only superior to photons if their relative biologic effectiveness (RBE) is higher within the tumor than in sound organs. It was therefore the object of this study to test the effects and side effects of rapid neutrons in an especially appropriate tumor model. The bronchial carcinoma was chosen because, according to radiobiologic experiences, the relative biologic effectiveness of neutrons is significantly higher in the Lewis bronchial carcinoma than in the normal lung. These experiences showed furthermore that, compared to other organs, the lung is relatively unsensitive to neutrons, so that the conditions for a treatment with this new type of radiation are favorable. Despite these favorable conditions, no local superiority of neutrons with respect to photons could be established by a clinical study including 115 cases. It shall be examined in a further study if a therapeutic advantage can be realized by a combination of neutrons and photons.