[Biomedical use and dosimetry of pions of the sin 590 MeV isochrone cyclotrone. VII. Radiation therapy using negative pions (author's transl)].

The scheme of radiation of Schumacher for high energy electrons is investigated. In it 3 high individual doses are given at first. In the second phase which follows immediately, weekly single doses of 500 rad are given until the tumor is completely destroyed. Reoxygenation and transformation of anoxic cells are important here for the number of surviving tumor cells but unfortunately still rather unknown. This uncertainty can be removed with the Pion therapy in which transformation does not take a large part. About 10 single doses of negative pions of 150-200 rad should be clearly superior to 5000 rad electron doses (D1 = 500 rad) and should not exceed the limits of tolerance with a weekly treatment. Finally the importance of contamination with electrons of the pionrays is examined. Exact measurement of this contamination is necessary.