Clinical results after therapy with fast neutrons (DT, 14 MeV) since 1976 in Hamburg-Eppendorf.

In Hamburg since 1976 to 1980 we have treated 328 patients with fast neutron (DT, 14 MeV) and after reconstruction of the generator further 69 patients in 1984. The therapy with DT-neutrons had the best curative effect on high differentiated tumors. With the standard dose of 16 Gy in four weeks or--treating tumors in radiosensitive organs like brain and intestine--with a photon-neutron schedule, we have seen no necroses in normal tissues. The rate of medium or slight subcutaneous fibroses is not more than 10%. The local effect on tumors in our pilot study has been better than with megavoltage therapy in invasive thyroid cancer, prostate cancer stage C, soft tissue sarcoma and also in rectum-carcinoma. The best results have been achieved with neutrons only, but a photon-neutron schedule may be more effective as megavoltage therapy only. With our DT-neutrons we find some indications for better results than with megavoltage therapy if we use sophisticated treatment planning and if we strictly observe the tolerance dose of the different tissues and organs. The therapeutic index of our monoenergetic DT-neutrons is higher than with cyclotron-produced neutrons.