[Hard-x-ray therapy. The position between orthovolt- and ultra hard ray therapy (author's transl)].

The special position of "hard-ray therapy" (RT 305, 300 kV) between the orthovolt-therapy and the ultra-hard-ray therapy is described in physical respect and clinical practicability. In comparison with the orthovolt-therapy there is an advantage in better skin tolerance, the absence of bone shadows and the possibility to increase the depth-dose up to 50%. The main indications are given in the intermediate therapy and the short distance therapy of greater tumors. The palliative deep therapy is administered under better conditions as with the conventional x-ray irradiation.