Radiation reactions and injuries of normal tissues in contact neutron 252Cf therapy

The results of observation of radiation reactions in 76 patients with different malignant neoformations after contact neutron sup(252)Cf therapy are presented. The time of development, character and duration of the radiation reaction course depend upon the radiation dose, localization of the tumoral process and the preceding radiation treatment. The duration of the course of laminated epithelium in the intervals between doses 1500-1800 rad linearly depend upon the radiation dose. The regression equations have been calculated by the method of the least squares. The treatment of patients with relapsing tumours with the use of a complete canceroid dose has not been accompanied by serious radiation changes of normal tissues. The threshold and epilation and erythemic doses in neutrons are equal to 169+-9 and 465+-17 rad correspondingly. On the basis of available data on the indices of the threshold and erythemic doses the value of RBE of sup(252)Cf radiation has been evaluated