Effect of small doses of 252Cf on the tumour regression in cervix uteri during combined radiotherapy.

The results of a randomized study on the regression rate of the cervix uteri tumour for a group of 56 patients, investigated during and after radiotherapy with 2 Gy dose of the 252Cf neutron component applied by means of intracavitary therapy at the beginning of the therapeutic cure are presented and compared with the conventional 226Ra therapy. It was found that the tumour regression curve after 252Cf irradiation is significantly steeper than the curve of the control group. The quantitative evaluation of the results regarding the time required for a 50% regression of the original tumour shows that a group of patients treated by 252Cf needs a 27 days' cure in comparison with 40 days' cure for patients treated only by gamma radiation. The regression rate of the irradiated tumours shows a difference of approximately 30% for the treatment using small doses of 252Cf.