Failure of accelerated neutron therapy to control high grade astrocytomas

Sixty-two patients with high grade malignant astrocytoma were treated with fast neutrons using three different treatment schemes to evaluate the effect of shortening the overall time. Dose and fraction number were kept constant. The total dose was 16-18 neutron Gy delivered in six fractions, weekly for 6 weeks, twice a week over 3-4 weeks, or three times a week over 2 weeks. There were no obvious differences in survival times among the three groups. We conclude that accelerated neutron therapy does not improve survival of patients with grade 3 and 4 astrocytoma.