Fast neutrons compared with megavoltage X-rays in the treatment of patients with supratentorial glioblastoma: A controlled pilot study

Abstract The radioresistance of glioblastoma presumably results from the presence of hypoxic cells. In an attempt to overcome this problem, fast neutrons were compared in a controlled pilot study with conventional megavoltage X-rays (photons). 63 patients entered the study between January, 1973 and July, 1976, 30 patients received neutron and 33 received X-ray therapy. The overall mean survival was 11.4 months for those who received photon and 10 months for those who received neutron therapy. Survival rates at 6 and 12 months were 72 % and 36 % respectively for photon treated patients, and 77 % and 30 % for those treated with neutrons. Although neutron therapy did not improve overall survival, examination of the histological material indicated a considerably greater antitumor effect after neutron therapy than after treatment with photons. In the neutron treated group, at post-mortem examination no tumor or only minimal tumor was found in 10 of 12 patients and in one of 4 patients where tissue was obtained from a second craniotomy. In some cases, there was evidence of diffuse damage to normal brain which was in keeping with a clinical syndrome of progressive dementia without localizing signs. Dose, time, and volume factors for neutron therapy to the brain and possible ways of improving results are discussed.