Fast neutron therapy for malignant gliomas--results from NIRS study. National Institute of Radiological Sciences.

The results of combined radiotherapy with fast neutrons and photons for 39 malignant gliomas were analyzed. The patients consisted of 16 astrocytoma grade 3 and 23 glioblastoma multiforme. There were two kinds of combination methods which were either "boost therapy" or "mixed beam therapy" with a localized fast neutron field. The average dose of fast neutrons was 569 cGy (n, gamma) and that of photons was 36.86 Gy. The median survival of astrocytoma grade 3 was 15.5 months, and that of glioblastoma multiforme was also 15.5 months. With respect to the combination methods, there was no difference between the boost regimen and the mixed beam regimen. This result seems to have no impact on survival compared to other reports. Patients' ages, surgical debulking procedures, and photon doses were listed as significant prognostic factors, but doses of fast neutrons had no prognostic significance for survival. Because there were no moderate or severe complications for the brain except permanent epilation in all cases, neutron dose escalation study with a localized field will be recommended.