[en] In recurrent glioblastoma, the mean survival period is approx. 6 months by the routine methods of treatment, but is extended more than 3-fold by neutron capture therapy. This method and a routine method with ₆₀Co or an accelerator were used for comparison in the clinical treatment of 26 patients with supratentorial malignant glioma. There were no significant differences as for prognostic factors of the group treated by this method and those of the control group; No. of cases 14 and 12, the mean age 46 and 53.5 yr, and the stage (TNM) 3.14 and 2.83, respectively. As of the end of Feb. 1980, this method showed a lifeprolonging effect 3 times that of the control, the mean survival period being 67 weeks for this method and 21 for the control. Although 100% improvement was observed in about one half of the cases by this method, the control group showed improvement of only 80% at maximum. It is also possible to treat any deep portion of the brain with thermal neutrons. As a Boron compound, mercaptoundecahydrododecarborate with a low toxicity has been put into practical use for brain tumors, and as Li, the use of ₆LiCl for lung cancer is under examination. (Chiba, N.)