Boron Neutron Capture Therapy

Abstract

Boron neutron capture therapy in Japan was started by H. Hatanaka at HTR in 1968. Successively, four reactors (HTR, MuITR, KUR, and JRR-2) were authorized for medical use (Figure 1). He modified the method developed by W. Sweet. Furthermore, he decided to introduce BSH, which was discovered and tested by his coworker A. H. Solway in Boston, into the new trial as a boron compound. He placed BNCT as radio-surgery and combined surgical procedures and thermal neutron irradiations at the reactor. Hatanaka reported the outcome of the clinical trial in 1986 and showed significant improvement of the results, with long-term recurrence-free survivals in selected patients with malignant gliomas1. Many researchers not only in Japan but also in foreign countries were stimulated by his result and began to plan new basic and clinical trials. Following the standstill of MuITR in 1989, KUR and JRR-2 became new research facilities for BNCT in Japan. It was a fortunate timing for Dr. Oda and his group to start clinical trials at KUR. They modified the methods of Hatanaka and started BNCT using BSH in 1990. On the other hand Mishima started a study of a boron neutron capture therapy for melanoma in 1972 and developed BPA as a boron compound. BPA was introduced into treatment for brain tumor afterwards by Ueda in 1994. A new group led by Matsumura started clinical trials at JRR-2 in 1996 with BSH. We missed Dr. Hatanaka because of intracerebral hemorrhage and Dr. Nakagawa succeeded his group and has developed clinical trial using both KUR and JRR-2,2,3. Since 1968 to present, more than 200 patients with malignant intracranial tumors, especially malignant gliomas such as glioblastoma, anaplastic astrocytoma etc. were treated by BNCT in Japan (Table 1).