By Akira Matsumura
From 1992, I participated in clinical research on neutron capture therapy (BNCT) under Professor Hatanaka of Teikyo University at the JRR-2 reactor in Tokai-village, Japan Atomic Energy Research Institute (JAERI). When BNCT was performed, a boron drug was administered to the patient at midnight the day before at a hospital in Saitama Prefecture hospital, and at dawn we drove an ambulance and one-box cars headed for Tokai-village (approximately 3 hours one way), where the patient was craniotomized under general anesthesia in a room with almost no medical facilities. A gold wire to measure the neutron dose was punctured on the surface and depth of the brain and pulled out halfway through to determine the irradiation time. The irradiation took about 6-8 hours, after which the head was closed, the anesthesia was awakened and the patient was transported to a hospital in Saitama, an extremely hard schedule.
In such a hard environment, Dr Hatanaka suffered a cerebral hemorrhage in 1992 and came to Tokai-village again after undergoing rehabilitation for a while, but later suffered another hemorrhage in 1994 and passed away.
At that time, BNCT was not taken seriously at academic conferences, and when I submitted an abstract for a presentation at a certain conference, which was rarely rejected, I was not selected, which made me realize the position of BNCT. Moreover, in BNCT research at that time, reactors went into frequent and long-term maintenance, cases were not easily collected, and randomized clinical studies were difficult to conduct and it was difficult to show evidence.
In 1999, the modification of the JRR-4 reactor was completed and a clinical study on malignant gliomas was initiated. Patients were admitted to Naka Chuo Hospital near Tokai-village, administered a boron drug in the middle of the night, transported to JAERI by hospital car (about 20min.), then general anesthesia in JRR-4, craniotomy, irradiation for about one hour (much shorter than in JRR-2 reactor), awakened after completion, and then transported by Ibaraki Prefecture disaster prevention helicopter through Tokai-village emergency team to Tsukuba University Hospital. With the help of various people, we were able to start clinical research at JRR-4, but then it was discovered that the fuel rods in JRR-4 were damaged and it took several years to repair them, and finally the reactor was decommissioned, as it could no longer be used after the Great East Japan Earthquake.
Meanwhile, around the same time, talk of an accelerator neutron source emerged, instead of a nuclear reactor, and a project was initiated with NEDO research funding (2005-2007), mainly by accelerator researchers and involving the private sector. However, the principle of the accelerator was completely different from that of ordinary accelerators, and the project was terminated without producing a sufficient neutron dose. At the time, I remember feeling quite discouraged, thinking that this was the end of my BNCT research career.
When I was about to give up on the BNCT accelerator research, I got together with professors of the High Energy Accelerator Research Organization (KEK) at a small workshop held at the Tsukuba International Congress Centre, and from there the project to develop an accelerator for BNCT using part of the linear accelerator at J-PARC started. With the support of NEDO, the International Strategic Comprehensive Special Zone, the Ministry of Economy, Trade and Industry, AMED, Ibaraki Prefecture, Tsukuba University and others, this project started in 2011 and finally reached the stage of ‘physician-led clinical trials’ in 2023. It has taken 31 years since 1992, when we started BNCT research in a small way at the nuclear reactor, to finally reach this point.
Originally, I was a neurosurgeon who wanted to be able to perform good surgery and spent all my time in surgery, but my path suddenly changed and I became absorbed in BNCT, which uses very special neutrons. BNCT has given me many opportunities and connections.
I feel that BNCT has given me a twisting and turning path, but I have had a fortunate life so far. I sincerely hope that the time will come when BNCT will be of use to even more cancer patients in the future.
Cited from: Nagase Landauer, NL Dayori: Originally in Japanese and translated to English