So let's say this human being has a lung tumor, which is the green spot in the illustration. The normal treatment would be to go after this tumor with fast neutrons down a variety of channels. On a specific day, you might come in from one direction and hit the tumor. A few days later, you might come in another way and hit the same tumor using another pathway.Now, fast neutrons are quite deadly to tissue. But in each of these neutron irradiation sessions, you're attacking the tumor and you're killing it. You are controlling it. However, you're also doing some damage to normal tissue as neutron irradiation proceeds, but this collateral damage is being spread around so it's not going to be irreversible in any sense. Nonetheless, there's a limit to how many times you can apply fast neutrons. That limit, in the case of a lung cancer, is often determined by the proximity of the tumor to the spinal column and the unavoidable collateral damage that could be done to the spinal column by these fast neutron beams when they are applied.
Professor George Laramore at the University of Washington Cancer Center thought a lot about this fast neutron radiation process and also coupled it with the boron-10 neutron capture idea. Because he is a Ph.D. physicist as well as a physician, he modeled fast neutron therapy and found that during this process about 5 to 10 percent of the fast neutrons employed have been slowed down sufficiently by the time they reach the tumor to be captured by a boron-10 nucleus. In the new procedure, before we begin the normal fast neutron treatment, we load the tumor with boron-10. We go ahead and give normal fast neutron treatments, but the slow neutrons that are produced at the tumor and normally thrown away can be captured by the waiting boron-10. That capture process gives us a 10 to 20 percent boost in total radiation dose at the tumor.
The enhanced radiation dose which arises from the BNC boost should markedly improve tumor control due to the shape of the tumor control versus radiation dose curve. This is an exciting prospect.