BNCT, or Boron neutron capture therapy is a radiation therapy of tumors, which profits from the  property of the nonradioactive isotop Boron-10 to capture thermal neutrons to a high degree.

From that capture reaction emerge two charged nuclei, one helium and one lithium nucleus. These two emit their energy to the surrounding tissue in a short distance, in the dimension of a cell diameter and kill that way the cell. The aim of the BNCT is to generate this reaction as much as possible solely in the tumor cells.

Radiation therapy is a highly effective tool to treat cancer. But still there will be radiated healthy tissue, even with the actual most accurate method. The radiation passes healthy tissue on its way to the tumor and diagnostic techniques locate the tumor only with a certain accuracy.

The attending doctor finally has to determine the target volume to be irradiated, based on his experience, established routines and the applied diagnostic procedure. The so determined target volume is consequently different from one to another attending doctor. Even if the same doctor determines the target volume in different time intervals differences appear because even the best imaging method only shows a snap shot or a short period of time. At the next day the situation may be different.

The extent of these influencing factors is different from method to method. However these uncertainties seem characteristic in the actual radiation therapy, although new methods are reducing these, like the MRT guided radiation therapy or the proton therapy. But they are currently not able to eliminate them. That is why we have to assume, that substantial improvements will be achieved not until complete new developments in the radiation therapy to determine and mark the target volume to be irradiated at a biological level. Thereby will be treated only the marked, diseased cells, whereever they are located and healthy tissue will not be damaged , even in the immediate vicinity.

The BNCT has the potential to be such a radiation therapy of the future. She combinates irradiation and an agent which brings the radiation into action. Then only the tumor cells will receive a destroying dose.