System for simultaneous monitoring of thermal and epithermal neutron flux during boron neutron capture therapy

The absorbed doses in the tumor and in the brain of a patient treated by boron neutron capture therapy are determined by the neutron fluence and the concentration of boron-10 in the tumor and in the blood. In the past the authors used a gold foil activation method to determine the neutron fluence. This method has the drawback that the exact neutron fluence can be determined only after the irradiation is over. They developed in 1977 a system for simultaneous monitorig of thermal neutron flux during irradiation of the patient. Although they reported this in 1978, further advances have been made. They also report briefly on the measurement of boron-10 concentration in tissues. The neutron intensity in the brain is influenced by many factors, such as the distance between the patient's heat and the irradiation port, the size of the irradiation field, and the depth of the tumor. They developed a small detector for simultaneous monitoring which can be implanted into the brain of the patient