REAL-TIME DOSIMETRY FOR BORON NEUTRON-CAPTURE THERAPY

Epithermal/thermal boron neutron-capture therapy (BNCT) is a promising treatment method for malignant tumors. Because the doses and dose rat es for medical therapeutic radiation are very close to the normal tiss ue tolerance, small errors in radiation delivery can result in harmful overdoses. A substantial need exists for a device that will monitor, in real time, the radiation dose being delivered to a patient. Pacific Northwest Laboratory (PNL) has developed a scintillating glass optica l fiber that is sensitive to thermal neutrons. The small size of the f ibers offers the possibility of in vivo dose monitoring at several poi nts within the radiation field. The count rate of such detectors may a pproach 10 MHz because the lifetime of the cerium activator is fast. F luxes typical of those in BNCT (i.e., 10(9) n/cm(2)/sec) may be measur ed with a single fiber because of this potentially high count rate and the small diameter of the fiber.