Slow neutrons pass through the human body with very little damage, so a fairly strong dose of them can be safely applied to the head. Many of them will be absorbed by the boron-10, and maximum destruction of the cancer will occur, along with minimum hazard to the patient. This treatment is accomplished by placing the head of the patient in a beam of slow neutrons emerging from a nuclear reactor a few minutes after the boron-10 compound has been injected into a vein.
SEQUENCE OF EVENTS IN NEUTRON CAPTURE THERAPY USING BORON-10
Neutron capture treatment of a brain tumor, using the Brookhaven National Laboratory research reactor (center).
(1) A lead shutter shields the patient from reactor neutrons.
(2) A compound containing the stable element boron is injected into the bloodstream; the tumor absorbs most of the boron.
(3) After 8 minutes, when the tumor is saturated, the shutter is removed and neutrons bombard the brain, splitting boron atoms so that fragments destroy tumor tissue.