Abstract: This invention provides a method of increasing sensitivity of cells to the cyctotoxic effects of ionizing radiation which includes incubating the cells with a spindle poison in a suitable carrier at a concentration effective to inhibit the cells from progressing through G.sub.2 or M phases of the cell cycle for a time effective to inhibit division of the cells and then administering a cyctotoxic dose of ionizing radiation to the cells.

Abstract: A radiation therapy apparatus and method for applying radiation to a patient in synchronism with one of a plurality of states of a cardiac cycle of the patient and one of a plurality of states of a respiratory cycle of the patient. An electrocardiograph is operatively connected to the patient and a respiratory monitor is operatively connected to the patient. A controller is provided for receiving an output from said electrocardiograph indicative of which of said plurality of cardiac cycle states the cardiac cycle is presently in and for receiving an output from said respiratory monitor indicative of which of said plurality of respiratory cycle states said respiratory cycle is presently in. A radiation applicator applies radiation to the patient in response to a trigger signal from the controller, said trigger signal being generated by said controller in response to said output from said electrocardiograph and said output from said respiratory monitor.