Pion radiotherapy: studies with nuclear emulsions.

Nuclear emulsions were used to provide information on (1) the pion star distribution for a therapy beam; (2) star production as a function of pion energy and residual range in nuclear emulsion; (3) the distribution of nuclear framgent ranges in emulsion; and (4) the neutron energy spectrum and fluence produced by negative pion capture in tissue, during treatment of a patient. This last item is important for determining the whole-body dose delivered to a patient undergoing pion radiotherapy.