a treatment method and apparatus for debilitating or killing helicobacter pylori or other microorganisms within the body of a patient is especially suited for treating stomach or duodenal ulcers . the present therapeutic method involves the use of ionizing radiation for eliminating pathogenic microorganisms within or supported upon the lining of a body cavity of a patient , e . g ., the stomach . an elongated flexible shaft is provided for insertion into the body in any of various ways selected by the surgeon . it can be placed endoscopically , e . g ., through the esophagus , placed surgically , placed laparoscopically or by cat scan - guided percutaneous insertion . a radiant energy distribution head is provided at the end of the flexible shaft to transmit ionizing radiation for destroying microorganisms within the body . radiant energy , e . g ., x - ray , ultraviolet light , beta radiation , gamma radiation , radio waves , microwaves , or infrared energy , is then transferred from the head of the instrument to the epithelium around the head of the instrument in an amount sufficient to debilitate or kill the helicobacter pylori or other microorganisms in the lining of the body cavity .