Brachytherapy positioning system

A brachytherapy positioning apparatus and a method of positioning a radiation source within a passageway of a patient's body are disclosed. The apparatus is configured to position a radioactive source in the center of the passageway being treated so that all regions of the passageway wall receive the same dosage of radiation. The brachytherapy positioning apparatus may include an elongated member, a distal end cap, a reconfigurable positioning element, and a control member. The positioning element may be positioned between the distal end cap and the elongated member about a portion of the control member and may be selectively changed between a radially expanded state and a retracted state with the control member. In one embodiment, the positioning element includes a plurality of generally parallel wires that each expand and retract along a different radius originating from a centerline axis of the control member.