Tis invention is new apparatuses and methods for treatments to be used from inside conduits or biological pathways. Examples of the biological pathways in which these new apparatuses and methods may be used include arteries, veins, and respiratory ways. Multi-purpose catheters (10) and catheter systems using structures including wires (2108), balloons (2150), and cords (2204) are described as well as methods to use such catheters and catheter systems. One of the embodiments is a configurable wire system which carries or transports radioactive sources. The wire is used in conjunction with a closed-end channel catheter.