Abstract: A device senses the presence of the distal end of a source wire in a reference position within a guidance channel of an afterloading apparatus for positioning an energy emitting source at a desired position within an animal body for radiation therapy treatment. The source wire is driven from the reference position through a guidance channel and a catheter tube. A sensing device detects the presence of the distal end of the wire. The sensing device has a pivotal lever element mounted near the guidance channel. The lever element is in a first position, when the distal end of the source wire is not present in its reference position and the lever element is in a second position, when the distal end is present in its reference position. The presence of the distal end and the energy emitting source can be sensed at several important operational positions.

Abstract: The invention relates to a device for sensing the presence of the distal end of a source wire in a reference position within a guidance channel of an afterloading apparatus, said afterloading apparatus being used for positioning an energy emitting source fixed to said distal end of said source wire at a desired position within an animal body for radiation therapy treatment purposes, by driving said source wire from said reference position towards said desired position through said guidance channel and a catheter tube, which catheter tube is connected with one tube end to the afterloading apparatus and implanted with its other tube end in said animal body.