A treatment device (100) and a treatment system are provided. The treatment device (100) is suitable for temporarily or permanently placing a therapeutic device (112) in a part of a corpus of a living being. The treatment device (100) comprises an elongated body (102) for being inserted in the part of the corpus. The elongated body (102) comprises a channel (110) and an impedance sensor element (104). The channel (110) is for guiding the therapeutic device (112) to a specific position (PI) within the channel (110) and/or for holding the therapeutic device (112) at a specific position (PI) within the channel (110). The impedance sensor element (1040) is configured to be coupled to a detection device for detecting the presence of the therapeutic device (112) at the specific position (PI) on basis of a change of a signal provided by the impedance sensor element (104).