An apparatus and a system for performing thermotherapy on at least a portion of a tissue site is described. The apparatus and system comprise a heating probe comprising an emitting area. The heating probe is connectable to an energy source for heating the tissue by the emitting area. The apparatus and system comprise a sleeve. The heating probe is arrangable in the sleeve, and the sleeve is configured to be slid along the heating probe in a distal and/or proximal direction for positioning of the emitting area in said portion of tissue for controlling the thermotherapy.