CNERGY Breath Hold consists of a single full HD real time depth camera. The camera is installed at the ceiling of the treatment room. With sub-millimeter accuracy the distance is measured during deep inspiration breath hold to the breath hold monitoring point (isocenter). If the distance is within personalized threshold values the interlock is released and the treatment can be started. Breath hold monitoring can be used during the entire fraction with imaging and treatment beams. Visual feedback using graphs is used to monitor the patient position.