Graphical output from the Respisens system of a typical sequence of prone deep inspiration breath holds (DIBH). The horizontal axis defines time (t), the vertical axis amplitude (A). The upper part (a) demonstrates a typical breathing curve during treatment. kV-kV imaging (Im) was used to correct translational errors of DIBH (between Im-T1). Afterwards different DIBH-maneuvers (T1-T5) were performed for irradiation, note the gap between T3 and T4 to rotate the gantry. The SB-range was defined to calculate the SB-amplitude. The lower part (b) shows the details of a DIBH-maneuver with two preparatory breaths followed by deep inspiration and breath hold during approximately 15 seconds. A systematic peak is visible at the beginning (B) as well as a smaller peak at the end (after E). The following parameters, A till E, are assessed to gain data on prone DIBH amplitude, instability and time.