Extracorporeal treatment apparatus

An extracorporeal treatment apparatus comprising an electroacoustic transducer for producing focused sound waves for treatment of a patient, a patient support and means for moving the support for positioning a patient with respect to the transducer, the transducer having a focus and means for pivoting the transducer about its focus with respect to the patient support, an external X-ray location device comprising an X-ray source, an X-ray image-receiving device and a support frame connecting them, said location device having means for supporting the location device independently of the transducer, means for releasably coupling the X-ray location device to the transducer such that the X-ray location device follows pivoting movements of the transducer, an actual spot film marker (M) positioned between the x-ray source and the x-ray image-receiving device, and an electronic spot film marker generator which generates an electronic spot film marker (E), wherein the X-ray image-receiving device has an electronic image-reproducing device for representing the electronic spot film marker (E), and means for tracking the electronic spot film marker (E) on the actual spot film marker (M).