a minimally invasive intervention for therapy of a tumor it comprises an x ray device 18 with a c arm 20 arranged on a floor mounted articulated arm robot 19 with six degrees of freedom on which a radiation source 21 and a detector are provided opposite one another the x ray device 18 further comprises a patient support table 23 with a patient support plate 24 on which a patient 25 lies during the intervention furthermore a display device 50 with a number of monitors 26 is provided integrated into the x ray device 18 and only shown schematically is a position determination device 27 in this example an electromagnetic position determination device also integrated into the x ray device 18 is a treatment apparatus 28 i e an ablation apparatus and or embolisation apparatus for example which in the present example includes an articulated arm robot 29 arranged on the patient support plate 24 with six degrees of freedom as well as the medical instrument 30 arranged thereon naturally especially in the case in which the medical instrument 30 is a catheter other embodiments are also conceivable also provided at the side of the patient support plate 24 are operating consoles 31 and 32 for the x ray device 18 and the treatment apparatus 28 close to the patient all components of the inventive apparatus are controlled via a control device 33 likewise shown only schematically which is also embodied to carry out the inventive method as has been described for example in relation to fig1 fig3 finally shows in the form of a schematic diagram a system overview of important components of the inventive apparatus the figure again shows the patient 25 on the patient support plate 24.