In subdiaphragmatic Hodgkin's disease the most common sites of involvement include the para-aortic region, in particular the celiac trunk, the splenic pedicle, and the spleen. In treatment planning, no imaging modalities (i.e. lymphography, CT, US) have so far been able to realize the need for direct imaging of any of these areas on a simulation film, necessary for individual beam shaping. With intravenous digital subtraction angiography (IV DSA) a new imaging method is available that allows direct imaging of these regions in a frontal view. The way and extent the splenic artery crosses the left kidney can exactly be delineated. By using a subtrascope (as common in angiography) the DSA can exactly be superimposed and documented on a simulation film. The DSA drawn onto the simulation film serves as a base for defining an individual target volume in the upper abdominal region (splenic pedicle etc.). The kidney can be shielded in a highly individualized way by individual beamshaping blocks. From December 1985 to December 1986, we treated 35 patients by using this technique for treatment planning. In 32 evaluable patients the imaging accuracy for all sites was judged as "excellent" in 74%, "reasonable" in 19%, and "poor" in 7%. The course of the splenic artery in relation to the left kidney revealed 78% within or above the upper third. By DSA assisted localization the target volume could be accurately defined in every case with shielding of the kidney as much as possible. Compared to nonindividualized standard definitions ("including L1" and "including upper third of the kidney") DSA assisted individual target volume definition was more precise: "including L1" overestimates in 63%, "including upper third" underestimates in 53%. Compared to the standard definition ("including L1") reduction of up to 25% kidney volume to be irradiated could be achieved in 63%. DSA could be performed on an outpatient basis. The median duration of DSA performance was 20 minutes; superimposing and drawing at the subtrascope took median 20 minutes. There were no severe side effects.