Radiation catheters optimized for stepped delivery technique

The present invention relates to radiation delivery catheters having inflation balloons, and more particularly to radiation delivery catheters having a plurality of inflation balloons or other means independently inflatable for providing stepped radiation delivery and treatment. A radiation catheter for intraluminal treatment of a patient has a plurality of separably inflatable and deflatable balloon segments located along the length of the catheter, and a radiation source within a lumen of the catheter. As the radiation source is moved, one or more balloon segments closest to the source is inflated with the remainder deflated thereby allowing blood to perfuse in areas where inflation of the segments is not needed to effect centering of the source in the luminal structure.