| abstract |
A catheter assembly for use in radiation therapy of a patient by insertion into a vessel, passageway or cavity to deliver radioactive material to a treatment site within the patient. The distal end of the catheter assembly ( 10 ) includes a noncompliant inner balloon ( 18 ) therearound that is inflatable with a non-radioactive fluid (such as CO 2 or saline or contrast medium), and an outer balloon ( 16 ) therearound that is inflated with radioactive fluid (such as radiogas like xenon-133 ) and is noncompliant to conform the vessel wall to the balloon's shape at the treatment site for optimal distribution of dose. The inner balloon allows reduction in volume of the amount of radioactive fluid necessary to achieve a desired dose. The inner and outer balloons ( 112,108 ) may be affixed to inner and outer catheters ( 104,102 ), respectively. Further, a booster radioactive source, preferably removable from the catheter, may also be used to supplement the dose from the outer balloon, such as a radioactive line source (a wire or a seed train ( 118,234 )) within the central catheter lumen ( 116,230 ) at the distal end, or a plurality of seeds ( 320 ) within flexible cylinders ( 318 ) spaced circumferentially around the inner balloon ( 308 ) but within the outer balloon ( 310 ), or a sleeve ( 402 ) around the inner balloon ( 406 ) that may be impregnated with iodine-125. A method of providing radiation therapy is disclosed. |