Combination ionizing radiation and radiosensitizer delivery devices and methods for inhibiting hyperplasia

Abstract

The present invention provides improved devices, methods, and kits for inhibiting restenosis and hyperplasia after intravascular intervention. In particular, the present invention provides controlled radiosensitizer delivery in combination with ionizing radiation to selected locations within a patient's vasculature to reduce and/or inhibit restenosis and hyperplasia rates with increased efficacy. In one embodiment, the combination radiation and radiosensitizer delivery catheter for inhibiting hyperplasia comprises a catheter body having a proximal end and distal end, an ionizing radiation source coupleable to the catheter body for applying a radiation dose to a body lumen, and means coupleable to the catheter body or the radiation source for releasing a radiosensitizer to the body lumen.

1 . A combined radiation and radiosensitizer delivery catheter for inhibiting hyperplasia, comprising: 
 a catheter body having a proximal end, a distal end, and an infusion lumen for releasing a radiosensitizer;    a pair of axially spaced apart balloons on the catheter body; and    an ionizing radiation source coupleable to the catheter body for applying a radiation dose between the axially spaced apart balloons.    
     
     
         2 . A delivery catheter as in  claim 1 , further comprising a source for releasing at least one radiosensitizer selected from the group consisting of taxol, misonidazole, metronidazole, etanidazole, 5-fluorouracil, texaphyrin, C225, and cyclooxygenase-2 inhibitor.  
     
     
         3 . A method for inhibiting hyperplasia in a body lumen, said method comprising: 
 releasing a radiosensitizer at a target region within the body lumen; and    directing ionizing radiation at the target region, wherein the radiosensitizer and radiation combine to inhibit hyperplasia.    
     
     
         4 . A method as in  claim 3 , further comprising inflating a balloon at the target region, where the radiosensitizer is released from the balloon.  
     
     
         5 . A method as in  claim 4 , wherein the balloon is inflated with the radiosensitizer and the radiosensitizer is released from an interior of the balloon through pores.  
     
     
         6 . A method as in  claim 4 , wherein the radiosensitizer is released from a surface of the balloon.  
     
     
         7 . A method as in  claim 6 , wherein the radiosensitizer is released through a rate controlling matrix.  
     
     
         8 . A method as in  claim 3 , further comprising isolating the target region, wherein the radiosensitizer is released into the isolated region.  
     
     
         9 . A method as in  claim 8 , wherein isolating comprises inflating a pair of axially spaced apart balloons.  
     
     
         10 . A method as in  claim 8 , wherein isolating comprises expanding a pair of axially spaced apart mechanical barriers.  
     
     
         11 . A method as in  claim 4 , wherein the directing comprises positioning an ionizing radiation source within the balloon.  
     
     
         12 . A method as in  claim 8 , wherein the directing comprises positioning an ionizing radiation source within the isolated target region.  
     
     
         13 . A method as in  claim 11  or  12 , wherein the ionizing radiation source is an x-ray tube and positioning comprises energizing the x-ray tube and translating the x-ray tube to traverse the target region.  
     
     
         14 . A method as in  claim 11  or  12 , wherein the ionizing radiation source is a radioisotope.  
     
     
         15 . A method as in  claim 11  or  12 , wherein the ionizing radiation source is a receptacle in the catheter body and positioning comprises introducing a radioisotope into the receptacle.  
     
     
         16 . A method as in  claim 3 , wherein the body lumen is a blood vessel and the target region is a region at risk of hyperplasia.  
     
     
         17 . A method as in  claim 3 , wherein the directing comprises applying a total radiation dose in a range from about 4 Gy to 24 Gy.  
     
     
         18 . A method as in  claim 3 , wherein the releasing a radiosensitizer and directing an ionizing radiation dose are carried out simultaneously.  
     
     
         19 . A method as in  claim 3 , wherein the releasing a radiosensitizer and directing an ionizing radiation dose are carried out sequentially.  
     
     
         20 . A kit comprising: 
 a catheter capable of applying a radiation dose and releasing a radiosensitizer in a body lumen; and    instructions to use the catheter according to  claim 3 .    
     
     
         21 . A kit as in  claim 20 , further comprising a source of radiosensitizer.