Device and method for controlling dose rate during intravascular radiotherapy

摘要

A method is disclosed for treating a blood vessel which has been subjected to interventional dilatation, to inhibit restenosis that would otherwise occur from cellular proliferation attributable to traumatic response at the site of the vessel interior wall where the dilatation was performed. The method includes introducing a radioactive source into the blood vessel so that the source is positioned adjacent to the site, and exposing targeted tissue of the vessel interior wall at the site to said radioactive source for a period of time sufficient to deliver a prescribed dose of radiation to the tissue. The rate at which the prescribed dose is delivered to the targeted tissue is adjusted to positively assure that the rate is held in a range with an upper limit of about 60 rads per second. Dose rate adjustment is controlled by selectively setting the distance between the source and the targeted tissue, or by appropriately selecting the length of the source according to the length of the site of targeted tissue along the vessel interior wall, and/or by appropriately attenuating the radiation emitted by the source to a desired reduced magnitude at the site of the targeted tissue, to positively assure that the dose rate delivered to the targeted tissue will not exceed 60 rads per second.