Intravascular radiotherapy (IVR) is a form of radiation treatment (radiotherapy) in which radiation is delivered within a blood vessel (intravascularly). Currently, IVR is approved for use in arteries that have already had a stent implanted in them, but the stent has re-narrowed (in-stent restenosis). Restenosis occurs after about 20 percent of stent placements, and about 10 percent will require physicians to reopen the clogged stent. IVR may be recommended in this situation, usually in conjunction with angioplasty.

IVR is one of several forms of radiotherapy (the delivery of radiation to a small and specific area). Other types are often used to treat cancer in conjunction with other therapies.

Although IVR has been proven effective in treating in-stent restenosis, it has certain side effects, including an increased risk of a blood clot (thrombus) forming within the stented area. Thus, IVR is not recommended for patients who cannot take medications that inhibit the blood’s ability to clot (e.g., antiplatelet agents), which are routinely prescribed after IVR. Patients are encouraged to discuss the potential risks and benefits with their cardiologist.

Balloon angioplasty and stenting are both catheter-based procedures used in the treatment of coronary artery disease (CAD) and peripheral arterial disease (PAD). During angioplasty, a balloon is inflated, pushing the plaque that is blocking the artery against the artery wall. During stenting, a small, expandable wire mesh tube (stent) is expanded and permanently implanted in the artery, holding plaque against the artery wall like scaffolding.