Journal Investigates Radiotherapy Treatment for Arterial Stenosis

The Journal of Endovascular Therapy has published an article exploring whether endovascular brachytherapy (EVBT) with liquid beta-emitting Rhenium-188 (Re-188) is an effective treatment for long-segment femoropopliteal in-stent stenosis.

EVBT is an internal radiotherapy method, and Re-188 is a radioactive metal usually used for the treatment of liver cancer.

Placement of an endovascular stent has become a common procedure to successfully reopen blocked arteries—narrowed arteries being the definition of stenosis. Even so, the treated vessel may once again narrow (restenosis), restricting blood flow. In the femoral (in the thigh) and popliteal (behind the knee) arteries in the leg, the use of nitinol stents magnifies this problem. About 20 to 40 percent of these stent patients experience restenosis two years after angioplasty. Now, an improved radiation technique may provide a safe and effective solution.

According to the article, implantation of the nitinol stent has improved angioplasty outcomes for occlusion of the femoropopliteal arteries, increasing the use of this minimally invasive alternative to surgery. However, stents also exhibit a high rate of in-stent stenosis—new narrowing within the stent due to the vessel’s exaggerated wound healing response. Endovascular brachytherapy is one option for treating this condition.

In some vessels, such as the coronary arteries, radiation localized to the treatment area has prevented recurrent restenosis. Unlike coronary stents, however, femoropopliteal stents have not shown improved response to radiation in the past; results were similar to those after performing angioplasty alone.

The authors of the article evaluated the effectiveness of EVBT using liquid beta-emitting rhenium-188 delivered in an angioplasty balloon, an improvement over earlier delivery methods: The balloon provides more accurate dose control than previous catheter techniques. In the clinical setting, the use of beta radiation also offers logistical advantages over the gamma radiation used in previous trials.

Ninety patients underwent angioplasty and endovascular brachytherapy for long-segment in-stent stenosis in the femoropopliteal segment. The treated stents were open in 95 percent of the cases at six months after brachytherapy and in 80 percent at one year. Only nine patients experienced in-stent stenosis and 10 had reocclusion of the treated segment of the artery. At 12 months, 62 percent of the patients showed clinical improvement.

In a commentary accompanying this clinical investigation, the Leipzig physicians who studied this EVBT technique were praised for resurrecting this promising procedure, which had been abandoned primarily because of logistical problems. The improved delivery mode shows new promise that endovascular brachytherapy may one day be a viable means of treating in-stent stenosis.