Deborah Cardiologists Begin Using Beta Radiation to Prevent In-Stent Restenosis
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Deborah Cardiologists Begin Using Beta Radiation to Prevent In-Stent RestenosisDeborah Heart and Lung Center recently became one of two hospitals in New Jersey, and the only hospital in South Jersey, to offer patients Vascular Brachytherapy, a new catheterization treatment in which cardiologists deliver low-level beta radiation inside a previously stented artery to prevent blockages from overgrowth of cell tissue. The new procedure helps prevent the need for additional procedures, such as repeat angioplasty or bypass surgery. More than 25 million people worldwide have been diagnosed with coronary artery disease, the leading cause of death in the United States. Each year, 800,000 people in the U.S. alone undergo coronary angioplasty to open narrowed and/or blocked arteries. More than 80 percent of these patients will receive stents, stainless-steel mesh tubes, which are placed in the narrowed arteries and act as “scaffolding” to keep the artery open. However, within six to nine months, approximately 25 percent of these patients will experience restenosis, or in-stent restenosis, due to scar tissue build-up.“In-stent restenosis poses a very difficult challenge to cardiologists because the probability of a recurrent restenosis in previously stented patients is in the 40 to 80 percent range,” said Charles DeBerardinis, DO, Assistant Director of Deborah’s Adult Cardiac Catheterization Laboratory. “Until now, there were no therapies available to effectively treat in-stent restenosis other than repeat angioplasty or bypass surgery, which is an expensive and highly-invasive procedure that requires a long recuperation period.” At Deborah, Vascular Brachytherapy is performed using the Beta-Cath™ Delivery System, a hydraulic pressure system, about the size and shape of a shampoo bottle, which temporarily drives seeds of radioactive strontium-90 through a closed-end catheter into the patient’s heart following repeat angioplasty. The treatment adds only about ten minutes to the angioplasty procedure, patients feel no sensation as a result of the radiation, and there is no additional hospital stay beyond the typical stay associated with angioplasty. |
The Beta-Cath System, developed by Novoste™ Corp., works by delivering low-dose beta radiation locally to the treated area to inhibit the overgrowth of normal tissue as the healing process occurs following angioplasty for in-stent restenosis. This strand of strontium-90 seeds, typically called a source train, at no point comes in contact with the patient’s tissue or blood and poses no additional risks to patients or staff. “The principle is the same as treating cancer cells,” explained Dr. DeBerardinis. “However, during a Brachytherapy procedure, we use a low dose of localized radiation to inhibit the cells from replicating. Therefore, the only place being treated with radiation is in the vessel wall, so the risk to the surrounding tissue is negligible.” A clinical feasibility study using the Beta-Cath System showed a greater than 50 percent improvement in restenosis rates when compared to a control group that did not receive Vascular Brachytherapy. “Radiation oncologists have known for many years that radiation in small doses can prevent cancer cells from proliferating,” said Edward Soffen, MD, Deborah’s Radiation Oncologist. “We also know that radiation can inhibit non-cancerous cells, like scar tissue, from reproducing. Through clinical trials, it has been proven, rather significantly and dramatically, that radiation at the time of repeat angioplasty considerably lowers the risk of in-stent restenosis.” The National Regulatory Commission (NRC), the federal agency that guides all radioactive material, requires that in addition to the cardiologist, a radiation oncologist and a physicist be present for all Vascular Brachytherapy procedures. The radiation oncologist is responsible for assisting the cardiologist in determining a patient’s eligibility for the procedure, as well as actually deploying the source train to the affected site. The physicist is responsible for calculating, to the exact second, the amount of time the source train must dwell in the vessel.The dwell time, which varies from about two to five minutes, is determined by establishing the diameter of the affected vessel and then, using a precise formula, calculating the dwell time to within a tenth of a second. The physicist is also responsible for ensuring all NRC safety precautions. |
“Radioisotope usage is carefully monitored by the radiation physicist, the radiation safety officer, as well as Deborah’s Department of Nuclear Medicine,” said Elizabeth Paczolt, MD, Co-Director of Deborah’s Nuclear Medicine Department and the Center’s Radiation Safety Officer. “The radioisotope is carefully housed in the delivery system, which protects both the patient and employees from any unnecessary exposure.”
While the FDA approved the use of Vascular Brachytherapy for in-stent restenosis in November 2000, there are ongoing trials in centers across the country exploring the effectiveness of Vascular Brachytherapy in other areas, such as first-time lesions and non-stent restenosis. According to Dr. DeBerardinis, Deborah Heart and Lung Center will be one of several centers investigating alternative applications for Vascular Brachytherapy in the coming months. “We are very excited by this new technology, which is proven to lower the in-stent restenosis rate to less than 20 percent,” said Dr. DeBerardinis, who had performed 11 Vascular Brachytherapy procedures in Deborah’s Adult Cardiac Catheterization Laboratory at the time of this writing. “Restenosis remains the limiting factor in angioplasty, and Vascular Brachytherapy offers a potential benefit in reducing restenosis to a more clinically acceptable rate.” Dr. DeBerardinis continued, “As clinical studies evolve, we hope to be able to offer this therapy to a wider variety of angioplasty patients.” Charles DeBerardinis, DO., Assistant Director, Adult Cardiac Catheterization Laboratories |
