Nuclear Stress Testing: Is The Radiation Worth It?
Gaetano N. Pastore, M.D., F.A.C.C.
50% of patients who suffer a heart attack never make it to the hospital!
Nuclear stress testing (SPECT imaging) has been the gold standard for the non-invasive evaluation of patients with symptoms that suggest the presence of coronary artery disease. SPECT imaging has been in existence for decades and has proven itself to be highly sensitive and specific for the detection of significant coronary artery disease. Moreover, SPECT imaging has proven to be life saving in many cases by detecting severe coronary artery disease before a major heart attack or sudden death. In order to image the heart and its blood supply the patient receives an intravenous radioactive isotope such as Technetium 99 so that a special gamma camera can visualize the heart and its blood supply. The test also provides vital information about the heart’s wall motion and ejection fraction which is an expression of the heart’s strength as it pumps blood to the body. This information is invaluable to the physician as it provides a comprehensive evaluation of the heart in a single test!
Humans are exposed to many types of radiation on a daily basis from natural background radiation, irradiated foods, UV exposure, microwaves, cell phones and even your TV and computer screen! Medical imaging exposes patients to what is known as ionizing radiation, perhaps the most potent and potentially harmful form of radiation exposure. During SPECT imaging the patient is exposed to this radiation from the administered isotope. During the last decade the utilization of medical imaging has expanded, as new technologies have emerged designed to aid in the diagnosis of various medical conditions. The most common of these diagnostic tests include x-ray, CAT scan and nuclear SPECT imaging. Given this expansion of medical imaging there has been heightened concern about the sometimes significant radiation exposure to patients undergoing some of these specialized diagnostic tests.
The primary concern regarding this exposure is the risk of developing cancer. In fact, ionizing radiation is a proven cancer-causing agent. The primary evidence for this comes from studies from atomic bomb survivors in Japan and from those exposed to high doses of radiation from the Chernobyl nuclear accident. In most cases these exposures were significant, much higher than the radiation exposure of any one patient undergoing a diagnostic test. Therefore, it is not clear what effect these medical tests have on patients and their subsequent risk of cancer. It is important to understand that it has never been proven that nuclear SPECT imaging has ever caused cancer. However, nuclear SPECT imaging and CT scanning do have some of the highest radiation exposure levels compared to other diagnostic imaging modalities and therefore it is imperative that these tests should be reserved for those patients who would benefit the most.
Thanks to the latest technology, the amount of radiation exposure to patients during their stress test continues decrease. Newer isotopes with higher energy but less radiation exposure are now used almost exclusively. More sophisticated CT/PET scans are now available that expose patients to a fraction of the radiation. Newer scanning protocols are also utilized today that further reduce patient exposure.
The American College of Cardiology (ACC) is a worldwide medical society dedicated to enhancing the lives of cardiovascular patients through continuous improvement in quality, patient-centered care and professionalism. The ACC has channeled much of its efforts in the last several years to insure the safety and continued quality of SPECT cardiac imaging. Worldwide experts in the field of cardiology have devised specific recommendations for appropriate stress testing. These recommendations are designed to assist the physician’s decision as to which patients should appropriately receive stress testing. In doing so, patients can be assured that they are receiving the appropriate test for the appropriate reason at the appropriate time. As a general rule, the benefit of the information obtained from a nuclear stress test, when done appropriately, far exceeds the danger from radiation exposure!
In conclusion, nuclear stress testing remains a safe, highly effective modality for the diagnosis of coronary artery disease and impending heart attack. It is the goal of your physician to keep your lifetime exposure to radiation to a minimum. It is also important to remember that medical testing, including nuclear stress testing, can provide valuable and sometimes life-saving information; therefore, the risks of exposure should be weighed against the benefits of performing the test.
Dr. Gaetano Pastore has been a member of Cardiology Physicians since July of 1998. He attended Villanova University graduating with honors. He then went to the Milton S. Hershey Medical Center of the Pennsylvania State University for his medical degree. He completed his Internal Medicine Residency at Hahnemann University Hospital and his cardiovascular fellowship at the Hahnemann University Heart Hospital in Philadelphia. Dr. Pastore has contributed as a co-author on papers that have appeared in the New England Journal of Medicine and has presented at the annual scientific sessions of the American College of Cardiology.
The Christiana Care Family Practice Residency Program has recognized Dr. Pastore as an outstanding teacher/preceptor. He is an active staff member in the Christiana Hospital System as well as St Francis Hospital. He is a fellow of the American College of Cardiology and served as the Governor of the American College of Cardiology for the state of Delaware. He is currently serving his fourth consecutive year as president of Cardiology Physicians, P.A. He remains an active ACC member serving on national physician and patient advocacy committees, with a strong focus on patient advocacy and quality care improvement.
Dr. Pastore has a strong commitment to clinical and consultative cardiology with a special interest in echocardiography. This includes transthoracic, transesophageal, and stress echocardiography. He has expertise in the interpretation of nuclear imaging in cardiovascular medicine.
Dr. Pastore resides in Avondale, Pennsylvania with his wife Linda and three children Mia, Luke and Gianna. He enjoys spending his spare time with his family, generally on vacation in warm climates. Dr. Pastore enjoys tending to his 183 gallon saltwater coral reef tank and is an avid fan and owner of thoroughbred race horses.