It is easy to forget that a mere 120 years ago, physicians practiced medicine in much the same manner as physicians in ancient Rome. In the late 1800s, doctors had no antibiotics, possessed rudimentary surgical skills, and could only wonder about the marvels that lie inside a living human being.
In 1895, the world of medicine changed irrevocably with the discovery of x-rays by Willhelm Konrad Roentgen.
Following Roentgen’s invention, it took less than a year for scientists and physicians to begin setting up and using x-ray machines. For physicians, the opportunity to be able to peer inside the body of a living human being was nothing short of a minor miracle. Soon, x-ray machines were being used to diagnose fractured bones, to image swallowed foreign bodies, and to locate bullets inside the bodies of soldiers wounded in battle. X-rays were also being touted, without any scientific evidence, as a cure for almost any and every malady, from acne to ringworms to depression.1
Ionizing radiation—potentially lethal
Although the medical and lay community embraced x-rays early on, some scientists soon came to see the dark side of this new technology. Thomas Edison, the great American inventor, quickly recognized the importance and possible practical implications of x-rays and soon set up his own x-ray laboratory. In 1896, Edison’s “improved” x-ray machine, which he called a fluoroscope, was a hit at the National Electrical Exposition in New York City. Edison and his assistant, Clarence Dally, exposed themselves to x-rays multiple times each day as they showed off Edison’s new machine.
Unfortunately for Mr. Dally, exposure to x-rays from Edison’s fluoroscope proved disastrous. Just a few months after the exhibition, Dally began suffering from debilitating fatigue, body aches, and multiple burn-like lesions on his hands. These lesions turned out to be cancer that rapidly spread throughout his body. Dally lost both his arms to these malignant lesions, and finally died a painful death in 1904. Thomas Edison was said to be haunted for the rest of his life by Dally’s cancer and death, and adamantly refused to have anything more to do with x-rays for the rest of his life.2
While it was not known during Edison’s time, it is now clear that x-rays exert their dangerous effects on the human body via ionizing radiation. This type of electromagnetic radiation is known to physicists as “high-energy,” meaning that each x-ray particle is able to literally penetrate most solid substances, including the human body. In contrast, visible light, which is another form of radiation, is much less energetic, and is physically stopped by something as simple as paper or cloth. When ionizing radiation from x-rays enters the body, it transfers some of its energy to cells in the body as it passes through. This transfer of energy can cause complex, non-repairable damage to the cell and its genetic contents, which are coded by the cell’s DNA and chromosomes. If the damage is great enough, the cell will die. If the cell does not die, however, the subsequent genetic damage caused by the ionizing radiation can induce both benign and malignant (i.e., cancerous) tumors. The cellular and genetic damage caused by x-rays is cumulative throughout a person’s lifetime, with each dose of ionizing radiation causing more and more damage. It does not matter to your cells if an x-ray was given 20 years or 20 minutes ago—the cellular and genetic damage sustained will be the same.
In 1927, Hermann J. Muller demonstrated that x-rays can cause irreversible genetic damage, work that eventually won him a Nobel Prize. Yet despite such solid scientific evidence and the tragic deaths suffered by radiation pioneers such as Clarence Dally and Marie Curie (who died of leukemia), many physicians and scientists continued to tout the benefits of x-rays and other forms of radiation well into the 1950s. Radioactive radium was the rage for decades and was recommended and used by physicians to treat impotence, ulcers, arthritis, and high blood pressure. As late as 1952, Life magazine published articles describing the beneficial health effects of inhaling radioactive radon gas, which is now known to be a significant cause of lung cancer.
In the late 1950s, well after the devastation of Hiroshima and Nagasaki by atomic bombs had revealed the destructive power of radiation, a few brave voices in the medical and scientific world began to publicly speak about the dangers of x-rays and ionizing radiation. Among the loudest voices was Dr. Russell E. Morgan, the chairman of radiology at Johns Hopkins Medical School. In 1959 Dr. Morgan chaired a National Advisory Committee on the possible dangers of medical x-rays and ionizing radiation for the US government. In a 20-page report, the committee stated that “during the past several years, a number of scientific bodies, including the National Academy of Sciences of the United States (1956) and the United Nations Scientific Committee on the Effects of Atomic Radiation (1958), have reported extensively on the influence of ionizing radiation on biological systems. From these reports it is evident that serious health problems may be created by undue radiation exposure and that every practical means should be adopted to limit such exposure both to the individual and to the population at large.”3
X-rays linked to heart disease, cancer
No longer should there be any debate about whether ionizing radiation from x-rays can cause cancer. A multitude of sound scientific studies clearly shows that exposure to x-rays, especially early in life, can directly cause cancer, including cancers of the breast, thyroid, lung, brain, stomach, colon, bladder, ovary, salivary glands, skin, and central nervous system, as well as leukemia.4-7
Recently, the hypothesis that medical x-rays are a significant cause of the current cancer and heart disease epidemic in America was put forth by Dr. John W. Gofman in his book entitled Radiation from Medical Procedures in the Pathogenesis of Cancer and Ischemic Heart Disease.8 This exhaustively researched, 699-page book presents data, based on mortality rates among 130-250 million people—the entire population of the US from 1940 to 1990—to support the hypothesis that, in the author’s words, “over 50% of the death rate from cancer today, and over 60% of the death rate from ischemic heart disease today, are x-ray induced.”
While Dr. Gofman presents chapter after chapter of meticulous studies to prove his hypothesis in a book that should be read by all physicians, he is by no means against the use of x-rays for clearly defined medical studies. In fact, he states, “the finding that radiation from medical procedures is a major cause of both cancer and ischemic heart disease does not argue against the use of x-rays, CT scans, fluoroscopy, and radioisotopes in diagnostic and interventional radiology.” What Dr. Gofman does make clear is that physicians and others who use x-rays and other forms of ionizing radiation in their practices should, in the author’s words, “treat dosages of ionizing radiation at least as carefully as we treat dosages from potent medications.”
Head and Neck:
Sonograms: safe, effective alternative to x-rays
Many times in my medical practice, patients will come in with various complaints, from shoulder injuries to abdominal pain, and expect to get an x-ray. It seems that for many people, getting an x-ray at their physician’s office is just a part of a “normal” exam. Of course, if an x-ray is warranted, then I certainly do not hesitate to order one; however, we now have multiple technological alternatives to x-rays and harmful ionizing radiation, with sonograms being one of the most useful.
Most people know abut sonograms, or ultrasounds, from the fuzzy pictures of babies in their mothers’ wombs that are now routinely done in the obstetrician’s office to check for any gross fetal abnormalities and also to determine the sex of the child before birth. While the importance of sono-grams in obstetrics should not be minimized, modern ultrasound machines have the potential to safely and effectively help prevent many devastating diseases without exposing patients to any amount of ionizing radiation.
The early 1900s saw the proliferation of x-ray machines in doctors’ offices while another technology that would also have a great impact in medicine was being developed. Sonography, the use of sound waves to detect objects, was developed in 1915 to aid in the detection of submarines. While the military was quick to exploit this new technology, it took decades for medical researchers to realize that sound waves could detect images in the human body just as they could detect submarines prowling deep in the ocean depths.
Like sonar used in the military, the ultrasound machines of today use an ultrasonic sound wave (inaudible to the human ear) that travels at the speed of 1,500 meters/second. These sound waves are sent into the body via an ultrasound transducer, a device that functions as both a loudspeaker (to create the sound waves) and microphone (to record the sound waves). When the transducer is passed over a person’s body, harmless “waves” of sound are directed into the body; as the sound waves hit various body structures and organs, some of the waves bounce back and are captured by the transducer microphone. These recorded sounds are then instantly measured and analyzed by a computer and are turned into real-time pictures on a monitor. Through analysis of these pictures, doctors can tell how deep an organ or structure is in the body, its three-dimensional shape, how large it is, and whether it is hollow or solid. All this is done without any discomfort to the patient, and more important, without the use of ionizing radiation.
The use of sonograms continues to grow as technology has allowed doctors to use ultrasound technology to study almost any part of the body. Table 1 shows just a sampling of the parts of the body on which ultrasound can be used, and some common maladies that sonograms can detect.
Sonograms shown useful in preventing strokes
A cursory glance at Table 1 shows that sonograms can help detect and prevent many potentially deadly health conditions, including stroke. Cerebrovascular accidents, or strokes, occur when the blood flow to the brain is compromised in some way, such as by the rupture of a blood vessel in the brain or by blockage of blood vessels by cholesterol-derived plaque that has built up in the carotid arteries. No matter the cause, when a stroke occurs there is immediate brain damage, and if the damage is severe enough, death. Strokes strike approximately 700,000 Americans a year, and are the third leading cause of death (killing approximately 160,000 Americans each year) after heart disease and cancer.9 Strokes are the number-one cause of serious, long-term disability in the US and affect both men and women; although more men than women suffer strokes (57% vs. 43%), women are more likely then men to die from strokes.10 While strokes are often thought of as something that happens only to the elderly, nearly 30% of people who have a stroke are under 65 years of age, and each year approximately 120,000 women and 105,000 men under 45 years of age suffer strokes.11
With such grim statistics, it is disheartening to think that just a few short years ago, one of the only ways doctors had to detect strokes was to use a stethoscope to listen for evidence of plaque buildup in their patients’ carotid arteries, the same way that doctors examined patients for stroke risk 100 years ago. Through the use of specialized sonograms, however, doctors can now detect deleterious changes in carotid arteries and also in the arteries inside the brain itself, and thereby help prevent strokes.