Part 1. Some Seriously Unwarranted Early Optimism
Concerning Fluoroscopic Hazard
Preston Hickey, M.D., of Ann Arbor, was one of the illustrious radiologists of the early period. In 1922 he addressed the American Roentgen Ray Society. He made some points which, in retrospect, should scare us all --- especially with what came to pass.
In his published paper (Hickey 1923) we find the following: "A more liberal use of fluoroscopy in the removal of foreign bodies is also traceable to the army training. No longer is the hand or foot extensively mutilated in long-continued efforts to find a needle or a bullet. Operation under fluoroscopic control is now perfectly safe by the intermittent method, and results in easy removal, with a minimum of laceration of tissues." And:
"The extensive use of the fluoroscope in the manipulation and control of fractures is also a step in roentgenologic progress." And:
"Another outcome of the development of war activities has been the diminution in the size of machines. With the self-rectifying tube and the bed-side type of transformer, the internist is now able to do adequate fluoroscopy and still not encroach on valuable office space. In planning or installation of x-ray outfits in buildings where the price per square foot is high, this constitutes a very important item. Practically very little floor space is needed for the electric part of an x-ray outfit." And:
"It is interesting to note also the large number of internists who have placed fluoroscopes in their offices, not with the idea of specializing in x-ray work, but simply wishing to have conveniently at hand an x-ray control of their physical findings. Here again, the simplified apparatus which has developed from war-time practice is conspicuous."
It would be a gross understatement to say that Dr. Hickey was a bit optimistic about the virtues of these machines getting into the hands of those totally untrained to handle them appropriately. (See Chapter 31, where Leddy, Taft, and West make highly relevant comments many years later.)
Part 2. Ardent and Sincere Advocates for the Fluoroscope
Dr. Louis Faugeres Bishop must certainly be cited as the advocate of advocates for fluoroscopic investigation. And he undoubtedly had the expertise to know the benefits in experienced hands. He gave a talk at the Medical Society of the Greater City of New York in 1922 [published].
We single this paper out, not only for its advocacy of fluoroscopy, but because his focus is heavily on the use of the fluoroscope in diagnosis of diseases of the heart. There appeared to be a whirlwind of interest in all aspects of heart measurements, heart motions, and heart disease diagnosis via heart roentgenography and fluoroscopy in the 1920s and 1930s. Many children and young adults received appreciable doses in a variety of large scale studies of cardiac measurements by fluoroscopy.
Dr. Bishop is very critical that in the early years of this century, lots of attention was paid to dimensions of the heart, and x-ray measurements of the size of the heart, but very little attention was given to what he regarded as more important features of heart disease.
We quote Dr. Bishop at page 489:
"It was the custom at that time, if any of you remember, to speak of enlargement of the heart as a matter of importance from a point of view of treatment and to measure the benefits of treatment by supposed reduction in the size of the heart ... Curiously enough the fluoroscopic diagnosis of the activities of the different chambers of the heart and the probable auricular and valvular defects as well as the discovery of congenital lesions was passed over lightly. The idea that this method could compete with the ancient and honorable institution of auscultation and percussion [listening with a stethoscope and thumping on the chest] never entered the mind of even so skillful as worker as Franz Groedel." And:
"Nevertheless, unconsciously they gained a great deal of skill and I remember how often the younger Franz Groedel could independently conclude by sight what his father had determined by history, auscultation, and a general examination of the person. In fact, it is extremely easy to distinguish a mitral heart from an aortic heart and many other important points." And:
Every Doctor's Office Needs One --- a Fluoroscope, That Is
"Fluoroscopy, I venture to assert, will become a routine measure in every physician's office before very long."
We interject here, "Many women can be most thankful that this prediction did not materialize in quite the fashion that Dr. Bishop predicted."
We quote further from Dr. Bishop: "For several years I have examined with the fluoroscope every patient who has come to me. I have at the same time recorded the picture with a film. The fluoroscopic examination which allows me to observe the relative activity of the various chambers of the heart and the pulsations of the large vessels, has furnished me with a real impression of the condition." And:
"Although a series of x-ray plates furnish a permanent record, many people are excluded from the benefits of an x-ray examination entirely on account of the labor and expense involved, thus making it a rather formidable matter. As a result, physicians are deprived of the training which comes only from repeated examinations. In my opinion there is nothing that can take the place of fluoroscopy as a short cut in the diagnosis of cardiac disease ... (to his closing sentence of this paragraph)." And:
"I venture to say at this time, what I do not believe ten years from now any one will deny, that in the detection of minor impairments of the heart the fluoroscope is vastly superior to the stethoscope, and when it is supplemented by the electrocardiograph, at least 30 % of otherwise unknown conditions are added to the factors that must be considered." And:
"Medical students are now receiving an intensive training in the anatomy and physiology of the heart so that facts which are at present known to only a few will be a matter of course to the next generation of physicians. In the interim, it behooves our larger institutions to adopt fluoroscopy as a routine matter because it will reveal a large per cent of unsuspected impairments and will thus save an immense amount of labor in drawing inferences without sufficient data. It will also occasionally reveal a condition of of the abdomen or chest which calls for prompt operative intervention and as a result save life."
One must contemplate the radiation dose to the chest (and breasts) from the following description of Dr. Bishop:
"The fluoroscope gives only a general view of the thorax. When the chest is placed behind the screen and the roentgen tube is charged one sees the shadow of the mediastinum outlined on the clearer borders of the lungs. The heart pulsations are clearly perceived and the respiratory movements are interpreted by the vertical displacement of the heart, by the raising of the ribs, by the outline of the thoracic cavity, and by the raising and lowering of the diaphragm. The anterior and posterior mediastinal spaces are shown by rotating the body of the patient from right to left and left to right. These appear clearly because of the slight density of the tissues and it is easy to observe the outline of the denser organs as well as to discover additional shadows of pathological origin. Finally, examination in the dorsal or lateral positions complete in a very short time a series of observations of the thoracic shadows as a whole."
We surely admire a man who so obviously loves his work, but we might choose a different physician if breast-cancer were to be avoided.
In re-assuring us that some of the shadows seen during the examinations do not interfere too much, Dr. Bishop states:
"The mental process of discounting a distortion of the shadows due to the nearness of the tube in fluoroscopy is much easier than one would suppose. I have records of 2000 such examinations. In each instance I studied the heart with the fluoroscope and subsequently in a teleoroentgenogram. I believe that I have acquired the faculty of mentally discounting the larger shadows of the fluoroscope. At any rate the observation of the heart with the fluoroscope enables me to form an opinion of the condition that is usually confirmed by collateral investigations."
Requires Personal Skill ... But Should Become "a Routine Procedure"
"The one disappointing element in this subject of fluoroscopy is that the question of personal skill comes in and training of the observer is necessary. It is always the ideal of scientific work to substitute some mathematical formula or instrument of precision that will eliminate the personal equation. In cardiology nothing is more popular than the arithmetical formula, but so far it has failed to be useful." And:
"Fluoroscopy, however, is capable of systematic development and of very definite interpretation. It is particularly valuable in proving and disproving a negative diagnosis. Striking instances appear in daily work where pretty good men pronounce a heart normal when the fluoroscopic examination, even to the casual observer, shows enlargement or deformity of the cardiac image." And:
"I particularly advocate fluoroscopy as a routine procedure in the examination of large numbers of patients to determine which are deserving of detailed cardiologic study and which are not."
We would add that this sort of program would certainly add materially to the breast-radiation-doses in the population. But we can be sure that Dr. Bishop was an influence, and that many persons did have fluoroscopy in offices and in hospital practices, and only rarely might the radiation doses be available for us to add to the totals for our Master Tables.
Other Major Advocates for Fluoroscopy,
Particularly in Relation to Studies of the Heart
If other advocates were not so eloquent as Dr. Bishop, they were nonetheless enthusiasts in recommending more fluoroscopic studies. Some prominent ones were:
J.G. VanZwaluwenberg: A plea for more use of the fluoroscope in examination of the heart and great vessels. American Journal of Roentgenology 1920, Vol. 7: 1-6.
Charles Martin: An enthusiast for extensive fluoroscopic studies of the heart. American Journal of Roentgenology 1921, Vol. 8: 295-315.
Gonzalo Martinez: Spoke of the advances in heart and great vessel diseases because of fluoroscopy. American Journal of Roentgenology 1921, 8: 491-496.
Rolla G. Karchner and Robert H. Kennecott: Fluoroscopy of heart steadily growing because the method is so precise for heart measurements, American Journal of Roentgenology 1922, Vol. 9:305-314.
Clarke, T. Wood, 1924, "The value of gastrointestinal x-rays in the diseases of children." Archives of Pediatrics, December 16, 840-844.
The enthusiasm here is for fluoroscopy of the gastro-intestinal tract in children, rather than for the heart. The plea suggests that a thorough gastrointestinal examination by the roentgen ray is a valuable adjunct to the clinical examination and blood, stool, and stomach analyses in the clearing up of gastrointestinal abnormalities in children. Clarke felt that the same roentgenoscopic [fluoroscopic] attention to the child's abdomen is indicated, such as that which is becoming more universally accepted as a routine procedure for the adult.
Other Roentgen Exposures for Which
Population Doses are Difficult to Assess
- In 1925,
W.W. Wasson wrote "Radiography of the Infant Chest,
with Special Reference to the Progression of the Chest and
Determination of the Normal," Radiology Vol. 5, November:
365-398. We cite Wasson's justification for his study of
infants. He had developed what he considered a technique for
roentgenography of the adult chest, which he considered
portrayed quite accurately the minute structure of the adult
lung. The same technique was adapted to infants, and Wasson
felt that the same principles held true.
Therefore, he launched a study "of the infant at birth before any changes in the lung have taken place." Then he roentgenographed babies during the first two weeks after birth, "and every four weeks thereafter until they were three months of age, then every three months until one year of age, and every three months thereafter unless conditions warranted more frequent roentgenograms. The chest is roentgenographed in the anteroposterior and lateral positions, usually recumbent, at both inspiration and expiration. The series at present includes 56 babies [emphasis added] varying from a few weeks to three years of age. The series is also supplemented by group studies of varying ages and by a considerable post-mortem series."
While these studies did not include roentgenoscopy, the two types of roentgenograms used are the worst in terms of exposure to the breasts. And there were many, many shots taken over time at ages of great sensitivity to breast-cancer induction.
This was an era when "studies" of heart and great vessels each involved examination of hundreds, and even over a thousand persons, by roentgenoscopic and/or roentgenographic methods to acquire data for the "normal." We are not being judgmental about issues such as informed consent. Rather, our problem with these studies is that they do not fall anywhere into a defined group from which we can readily ascertain the population radiation dose to the breasts, which surely occurred, and can not be overlooked.
- In the 1920s, George E. Pfahler, the very eminent
Philadelphia radiologist, decided he needed some measurements on
liver size in the normal state:
1926, "The Measurement of the
Liver by Means of Roentgen Rays Based upon a Study of 502
Subjects," American Journal of Roentgenology and Radium
Therapy, Vol.16 (6): 558-564.
We let Dr. Pfahler describe his study himself:
"No accurate roentgenological measurements seem to have been made previously to indicate what measurements may be accepted as standard or what may be considered even relatively normal. Therefore, with the hope of determining the practical value of such measurements and with the hope of establishing at least a relatively normal standard, I have been making routine measurements in every abdominal examination in my private laboratory, and have had made at two of the hospitals (Medico-Chirurgical and the Polyclinic Hospitals, of the Post-Graduate Medical School of the University of Pennsylvania) with which I am connected, 324 similar examinations upon subjects who are in general good health, but who came to our clinics because of some minor accident such as a broken wrist, or ankle, etc. From this group I believed I could obtain a more accurate estimate of the normal for various ages, height, weight, and thickness than could be obtained from a study of any group of students or nurses who would be likely to show much less variation."
The exams appear to have been postero-anterior roentgenograms, not fluoroscopy. Studies such as these leave a legacy of persons carrying a radiation dose which is obscurely recorded, but which still contributes to the production of breast-cancer.
- In 1925,
L.R. DeBuys and E.C. Samuel wrote, "Growth of the
Heart, Roentgenographic Observations." American Journal of
Diseases of Children, 30:355-358.
This is a continuation of an earlier study of the shape of the heart at various ages. The authors wished to convince themselves of the correctness of their earlier impressions, and have therefore extended their studies up to the thirty-ninth month after birth.
They took roentgenograms within the first twenty-four hours after birth and thereafter every three to six months out to 39 months. Only true antero-posterior roentgenograms were considered acceptable. They made 623 observations on 400 persons, extending over the entire 39-month period. No fluoroscopy was involved.
Incidentally, from the point of view of breast-cancer, their exams were the worst, in terms of dose to the breasts. This work is from the Department of Pediatrics of Tulane University.
- In 1928,
Edith M. Lincoln and Ramsay Spillman wrote,
"Studies on the Hearts of Normal Children II. Roentgen-Ray
Studies," American Journal of Diseases of Children, Vol. 28:
791-810.
Lincoln and Spillman state: " Many studies of this kind have been made on adult hearts. The literature on the size of children's hearts is not abundant, and a considerable amount of the work was done on small groups and on children in clinics who did not have obvious organic heart disease." And:
"The study was made over a period of seven school years and was based on yearly roentgenograms of 246 of the same group of normal school children ... All the roentgenograms were made with the child in a standing dorsoventral position, at a distance of 6 feet. The exposures varied from three-eighths to three-fourths of a second, with the central ray passing approximately through the fourth dorsal vertebra..." These children ranged in age from 2 years to 13 years.
The taking of the x-ray postero-anterior is of lesser harm with respect to breast irradiation. We would like to say here that we realize fully that a small series of children so studied is not going to have an impact on national breast-cancer rates. The aggregate impact of innumerable studies of children and adults by fluoroscopy (which was not done in the Lincoln study) may not be insignificant --- depending upon how many studies and how much time was spent under the fluoroscope. We have no access to such information for the relevant period, so that if the net dose is an appreciable increment, there is no way to add it to the Master Tables.
- A good example of our concern is the work of Robert O. Moody,
Roscoe Van Nuys, and W.E. Chamberlain of Berkeley, California
(Moody 1923,
1928). Their two reports
are cited here of roentgenoscopic and roentgenographic studies first of
600, and then of 1,200 healthy students at the University of
California. These investigators were conducting extensive
studies of the anatomical features (size, etc.) of internal
organs. We do not get an estimate of the radiation dose, but
with roentgenoscopic studies being done, this is an issue of
some importance. If many studies of this sort were being
casually done, the person-rads to the breast and other tissues
could be significant for our concerns. One cannot have many
studies of 1,800 young persons, 400 young persons, 1722
roentgenograms of 246 normal children, etc. without adding to
the radiation exposure of the population during the relevant
period of our study. The numbers of cases we report here are by
no means inclusive --- we have no idea of the number of similar
studies that may well have gone unreported.
Cinematography in Studies of the Heart
A "close relative" of roentgenoscopy, in one sense, is the use of cinematography. In the American Journal of Roentgenology and Radium Therapy, 13: 508-509, 1925, work in France by Lomon and Comandon is cited, "The Roentgenologic Cinematograph." We quote a paragraph from a summary of this article:
"The practical use of cinematography in recording the cardiac contractions is described in some detail. Aside from the immediate value of such pictures, there is also the future use of these in watching the changes in heart contractions at stated intervals; comparison of these pictures may be of much value in following the condition of certain cases. In the method described, 25 roentgenograms can be made per second." The article states that under the conditions used, erythema results only after 20 seconds of exposure. "Because of the extreme heat and tension on the tubes," the writers established 5 seconds as the maximum exposure. In this time, at least 2 complete cardiac cycles were obtained. "From 17 to 18 images per second seem to give the best results, although 25 per second are possible."
Let us consider this procedure. An erythema dose would have been in the neighborhood of 300 R of skin exposure. The authors say 20 seconds produce an erythema, but therefore they limited exposure to 5 seconds. So we have a skin exposure of 75 R. For an anterior entry of the beam, this would be a dose in the neighborhood of (0.693 rads/R x 75 R), or about 52 rads to the breast. This would have to be regarded as "a new dimension" in doses associated with roentgenography, although not so rare with roentgenoscopy. Since this publication was in 1924, we shall be interested in the future to try ascertaining just how frequent such exams might have become in the United States in the many decades which followed.
Part 3. Fluoroscopy as a Major Problem Refuses to Disappear
There existed so much good work in the 1920s, the 1930s, and the 1940s by people like Leddy, Braestrup, and Blatz, it seemed reasonable to believe that fluoroscopy, the outstanding hazard of radiology, would at least not be the problem in the second half of the 20th Century that it had been for the first half of the century.
But that simply did not happen and is not happening today. A large part of the problem of fluoroscopy is its enhanced use in techniques of medicine and surgery in the diagnosis and treatment of blood vessel disease and heart disease. It simply requires no disclaimer concerning the very wonderful advancements in surgical therapy which have characterized the second half of the 20th Century, especially with the life renewal of children with otherwise lethal, or severely crippling congenital heart problems.
Unfortunately, we need to be concerned that we are building into our society future breast-cancers as a result of the chest-dose to the female children undergoing the surgery. Who would not be happy to accept decades of full happy life in exchange for the risk of a later cancer? We need to be concerned since we may not see the ultimate decline in breast-cancer rates that would otherwise accompany the elimination of such practices as thymus irradiation.
The evaluation of the status of population exposure from high dose individual exposure in connection with cardiovascular therapy and other radiation sources will be a focus of the study of breast-cancer risks being generated in the 1960-2000 period, as a follow-on to the study of the current breast-cancers occurring by the thousands as a result of the radiation exposure during the 1920-1960 period.
Just as a matter of keeping our eyes on the problem, let us examine the order of magnitude of doses which can be involved in this second half of the 20th century. We look at Table 9, page 312 in the UNSCEAR Report of 1977. Table 9 is described as
"Mean Energy Imparted to Patients During Radiological Investigations of the Heart and Larger Vessels."