At the 33rd Annual Meeting of the American Roentgen Ray Society in September 1932, a series of superb papers was delivered on the general theme of tuberculosis detection and treatment as a public health problem in the city of Detroit in Wayne County, Michigan. The description covers the period of the later 1920s and the early 1930s. As the papers in that Symposium show, this was a remarkable water-shed period in the medical history of tuberculosis. In this period, it was learned unequivocally that just bed rest, good food, and lots of fresh air was not likely to reverse the course of tuberculosis in someone who had already experienced what is called "cavity-formation" in the course of the "adult-form" of tuberculosis, which is generally a re-activation of infection in persons who had been exposed to the tubercle bacillus earlier and had healed the initial lesion of "childhood" tuberculosis.
Once cavitation had occurred --- even not major cavitation --- the person was likely to be spewing tubercle bacilli into the air with coughing, and not to be getting anywhere on the road to recovery because the cavity failed to close. Unless the cavities can undergo closure, the person continues to cough out tubercle bacilli, the lesion itself spreads in the affected part of the lung, the disease spreads to the uninvolved parts of the lung (for example from right to left) and to other people. And the chances of cure were remote. It became understood that some form of "collapse therapy" was the key to recovery from tuberculosis. It was essential to put the affected part of the lung at rest, so that the cavity could heal over. The chest x-ray, properly taken, and read by experts, made it possible to tell what was really going on in the person's lung so far as the tuberculous process was concerned --- and reliance on the physician's stethoscope was not good enough. Closure of the cavities meant virtually everything, and this was where the effort needed to be placed.
The possibilities for "collapse therapy" were, in increasing order of effectiveness, (a) crushing the phrenic nerve to rest the diaphragm on one side or the other, (b) cutting the phrenic nerve (since the crushing causes the nerve paralysis only for months to a year), (c) pneumothorax (introduction of air into the pleural space), and (d) thoracoplasty, a surgical removal of some of the rib cage to permit partial lung collapse. We have already discussed the use of pneumothorax as a procedure which involved repeated fluoroscopic examinations before and after air introduction into the pleural space (Chapter 1). That led to very high doses accumulated to the breast tissue, and a high rate of later breast-cancer in those who had been treated with pneumo-thorax.
We should pause here to take note that, while the late results were breast-cancers in some of the women who were so treated, the enormous benefit to the entire group of people was that "many lived to tell the tale." What we are saying is that without "collapse therapy" many, many of the people with tuberculosis would have died an early miserable death of tuberculosis. There was little chance of recovery. But with the use of "collapse therapy" and the x-ray guidance in air refills, cavities did indeed close, the spewing of tubercle bacilli stopped, the spread of the disease locally stopped, the spread to other persons and to other parts of the lung of the person infected with tuberculosis stopped, and recovery processes proceeded. The two keys in all this were (a) stopping of spreading of tubercle bacilli, and (b) insuring (by x-ray evidence) that cavities were indeed undergoing closure. Both were required to assure that progress toward health of the individual and the community, not advancement of disease, was occurring. It behooves us to remember that tuberculosis has been (and could yet again be) one of humanity's greatest scourges.Part 2. Case-Finding for Tuberculosis in the Detroit Program
Case-finding had been going on with diagnosis of tuberculosis in people who had symptoms, which is already late, and with the vigorous effort to find the contacts of each diagnosed case, because that is the major place where the additional new cases are to be found.
There was a new program in Detroit: Dealing on a large scale with the apparently healthy persons. Health officials decided to study 35,000 school children, of which 9,000 were of high school age. Starting with one high school examined, with x-rays of the chest in those with positive tuberculin history, they found 14 cases of adult-type tuberculosis --- the really serious immediate threat. Definite symptoms of disease were found in only 3 of the 14. And a major point was that only one of the fourteen had a contact history. So had only the usual program of just seeking contacts of known cases been in effect, only one of the fourteen would have been discovered to have adult-type tuberculosis. A 14-fold leap in case-finding !
There was one girl, 16 years of age (out of the 14 cases discovered in this high school) who had a very markedly advanced lesion in the left lung. Yet she was well nourished and developed. She played on two of the school teams, and did not have the faintest idea that anything was wrong with her. And in attempting to study the spread of tuberculosis in that school, the officials found that when checked by "home room" in school, in no case were more than 2 cases discovered in any home room, except for that where the 16 year old was, and there 7 of the 14 cases of adult-type tuberculosis were found. So it was clear that where large numbers of children congregate day after day, a definite source of contact with tuberculosis will be found, in this instance an "innocent" source because the source did not know of illness.
From all the 35,000 children investigated, there were two major findings: In the overall high school program, they found the general average to be 0.5%, or one case of adult-type tuberculosis per 200 children examined. They found that 4.9% had childhood type tuberculosis, and an additional 1.5 % were suspects for possible tuberculosis.
Now we will develop entries for our Master Table, Column G. This chapter does not quantify radiation dose from tuberculosis screening procedures --- only from management of identified tuberculosis cases. We start with the data presented by Dr. Henry Chadwick, in his 1933 article entitled "Tuberculosis Problem in Detroit," from the American Journal of Roentgenology and Radium Therapy. The data are for the year 1932.
Determining the Radiation Dose
from Fluoroscopic Management of Pneumothorax Therapy
There are two parts to the radiation-dose determination. The first part is to determine the cumulative breast-pair rads for all the female persons who actually received the fluoroscopic doses. The second part is to determine what we have been calling "the population dose," which spreads the dose out into the entire population of Detroit, so that we get an average dose per person in the Detroit female population as a whole.
The First Part of the Calculation of Radiation-Dose
7,383 cases of tuberculosis were on the register in Detroit. Of the known cases, 30% were in hospitals, and 70% were at home (often after a period of sanatorium treatment).
In their two hospitals together, over 2,000 pneumothorax treatments were given each month --- with a roentgenoscopic examination before and after each treatment. So each treatment meant two roentgenoscopic exams.
The Massachusetts tuberculosis study (Boice et al 1977, p.830) assigned 1.5 rads of breast-dose for each fluoroscopic exam. If we assign 1.5 rads to the breast for each fluoroscopic examination, this means 4,000 times 1.5, or 6,000 breast-pair rads per month, or 72,000 breast-pair rads per year associated with pneumothorax treatment. We need to exclude the males, so we cut the 72,000 breast-pair-rads in half, to 36,000 breast-pair-rads from the fluoroscopic exams during pneumothorax treatment.
The Second Part of the Calculation
of Radiation Dose with Pneumothorax Treatment
We need to know the female population of Detroit in the average year of 1920-1960. We know from Chapter 8 that the female population of the United States was 69,037,400 females, for all ages combined, as the average value in the 1920-1960 period. We ask, "What part of that total female population resided in Detroit, Michigan?"
Detroit had a population of 1,670,144 in 1960 (County and City Data Book 1962). The U.S. Population in 1960 was 179,333,000 persons. The ratio, Detroit / United States is (1,670,144 / 179,333,000). We shall asssume this ratio was essentially the same in the mid-period of 1920-1960, and no different for females versus males.
Therefore, female population of Detroit in mid-period of 1920-1960 = (1,670,144 / 179,333,000) x (69,037,400) = 642,951 female persons.And, Population Dose = (Total Breast-Pair-Rads) = 36,000 ------------------------ --------- (Total Female Persons) 642,951 = 0.0560 breast-pair rads per person.
Average dose per female person in Detroit = 0.0560 rads per person, annually. This entry would apply for every age and we can generalize this to the United States. This is our by-now-familiar "population-dose."
However, we should eliminate the dose to the very young. Collapse management of tuberculosis is virtually absent in the very young children. A reasonable approach is to re-allocate the total delivered dose to all ages except those under 10 years of age by increasing the dose by 10% to those 10 years of age and older. Then the average per person which is effective is 1.1 x 0.0560, or 0.0616 rads per person. This will be applied for the entire country.
An Additional Source
of Radiation Dosage beyond the Pneumothorax Fluoroscopy
There is an additional item to consider in the Detroit population. We know that 70% of the cases were at home and 30% were at the hospital. And we know that approximately 50 % of the hospitalized cases were not on pneumothorax and hence were not subject to the before-and-after fluoroscopic exam with each refill of air, since there were no refills (Table at p.326 in Chadwick 1933). But those not receiving air refills were nonetheless examined with some regularity to assess the progress of their disease.
One-half of those in hospital would be (1/2) x (30% of 7,383), or 1,107 persons. These persons would undoubtedly be having a fluoroscopic exam at least 4 times per year, so we have 4 x 1,107, or 4,428 exams at 1.5 rads each, or a total of 6,657 person-rads.
And for the 70% at home, we have 70% of 7,383, or 5,168 persons. We feel certain these were watched with fluoroscopic exams at least every 6 months. So this is (2 exams) x (5,168 persons) x (1.5 rads per exam) = an additional 15,504 person-rads.
Total additional person-rads = 6,657+15,504 = 22,161 person-rads. We divide by 2 to exclude the males, so the person-rads = 11,081 for females.
The contribution to population dose = 11,081 person-rads divided by 642,951 persons = 0.0172 rads to breasts. And with the 1.1 adjustment factor to leave out those under 10 years of age, we have 1.1 x 0.0172, or 0.0189 rads to to add to breast-dose of everyone of 10 years of age or higher.
We have no reason to believe that this general experience would have been different with respect to breast-rad dose in other parts of U.S. Therefore, total population-dose would be 0.0616 rads + 0.0189 rads, or 0.0805 rads.
But because the program might not have generated as many person-rads in the first few years of 1920-1960, and because of tapering off in tuberculosis in the 1950s, we shall reduce all these doses by 25 %, and enter the following in Col.G in the Master Table for every female age-year starting with age 10.
(0.75) x (0.0805 rads) = 0.0604 rads per person, annually.
A Word of Appreciation
This book is being completed in 1995 --- some 62 years after the series of papers from the health officials in Detroit who wrote so well on the public health aspects of tuberculosis. We wish to express our deep gratitude, these 62 years later, for their monumental contribution to everyone's opportunity to learn a major set of medical lessons about this unremitting disease, tuberculosis. The specific papers in the series are in the list which follows.
All of them appeared in the September, 1933 issue of American Journal of Roentgenology and Radium Therapy, in Volume XXX, No.3. The editors of the Journal at that time deserve commendation for excellent judgment.
Vaughan, Henry F. Commissioner of Health, Detroit, Michigan "Public Health and Tuberculosis", pp. 300-302.
Brachman, D.S., "The Value of the Roentgen Ray in Apparently Healthy Children of School Age" pp. 303-304.
Douglas, B.H., Superintendent, William H. Maybury Sanatorium, "The Importance of the Roentgen Examination in the Modern Treatment of Pulmonary Tuberculosis," pp. 305-308.
Morgan, Richard, "Artificial Pneumothorax in a Group of Cases of Pulmonary Tuberculosis Formerly Looked upon as Hopeless," pp. 309-314.
O'Brien, E.J. "Collapse Therapy in Early Minimal Lesions of Pulmonary Tuberculosis," pp. 315-320.
Chadwick, Henry D., Detroit Department of Health, "The Tuberculosis Problem in Detroit," pp.321-327.
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Preview of Another Use: Skin Disorders
"It is now pretty generally admitted that the roentgen rays constitute the most useful and successful single remedy we possess for the treatment of dermatological diseases. The only competitor for this distinguished position is radium." And:
"That the roentgen rays constitute the most valuable remedy in dermatotherapy, or that the roentgen rays and radium constitute the most useful single agents in the armamentarium of pure dermatology, is shown by the following list of diseases and conditions that are amenable to such treatment, over 80 in number." The list of these diseases is presented.
o - Excerpts from "The Value of Roentgen Therapy in Dermatology," by Dr. George M. MacKee and Dr. George C. Andrews, in American Journal of Roentgenology and Radium Therapy, Vol.9: 241-246. 1922.
In the 3rd Edition of his obviously successful "X-Rays and Radium in the Treatment of Diseases of the Skin," Dr. MacKee states, p.6:
"Over thirty years ago Dr. William Allen Pusey, one of the pioneers of cutaneous roentgen therapy, remarked; `It is hardly too much to say that roentgen therapy is the most widely useful addition to the treatment of skin diseases that has been made.' In spite of the foregoing paragraphs and the remarkable advance in American dermatology during the past two decades, Pusey's statement may be repeated today. It is the consensus of opinion that x-rays constitute the most important single therapeutic agent in the armamentarium of the dermatologist."
A very persistent therapy --- extending over decades.