Part 1. Pneumococcal Lobar Pneumonia Treated with X-Rays ?
Not many physicians today will really believe that lobar pneumonia was once widely treated with roentgen radiation. Rousseau was one of the investigators who was active in the field of therapy of lobar pneumonia in the early period. Rousseau (1942) has cited a number of publications which had appeared over the years showing favorable and uniform results in treating well-controlled groups of lobar pneumonia cases with roentgen therapy. In the paper by Rousseau and his colleagues in 1942, a series of lobar pneumonia cases is presented. These were 104 cases of pneumococcic pneumonia treated in the winters of 1937, 1938, amd 1939. Additionally, a small series of patients was treated, after they had been doing poorly for a period of three to seven days on sulfonamide therapy.
We quote Rousseau et al about these latter cases:
"In this group of cases, it was evident that the course of the disease had not been favorably affected in any way by sulfonamide therapy. The patients were growing rapidly and progressively worse with adequate doses of the drug. By all clinical standards, it appeared that death was inevitable in all cases of this group."
This group of 29 cases showed 22 recovered and 7 died --- which Rousseau and co-workers take as excellent evidence of help from roentgen therapy after sulfonamides had failed. Clinically, their expectation was against any of the 29 surviving.
We shall analyze the Rousseau data below, but first we wish to re-introduce the name of Dr. Arthur U. Desjardins of the Mayo Clinic from pages 96 and 104. Many volumes of American Journal of Roentgenology and Radium Therapy carried scholarly discussions by Arthur Desjardins concerning the facts and the ideas involved in the use of roentgen therapy for every entity in which it was used, including pneumonia. Animal experiments, physiological background, clinical features --- all were treated in a series of articles which the roentgenologists were presenting to say to the skeptics, "We do have a logic for all this." Dr. Desjardins must have been a remarkable scholar, considering the breadth of medicine taken on in his series of essays on roentgen therapy. Mechanism of action was very high on the list of items discussed in the Desjardins articles.
In a 1942 paper in Radiology, Dr. Desjardins made a couple of statements that are worth repeating here, for assuredly some readers are going to wonder about this issue today.
(At page 274) "There is no longer any doubt that roentgen rays often have a beneficial effect on many varieties of acute and chronic inflammation. The evidence is now so abundant that it cannot be disregarded."
(And at page 277) "The action of the rays on acute inflammation cannot, therefore, be attributed to a direct bacteriocidal effect of the rays."
We wanted to bring up the stature of Arthur Desjardins here to show that a leading figure in roentgenology, and a leading figure at the Mayo Clinic itself is speaking to the issue of therapy of inflammatory diseases with roentgen rays. So the reader should steer far away from suggesting that Dr. Rousseau and colleagues were not in mainstream medicine. They certainly were. Not only were they mainstream with respect to the use of radiation therapy of inflammatory diseases, they were from a leading Southern University, Bowman Gray School of Medicine, Wake Forest College, in Winston-Salem, North Carolina.Part 2. Detailed Consideration of the Pneumonia Studies of Rousseau
- Item 1: These cases, studied at Bowman Gray, were from North Carolina. The mean age of all these pneumonias was 29.8 years, with a range of ages from 9 weeks to 94 years (pneumococci showing no respect for any age group). For our purposes, we would really love to know how many young children were involved, and we are not using exposure data for persons beyond 64 years of age. In the absence of data, and as a reasonable approximation, we shall assume that 80% of the cases were of ages between 15 and 45 years, and simply leave out consideration of the others. This is conservative, since irradiation of children under 15 would thereby be eliminated from the series. It is consistent with our general policy of seeking a credible lower limit for past radiation exposure.
- Item 2: Estimating population sizes at various ages in the North Carolinians of Forsyth County.
In 1960 U.S. Population was 179,333,000 persons.
In 1960 Forsyth County, of which Winston-Salem is the county seat, the population was 189,428 (County and City Data Book 1962).
We shall illustrate estimation of the female population of Forsyth County in the 1920-1960 period for a single age-year (15 year olds).
The Master Table, Col. A, gives a value of 888,277 female persons at 15 years of age Nationwide in the average period 1920-1960. Therefore, in Forsyth County, we estimate there must be (189,428 / 179,333,000) x 888,277, or 938 female persons, age 15.
For the number of female persons of other ages out to 45 years, in Forsyth County, the same sort of steps have been used.
- Item 3: There was a total of 104 cases of pneumococcal pneumonia. We shall assume 1/2 of the cases were female, yielding 52 cases of women treated with x-rays for pneumococcal pneumonia.
But we are using 80% of the total group for our calculations. So we reduce that number to (0.8) x (52), or 41.6 cases.
And we know these cases were distributed over three years, so the number per year must be obtained through division by 3, yielding 13.87 cases per year of accumulation of cases (all ages put together).
The beam was directed anteriorly in these cases, with 200 R over the total breasts. From Gofman and O'Connor 1985 the dose to breasts per R at surface = 0.693 rad.
Therefore, the dose to the breasts was 200 R x 0.693 rads/R, or 138.6 rads. This dose must be adjusted for supra-linearity (Chapter 8, p.58). The adjustment factor is 0.435. Therefore, we reduce the dose to (138.6 x 0.435), or 60.3 rads to the breast.
For our 13.87 cases treated per year, person-rads per year = (13.87 persons) x (60.3 rads) = 836.4 person-rads.
We are distributing these 836.4 person-rads into 31 age groups, from 15 through 45 years of age. The entry in person-rads for each of those years will be 836.4 / 31, or 27.0 person-rads.
Acquiring the "Population Dose" for Forsyth County
In our illustrative calculation for 15 year-old females, we found that in Forsyth County we expect there to have been 938 persons. Therefore, if we distribute 27.0 person-rads into 938 persons, the average dose to the breasts will be (27.0 person-rads / 938 persons), or 0.0288 rads per person (the population dose for 15 year-olds).
From the nature of the calculation, we can see that estimation for each of the additional age brackets, 16 through 45 years, will give average doses slightly higher than that for 15 year-olds, simply because the remaining population is smaller with increasing age. Of course, for our Master Table entries, all doses are to be calculated as demonstrated for our 15 year-old example set.
- Item 4: Have we underestimated the total radiation dose actually received in Forsyth County, from cases of pneumonias being treated in other parts of the County? We must ask whether the cases reported by Rousseau and co-workers represent all the cases treated in the same period, if we are to evaluate true dose received per person, on average.
A careful reading of the paper of Rousseau and colleagues informs us that their group is chiefly interested in the treatment of pneumonia centered around the pneumococcal type. As a result of this special interest, Rousseau and colleagues state that they have eliminated 72 of a total of 176 unselected and consecutive cases of pneumonia. The elimination is solely on the basis of whether or not a pneumococcal etiology exists. The 72 cases are eliminated because the combination of sputum and roentgen examinations led to a diagnosis of atypical bronchopneumonia or to lobar pneumonia due to non-pneumococcic and mixed infections.
As an academic matter, these physicians could construct any series that interested them, but we doubt in the extreme that the 72 cases of acute pneumonia of other etiologies were denied treatment with roentgen rays. So, quite probably a more accurate population dose estimate for our Master Table would be (176 / 102), or 1.73 times as high as the doses entered. Fifty years have elapsed since that publication, so it is not possible to find out just how the additional 72 cases were treated. We shall elect here, for adherence to our credible lower limit philosophy, not to enter this additional sizable contribution to radiation dose. We are also not including any contribution to radiation dose from radiation treatments that might have been given by other practitioners in the county, again potentially leading to a significant underestimation of dose received.
- Item 5: It is a reasonable expectation that the 1920-1940 part of the entire 40 years may have seen even higher usage of this type of therapy than is reported for 1937-1939. But surely, after 1945, there were probably very few cases treated this way. Therefore, before final entry into Master Table at Col.S, all doses will be reduced by a factor of 0.75, reflecting the probable lack of use of radiation therapy in the last quarter of the 1920-1960 period.
The entry at Col.S for our illustrative 15 year old female person is (0.75) x (0.0288 medical rads), or 0.0216 medical rads. As stated above, there is very good reason to think we have underestimated all entries by the factor of 1.73, as a result of eliminating the non-pneumococcal bacterial pneumonias which were probably treated.
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