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‘In view of the seriousness of these findings it was decided to initiate
thyroid hormone therapy on the exposed people.
The rational for this form
of therapy was that by furnishing normal levels of exogenous thyroid hormone,
pituitary TSH levels would be repressed and remove the thyroid gland from
stimulation of that hormone.
It is thus hoped that further development of
nodules and possible malignancy might be prevented and, of equal importance,
enhancement of growth and development in the children might result.
Conclusive
results of this treatment must await further observations and a stricter
treatment regimen.
However it does appear that several nodules have reduced
on this treatment and some children may be showing increased growth.
Figure
26 shows the results of hormone treatment on the 2 boys who had shown growth
retardation, referred to before and shown in Figure 21.
It can be seen
that there has been a tendency to an increase in skeletal development coincident
with the institution of the thyroid therapy.
The exclusive development of these thyroid abnormalities in the irradiated
Marshallese children seems clearly to indicate the radiation etiology.
The
development of such abnormalities is consistent with the known etiological
relationship of irradiation of the thyroid gland and the development of such
lesions(Doniach, Kneeland et al.; Lindsay et al.; Goldberg and Chaikoff; Potter
et al.).
The high incidence in the children is probably related to the larger
dose of radiation received by their smaller glands.
Though the pathological
changes in the nodules are similar to those seen in iodine deficiency goiter
there is no reason to suspect such causal relationship in the Marshallese
cases since dietary iodine is normal, urinary excretion of iodine is in the
normal range and there are no known goitrogenic foods.
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