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4
NATIONAL INSTITUTES OF HEALTH CLINICALSTAFF
ICAL STA
1232
B
TABLE 8.
"N
.
.
‘
.
Annals of
Internal Medicine
Kinetic Analysis of 1®F Studies (March 1965) in Subjects Without Thyroid Abnormality
Group
No.
Urine*
12
1.10
(0.34-2.57)
0.81
(0.17-1.99)
Subjects
Marshaltese-—exposed
Marshallese—unexposed
9
North Americans
2.0
-, Thyroidt
Thyroid
ce
0.67
(0.33-1.27)
0.79
(0.23-1.47)
1.0
Fractiont
.
0.40
(0,25-0.65)
0.52
(0.26-0.77)
0.33
Mean and ranges are given,
* Fraction of extrathyroidal! iodide excreted in urine per day (Ag:).
t Fraction of extrathyroidal iodide transferred to the thyroid per day (Asi).
.
An
thyroid
uptak ("5-).
t Theoretical
Theoreti
yroid uptake
Xn he
amount of radiation that it would deliver
to the thyroid gland. A *8?Te generator was
used, capable of producing a supply of 1371
for a period of several weeks. Radioiodine
accumulation in the neck was measured
4 hr after the oral dose and at hourly inter-
vals for approximately 4 hr. (Details are
given in reference 12.) Urine was collected
at the end of this time and measured for
132], The data were analyzed by Dr. Mones
KCI QO
‘
‘
-_—— oo
—-3-5
men
ot
’
_,
Mathematical
Research
Branch,
National Institute of Arthritis and Metabolic Diseases, using the computer program
that he has in operation for kinetic studies
and particularly for thyroid studies (16).
‘The calculation used the gross neck uptake,
uncorrected for extrathyroidal iodine, and
the analysis indicated that the counter
“saw” more than 99% of the thyroidal radioactivity and that 8% of the neck radioactivity was extrathyroidal. In Table 8 we
have listed the fraction of the body iodide
that is taken up in the thyroid per day and
the fraction going into the urine per day.
Interestingly enough, both of these values
compared with United States values are
low, again an abnormality for which there
is no explanation. The balance between
o
NECK UPTAKE (*%)
nol
Berman,
these two depressions was such that when
the theoretical maximal thyroid uptake is
calculated tt actually comes out higher than
is normal in the United States. Although
the low urinary excretion rate might well
with thyroid abnormality. Values are gross neck
counts, as percent of dose, uncorrected for blood
background after oral administration of ™I. Com-
puter analysis of these data indicates that 7% of the
extrathyroidal iodide pool is “seen” by the neck
counter. At the verticai lines, 500 mg potassium
perchlorate (KCIO,) was given by mouth. A = Case
54; WP Case 2 (partial thyroidectomy); © = Case
65; @ = Case $; [J] = Case 3; @ = Case 69 (partial
thyroidectomy).
in doing some further studies on the indi-
viduals who had developed thyroid nodules,
and we were able to carry out a few such
studies. The patients stopped their thyroxine therapy 3 weeks before testing. In
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HOURS
Fictre 15. Neck accumulation of **{ in subjects
be due to incomplete urine collection,
which was very difficult under field conditions, this does not significantly alter the
calculated thyroid accumulation rate.
I joined the survey for the first time in
March 1966. At this time we wereinterested