‘exclude that diagnosis. Nevertheless,the clinical
evaluation required to establish a diagnosis is
associated with its own morbidity. Prominent in
this morbidity is thyroid surgeryitself, a procedure that requires general anesthesia and
results in a cosmetic defect and the unavoidable
removal of some normalthyroid tissue.
C. Hypothyroidism, postsurgical:
In 1972 to 1974 it was noted that 11 of 20
exposed persons from Rongelap who underwent surgery for removalof thyroid nodules had
elevated levels of thyroid-stimulating hormone
(TSH). Because this evidence of postsurgical
hypofunction was morefrequent than expected
it was surmised that thyroid insufficiency might
be developing in the exposed Rongelap population as a whole, rather than being limited to the
two hypothyroid children diagnosed some ten
yearsearlier (Sutow et al., 1965). Such an event
was likely to be clinically inapparent becauseall
of that group had been placed on suppressive
doses of thyroxin since 1965 to prevent thyroid
neoplasia. Therefore, after temporarily discontinuing thyroxin, a survey of thyroid function
was undertaken, and twelve persons were found
to have biochemical evidence of thyroid insuffi-
B. Thyroid hypofunction, radiation-induced:
Overt hypothyroidism was diagnosed in two
Rongelap boys who wereinfants at the time of
exposure (Sutowet al., 1965). In addition, subclinical hypothyroidism unrelated to thyroid
surgery was confirmed in twelve other Rongelap
persons (Larsen et al., 1982). In 1987 a Utirik
man was diagnosed as biochemically hypothyroid. He was two years of age at the time of
exposure, and he is the first exposed person
from Utirik to have this diagnosis.
THYROID DISEASE vs. RADIATION DOSE
100
-—
& gob
!
|
2
[7] BENIGN NODULES
S 80
[X) HYPOTHYROIDISM
S 70
|
-
|
77
THYROID CANCERS
3 eb
]
Z
yZ
=
YN
(IN
YN
Y,
Y
S 40+
= of
-
A
Z
:5LT
a
yWo
44~
N-
AW W-
=
Y
&
YN
)
5S ak
"» Ava
Arm ZLAVA
SL
1-250
251-500
501-1000
Y,
VAY
1001-2000
YIN
IN
UY VIN
TAS
LR
UN -
ZN
GIN
A
VANA PIAS
2001-3000
3001-4000 4001-5000
REM
Fig. 5: TMGabsorbed radiation dose vs. benign thyroid nodules, carcinoma, and hypofunction.
wt
co
oe
~
ren)
cm
15