minimal instruction to obtain and record data in a consistent manner. Completed records should
be reviewed for clarity, and consistency. Any missing information should be obtained if possible.
Additionalservices will be required to validate the quality of medical data collected,(e.g,, referral
to original records to verify pertinentitems of self-reported data). These data should be preserved
and retained indefinitely.
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Other Procedures Considered but not Recommended
7.4.6.1 Screening by High Resolution Ultrasonic Imaging
Although most experts agree that high resolution ultrasonographyis useful at referral centers to
evaluate palpable thyroid nodules, opinions differ about its usefulness as a screening tool in the
field because of its high sensitivity and lack of specificity in identifying non-palpable lesions. For
example, in the adult U.S. population the prevalence of palpable thyroid nodules is estimated to
be about four percent; however, the true prevalence of nodules as indicated by autopsy studies or
by high-resolution ultrasonographyis estimated to be about 40 to 50 percent. Theclinical
significance of such non-palpable lesions is considered to be negligible. Should U.S. DOE decide
to include its use in future medical evaluations of the Marshall Islands’ population, only palpable
nodules should be biopsied; non-palpable nodules should remain under medical surveillance
pending observation of any significant changes in their clinical status (39-41).
7.4.6.2 Chromosomestudies of cultured lymphocytes
Chromosomestudies of cultured lymphocytes for radiation dose estimation are not recommended
for this population.
Long-term follow-up evaluations have been conducted in several populations having previous
radiation exposures, including survivors of the atomic bomb at Hiroshima and Nagasaki. The
CF
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CSF
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