To assess the therapeutic effect of radioisotope imaging in patients with thyroid disease, we reviewed the thyroid clinic charts of 730 consecutive patients from September 1981 through September 1983. Two-hundred fifty-one patients had received a thyroid scan as part of their initial evaluation. The clinical impression (based on the history, physical findings, and thyroid function test results), scan interpretation (provided by the nuclear medicine staff), and subsequent therapy were recorded for each patient. Iodine-131 was used to evaluate patients with substernal mass; all other patients were scanned with 123I. The terms 'cool' or 'cold' describe discrete areas with diminished or absent uptake compared to that of surrounding tissues. 'Hot' describes discrete areas with increased radioiodine uptake. These regions did not necessarily correspond to palpable nodules. Thyroid images correlated poorly with physical findings in patients with nontoxic goiters. Scans in 18 of 45 patients with diffuse goiters had a heterogeneous appearance while scans in 7 of 27 patients with multinodular goiters showed a homogeneous pattern. These patients were uniformly placed on L-thyroxine suppression therapy. Due to the poor specificity of thyroid scanning, the presence of a hypofunctioning area does not significantly increase the risk of malignancy in patients with a solitary nodule. Thyroid scans provide little information beyond that obtained by careful palpation of the thyroid gland in hyperthyroid patients. The radioiodine uptake provides useful information if thyroiditis is a diagnostic possibility. Palpation is more sensitive than scanning in defining clinically significant thyroid nodules. Although clinically occult carcinomas are common, occult thyroid cancer does not diminish the quality of life or result in premature death. Thus, attempts to identify such tumors are not justifiable. The routine use of thyroid scanning as an initial diagnostic procedure should be abandoned in patients with euthyroid goiters, suspected Graves' disease, hypothyroidism, or suspected nonpalpable nodules. Scanning is useful for patients with solitary or dominant nodules, although fine-needle aspiration biopsy may significantly reduce the number of these patients for whom scanning is helpful. By eliminating unnecessary thyroid imaging, the cost of health care can be effectively reduced without diminishing the quality of medical are delivered.
ASJC Scopus subject areas
- Internal Medicine