Evaluation of "solitary" thyroid nodules in a community practice: a managed care approach

Evaluation of thyroid nodules remains a challenge for primary care physicians. To include or exclude the presence of malignancy in a thyroid nodule, radioisotope scan, ultrasound, and fine-needle aspiration biopsy of the thyroid generally are used. The objectives of this study were to determine the utility and cost effectiveness of fine-needle aspiration biopsy of solitary thyroid nodules in a community setting; to compare the cost of fine-needle aspiration biopsy with that of radioisotope scan and ultrasound; and to determine whether the practice of obtaining radioisotope scans and ultrasound has changed in the 1990s compared with the 1980s. Patients were referred by community physicians to university-based endocrinologists for evaluation of thyroid nodules. Many of the patients had previously undergone radioisotope scans and ultrasound scans at the discretion of their primary care physicians. All patients underwent fine-needle aspiration biopsy. The biopsy results were evaluated prospectively, and the practice of community physicians' obtaining radioisotope scans and ultrasound scans was compared for the 1980s and 1990s. Eighty-three patients underwent 104 biopsies. In 20 biopsies the specimens were inadequate; the others showed 70 benign, 9 suspicious, and 4 malignant lesions. All four patients with biopsy findings read as malignant were found to have malignant growth at surgical procedures. Two benign biopsy findings were false-negative results. Malignant growth was correctly diagnosed later for one patient at a second biopsy and for the other because of growth of the nodule. The cost of 104 biopsies was $20,800. The cost of radioisotope scans was $22,400, and the cost of ultrasound scans was $10,640. The frequency of obtaining radioisotope scans (84.5% vs 77%) and ultrasound scans (65% vs 45%) was slightly higher in the 1990s compared with the 1980s. Fine-needle aspiration biopsy is a safe and cost effective initial evaluation modality for smaller community-based centers, as it is at large tertiary centers. The cost incurred ($33,040) in obtaining the radioisotope scans and ultrasound scans could have been saved if fine-needle aspiration biopsy had been used as the initial diagnostic procedure for evaluation of these nodules. Although radioisotope scan and ultrasound scan are of little diagnostic help in the evaluation of thyroid nodules, they continued to be obtained at a high frequency during the last decade.