Radioiodine I-131 therapy in the management of differentiated thyroid carcinoma: a review of 202 patients.

During the 13-year period from 1978 to 1991, 202 patients with differentiated thyroid carcinoma were treated with radioactive iodine-131 (I-131) post-operatively. The therapeutic response and survival rates were studied. Of these patients, 172 (85%) patients were shown to be totally disease-free; others showed a partial response or persistence of disease. A total of 134 patients (66%) achieved total thyroid ablation with only one therapeutic dose of I-131, ranging from 100-200 mCi. Patients over the age of 40 years at the time of diagnosis had a lower survival rate than those under 40 years old (98.6% vs 68.9%; p < 0.001). However, patients over the age of 50 years and follicular patients had a lower recurrence rate than patients under the age of 50 years and those with papillary carcinoma. Eight of the 32 patients (25%) with lung metastases were detected by a therapeutic I-131 whole body scan (WBS), in which the diagnostic I-131 WBS was negative. In six of the 16 patients (37.5%) with bony metastases, the I-131 WBS showed more obvious positive results than the Tc-99m methylene diphosphonate (MDP) bone scanning. Most of the remaining patients exhibited the same findings for the two methods. Therefore, I-131 WBS is superior to Tc-99m MDP bone scanning in the detection of bony metastases from thyroid carcinoma. The mortality rate of patients with bony metastases was four times that of patients with lung metastases (40% vs 10%). Patients with follicular carcinoma had higher rates of distant metastases than those with papillary carcinoma (13% vs 4%).(ABSTRACT TRUNCATED AT 250 WORDS)