Percutaneous ethanol injection treatment of autonomously functioning single thyroid nodules: optimization of treatment and short term outcome.

Twenty-five patients with solitary autonomous thyroid nodules (15 nontoxic, 10 toxic) received percutaneous ethanol injection treatment (PEIT) under sonographic guidance in 4-7 sessions (1-2 weekly). To test different doses, smaller nodules (volume less than 15 mL) were given 0.75-2.8 mL ethanol/mL nodular tissue while larger nodules received 0.5-1 mL/mL. Except for 1 patient who developed hyperpyrexia, no relevant adverse effects were observed. A slight, asymptomatic increase in serum thyroid hormone levels was observed in both groups during the treatment. Three months after treatment, a biochemical and clinical remission of hyperthyroidism was observed in 8 of 10 patients with toxic nodules. A significant increase of TSH level was seen in both groups (p less than 0.01). Significant shrinkage of volume (p less than 0.001) as well as structural alterations of nodules were consistently recorded at sonography. A linear relationship (r = 0.98; p less than 0.0001) between pretreatment volume and volume reduction was found both for large and small nodules, thus suggesting that even limited ethanol doses may be therapeutically effective. A recovery of extranodular parenchyma activity at scintiscan occurred in 16 (64%) of 25 patients. These data confirm that PEIT is effective in obtaining functional ablation and in inducing remission of hyperthyroidism. Adverse effects are infrequent. In spite of the small patient sample, a 0.5-1 mL ethanol dose per each mL of tissue appears as effective as larger doses and seems appropriate for treatment.