Possibilities of nontoxic autonomous thyroid nodules treatment by percutaneous ethanol injection.

Background/aim: According to the current principles, autonomous functional thyroid nodules are treated by surgery or by radioiodin therapy. Ultrasound guided percutaneous ethanol injection into solid tumors of the soft tissues was a starting point in attempts to treat the thyroid nodules by the same method. The aim of the study was to assess the efficiency of percutaneous injection in treating solitary, nontoxic, autonomous thyroid nodules of up to 15 mL volume.

Methods: In 25 patients with solitary nontoxic autonomous thyroid nodules diagnosed by tehnetium-99m scanning as an intensive area having a complete supremacy in the paranodal tissue, an ultrasound guided percutaneous ethanol injection was applied. The procedure was carried out repeatedly once a week until the reduction in nodule size to 50% of the initial size was achieved.

Results: An average size of the nodule before curing was 9.68 +/- 5.01 mL. An average quantity of the injected ethanol was 9.52 +/- 5.08 mL, ie 1.06 +/- 0.48 mL/mg of the tissue. The regression of the nodule size in the successfully (deltavol% u -57.09 +/- 13.75%, p < 0.001) and partly successfully cured (deltavol du = -48.45 +/- 14.35%, p < 0.05) was statistically significant compared to the size before the treatment. After ceasing ethanol injection, 18 months later, a further size regression (deltavol% = -79.20 +/- 9.89%) compared to the initial one (p < 0.001) was noticed. Soon, after the procedure was finished, a statistically significant concentration increase of Thyroid Stimulating Hormone (TSH) was noticed compared to the initial values (0.18 +/- 0.16 vs 0.34 +/- 0.31 mU/L, p < 0.01). According to the given criteria, in two female patients satisfactory results were not achieved, but, a year later, in one of them the nodule was not seen by repeated scintigram. The number and frequency of side effects were insignificant.

Conclusion: Repeated percutaneous ethanol injections into nontoxic solitary autonomous thyroid nodules result in disappearing of authonomy. The regression of the nodule size of more than 50% compared to its initial volume, as well as the increase in concentration of TSH for more than 50% are the signs of a successful treatment.