Ultrasound guided percutaneous ethanol injection in the treatment of cystic thyroid nodules

The management of cystic lesions in the thyroid remains controversial. We examined the efficacy and safety of ultrasound guided percutaneous ethanol injection for the treatment of benign cystic thyroid nodules in euthyroid patients.

(A) Preliminary randomized trial: 20 patients with predominantly cystic thyroid nodules were randomized in two groups and followed up for 1 month. Group 1 underwent fine needle aspiration of the fluid component of the nodules; Group 2 underwent percutaneous ethanol injection at the end of fine needle aspiration of the cyst fluid. (B) Prospective study: 32 patients with the same clinical characteristics (Group 3) were treated by fine needle aspiration and percutaneous ethanol injection, and followed up for 12 months.

Groups 1 and 2: clinical evaluation, thyroid ultrasonography, thyroid scintiscan and serum thyroid hormone profile were performed before treatment and one month later. Group 3: clinical evaluation, thyroid ultrasonography and serum thyroid hormone profile were performed in basal conditions and 1, 3, 6, 9, 12 months after treatment. Thyroid scintiscan was performed before treatment and 3-6 months later.

(A) Randomized study: one month after treatment, nodule volume decrease in Group 2 was significantly higher than in Group 1 (Group 2: median 14.75 range 6-29.9 ml; Group 1: median 3.65 range 0.2-18.5 ml; P < 0.01). Nodule volume reduction was greater than 50% versus baseline in 8 (80%) patients in Group 2 and in 3 (30%) patients in Group 1 (P < 0.01). (B) Prospective study (Group 3): a significant nodule volume reduction (P < 0.01 vs pretreatment) was observed 1 and 12 months after percutaneous ethanol injection (pretreatment: median 14.5, range 1.5-65.8 ml; 1 month: median 3.5, range 0.4-38.9 ml; 12 months: median 2.5, range 0.4-34.5 ml). Nodule volume reduction greater than 50% was recorded in 24 (80%) patients. Groups 1-3: recurrence of cyst fluid was demonstrated by ultrasonography in 8 patients of Group 1, in 3 patients of Group 2 and in 1 patient of Group 3. No relevant adverse effects or significant biochemical changes were observed.

Ultrasound guided percutaneous ethanol injection of cystic thyroid nodules is a safe, low-cost and effective therapeutic procedure in patients with benign thyroid cystic nodules. Indeed, nodule volume reduction was significantly greater and more frequent in patients treated by percutaneous ethanol injection than in those patients who underwent fluid aspiration alone. These results were confirmed in a long-term prospective trial and only one fluid recurrence was observed during 12 months of follow-up.