Laser ablation is more effective for spongiform than solid thyroid nodules. A 4-year retrospective follow-up study

Purpose: Laser ablation (LA) is used as therapeutic modality for reducing the volume of large benign thyroid nodules. The aim of this retrospective study was to assess the efficacy of LA therapy in patients with benign non-functioning thyroid nodules in a 4-year follow-up and evaluate whether different compactness of nodules may influence the final shrinkage. Patients and methods: Fifty-six euthyroid patients (42 females; mean age 54.7 +/- 11.7 years) with benign cold thyroid solitary nodules or a dominant nodule within a multinodular goitre underwent LA between July 2009 and March 2012. Nodule volume, thyroid function test and ultrasound were monitored at baseline, and at 3, 6 and 12 months after the procedure, then annually. Results: With a mean baseline volume of 15.7 +/- 11.7 mL, nodule volume decreased by 55.5% (6.5 +/- 5.7 mL) 4 years after LA (p<.01). Nodules had a significant decrease at 3 and 6 months, thereafter they remained stable, with an insignificant tendency to re-growth at 48 months. Thyroid functions and antibodies were unchanged throughout the follow-up. When dividing nodules into solid and spongiform, the former decreased at 6 months, remained stable up to 24 months, but showed a nonsignificant tendency to increase thereafter. Spongiform nodules progressively decreased up to 48 months. The difference in nodules' reduction between solid and spongiform nodules was significant from 3 months (p = .04) and became even more significant up to 48 months (p = .001). Conclusions: The LA technique succeeded in reducing thyroid nodules by about 50% at 4 years, but was more effective for spongiform than solid nodules.