Long-term outcome following laser therapy of benign cystic thyroid nodules

Laser therapy (LT) is a safe and effective procedure for inducing thyroid nodule necrosis and shrinkage. Here, our aim was to evaluate long-term efficacy of LT in patients with a predominantly cystic benign recurrent thyroid nodule. Eighty-seven euthyroid outpatients (21 men and 46 women; mean age: 48 years; range; 17-82) with a recurrent cytologically benign cystic ( > 2ml cyst-volume) thyroid nodule causing local discomfort were assigned to LT. LT, using one laser fibre, was performed after complete cyst aspiration and under continuous ultrasound (US) - guidance. The output power was 2.0-3.0 W, and mean delivered energy was 1305 J (range; 94-4392 J). Mean treatment duration was 569 sec. (range; 47-1545). 16 patients (14 within 6 months) had surgery after LT. All had benign histology. The mean follow- up for the remaining 71 patients was 50 months (range; 12-134). Pressure symptoms and cosmetic complaints were evaluated on a visual analogue scale (0-10 cm). The overall mean nodule volume in the 71 patients decreased from 12.2 ml (range; 2.3-45.0) to 1.5 ml (range; 0.7-11.0) (p <0.001) at the final evaluation, corresponding to a mean reduction of 82% (range; 14% - 100%). Remission of the cystic part (cyst volume <1 ml) was obtained in 66 of 71 (93%) patients after LT. The mean cyst volume decreased from 9.8 ml (range; 2.0-45.0) to 0.3 ml (range; 0-4.0) (P <000.1), corresponding to a reduction of 95% (range; 43%- 100%). The mean volume of the solid part of the nodule was reduced from 2.6 ml (range; 1.8-15.1) to 1.1 ml (range; 0.5-6.1) (P <0.001). These results correlated with a significant decrease in pressure as well as cosmetic complaints. Thyroid function was unaltered throughout and side effects were restricted to mild local pain. US-guided aspiration and subsequent LT of benign recurrent predominantly cystic thyroid nodules results in a satisfactory longterm clinical response in the majority of patients. It is a safe and well tolerated procedure and significantly reduces long-term recurrence rate, size of the solid portion of the nodule, and nodule related symptoms. LT constitutes a clinically relevant alternative to surgery in such patients.