Reports evaluating the efficacy of LA for therapy of hyperthyroidism due to hyperfunctioning nodules have less consistent results. A few small series of hyper-functioning thyroid nodules treated with laser ablation report normalization of thyroid function and the resolution of the previously hyperfunctioning area at post-treatment radioisotope scan [50, 55, 60]. Others demonstrated that LA was not invariably effective, and that multiple LA sessions were required to normalize TSH levels [48, 61, 74]. Finally, a randomized trial on 30 solitary hot nodules with extraglandular suppression, treated either with a single LA session or one radioiodine dose, demonstrated that LA and ¹³¹I therapy had a similar effect on nodule volume reduction. However in contrast to ¹³¹I, LA was less likely to results in a normal serum TSH (only 50 % of patients) [75]. Overall, these results demonstrate the effectiveness of LA when treating small, solitary and mildly hyperfunctioning nodules [65, 74]. In toxic nodular goiters or large autonomously functioning thyroid nodules, LA therapy results are more inconsistent and the normalization of thyroid function usually requires repeated treatment sessions [48] (Table 37.2). A recent pilot study [76] compared outcomes in patients large toxic nodules treated with LA followed by ¹³¹I with those treated by ¹³¹I only, and demonstrated that combined treatment induced a more rapid and substantial improvement in local and systemic symptoms compared to ¹³¹I only. In addition, for three patients, no ¹³¹I treatment was needed after LA. This approach seems a possible alternative to thyroidectomy in patients who refuse surgery.

In a recent report, 44 subjects with predominantly cystic thyroid nodules were randomly assigned to aspiration alone or to fluid drainage immediately followed by laser ablation [59]. At 6 month follow-up, both clinically significant volume decrease and improvement of local symptoms were observed in 15 of 22 (68 %) of cases in the thermal ablation group compared to only 4 of 22 (18 %) cases in the fluid drainage group. Laser ablation significant decreased the solid component of the cystic lesion (from 1.8 to 1.0 mL), while in the drainage alone group, the solid part was not reduced. No side effects were reported and thyroid function was maintained.

Even if the outcomes of laser ablation for cystic nodules are favorable, percutaneous ethanol injection still remains the first-line minimally invasive treatment for predominantly cystic lesions due to its low cost, safety, and easiness [77]. Laser ablation should be considered only for the management of complex lesions with a relevant solid component because it will both prevent fluid recurrence and reduce of the solid part of the nodule.

Laser ablation is a fairly well tolerated procedure. Mild to moderate cervical pain, minor neck swelling and a low-grade fever may occur after treatment and commonly last 1 or 2 days. These side effects may be controlled with the oral administration of acetaminophen.

Minor complications are infrequent and include persistent cervical pain that radiates to the ear, lower jaw or chest that does not dissipate after the laser ablation procedure. Pain subsides spontaneously but may last up to 24 h is done [61, 62]. Subcapsular hematoma and skin burns are extremely rare [52, 69]. Severe neck swelling due to subcutaneous edema, and cystic transformation have been occasionally reported [66]. The occurrence of transitory hyperthyroidism or late hypothyroidism is rare in patients with normal thyroid function [66].