Endocrine Abstracts

Background: Thyroid nodule is the most common endocrine disorder with the prevalence of more than 50% in adults. Majority of nodules are small in size and can be detected only by various imaging methods. Thyroid nodules are usually benign, asymptomatic, and do not need treatment. Growing and large symptomatic thyroid nodules are usually treated with thyroidectomy. Novel minimally invasive ablation techniques can be alternative to surgery. Percutaneous laser ablation is causing irreversible thermal destruction of tissue by conversion of the absorbed laser light into heat. Method is only applicable in benign thyroid nodules.

Aim: To evaluate efficiency and safety of ultrasound (US) guided percutaneous laser ablation of thyroid nodules.

Patients and Methods: In our prospective study, we included two male and four female patients with a mean age of 50.5 ± 10.9 years with US isoechoic homogeneous thyroid nodule larger than 3 cm in diameter and 5 ml in volume, which was scintigraphically ‘cold’ and two times benign on cytology examination (Bethesda 2). Under US guidance optical fiber(s) were inserted percutaneously directly into the nodule through inserter using cranio-caudal approach. In order not to damage surrounding tissue the optical fiber(s) were positioned at least 10–15 mm from nodule border. Depending on nodule volume and size we applied from 1800 J to 8400 J of energy. We used one or two fibers and zero to two ‘pull backs’. Outcome was evaluated one week, one month and three months after the procedure. Results are reported as mean ± standard deviation. T-test was used for statistical analysis.

Results: Initial mean volume of thyroid nodules was 20.6 ± 7.6 ml (range, 9.4–31.6 ml). Volume of nodules decreased to 14.6 ± 6.6 ml (reduction of 29.1%) at one week, 13.0 ± 5.7 ml (reduction of 36.9%) at one month and 10.8 ± 5.6 ml (reduction of 47.6%) at three months after the procedure (P = 0.0573, P = 0.0005, P = 0.0003, respectively). Regarding adverse effects, one patient reported periprocedural pain in the nodule (VAS score, 3/10), which was not observed after the procedure. In the first week after the procedure two patients reported tension in nodule and headache. No voice changes or other adverse events were observed.

Conclusion: In our initial experience, US guided percutanoues laser ablation of thyroid nodules is effective and safe procedure. Inclusion of a larger group of patients and follow-up for a longer period of time is needed in order to obtain more reliable results regarding efficiency and safety of the procedure.