Percutaneous laser ablation (PLA) in non-functioning benign thyroid nodules: a 3-year follow-up study
Roberto Valcavi1, Fabrizio Riganti1, Angelo Bertani1, Debora Formisano2 & Claudio M Pacella3
Aim of the study: To evaluate efficacy and safety of ultrasound-guided percutaneous laser ablation (PLA) on benign thyroid nodule size reduction, thyroid function and autoimmunity.
Methodology: This study was approved by local institutional review committee. All data are mean±S.D. Two hundred and ninety-eight euthyroid outpatients (F=241, M=57; age 50.7±12.0 years) with a benign thyroid nodule (volume 23.1±21.3 ml) causing either local discomfort or cosmetic complaint, were submitted to PLA. Under US guidance, optic fibers were carefully placed into the length of the lesion, then illuminated with Nd:YAG laser. According to nodule dimension, 14 fibers were used simultaneously. An output power of 24 W and a mean energy delivery of 8769±5311 J in a single session were used. Side effects, US images and hormonal changes were recorded at baseline and during a 3-year follow-up.
Results: Nodule volume changes are summarized in the following table.
|Baseline||1 week||1 month||6 months||1 year||3 years|
|Mean vol (ml)±S.D.||23.1±21.3||24.0±22.3||20.5±20.5||12.8±15.1||11.7±14.9||12.8±15.7|
|Mean Delta vol (% versus baseline)||+8.3%||−6.2%||−47.5%||−54.3%||−48.5%|
Mean TSH and fT4 values slightly and significantly changed immediately after PLA (baseline versus day 1: TSH=1.16±1.06 vs 0.62±0.81 mU/l; fT4=11.68±1.88 vs 13.20±3.32 pg/ml) and returned to baseline within 1 month. No change in fT3 value was observed. Two patients developed overt hyperthyroidism, whereas two patients developed hypothyroidism during follow-up. Anti-Tg and anti-TPO antibodies did not change significantly as a mean value. No major side effect was observed.
Conclusions: In our study, PLA was highly effective and safe in benign thyroid nodule size reduction. Energy delivery and number of optic fibers should be tailored to nodule size. Patients compliance and satisfaction was very high. On these basis, PLA may be a new promising therapeutic modality in benign thyroid nodule management.