Endocrine Abstracts

Background: Percutaneous laser ablation (LA) is a therapeutic procedure used for the reduction of benign thyroid nodules. After LA a 50% nodule reduction was observed by most authors. However, eligibility criteria for LA based on long term efficacy have not been established.

Methods: Seventy-two patients (51 women and 21 men) with benign cold thyroid solitary nodules or a dominant nodule within a normo-functioning multinodular goiter underwent thermal Nd:YAG LA of thyroid nodular tissue by 1–4 optical fibers positioned into the tissue by 21-G needles under ultrasound real-time assistance. Mean±SD nodule volume was 28.1±29.3 ml. Energy delivered was 8842±6086 Joules with an output power of 2–4 Watts.

According to internal content, nodules were classified as follows: a) compact: iso/hypoechoic, homogeneous, ≤10% of cystic content; b) mixed: solid, inhomogeneous, with a 20–50% cystic content; c) spongiform: aggregation of multiple microcystic components in more than 50% of the nodule. Cystic nodules (fluid content ≥50%) were excluded from this series.

Results: Five years after LA, nodule volume decreased to 14.5±17.6 ml, with a reduction of −49.6% from pretreatment in the whole group of 72 patients. In 25 spongiform nodules, volume decreased from 24.8±25.9 to 7.7±7.5 ml, with a reduction of −58.7%. In 14 mixed nodules, volume decreased from 41.1±47.3 to 16.1±17.4 ml, with a reduction of −48.3%. In 33 solid nodules, volume decreased from 26.4±24.5 ml to 17.9±22.0 ml, with a reduction of −26.8%.

LA was more effective in patients with spongiform nodules as compared to mixed (P≤0.01) and compact (P≤0.001) nodules.

Conclusions: After 5 years, percutaneous LA achieved the expected 50% shrinkage in a variety of benign cold thyroid nodules. However, our data demonstrate that LA procedure was more successful and durable in patients with spongiform nodules. These patients are therefore the best candidates for percutaneous LA procedure.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.