Effect of ultrasound-guided interstitial laser photocoagulation on benign solitary solid cold thyroid nodules:: One versus three treatments

Objective: Interstitial laser photocoagulation (ILP) is a safe and effective procedure when inducing thyroid nodule necrosis. In this prospective randomized study, we evaluated a possible dose-response relationship as well as patient satisfaction. Design: Thirty euthyroid outpatients with a cytologically benign solitary solid and scintigraphically cold thyroid nodule causing local discomfort were assigned to one session of ILP (ILP-1) (n = 15) or three monthly ILP sessions (ILP-3) (n = 15) and followed for 6 months. ILP was performed under continuous ultrasound (US) - guidance and with an output power of 2.5-3.5 W. Thyroid nodule volume was assessed by US. Pressure and cosmetic complaints were evaluated on a visual analogue scale. Main outcome: In the ILP-1 group, thyroid nodule volume decreased from 10.1 +/- 4.3 mL (mean +/- standard deviation [SD]) to 5.7 +/- 3.2 mL (p = 0.0004), and in the ILP-3 group from 10.8. +/- 5.5 mL to 4.6 +/- 3.0 mL (p = 0.0005) during follow-up. The overall mean difference between the two groups was 13%, corresponding to an improved mean thyroid nodule volume reduction of 30% (p = 0.03). In both groups subjective symptoms were significantly reduced, and without difference between the two groups (p = 0.7). No major side effects were seen in either group. Conclusion: As a nonsurgical therapeutic option, ILP-1 approximately halves thyroid nodule volume with concomitant symptom relief. There is little incremental effect of additional ILP treatment, which should be limited to patients with large nodules or limited nodule reduction after the first treatment.