To evaluate the efficacy of RFA procedure in reducing the volume of benign cystic thyroid nodules, measured by the volume reduction rate (VRR) at 1, 6, and 12 months post-procedure.

• To assess the safety of RFA procedure, including the incidence of major and minor complications.

Radiofrequency ablation (RFA) is a minimally invasive procedure used to treat benign thyroid nodules without surgery. It involves inserting a thin, needle-like electrode into the nodule under ultrasound guidance. Using high-frequency alternating current, the electrode generates heat to destroy targeted thyroid tissue, causing the nodule to shrink over time.

The volume reduction rate (VRR) is used to assess the effectiveness of radiofrequency ablation (RFA) in shrinking thyroid nodules over time. It is calculated as the percentage decrease in nodule volume compared to baseline:

VRR (%) = [(Initial Volume - Follow-up Volume) / Initial Volume] × 100

In this study, VRR will be measured at 1, 6, and 12 months after the RFA procedure using ultrasound. A VRR greater than 50% is generally considered a successful therapeutic outcome. Tracking VRR at these time points helps evaluate the progressive reduction in nodule size and the long-term efficacy of the treatment.

The volume reduction rate (VRR) is used to assess the effectiveness of radiofrequency ablation (RFA) in shrinking thyroid nodules over time. It is calculated as the percentage decrease in nodule volume compared to baseline:

VRR (%) = [(Initial Volume - Follow-up Volume) / Initial Volume] × 100

In this study, VRR will be measured at 1, 6, and 12 months after the RFA procedure using ultrasound. A VRR greater than 50% is generally considered a successful therapeutic outcome. Tracking VRR at these time points helps evaluate the progressive reduction in nodule size and the long-term efficacy of the treatment.

The safety of radiofrequency ablation (RFA) procedure for benign thyroid nodules is evaluated by monitoring the incidence and severity of complications following the procedure. Complications are classified as major (e.g., permanent voice changes, significant bleeding requiring intervention, hospitalization) or minor (e.g., transient pain, temporary voice hoarseness, mild swelling).

All adverse events are recorded during and after the procedure, and at follow-up visits at 1, 6, and 12 months. Safety assessments follow international guidelines for image-guided tumor ablation. The absence of serious complications and a low rate of minor, self-limiting events indicate that single-session RFA is a safe and well-tolerated alternative to surgery for selected patients with benign thyroid nodules.