Protocol of RFA
tumor
INTRAOPERATIVE COMPLICATIONS, TUMOR, TUMOR RECURRENCE, RESIDUAL TUMOR
Radiofrequency energy was generated using a VIVA radiofrequency generator (STARmed, Goyang, Korea) and an 18-gauge monopolar internally cooled electrode (VIVA; STARmed). Continuous cooling with distilled water circulation prevented overheating of the electrode shaft. The patient was positioned supine with a slightly extended neck. Local anesthesia with 1% lidocaine was administered, and fluid was injected between the tumor and surrounding tissues to create a distance from the tumor, thereby mitigating the risk of heat-related injury. Ablation was performed under ultrasound guidance with an energy output of 20–40 W until complete tumor coverage. Immediately following the ablation, CEUS was conducted to assess the ablation zone. If residual tumor tissue was suspected based on CEUS findings, repeat RFA was performed to achieve comprehensive tumor eradication. Neck compression was applied for a duration of 30 min. The duration of the procedure, as well as any intraoperative complications, were diligently documented. Following the ablation, each patient remained under observation at the hospital for a period of 1–2 h. Postoperative follow-up examinations were conducted at 1, 3, and 6 months using neck ultrasound and CEUS. Subsequently, every 6 months, the ablation zone and tumor recurrence were evaluated using two dimensional ultrasounds (2D-US). At 3 months post-RFA, an ultrasound-guided fine needle aspiration biopsy (FNAB) would performed on the RFA zone to confirm the therapeutic efficacy.