Ultrasound-guided percutaneous radiofrequency ablation for benign thyroid nodules

5.1 Nodule rupture was reported in 1 patient treated by radiofrequency ablation (RFA) in a non‑randomised comparative study of 400 patients. Nodule rupture was reported in less than 1% (2/1459) of patients in a case series of 1,459 patients: 1 patient recovered without treatment and 1 patient was admitted to hospital and treated with antibiotics and analgesics. In the same study, 1 patient had nodule rupture with abscess formation: the patient was treated by left thyroidectomy. Nodule rupture was reported in 1 patient in a case series of 40 patients: this occurred 26 days after RFA and was treated with anti‑inflammatory medication.

5.2 Vocal fold palsy was reported in 1 patient in a systematic review of 284 patients. This was diagnosed at 1‑month follow‑up, but the patient was subsequently lost to follow‑up. Permanent vocal cord palsy with inspiratory stridor without dysphonia was reported in 1 patient treated by RFA in a randomised controlled trial (RCT) of 84 patients.

5.3 Voice change immediately after the procedure was reported in 5% (2/42) of patients treated by RFA in the RCT of 84 patients; this resolved completely within 3 hours of the procedure. Transient hoarseness was reported in less than 1% (1/200) of patients treated by RFA and in 1.5% (3/200) of patients treated by surgery in the non‑randomised comparative study of 400 patients. Voice change was reported in 1% (15/1459) of patients in the case series of 1,459 patients; all patients recovered completely, except for 2 patients who were lost to follow‑up.

5.4 Brachial plexus injury was reported in 1 patient in the case series of 1,459 patients. The patient had numbness and decreased sensation in the fourth and fifth fingers of the left hand; this gradually recovered during the next 2 months.

5.5 Diffuse glandular haemorrhage was reported in 1 patient in the systematic review of 284 patients. This resulted in interruption of the procedure. The patient was given oral analgesics for pain relief for 3 days. Intranodular bleeding was reported in 8% (3/40) of patients in the case series of 40 patients: this was stopped by swift needle‑electrode insertion and heat administration. In the same study, pericapsular bleeding was reported in 1 patient, who had extensive neck bruising 5 to 10 days after the procedure. Haematoma was reported in 1 patient in the systematic review of 284 patients and in 1% (15/1459) of patients in the case series of 1,459 patients: most completely disappeared within 1 to 2 weeks.

5.6 Postoperative oedema was reported in 1% (3/284) of patients in the systematic review of 284 patients. This was treated with betamethasone medication.

5.7 A full‑thickness skin burn was described in a case report. The burn took more than 1 month to heal but its final appearance looked almost like the normal skin. First‑degree skin burns at the puncture sites were reported in less than 1% (4/1459) of patients in the case series of 1,459 patients: all patients recovered from pain and skin colour changes within 7 days without sequelae.

5.8 Vasovagal reaction during the procedure was reported in less than 1% of patients in the case series of 1,459 patients. This included sweating, difficulty breathing and hesitation; it was treated by elevation of the patient's legs and stopping the ablation. Vasovagal reaction was reported in 1 patient in the case series of 40 patients. The patient had bradycardia, hypotension, vomiting and defecation; the bed was tilted, ablation was stopped and the patient recovered within a few minutes. The patient had a subsequent RFA session 3 weeks later. Vomiting was reported in less than 1% (9/1459) of patients in the case series of 1,459 patients: this improved within 1 to 2 days after treatment with antiemetics.

5.9 Pseudocystic transformation was reported in 1 patient in the case series of 40 patients: the patient had a painful sudden swelling 3 weeks after RFA, which was treated with oral corticosteroids.

5.10 Permanent hypothyroidism was reported in 1 patient in the case series of 1,459 patients: the patient had gradual neck bulging and ultrasound showed diffuse enlargement of the thyroid gland without a thyroid nodule.

5.11 In addition to safety outcomes reported in the literature, specialist advisers are asked about anecdotal adverse events (events which they have heard about) and about theoretical adverse events (events which they think might possibly occur, even if they have never done so). For this procedure, specialist advisers listed the following theoretical adverse events: oesophageal or tracheal thermal injury, cardiac arrhythmia, and sympathetic or spinal nerve injury.