Radiofrequency ablation for management of thyroid nodules: a case report

Radiofrequency ablation for management of thyroid nodules: a case report Kristanto Yuli Yarsa1, Monica Bellynda2* Background: Thyroid nodules constitute a frequently seen clinical problem and the incidence of thyroid nodules has increased with the recently increased use of thyroid ultrasonography. Radiofrequency ablation (RFA) is an effective and safe method for treating benign thyroid nodules and recurrent thyroid cancers. Case Presentation: A 48 years old woman came to the surgical oncology clinic with the presence of a getting bigger, moves when the patient swallows, and painless mass on her neck since 20 years ago. The physical examination measured 5x5 cm mass, mobile on swallowing, no pain on palpation, and the laboratory examination shows a euthyroid state. The ultrasound result has revealed an enlargement of the right and left thyroid with increased echo intensity of parenchyma and increased vascularisation. This mass was concluded as struma nodus bilateral. The FNAB was follicular neoplasm, Bethesda system class 4. The patient underwent a single session RFA. RFA was performed employing transisthmic access using a 7 cm 18 gauge electrode-needle with a 1 cm active needle tip. The patient well tolerated the procedure and no adverse events were noted. Conclusion: Radiofrequency ablation for thyroid lesions is a safe and effective method for treating benign thyroid nodules and even recurrent thyroid cancers. Therefore, various factors, including serum TSH, clinical risk factor assessment, size of the nodule, ultrasound characteristics, patient preferences, and results of the FNA biopsy, should be considered to manage thyroid


INTRODUCTION
Thyroid nodules constitute a frequently seen clinical problem and the incidence of thyroid nodules has increased with the recently increased use of thyroid ultrasonography (US). 1 Although most thyroid nodules are benign and do not require treatment, some benign nodules may require treatment for associated symptoms and/or because of cosmetic problems. 2, 3 Since RF ablation of thyroid nodules was introduced in 2006, it has been reported to be both safe and effective for treating benign thyroid nodules and recurrent thyroid cancer. 4-6 Radiofrequency ablation (RFA) is an effective and safe method for treating benign thyroid nodules and recurrent thyroid cancers. 6-11 Since 2012, thyroid RFA has been adopted worldwide, with subsequent advances made in devices and techniques, such as shorter and thinner electrodes, bipolar electrodes, virtual needle tracking systems, and unidirectional electrodes. 12 Based on those mentioned above, this case study aims to evaluate the utilization of radiofrequency ablation to manage thyroid nodules at Dr. Moewardi General Hospital, Surakarta, Indonesia.

CASE REPORT
A 48 years old woman came to the surgical oncology clinic with the presence of a getting bigger, moves when the patient swallows, and painless mass on her neck since 20 years ago. The physical examination confirmed the presence of a soft-elastic mass in the left and right side of the neck, measured 5x5 cm, mobile on swallowing, no pain on palpation ( Figure  1). The laboratory examination shows a euthyroid state (TSH 2.4 mIU/L and FT4 1.2 ng/dL). The ultrasound result was the enlargement of the right thyroid (3.1 x 3.3 x 3.5 cm; Volume > 20 ml) with increased echo intensity of parenchyma, enlargement of left thyroid (2.6 x 3.4 x 3.4 cm; volume >16.6 ml) with normal echo intensity of parenchyma, solid lesion around 1.2 cm spongyosa type at left thyroid and

CASE REPORT
( Figure 2). The patient well tolerated the procedure and no adverse events were noted. Over the next 1 week, the patient went to the oncology clinic for follow up and the patient reported a progressive improvement of her neck symptoms ( Figure 3). One month, three months, and six months after the procedure, both patients followed-up ( Figure 4). The patient was followed up by ultrasound for six months. The result was a visible and progressive reduction of the nodule.

DISCUSSION
Benign thyroid nodules were found in 4-8% by palpation, in 10-41% by ultrasonography, and 50% by a pathologic examination. 6,7 It requires treatment for cosmetic reasons, subjective symptoms, or anxiety about a malignant change. The management for benign thyroid nodules consists of two parts: surgery and levothyroxine medication. However, both surgery and medication have disadvantages. Surgery is a curative procedure but has problems, including general anesthesia, scar formation, and iatrogenic hypothyroidism. Besides, the efficacy of levothyroxine medication therapy is still controversial. 7 Radiofrequency ablation is an effective and safe method for treating benign thyroid nodules and recurrent thyroid cancer. 12 This procedure has been proposed as an alternative treatment modality for primary thyroid microcarcinomas. In 2012, this procedure was adopted worldwide, with further progress in tools and techniques. 12 Radiofrequency ablation uses heat generated from high frequency oscillating electric currents around 200 to 1200 kHz. 12,13 RF waves passing through the electrodes move the tissue ions around the electrodes. They increase the temperature (by friction heat) in the tumor tissue, causing tumor damage located very close to the electrode. Heat conduction from the sanded area can cause tumor damage that is relatively slower or tissue far from the electrode's tip. 13 Complications of radiofrequency ablation including hematoma, skin burn at the puncture site, fever, pain, voice change, thyrotoxicosis, hypothyroidism, and edema, but most patients recovered   . A) One month after the procedure, B) Three months after the procedure, C) Six months after the procedure rapidly without sequelae. 13, 14 Hematoma, skin burn, and fever can occur because of mechanical injury to the anterior jugular vein or perithyroidal vessels. Mild compression stops bleeding to prevent hematoma and application of an ice bag prevents skin burn. Pain because radiofrequency ablation procedure radiates to head, ears, shoulders, chest, back, or teeth. The pain is rapidly relieved after the procedure stops or only 5.5 % of patients need oral painkillers. 14 Voice changes are caused by thermal injury to the recurrent laryngeal nerve or vagus nerve. Ablation carefully on the danger triangle and recurrent tumors to prevent voice changes. 13,14 Thyrotoxicosis and hypothyroidism can occur, but the mechanism is poorly understood because the patients show a continuous increase of serum peroxidase antibodies before and after radiofrequency ablation. 3

CONCLUSION
Radiofrequency ablation for thyroid lesions is a safe and effective method for treating benign thyroid nodules and even recurrent thyroid cancers. Therefore, various factors, including serum TSH, clinical risk factor assessment, size of the nodule, ultrasound characteristics, patient preferences, and results of the FNA biopsy, should be considered to manage thyroid nodule.