What is Thyroid Radiofrequency Ablation – How are RF used in the treatment of thyroid cancer?
Thyroid Radiofrequency Ablation (RFA) is a minimally invasive method for destruction of benign thyroid nodules and masses. Research results have shown that irradiation of target mass by RF waves reduces its volume about 33% – 58% and 51% – 85% after one and six month, respectively. This procedure has also demonstrated desirable response for malignant thyroid nodules (thyroid cancer). This less invasive treatment, with fewer complications than surgical treatment is preferred option by patients. In the following we introduce fundamentals of thyroid radiofrequency ablation.
What is Thyroid Radiofrequency Ablation?
Radiofrequency (RF) is a radio wave technology in which the transmission of radio waves through body tissues causes high frequency oscillation of constituent molecules. It also oscillates bipolar molecules in the tissue. Consequently, it produces a mechanical micro-stimulation (in molecular-cellular level) in cells, collagen and elastin, which eventually leads to cellular turnover and flexibility. This type of degradation is mainly used to eliminate solid nodules.
How does Thyroid RFA Works?
In short, in this procedure electrical waves with frequency of 200 to 1200 kHz stimulate ions in the target tissues which increases the temperature of the tumor by friction heat to the tumor and this increase in heat degrades the tumor cells. Temperature changes in cells up to 60-100 C lead to irreversible cellular while temperatures between 100 to 110 C prevent the spread of the tumor. In general, thyroid RFA is one of efficient methods for treatment of benign and malignant thyroid masses with optimal outcome. This procedure is performed under ultrasound or CT guidance.
Other RF Applications
This procedure is also being used for treatment of lymph node disorders. Clinical signs, including sore throat and cough, indicate the onset of the procedure effects.
Thyroid RFA in treatment of thyroid cancer
The results of RFA procedures in the treatment of patients with thyroid cancer and malignant tumors suggests that this method can be included in the physician armament and the outcomes of this procedure strongly supports its role in the treatment of thyroid cancer. However, RFA has limited applications in the treatment of other types of cancers and malignant nodules is not recommended for some other types of thyroid cancer, including follicular thyroid carcinomas. Different studies have shown no evidence for effectiveness of this procedure for other cancerous conditions.
Cautions in Thyroid RFA
Due to degradation of thyroid mass, caution should be exercised in using this procedure for pregnant women and people with serious heart conditions.
Complications of thyroid RFA
Before the introduction of RFA and minimally invasive procedures with low rate of complications, thyroid surgeries performed with high rate of complications including vocal cord injuries, infections, anesthesia adverse effects, damage to other cervical tissues or parathyroid glands.
This procedure has far fewer complications than surgical treatment, however all medical procedures including RFA may produce some adverse effects along with desired outcomes. Complications of thyroid RFA may include itching, hematoma, sore throat, or esophageal puncture or rupture. Since these complications are insignificant and infrequent, thyroid RFA is a reliable option for the treatment of thyroid cancer (malignant thyroid cancer) and benign thyroid nodule.
RF applications in other diseases
Radiofrequency ablation is not only used as a treatment for thyroid cancer, but it can also be a common treatment for liver diseases and dermatology conditions. In light of studies and trials to date, the application of RF technology in different subspecialties promise huge potentials.
History of Thyroid RFA in Iran
The first successful RFA procedure in Iran was performed in February 2009. In this procedure a thyroid mass was treated with excellent results that were published in accredited international journals and presented in Iranian endocrinology and radiology conferences. Since then RFA for thyroid has been used as a routine procedure in the country. Specialized physicians in some cities, especially the capital city (Tehran), accomplished excellent results in the treatment of thyroid nodules by this modality. In recent years, numerous successful procedures for the treatment of thyroid nodules have been reported. The ablation of nodules by the RF or other methods such as alcohol injection have achieved some success in this area, and efforts to promote and educate this technique to other specialists in the country continues.
Suitable cases for thyroid RFA
• Biopsy confirmed benign masses
• Contraindications for surgery especially in cases where the size of tumor is less than 1 cm
• Malignant lymph nodes that are not suitable for surgical treatment due to postoperative adhesions
• Hyperthyroid patients with one overactive nodule which is called autonomously functioning thyroid nodules (AFTN). In this case the primary choice is RFA because it can be used even for pregnant and lactating patients, and it simply treats exactly the overactive nodule. Unlike hypothyroidism that usually follows radioiodine therapy by I-131, this procedure is free from such complications.
Thyroid RFA preparation
The first step in the treatment of thyroid condition by RFA is patient consultation for proper selection. In the next step the patient status must be assessed by routine tests of thyroid hormone and coagulation. Unlike surgery, there is no absolute contraindication for using Aspirin and Plavix in RFA patients and the procedure can be conducted in patients with heart condition with caution.
RFA Procedure
After patient preparation, interventionist put the patient in supine position with a slight extension in the neck. The procedure completes within 10 to 20 minutes. After initial measurements the RFA instrument which is a special thin needle is directed to the target area, thyroid nodule or involved lymphatic node, without skin incision. Like thyroid biopsy, this procedure is performed under local anesthesia and the patient experience no patin. In the process for RFA the interventionist and patient have conversation to ensure the vocal cords remains intact and have proper function. This feature of RFA prevents vocal cords damage which is common in surgery. (During thyroid surgery the patient is under general anesthesia and vocal cords function test is impossible. Unlike RFA, vocal cords irreversible damage is probable in surgery).
Does patient experience any pain in RFA procedure?
Generally, RFA procedure is painless and in few cases some patients may experience a radiation pain in shoulder or maxillary area. This pain can be reduced by device adjustments and in such cases, the patient can inform the specialist.
Post-procedural conditions
After RFA procedure the patient usually is monitored for one or two hours and then discharged. Common complications of RFA includes stiffness in the area for three to five days, slight pain, pruritus, night sweats and loss of appetite. These complications implies the treatment effect and after this time, the patient returns to normal life. The pain and the above-mentioned complications are tolerable by supportive treatments and the use of fluids and painkillers. They do not interfere with life and after about 5 days the decrease in mass volume begins. The reduction is very significant in the first month and continues for 6 months.
The necessities of RFA post-procedural conditions
Regular and proper use of the recommended medications, especially in the first 5 days, is the most important contribution of the patient. One month after the procedure, new tests including hormone function tests ordered for the patient. The results are usually indicates no changes because the normal thyroid tissue remains intact in RFA. The follow up monitoring and evaluation of mass volume reduction performed in one-, three-, six- and twelve-months intervals. The necessity for re-treatment is evaluated in these follow up visits and the interval between two procedures is usually three months, if necessary.
Tirad Imaging and Ultrasound Center
We provide thyroid RFA services in Tirad Imaging and Ultrasound Center located in Tehran. If you need more information about the procedure or get an appointment, feel free to contact us. Follow us on Instagram to find more about our services.
You can also review the experiences of some patients in the Video Archives of the website to learn more about this procedure and post-procedural conditions.
Click here to play the audio file for descriptions of thyroid RFA by Dr. Hojjat Ebrahimi Nik (for members only)