Radiofrequency Ablation: A First-Line Treatment Option

Medscape

16-05-2025

This transcript has been edited for clarity.
Kaniksha Desai, MD: Welcome to the Thyroid Stimulating Podcast . This podcast was created in partnership with the American Thyroid Association to discuss up-to-date diagnosis and management of a wide array of thyroid diseases. I'm your host, Dr Kaniksha Desai, and today we're exploring an exciting and rapidly growing area in the management of hyperthyroidism: the use of radiofrequency ablation (RFA) for treatment.
For those of you less familiar with it, RFA is a minimally invasive technique that uses thermal energy to reduce or eliminate targeted thyroid tissue. Although it has been used internationally since the early 2000s, it was FDA approved in the United States in 2018. Initially adopted for the treatment of benign nonfunctioning thyroid nodules, RFA is now gaining traction as a promising option for patients with hyperthyroidism from toxic adenomas.
Joining us today is Dr Iram Hussain, associate professor of medicine in the Division of Endocrinology at UT Southwestern Medical Center in Dallas, Texas. She is the president of NASOIE, the North American Society of Interventional Endocrinologists, and she began one of the first endocrinology-led academic RFA practices in the US at UT Southwestern in 2022.
Dr Hussain has published extensively on this topic, including expert reviews in Clinical Thyroidology on the latest thermal ablation papers. She has also co-authored the American Thyroid Association's consensus statement on the safe performance, training, and adoption of ablation techniques for benign thyroid nodules, which was published in 2023.
We are honored to have her here today to share her experience and expertise with us. In today's episode, we'll dive into how RFA compares to more traditional therapies, such as surgery and radioactive iodine, including potential benefits, such as fewer side effects and a greater likelihood of preserving normal thyroid function rather than leading to permanent hypothyroidism.
Thank you, Dr Hussain, for joining us today.
Iram Hussain, MD: Thank you so much for having me. I'm thrilled to be here to talk about this exciting area of thyroid care.
Desai: I'd like to start off with a personal question. What piqued your interest in RFA, since it's a newer technique?
Hussain: My practice primarily consists of patients with thyroid nodules and thyroid cancer. When I was seeing patients in my clinic, many of them had symptoms or they would need some sort of intervention, but they were very reluctant to get surgery. Some of them were afraid of surgery, some of them didn't want a surgical scar, or they were afraid they would have to be on medication for the rest of their life.
When I discovered that this new technique was gaining popularity and a training course was available in the United States in 2018, I thought, Oh, I have to go and see what this is about. When I met Dr Jung Hwan Baek, from South Korea, who did the first cases of benign thyroid nodules, I saw that it was very similar to biopsies and fine-needle aspirations that we do in clinic.
I thought, We can do this in clinic and this is going to be great for patients. I love procedures, so I got trained and was like, let's set this up.
Desai: Thank you. I'm so glad you're here to talk to us about it. Can we start by talking about hyperthyroidism in general for our listeners? What are the different causes of hyperthyroidism and where specifically do toxic adenomas fit in?
Hussain: Hyperthyroidism can be caused either by too much production of thyroid hormone or by leakage of preformed thyroid hormone into the systemic circulation, which is usually thyroiditis.
Thyroiditis is typically self-limited, but when we're talking about overproduction of thyroid hormone, the most common cause is going to be autoimmune or Graves disease. About 5%-10% of hyperthyroidism is caused by autonomously functioning thyroid nodules. These are nodules that produce thyroid hormone independently of the pituitary's TSH regulation.
If there's just one thyroid nodule that's producing too much thyroid hormone, that's a toxic adenoma. If there's more than one, that's a toxic multinodular goiter. Essentially, the nodule just decides to produce hormone on its own, and that leads to suppressed TSH and elevated thyroid hormones.
Desai: How do you diagnose a toxic adenoma?
Hussain: Typically, you're going to do thyroid function tests first. You can have either subclinical hyperthyroidism, where the TSH is suppressed and you have normal circulating thyroid hormones, or you can have elevated thyroid hormones, which is hyperthyroidism.
Then, you are going to do an ultrasound to see if the patient has any nodules. Finally, you're going to do a radioactive iodine uptake and scan. This is going to tell you whether the nodules are producing too much thyroid hormone or if it's the whole gland.
Desai: That's very important to distinguish because the treatment options might be slightly different for the different causes of the hyperthyroidism. What are the standard treatment options? Can you go over them for our listeners?
Hussain: Traditionally, we've had three options for the treatment of hyperthyroidism. They include antithyroid medications, such as PTU, radioactive iodine therapy, and surgery.
Typically, in the case of toxic adenomas or autonomously functioning thyroid nodules, we don't prefer antithyroid medications because these nodules don't go into remission, so people end up being on antithyroid medications for life. In order to get them to definitive therapy, we either choose radioactive iodine or surgery, but both come with disadvantages.
Desai: I'm going to have you talk about some of those disadvantages later, but I wanted to switch now to RFA. Can you give us a little bit of background on how it works for thyroid conditions in general and for toxic adenomas?
Hussain: RFA is a minimally invasive procedure that uses thermal energy to essentially heat up the cells and cause necrosis. The cells die and then they scar over and shrink, and this shrinks the nodule. It's typically performed under ultrasound guidance using an electrode. It's been used internationally since the early 2000s for benign nodules and it's gaining popularity in the United States now. It's especially effective for solitary hyperfunctioning nodules because it targets a specific area.
Desai: When you are ablating it, you just ablate where the nodule is, and then that turns off all the thyroid function that's coming out of there.
Hussain: You're essentially going to insert a thin electrode into the nodule and start burning the tissue under ultrasound guidance. The aim is to burn the entire nodule so that there are no viable cells left. This way, the nodule will no longer produce too much thyroid hormone, and your thyroid function tests will normalize.
Desai: Can you tell us a little bit about who the ideal candidate for this procedure would be?
Hussain: Most of the studies show that this procedure works best in people who have nodules that are less than 12 mL in volume. If they're very big, it might not work in one session. It's particularly attractive for patients who want to avoid surgery or radioactive iodine, or for patients who have many comorbidities that make surgery risky.
Also, for patients who are planning pregnancy soon, because after radioactive iodine, you have to typically wait 6-12 months before getting pregnant. And especially for patients who are concerned about becoming hypothyroid, because the risk for hypothyroidism with this procedure is essentially zero.
Desai: That's amazing because for some of our other treatment options, including surgery and radioactive iodine, it's not zero. Is there anyone for whom you would not recommend this?
Hussain: It's typically not recommended in Graves disease because this is a diffuse disease process rather than a targeted area of excess thyroid production. You also want to avoid it in pregnancy because there are not enough safety data. The procedure uses an alternating current, and the patient has to have grounding pads on their thighs, so there are not enough safety data in pregnancy. You also can't do it in people who have bleeding disorders because that increases the risk for hematomas.
Desai: Can you walk us through what the RFA procedure looks like for your patients?
Hussain: This is typically going to be an outpatient procedure that you can easily do in the clinic. The patient is lying supine on your exam table, and you ask them to extend their neck. Then you use ultrasound to inject local anesthesia — typically lidocaine — into the skin and the parathyroidal area because the thyroid capsule is where most of the pain is.
After that, you insert the electrode into the nodule, keeping an eye on it with your ultrasound. You insert it parallel to the electrode probe and then move it using something called a moving shot technique. You're basically ablating the nodule layer by layer and treating it in sections until the entire nodule is ablated. This usually takes about 30 minutes for a very small nodule, but it can easily take over an hour if it's a very large nodule.
Desai: What complications can occur during or after the procedure?
Hussain: Because we are burning the nodular tissue, all of the complications are related to heat damage. The recurrent laryngeal nerve typically runs behind the thyroid and the tracheoesophageal groove. If there is heat damage to that nerve, there can be voice changes, and that's the most common complication.
Similarly, if you nick a vessel, you could potentially have a hematoma. There could also be damage to other surrounding structures, such as the vessels, the trachea, and the esophagus. There could be skin burns.
To avoid all of these, we keep the patient awake. We're talking to the patient throughout, making sure that they're not feeling heat or pain, and we're looking very closely on our ultrasound machine to make sure that we're ablating only the nodule and nothing else.
Desai: It sounds like it's pretty intensive for those 30 minutes.
Hussain: It definitely requires a large amount of concentration, but it gets easier with practice. I think that most people who do many thyroid procedures are quite comfortable doing it.
Desai: What happens if your patient who's now talking to you suddenly can't speak anymore? That can be kind of scary.
Hussain: That can be very scary. That means that you've caused some heat damage to the nerve, but you've picked it up very early because you're talking to them continuously. As soon as you notice the voice change, you're going to turn the machine off. Then you're going to wait a few seconds and talk to them to see if the voice is coming back.
If it's not coming back, then you're going to take a syringe with a needle and fill it with cold dextrose 5% in water, and inject it right on top of the nerve into the tracheoesophageal groove. Sometimes you need to inject a decent volume. If you're injecting enough fluid and cooling down the nerve fast enough, the voice will gradually come back.
It's very scary when it happens, but it's very exciting when the voice comes back and everything's fine.
Desai: Do you just continue the procedure then or do you have to do something else from there?
Hussain: You can continue the procedure if the patient's comfortable with that. It's happened to me twice, and in both cases, the patients continued the procedure successfully and had good outcomes.
Desai: Great. It is completely treatable. If that happens during the procedure, you just take a little break and you try to cool down the nerve. We talked a little bit about the preprocedural workup for hyperthyroidism, but is there anything special that you need to do before you consider RFA treatment in a patient?
Hussain: I will typically get their baseline thyroid function tests again, just to make sure they're not very, very hyperthyroid prior to the procedure because you may have to pretreat them with methimazole if that happens. Then I'll typically get platelet levels and an INR and PTT to make sure they don't have any risk of bleeding during the procedure.
Of course, in the case of toxic adenomas, you do want to have your ultrasound and your radioactive iodine uptake scan because you want to be targeting the correct area.
Desai: Speaking of that, you said the best patients would have one toxic nodule, but can you do this for a multinodular goiter?
Hussain: There's not much data for multinodular toxic nodular goiter, but I will say that it's possible if most of the thyroid hormone is coming from one dominant thyroid nodule. Otherwise, the challenge is that you would have to ablate each individual nodule that's making too much thyroid hormone, and this might result in the patient having to undergo more than one procedure, which comes with additional risk, additional cost, etc.
Desai: That can be a lot if you have three or four nodules.
Hussain: Yes, exactly.
Desai: Are patients cured immediately? What is the time lapse for this?
Hussain: Typically, they're going to notice a decrease in their thyroid hormone levels over the next few weeks. You can check the patient's thyroid function tests in 4-6 weeks, and you might notice an improvement.
Some people have a normalization of their thyroid function tests as early as 6 weeks, but most have it within 3 months. If the thyroid function tests have not normalized by 6 months, it usually means that the procedure wasn't successful and the patient may need a second session.
Desai: How often is a second session necessary?
Hussain: This depends on the initial characteristics of the nodule. As we discussed previously, nodules that are 10-12 mL in volume or lower respond very well and can typically be treated in one session. However, larger nodules, especially those larger than 30 or 40 mL, typically require more than one session. It really depends on the size.
Now, what's really interesting is that although all previous papers say that size is very important, recently a paper was published in Thyroid, in December 2024, which was the Latin American multicenter experience in treating solitary autonomously functioning thyroid nodules.
They noticed no difference in size. They had similar success rates with nodules that were less than 30 mL and those that were more than 30 mL, which was very interesting.
Desai: Do you think it's because they spent more time treating it or they had more experience treating it?
Hussain: I think as RFA gets more popular, people are starting to get better at it. Most of the people treating those nodules are very high-volume RFA practitioners, so they probably have been doing it for a while and they probably used a decent amount of energy on those nodules and used advanced techniques, such as the artery-first technique, and making sure that all the vascularity has been treated. I think experience definitely played a role there.
Desai: How much experience do you need? Is there an ideal number of hours or number of treated patients?
Hussain: There are a few studies on this, not very many. But typically, the learning curve of RFA is such that you continue to get better for the first 30-40 cases or so. After that, you consolidate your skills, and then there's not much improvement seen once you're past 60-90 cases. That's when you reach your peak. If somebody has done over 60-100 cases, they're probably going to be very good at it.
Desai: Do you think that makes a difference in the cure rate?
Hussain: I think it does in autonomously functioning thyroid nodules because the main difference between this and benign thyroid nodules is that, in autonomously functioning thyroid nodules, you have to ablate the entire nodule. In a nonfunctioning nodule, even if you leave a margin of unablated tissue, it's not going to start producing thyroid hormone. If you leave unablated tissue in an autonomously functioning thyroid nodule, you have a higher risk for recurrence later on.
Desai: Usually, is this in the first 6 months or can it be any time?
Hussain: It can typically be any time. It's usually after a year or so. Most people in the first 6 months will normalize their thyroid function unless they had an incomplete ablation.
Desai: Do you recommend long-term monitoring for these patients to ensure that they're cured years out?
Hussain: I think it would be prudent once they are past the first year to monitor at least yearly. They don't necessarily need to do it with their RFA specialist, but thyroid function tests as part of their annual physical should be sufficient.
Desai: Let's talk about RFA compared with other treatment procedures. How does it compare with radioactive iodine and surgery in terms of how effective it is?
Hussain: RFA is pretty similar in effectiveness to radioactive iodine. Most of the studies report a success rate of approximately 70%-90%, which is similar to radioactive iodine. Here's the interesting thing: When we talk about the success rate of radioactive iodine, we include patients who are made euthyroid and patients who are made hypothyroid. We, as endocrinologists, know that causing hypothyroidism isn't necessarily a success.
Because this procedure causes no hypothyroidism, I prefer it to radioactive iodine. It also shrinks the nodule, so if the patient has compressive symptoms, that also goes away. That doesn't happen with radioactive dividing surgery.
Surgery comes with surgical risks. It's a good option for a solitary toxic adenoma, to be honest. The hypothyroidism rate for surgery for a single toxic adenoma, getting a partial thyroidectomy, is only approximately 3%. It's fairly low, but you need a high-volume surgeon to avoid surgical risks. The patient has to go under general anesthesia and they do end up with a scar on their neck. All of those considerations factor into which procedure they might prefer.
Desai: Can you compare side effects of RFA vs radioactive iodine and surgery? I know you talked a little bit about it, but are there any main concerns?
Hussain: I would definitely say that, with surgery, you're going to be feeling the pain and be out of commission a little bit longer than with RFA. Typically, when we do an RFA, our patients just finish up the procedure and they can walk out the door and go live their life.
Radioactive iodine is fairly low risk on the side-effect-profile area. The main thing is that most thyroid disease occurs in women, and most of these women are of childbearing age. Many women don't want radiation exposure when they are trying to plan their families. I think that's a major disadvantage of radioactive iodine. RFA is quick and easy. There's no downtime. You can go to work the next day or the same day if you so choose. It's much easier to recover from this procedure.
Desai: It seems like it's a better option than radioactive iodine and surgery. With surgery, you are cured the next day, and then there's a little more time delay for the radioactive iodine and RFA, right?
Hussain: Definitely. We counsel patients that the nodule is going to shrink slowly over time. It usually shrinks the most in the first 4-6 weeks. Obviously, the results with surgery are immediate, but it depends on patient preferences here. After surgery, patients typically have to wait for the scar to heal up. They can't lift heavy things, and it interferes with their life quite a bit more.
People say that surgery is an easy procedure. As far as surgery goes, it is, but those patients are still discharged on pain medications. All you need is Tylenol after an RFA, if that, so it is much easier to recover from.
I give patients the option. I'm not opposed to people choosing surgery if that's what they want, if they want immediate relief. I think it's always nice to have an option.
Desai: For patients going to surgery, we often control their hyperthyroidism before surgery with antithyroid medications. We sometimes do that with radioactive iodine if they have severe hyperthyroidism. Can you talk about whether we do that for the RFA procedure?
Hussain: There is a small risk of causing thyroiditis due to inflammation because you're burning the cells. We try to keep the patient relatively euthyroid.
If somebody's starting out with subclinical hyperthyroidism, we might not necessarily start them on medication beforehand. If they have overt hyperthyroidism, then we're probably going to pretreat them with methimazole and at least get their free T3 and free T4 close to normal before starting the procedure.
After we've done the procedure, we might slowly taper off and recheck their thyroid function tests in 4-6 weeks, and then decide to stop the medication to see if they're now euthyroid.
Desai: How widely available is this procedure in clinical practice?
Hussain: It's becoming more popular and definitely growing in popularity. I want to say that there are probably over 250 physicians in the United States who are now offering RFA. More academic centers are starting to offer it, which is good. When academic centers start to offer it, that means people start to accept it more as standard of care. It's definitely growing,
Desai: I know you talked about who the ideal candidate is, but for those of our listeners who would be referring patients, how is it best to identify these patients and where do you send them?
Hussain: After you've determined that your patient has a toxic adenoma or a single autonomously functioning thyroid nodule, then you want to look at what size it is. There is a formula to calculate the volume, but if you don't want to do that, then you can look at the maximum diameter. If it's lower than 3-4 cm, they're probably a pretty good candidate for RFA.
If it's larger, they can probably still get it, but the practitioner doing the RFA might tell them that they may need more than one session. They can counsel them about that. There's no harm in referring out, getting a second opinion, and having the patient talk to somebody who does RFA to go over their options.
Reach out to centers with trained operators, so that could be endocrinology, surgery, or interventional radiology. Our society, the North American Society of Interventional Endocrinologists, has a directory, so you can search by city and send them to the person closest to you for a second opinion.
Desai: If someone wants to get trained in this procedure, how would they go about it?
Hussain: There are multiple training programs now available. Many of them are in collaboration with some major society meetings and many are done by the company representatives that are providing this technology.
I think it is important to observe somebody, who already does RFA in their practice, do it on an actual patient. I think that's very helpful when you're learning, so you can see exactly what the setup is like, how the patient tolerates the procedure, and whether or not you think you can incorporate it into your practice.
Desai: There you have it. If you want to get trained in the procedure, it's a relatively easy training. Tell me about reimbursement for this. I know that a CPT code recently came out for RFA, and hopefully now it should be covered more by insurance.
Hussain: It was very good news for patients when the CPT code came out on the first of this year, and we've noticed that many patients who previously could not get the procedure because they would have had to pay cash are now wanting to schedule it. We have not had any problems getting it reimbursed thus far. I think that access will only continue to grow.
Desai: This is wonderful for our patients as well. You mentioned that the ideal patient has a toxic adenoma, but are there any data on Graves disease?
Hussain: I reviewed a paper that was published in Thyroid in June of last year, and it was a really interesting paper because they took over 30 patients with Graves disease and treated them with RFA by essentially ablating both lobes. What they were trying to do is mimic a subtotal thyroidectomy. There was no distinct nodule, so they ablated all the tissue that they could safely ablate and then saw what the outcomes were.
They were actually not bad. I will say that it worked best in smaller thyroids. If the total volume of the gland was less than 20 mL, those patients tended to go into remission. Patients who had larger glands didn't go into remission that easily or they had recurrence of Graves'.
This is not entirely unexpected. When we published our early data in 2021 in the Journal of the Endocrine Society — those cases were done in the United States in 2018, 2019, and 2020, so the very early cases — we noticed that the best outcomes were with nodules that were less than 10 mL. If you have a thyroid that's 20 mL, essentially, one lobe is 10 mL or smaller on each side. Those were the cases that responded best.
It's still very early. It's not something that I would recommend except in truly exceptional circumstances. For example: You have a patient with Graves disease and they're allergic to antithyroid medication, so you can't give them that. They have an aversion to radiation exposure, so you can't give them radioactive iodine. They want to avoid hypothyroidism, and they have either strong opposition to a scar or they're not a surgical candidate.
In that situation, you could potentially consider this as a treatment option, but we don't have any long-term studies, so it's difficult to say.
Desai: How long were the long-term studies for toxic adenomas?
Hussain: We have studies for toxic adenomas for up to 5-10 years. It does have a durable response and people stay in remission, so it is a pretty good treatment option.
Desai: Do they get other nodules or does that one nodule just go away?
Hussain: Most of the studies are for single toxic adenomas, so that nodule just shrinks and becomes really small. Typically, you need about 80% volume reduction in the nodule to have normalization of thyroid function tests. If you have more than 80% volume reduction, the nodule just ends up being a very small nodule on ultrasound at the end of the follow-up time.
Desai: What excites you most about the future of RFA in managing thyroid disease?
Hussain: I really love that it's so patient centered. As I said before, patients come in and they don't want to be hypothyroid, they don't want a scar, they don't want radiation, and they don't want all these things. This is a way to treat them in such a manner that their nodule shrinks, their thyroid function tests normalize, and their neck looks completely normal. There's no evidence that you ever went in and did anything, so that's really great.
Desai: They can have this treated without everyone knowing about it as well.
I just want to review for our listeners. We talked about what RFA is and how it offers many more benefits than surgery and radioactive iodine treatment for toxic adenomas. It has an almost 0% rate of hypothyroidism, so patients don't have to take long-term medications of any sort.
Can you give us three clinical pearls for our listeners to remember about RFA?
Hussain: First, I'd want listeners to know that RFA is a legitimate first-line treatment option for autonomously functioning thyroid nodules. It's not like, oh, you're not a surgical candidate, you can't do this, and only then you can do RFA. It's a first-line treatment option, and if you want to do it, you should go see somebody who can do it for you.
Second, I think, personally, that smaller nodules do respond better despite the study that was published out of Latin America, I think it's easier to ablate smaller nodules. If you have a small nodule that's autonomously functioning, you should definitely consider RFA as a treatment option.
Finally, if you don't want a scar and/or don't want to be on levothyroxine, then this is the treatment option for you because this is the only treatment option that's going to guarantee that you're not on medication for the rest of your life.
Desai: Thank you for joining us today. For our listeners, please stay tuned for next month's episode, which will be on molecular testing for thyroid nodules — are they worth the money? Thank you.
Hussain: Thank you so much for having me.