Learn about a minimally invasive way to address an exceedingly common condition in this short presentation by interventional radiologist Alexander Lam, MD. He explains when benign nodules warrant treatment, which patients are candidates for RFA, how the technique works, and what the data show on safety and efficacy.
So, hi, uh, my name is Alex Lamb. I'm one of the interventional radiologists, uh, at UCSF, and today I'll be discussing radiofrequency ablation of the thyroid, a minimally invasive intervention for benign thyroid nodules. Uh, so I have no relevant disclosures, OK. Um, so the objectives for this talk are to discuss the epidemiology of benign thyroid nodules, present the procedural steps and workflow, uh, briefly review the literature supporting thyroid RFA, and provide some guidance on patient selection and adverse events after RFA. And, with that in mind, here's the outline, and, and let's get started with a brief background. As we know, benign thyroid nodules are present in up to 80% of the population, with the vast majority of the nodules, uh, being typically benign. OK. Although benign, thyroid nodules can be felt and seen when they become large. RFA is a new minimally invasive technique to treat benign thyroid nodules that are symptomatic. Um, so how's it done? Um, well, RFA utilizes the moving shot technique via trans isthmus approach. Uh, here's a picture from the literature depicting what I mean. In this scenario, the patient is laying flat, uh, typically with the head somewhat hyperextended, and under ultrasound, the probe is advanced through the isthmus into the nodule. Once in the nodule, the RFA probe is activated, um, burning the nodule from the inside out. The probe is continuously uh moving during the procedure, creating these linear microbubbles, these ablation units, if you will. Uh, and this is shown on the ultrasound image to the right, um, where this, these, uh, echogenic structures are the bubbles. OK. Ultrasound is used during the entirety of the procedure to avoid damage to the nearby vessels and nerves, including the recurrent laryngeal nerve marked by D in this image, uh, the middle cervical ganglion, uh, which typically kind of Seen posteriorly, kind of around the area of C and the vagus nerves seem more laterally demarcated by the letter A. Uh, moving on to indications and contraindications, OK? Um, so who would benefit from this procedure? The simplest answer is any patients with a symptomatic thyroid nodule who's not interested in surgery or, or not a candidate for surgery, OK? Uh, symptoms often include, uh, difficulty breathing, shortness of breath, difficulty swallowing, pain, or, or pressure. Um, solely cosmetic concerns are possible. However, patients typically present with symptoms in addition to cosmetic concerns when nodules grow large enough to become noticeable. With that being said, that isn't always the case. OK. Um, toxic nodules, also known as autonomously functioning nodules or AFTNs for short, are also appropriate candidates. Um, this particularly, this is, uh, particularly in patients who would like to avoid radioactive iodine, um, surgery or medical management. Again, however, those treatments are more of the standard, uh standard treatment options. OK. Diving a little deeper, the ideal nodule is one that is between 2 to 3 centimeters in diameter and less than 20 cc's in volume. Beyond that size, RFA can be used. However, multiple treatment options or multiple treatments may be necessary to obtain a significant size reduction, uh, to result in clinical improvements. Um, and surgery is typically recommended for multiple nodules or diffusely enlarged uh thyroid, also known as a goiter. However, embolization or a staged ablation approach can be considered for patients who are not surgical candidates. The nodule needs to be completely visualized under ultrasound. If a significant portion of the nodule is retrosternal or subclavicular, or otherwise obscured by a bone, RFA may not be the best option. Um, at this point, only nodules shown to be benign or proven to be benign on two separate biopsies are considered appropriate candidates. Um, as I mentioned, AFTNs less than 20 cc's in size are appropriate. Um, RFAs, RFA is less effective for larger nodules greater than 20 cc's at restoring eu thyroidism, so it's typically not, uh, not a great option in this scenario. Um, here are a list of contraindications, OK. This technology has not been tested in pregnant patients or in those with pacemakers, and it's currently not indicated in those, uh, in those patient populations. Uh, relative contraindications include malignancy, uh, a predominantly cystic nodule, uh, where ethanol ablation may be better and cheaper, uh, in patients with pre-existing contralateral vocal cord palsy. Injury of the recurrent laryngeal nerve during an ablation can result in significant disability. Um, so we have to be cautious in, in treating those patients, OK? As we discussed, um, Nodules with the large substernal or subclavicular components, um, uh, may not be best candidates because the nodule can be obscured by the thumb. Similarly, nodules with dense calcifications, uh, where we're unable to truly appreciate the size of the nodule, um, may not be good candidates as well. It's moving on to the evaluation and workflow. So ultra ultrasound is the first step, um, in evaluating, evaluating these nodules, OK? We can appreciate their size, their volume, their vascularity, their composition, and the surrounding lymph nodes. Um, and all these characteristics go into determining whether RFA is, is, is a good option, OK? We need, we need two biopsies to confirm that the nodule is in fact benign and ideally this is done, uh, 4 to 6 weeks apart. Give or take. Um, with that being said, the caveat is that one biopsy can be sufficient for nodules that have ultrasound features that are highly specific, um, for benign nodule, and that's your cystic spongiform nodules, OK. Um, one biopsy is also sufficient for AFTNs, OK, because those are, um, Typically, more often than not benign. Um, so here's the typical workflow for a patient who is found to have a symptomatic thyroid nodule. OK. Patients typically present to their primary care physician first, uh, who may then involve a surgeon, interventional radiologist, and or endocrinologist. At this time, a multidisciplinary discussion may occur among all the relevant providers as needed, and an evaluation for thyroid RFA is warranted, then a referral is sent to UCSF IR, OK. From there, the IR staff ensures that ultrasound, labs, and at least one biopsy is documented, uh, prior to the clinic visits. The patient is then scheduled for evaluation in IR clinic. In clinic, uh, we assess the patient's concerns, whether it's cosmetic, hoarseness, dysphagia, pain, what have you. Uh, we, uh, we ask, we discuss any prior interventions that the patient may have had, uh, we review their imaging, their labs, um, and their pathology results. We also perform a physical exam, uh, which can be done over Zoom, but also we're seeing patients in person more often these days. We can evaluate the size of the nodule, the overall appearance, of course, the presence or absence of any pre-existing neurologic involvement. OK. After that, we discuss the risks, the benefits, and the alternatives to RFA. If the patient would like to proceed, we place the order for the procedure. And then if necessary, we can coordinate any kind of pre-treatments for patients who are at higher risk for any kind of post ablation thyrotoxicosis. And this is typically done um with our endocrinology colleagues. Um, this is an outpatient procedure. It takes about 1 hour in length, uh, and patients can return to work in about 2 to 3 days at most. OK. It's all done with moderate sedation with, uh, IV fentanyl and Versed. Um, it's important to note that patients are still awake during the entirety of the procedure but mildly sedated. It's important that they're able to communicate with us in the event that uh there's any pain um during experienced during the ablation. Uh, if so, we can stop the ablation and perform the rescue maneuvers as needed. Um. Parathyroid anesthesia, um. With lidocaine is, is, is always provided. And we use hydrodissection with essentially um 5% dextrose water to separate the nodule from the adjacent sensitive structures such as skin, um, nerves, and vessels. OK. Um, the 5% dextrose in water is also used as our, um, Uh, rescue fluid as well in the event that, um, pain was experienced, um, suggesting any kind of nerve injury. So after the procedure, the patients returns to our, our recovery room for 1 to 2 hours of monitoring. And so we evaluate, we monitor their vital signs, evaluate for any pain, any discomfort, or any medications as needed, and, of course, um, make sure the patient recovers appropriately from sedation. I call all my patients, um, usually within 1 week after the ablation just to check in, see how things are going. Uh, and then I also see the patient in a formal clinic visit in 1 month. Um, I order an ultrasound evaluation at 3 months, and I also see the patient again with an ultrasound evaluation at 6 and 12 months. Um, so going on to efficacy and complications, OK? So what we hope to achieve is a volume reduction between 60 to 80% at 6 to 12 months. Some studies, um, a volume reduction of greater than 80% was seen at 2 years, OK? Um, studies have also shown that, um, that there's a significant improvement in multiple quality of life surveys, and that includes the SF 36, um, survey, as well as the Tro 39 questionnaire. OK. Uh, in addition, there is no significant impact on outcomes or safety of future thyroidectomy after RFA. So that means that we don't burn any bridges in the events that, um, the patient would like to pursue thyroidectomy, um, down the line. Compared to surgery, thyroid RFA has been shown to have a few notable benefits, including greater patient satisfaction. Improved postoperative quality of life, fewer complications, uh, shorter hospital stay, a lower incidence of, uh, hypothyroidism, and lower cost. And there is, however, a, a slower volume reduction, which makes sense, right? Because when after a thyroidectomy, the thyroid tissue is no longer present. However, after an ablation, it takes around 3 to 6 months for the, uh, nodule to decrease in size, to shrink. Um, overall, this, this procedure is very well tolerated and very safe, OK? Um, there's an overall risk of complication, uh, up to about 5% in the literature. OK, that includes transient nerve injury, uh, resulting in hoarseness, nodule rupture, transient hypothyroidism or hyperthyroidism, hematoma or pain, OK? Um, there's also an instance of nodule regrowth of about 5% at a meantime interval, about 22 months. It's not really a complication, but it's important to know that the nodules may, uh, increase over time. Uh, if this were to happen, if this were to happen, a repeat ablation, uh, has been found to be safe. Um, so in summary, uh, RFA is a novel, minimally invasive intervention for symptomatic benign thyroid nodules. It's safe and effective with a few significant benefits compared to surgical thyroidectomy. OK. Uh, in briefly, I'll go over a quick case. This is a 52 year old female with a benign left thyroid nodule. She has symptoms of dysphagia and hoarseness. Uh, the patient was not interested in any surgery. She did not want the scar. She had a very, uh, busy life. She didn't want to be, um, incapacitated for, for, for a week or so. She wanted an RFA. Uh, so here are just images from the procedure. You can see the trans dismiss approach. There's our probe, um, kind of, uh, being guided into the nodule. Um, here's the beginning of our ablation and you can see the, um, echogenic bubbles, uh, within the thyroid nodule as we pull back the, the, uh, the probe, OK? And here's our in conclusion showing the microbubbles dispersed throughout the nodule. Uh In this patient, in this case, we had a decrease in volume around 40% in vascularity at 1 month as you can see here. OK. Um, size continued to decrease over the course of multiple months, eventually reaching about 76%, uh, but hoarseness and dysphagia was essentially resolved that one month. Um, and that was a great outcome. And so here are some information, you know, if you're interested or have a patient who's interested, feel free to call the number to our uh to UCSF Interventional radiology. Again, I'm, um, Alex Lamb. And thank you for your attention.
