Radiofrequency ablation of thyroid nodules: current indications and future considerations

February 08, 2023

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Yale Cancer Center Grand Rounds | February 7, 2023

Presentation by: Dr. Courtney Gibson

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00:00Introduce myself.
00:00I I think some of you know me already.
00:03I'm Karen traga.
00:03I'm one of the new surgical
00:05oncologists here and came as the
00:07division Chief of Surgical Oncology.
00:09So it's really nice to meet all of you.
00:11And it is also my privilege to introduce
00:13one of us who's going to be speaking today.
00:16It's my privilege to introduce
00:18Doctor Courtney Gibson.
00:19Doctor Gibson is an endocrine surgeon
00:21and associate professor of surgery
00:23at the Yale School of Medicine.
00:25Courtney is an accomplished
00:27clinical surgeon who takes care
00:29of diseases of the thyroid.
00:30Parathyroid and the adrenal gland,
00:33including minimally invasive laparoscopic
00:34retroperitoneal scopic surgeries and
00:36is also the fellowship director of our
00:40Endocrine Surgery Program Fellowship,
00:42one of the premier fellowships
00:44in the country.
00:45Courtney's research interests include
00:47outcomes after minimally invasive surgery,
00:49outpatient thyroidectomy and
00:50parathyroidectomy is so newer sort
00:52of ways of thinking about how
00:54we take care of these patients,
00:55intraoperative laryngeal nerve
00:57monitoring and endocrine oncology.
01:00Courtney obtained her MD from VCU
01:02and was a postdoctoral research
01:03fellow at Shop in Philadelphia and
01:06completed her training in general
01:08surgery at Saint Barnabas and
01:09endocrine surgery at Scott and White.
01:11So it's my privilege to
01:13introduce Doctor Gibson.
01:19All right. Good afternoon,
01:21everybody and I thank you for
01:23the opportunity to kind of
01:24present an important topic.
01:25I think it's some cutting edge
01:27work that's being done in the
01:29management of thyroid disease.
01:30And so we're excited to kind
01:32of be implementing this in
01:34the near future here at Yale.
01:36So today's talk is going to be
01:37on the a discussion about radio
01:39frequency ablation of thyroid nodules,
01:41what current indications are and
01:43where are we headed in the future.
01:46I have no disclosures.
01:49So what we're going to do is
01:51define radiofrequency ablation,
01:52the technique on what what
01:54exactly it entails.
01:55And we'll discuss some of
01:56the current guidelines,
01:57which are largely international,
01:59but there's been a concerted effort
02:02to kind of get a consensus on
02:04management treatment guidelines
02:05for this technique.
02:06We're going to go into some more
02:08specifics about the specific
02:10technique of how to perform a
02:11thyroid RFA ablation of thyroid
02:13nodules and then briefly we'll
02:15go over some other non-surgical
02:17ablative interventions that.
02:19Can be used and and see how they
02:21compare to radiofrequency ablation
02:23and then lastly we'll discover
02:25discuss some future potential
02:27indications in the treatment of
02:29thyroid disease and particularly
02:31thyroid cancer.
02:33So first,
02:34what exactly is radio frequency ablation?
02:36It's not a new technique,
02:37that's just a newer indication for
02:39it and the management of thyroid disease.
02:41And So what it is,
02:42is it's a procedure in which a part
02:45of the a tumor or other dysfunctional
02:48tissue is ablated using the heat
02:51generated from frequency medium
02:53frequency alternating current.
02:55The radiofrequency ablation destroys
02:57targeted tissue through a combination
02:59of frictional and conduction heat
03:01that's generated from high frequency
03:03alternating electrical current,
03:05and the oscillations are typically
03:07between 200 and 1200 kilohertz.
03:09Frictional heat is created when the RF
03:12waves passed through the electrode,
03:14and they then agitate tissue ions as
03:15they try to follow changes in the
03:17direction of the alternating current.
03:19The result is an increase in the
03:21temperature of the surrounding
03:22tissue within a few millimeters
03:23of the electrode tip,
03:25and then heat conduction from
03:26the ablated area yields a slower
03:28additional form of thermal damage
03:30to the target tissue and eventually
03:32tissue that is further away from
03:35the electrode.
03:35So immediate coagulation necrosis is
03:37achieved by friction heat generated
03:40in the vicinity of the electrode.
03:42However,
03:42the tumor tissue remote to
03:43the electrode is also ablated,
03:45but at a much slower rate due
03:47to conductive heat.
03:48Friction heat is more powerful
03:50than conduction conduction heat,
03:52and although conduction heat near
03:54blood vessels is more affected by
03:56a heat sink effect whereby the heat
03:59dissipates pretty quickly because of
04:00the flow of blood through those vessels,
04:03the ablation range or the friction
04:05heat is very narrow and focused and
04:07is limited to just a few millimeters
04:09beyond the tip of the electrode,
04:11so therefore the majority of the
04:13nodule is ablated by conduction heat.
04:15This technique has been used for decades,
04:17at least 20 years or longer,
04:18in the non-surgical treatment
04:20of various solid organ tumors,
04:22but has only recently been applied
04:24to tumors of the thyroid gland and
04:25with the most robust experience,
04:27has been occurring in South Korea.
04:32For this approach, typically there's
04:34a transit ethnic approach that's used,
04:36and so in this approach the entire length
04:39of the electrode can be visualized.
04:41There's minimal exposure of the heat
04:43tip to critical structures such as
04:45the recurrent laryngeal nerve or the
04:46esophagus in the left cervical neck.
04:48And additionally,
04:49because the electrode passes through
04:50an ample amount of thyroid tissue,
04:53this prevents a change in position
04:54of the electrode as a patient speaks
04:56or swallows during the procedure,
04:57and it also prevents the leakage of
05:01ablated thyroid liquified tissue.
05:03So here you see,
05:04through the transmit approach
05:06the electrode is being introduced
05:07through the isthmus and headed over,
05:09in this case to the right thyroid lobe.
05:13And the needle is inserted a few
05:15millimeters from the border of
05:16that thyroid nodule.
05:17Because again the heat generated is
05:19going to extend beyond electrode tip.
05:21And then successively the and
05:23matters of millimeters of distance,
05:25the electrode tip is moved back to
05:28ablate the area and then it continues on
05:30to get the majority of the nodule ablated.
05:34In this manner you avoid this what
05:36we call the triangle of danger.
05:39So this is where the recurrent laryngeal
05:41nerve is located in the tracheal
05:43esophageal groove and on the left side.
05:45This depiction is actually
05:46the cervical esophagus.
05:48It's very mobile and so it can
05:49be on the left or right side,
05:51and it's important to know
05:52your anatomic structures,
05:52but typically it lies in
05:54the left cervical neck.
05:57In addition to the transmit approach,
05:59there's a technique called the
06:01moving shot technique which I
06:02kind of started to describe.
06:04And in this technique,
06:05the thyroid nodule is conceptually divided
06:07into multiple small ablation units,
06:09so these units are smaller at the
06:11periphery and then get larger as you get
06:14to more centralized areas of that nodule.
06:16The RFA procedures then perform unit by unit,
06:18moving the electrode tip from the most
06:21distal or deep location to a more
06:23superficial location and although this
06:25technique can successfully prevent.
06:27Nodule regrowth in a majority
06:29of thyroid nodules,
06:30there can be some undertreated portions,
06:32particularly if you are concerned
06:34about surrounding critical structures.
06:36So you want to be a little bit
06:37away from the the very border,
06:38the very margin margin of that
06:40thyroid nodule.
06:41So in cases of recurrence is
06:43usually marginal regrowth,
06:44but oftentimes it's not significant,
06:46significant enough to cause
06:48recurrence of symptoms in patients.
06:51Undertreated portions of the nodule so
06:53near that triangle of doom can occur,
06:56or in cases where the nodules are larger,
06:59so larger than like 20 millimeters,
07:01and sometimes they require more
07:02than one treatment.
07:06Let's see, hopefully this
07:07video will show here.
07:08So this is just showing the
07:10actual moving shot technique.
07:12So in this approach the transmit
07:14approach and movie shot technique are
07:16used in combination and they're record
07:18recommended as a standard procedure.
07:20But it's important to note that the
07:22best approach is the one in which the
07:24operator is most comfortable with.
07:25As a thyroid surgeon and in my
07:27training we learned to do fine needle
07:30aspirations through a different approach,
07:32not going through the isthmus but facing
07:34the patient so that the left side of that.
07:36Question is what you see
07:37on the ultrasound screen.
07:38So whatever you're most comfortable
07:40and way in performing your ultrasound
07:42and your fine needle biopsy is
07:44typically the way that you're
07:46going to perform the RFA ablation.
07:48The electrode is inserted via the
07:49isthmus and the midline to lateral
07:51direction to approach the target
07:53nodule through either the right
07:55or left thyroid lobe and then the
07:56ablation proceeds from the deepest
07:58and most remote portion of the to
08:00the most superficial portion of
08:02the nodule by slowly pulling back
08:03on the electrode tip and this is
08:05known as a moving shot technique.
08:07So during ablation echogenic bubbles
08:09are generated from the active tip and
08:11the location of the electrode should
08:13always be continuously monitored
08:14by real time ultrasound guidance
08:16during the procedure to prevent.
08:18Possible thermal thermal damage
08:19to other important structures.
08:23So more recently the.
08:28Marginal venous ablation
08:29technique has been added on.
08:31And so most of these nodules have
08:33a feeding vessel that is along
08:35the periphery of the nodule right.
08:37And so we found that a lot of the
08:40recurrences occur because there's
08:41not been an appropriate amount of
08:44devascularization of that thyroid nodule.
08:46So by ablating the feeding vessel,
08:48you decrease the risk of recurrence.
08:51And so in a similar way to the actual
08:53ablation of the thyroid nodule,
08:55the marginal vein is punctured
08:56by the electrode tip and ablated.
08:58Let's see if this shows here.
09:00And So what you'll see is that
09:02air bubbles start to feel that
09:03that marginal vein of the nodule,
09:05and initially the air bubbles flow
09:06pretty rapidly along the marginal vein
09:08as long as there's a remaining venous flow.
09:10But over time,
09:11the venous flow gradually decreases
09:13and eventually it stops completely,
09:14and so the air bubbles stay inside the veins,
09:16and that indicates complete
09:18ablation of that of that vein.
09:20The tip of the electrode is located at
09:22the main vessel that's feeding the nodule
09:24in the Hypoechoic area over this way,
09:26and then it's a blade for a few
09:27seconds and during ablation.
09:29Echogenic bubbles are generated
09:30from the active tip.
09:35So why thyroid RFA?
09:36So in general,
09:37thyroid nodules are a prevalent,
09:39prevalent clinical problem.
09:40So up to 70% of the population
09:43has one or more nodules.
09:45Thyroid nodule detection on ultrasound.
09:47And although most benign
09:48nodules can be safely observed,
09:50there's a good portion of the
09:52nodules that require definitive
09:53management for various reasons
09:55and significant increase in size,
09:57you know, continued growth of a nodule,
10:00compressive symptoms,
10:01some cosmetic concerns or
10:03autonomously functioning nodules
10:04that lead to hyperthyroidism.
10:06So surgical election surgical
10:08resection has long been the
10:09mainstay of treatment for these
10:11benign but problematic nodules
10:13and in fact of approximately,
10:14you know,
10:15140 to 170,000 thyroid procedures
10:18performed annually in the United States.
10:212/3 of them are for benign disease.
10:23And although they're associated
10:24with an excellent outcomes in low
10:27complications and experienced hands,
10:29thyroidectomy still carries a
10:30significant risk of complications,
10:32although it's low,
10:34most importantly including injury
10:36to the recurrent or superior.
10:37Imperial Erential nerve or in the
10:39cases of total thyroidectomy,
10:40the requirement of lifelong
10:42thyroid hormone supplementation
10:43even in thyroid lobectomy,
10:45you know,
10:46we as thyroid surgeons often quote a
10:48a potential risk of lifelong thyroid
10:50hormone supplementation of about 15% or so,
10:53but the true reported incidence
10:55is probably more closer to 30%.
10:57So that's not insignificant and a
10:59lot of our colleagues in medical
11:01endocrinology can attest to that.
11:02And so even after a lobectomy,
11:04those patients are in need of some
11:06form of thyroid hormone replacement.
11:08Which is not insignificant.
11:10RFA ablation pretty much eliminates
11:12that risk when performed properly.
11:15There's no requirement for thyroid
11:17hormone as long as the patients have
11:20been properly vetted for the procedure.
11:23So in the past couple of years,
11:25there's been a great enthusiasm for
11:27RFA in the United States and its
11:29potential role in the management
11:30of benign and in some cases for
11:32potentially malignant lesions
11:33of the thyroid gland.
11:37So the first RF ablation of a
11:40thyroid nodule actually occurred
11:42back in 2002 and Seoul, South Korea,
11:45and shortly after that the first
11:47case series was was reported by
11:49that group of researchers in 2006.
11:51After that, the Korean Korean
11:53Society of Thyroid Radiology,
11:55which is an organization of thyroid
11:58radiologists primarily involved in the
12:00diagnosis and management of thyroid nodules.
12:01They proposed some preliminary
12:04recommendations for thyroid RFA in 2009.
12:07And this primarily focused on indications
12:09and efficacy and since that time
12:11their guidelines have been revised,
12:13first in 2012 and then again in 2017
12:16based on newer evidence obtained
12:18from some clinical studies of
12:20RFA in patients with both benign
12:22and malignant thyroid disease.
12:24Shortly after that,
12:25our similar guidelines were
12:27developed in Europe in 2020.
12:31Right. So indications for thyroid RFA are
12:34largely for benign but symptomatic disease.
12:37So you know the majority of
12:39thyroid nodules are benign.
12:40In general, some nodules can cause
12:42some cosmetic problems or pressure
12:44symptoms that I described earlier, pain,
12:47dysphasia, foreign body sensation or
12:49some can be autonomously functioning.
12:51And in these cases radiofrequency
12:53ablation is a good technique that can
12:56improve the clinical problem by reducing
12:58the nodule size and in in management
13:01and assessment of these patients.
13:02Symptom scores,
13:03typically created by using a visual
13:06analog scale and a cosmetic score,
13:08is measured by the treating physician,
13:09with a score ranging between one and four,
13:11one being no palpable mass
13:13appreciated and four being a readily
13:15detectable cosmetic concern.
13:19So prior to performing a thyroid RFA,
13:22thyroid nodule should be confirmed as benign
13:25on at least two ultrasound guided F and
13:27a biopsies or one core needle biopsy 1.
13:30Caveat to that is that if the
13:32characteristics on ultrasound
13:33clearly look like a benign nodule,
13:35you can get by with just one F and
13:37a biopsy showing benign disease.
13:39The reason for the 2nd biopsy has largely
13:42been because in cases of larger thyroid
13:44nodules greater than 3 centimeters,
13:463 or 4 centimeters, there's about a 10%.
13:48This other false negative F and a biopsy.
13:51So we always like to have a second
13:53biopsy to confirm that we truly
13:55dealing with benign disease.
13:57However,
13:57in the area of molecular molecular testing,
14:00there's now you know opportunity to
14:02kind of downgrade nodules even when
14:04they have an indeterminate look on
14:06imaging and those patients can go on
14:08to have RFA treatment as an option.
14:11Ultrasound examination is important to
14:14characterize the nodules or recurrent
14:16cancers in some cases and to evaluate the
14:18surrounding critical anatomic structures.
14:20So you want to see the nodule in question,
14:23where is it proximity,
14:24proximity to the critical structures
14:26that we mentioned,
14:27the recurrent laryngeal nerve
14:28or the esophagus,
14:29and also how close it is to the surface of
14:31the actual thyroid capsule in the skin.
14:33Some people have very bulky necks
14:35and you have more leeway where others
14:37have very thin necks and there's
14:39not a lot of tissue separating the.
14:41Actual skin area from the thyroid lesion.
14:43That's important when you're using a,
14:44you know, heated probe.
14:47Laboratory tests are important
14:48and usually include a CBC,
14:50blood coagulation battery and
14:51some thyroid function testing.
14:56So on ultrasound, some benign features
14:59are typical hyper echogenicity,
15:01so looking a little bit more Gray
15:03than the surrounding structure,
15:04hypervascularity or a lack of
15:06vascularity to the thyroid nodule,
15:09macro calcification, so larger than
15:113 millimeters and smooth borders.
15:12And if the nodules have
15:14these these characteristics,
15:16then 1F and a biopsy is reasonable.
15:19Whereas some concerning features on
15:21thyroid ultrasound would be the opposite.
15:23Hypo echogenicity, hypervascularity.
15:26Microcalcifications or irregular borders?
15:32After RFA for non functioning
15:34benign thyroid nodules,
15:36again you want to look at the clinical
15:38laboratory and imaging checklist.
15:40RF should be terminated when the
15:41entire area of the nodule becomes
15:43a transient hyper coag zone of grey
15:45on grayscale ultrasound and then
15:47grayscale ultrasound and dot color
15:49Doppler should be used to identify any
15:52remaining vascularity to the lesion
15:54so that you can continue to perform
15:55RFA to ensure the best outcome.
15:57After RFA the nodule related symptom
15:59score again you know neck pain,
16:01dysphasia foreign body.
16:03Sensation is assessed, you know,
16:05reported by the patient and the
16:06cosmetic score reported by the
16:08physician to evaluate the effectiveness
16:10of that RFA therapy.
16:12Following RFA of autonomously
16:14functioning thyroid nodules,
16:15thyroid function should be monitored by
16:17measurement of the TSH T3 and free T4
16:20at each follow up and based on TSH changes,
16:23antithyroid medication
16:24can be reduced or stopped.
16:26The therapeutic response of the patient
16:28depends on their initial drug dosage
16:31required and is typically classified
16:33into 3 categories for autonomous
16:35autonomously functioning thyroid nodules.
16:37So a complete response means
16:38that after this treatment,
16:40usually,
16:40you know two to four months afterwards that
16:42patient is no longer on any anti thyroid.
16:44Medication.
16:44A partial response is that that
16:47patient still requires some
16:48anti thyroid medication,
16:49but it's significantly reduced and
16:51then no response as the patient
16:53is still deemed hyperthyroid and
16:55requires medication.
16:56And in those cases they get pushed
16:58on to a further intervention,
17:00whether that be a second RFA treatment
17:02or more definitive treatment with
17:04radioactive iodine therapy or surgery.
17:09On the ultrasound examination post procedure,
17:11you want to look for changes in size of
17:13the nodule or the volume of the nodule,
17:15intranodal vascularity and echogenicity I
17:17am and if the thyroid function symptoms
17:21are incompletely resolved again you know
17:23repeat RFA or another treatment such as
17:25medication or surgery may be required.
17:27You also want to look at the thyroid
17:29function of non functioning thyroid
17:31nodules as well too because one of
17:33the great benefits that is being
17:35reported is that these patients do
17:36not end up being hypothyroid.
17:38After these interventions,
17:39unlike fairy lobectomy where
17:40they may end up hypothyroid,
17:42so if a patient has normal thyroid
17:44function pre RFA procedure,
17:45they should also have a preservation
17:47of that youth thyroid state afterwards.
17:48So it's important to check a TSH.
17:50And along those lines too,
17:52if there's any concern that that
17:54patient may have autoimmune disease,
17:55that should be further investigated
17:57pre procedure with a check for
17:59thyroglobulin or antibody levels to
18:01see if that patient actually has
18:03autoimmune disease of the thyroid
18:05gland because they're at a higher risk
18:07of requiring thyroid hormone after.
18:08Any intervention, including surgery and RFA.
18:15I think I may have skipped.
18:21OK, here we go.
18:23So in terms of the management
18:25of cystic thyroid nodules or
18:27predominantly cystic thyroid nodules,
18:29these nodules are amenable to
18:31ethanol ablation and it's been
18:33proven to be extremely effective
18:34in the treatment of cystic thyroid nodules.
18:37Beck at all back in 2015 carried
18:39out a single blind randomized
18:40trial to compare the efficacy of
18:42RA versus ethanol ablation and
18:44the treatment of these cystic or
18:46primarily cystic nodules and inclusion
18:49criteria included patients with
18:51thyroid nodules that were at least.
18:5350% and no more than 90% cystic who had
18:56compressive symptoms from these nodules.
18:58Benign cytology was confirmed with F
19:00and a biopsy or corneal biopsy and
19:02normal thyroid function was demonstrated.
19:04Biochemically,
19:04the mean volume reduction reported
19:07was around 87% for RA and 82%
19:10for ethanol ablation,
19:11indicating no significant difference
19:13between the two techniques.
19:15And regarding the secondary outcomes,
19:18therapeutic success means symptom and
19:20cosmetic scores also showed no difference.
19:22There also were no major complications
19:24in either group and so these authors
19:26concluded that the therapeutic
19:28efficacy of RA.
19:29Is not superior to that of ethanol
19:31ablation and so that ethanol ablation
19:32might be more preferable as first line
19:35treatment for cystic or primarily
19:36cystic thyroid nodules due to the
19:38ease of the technique and the low
19:40lower cost of ethanol ablation.
19:46A prospective study out of Italy evaluated
19:48the safety and efficacy of RF in the
19:51treatment of solid thyroid nodules.
19:53In this study, there were 84 patients who
19:56with symptomatic and cytologically benign
19:59solid nodules were randomly assigned
20:01to either a single Rs RA session for
20:04Group A or surveillance for Group B.
20:07And again inclusion criteria was a solid
20:09thyroid nodule or predominantly solid
20:11with meeting less than that 30% fluid
20:13component normal thyroid function.
20:16No evidence of autoimmune disease and
20:17no previous thyroid gland treatment,
20:19surgery or otherwise.
20:203 subgroups were formed according to
20:23the baseline volumes of the nodules,
20:25so a small nodule was considered to be
20:27a volume of less than 12 milliliters.
20:30A large nodule was considered to be
20:32greater than 30 milliliters in in volume,
20:35and intermediate was in between
20:37those two parameters.
20:38And then the RFA group they RA
20:41was performed in a single session
20:43using the moving shot technique.
20:45The volume and local symptom
20:47changes were evaluated at one and
20:49six months after the procedure.
20:51So in Group A,
20:53the volume decreased from 24
20:55milliliters to 9.5 at six months post
20:57RFA and the greatest volume reduction
20:59was found in the smaller nodules,
21:02those being 12 million milliliters in volume.
21:04The pressure symptom score improved
21:06significantly only for the medium
21:08and large nodules and that's largely
21:09because they were larger and large
21:11enough to cause compressive symptoms
21:13or more significant compressive
21:14symptoms in those patients,
21:15whereas the cosmetic score improved
21:18in all treated patients in Group B,
21:21the surveillance group.
21:22The nodule volume remained unchanged,
21:24but the symptoms go are worsened at
21:26the six month time point evaluation.
21:28And in terms of any complications,
21:30there's only one patient who
21:34experienced vocal cord palsy due to
21:36a recurrent laryngeal nerve injury.
21:41So in terms of longer term
21:43efficacy of RFA treatment,
21:45results still remain favorable.
21:47Deandrea and his group evaluated a
21:50cohort of 215 patients who underwent
21:52single session RFA for benign
21:54thyroid nodules and then followed
21:55them for at least three years post
21:58procedure and they found significant
21:59shrinkage of the nodules throughout
22:01the entire observational period.
22:02And in particular the medium volume
22:04observed over six months after
22:06the procedure was significantly
22:07lower than at baseline.
22:09Progressive volume reduction
22:10was also seen at the one.
22:11Two year follow-up time points and
22:14also compressive symptoms and cosmetic
22:16concerns improved after the RFA therapy.
22:19There was a significant reduction
22:21in compressive symptoms at one year
22:23post procedure and this remains
22:24stable at five years and similarly
22:26COSMESIS was improved and remained
22:28stable over that same time period.
22:30No major complications occurred in
22:32the treatment group and the authors
22:34concluded that reliable and durable
22:36shrinkage of the benign non functioning
22:38thyroid nodules with improvement of
22:39subjective symptoms can be obtained with.
22:42Radiofrequency ablation.
22:46Now functional thyroid nodules are
22:48a little bit more difficult to treat
22:51whether it's surgery or medication
22:53or non surgical interventions,
22:55but they can also be targeted
22:57with radiofrequency ablation.
22:58It should be noted though that resolution
23:00of hyperthyroidism is less predictable
23:02than after radioactive iodine therapy
23:04for hyperthyroidism or surgery.
23:06And so reported success rates
23:08of RFA are very variable,
23:10ranging from anywhere from 24 to
23:1272% because the efficacy is is
23:14associated with the nodule volume.
23:16Reduction of 80% or greater RFA is best
23:18suited for patients with small nodules,
23:20so those that are three centimeters
23:22or less and a single autonomously
23:24functioning thyroid nodule,
23:25as opposed to toxic multinodular
23:27goiter or Graves' disease center.
23:29Graphy is also recommended to confirm
23:31the presence of an autonomous,
23:33autonomously functioning nodule
23:35as opposed to graves,
23:37disease or toxic multinational goiter.
23:40T3 and T4 should be measured whenever the
23:41TSH falls outside of the normal range,
23:43so sometimes there's
23:45subclinical hyperthyroidism.
23:46That can be picked up by measuring
23:48all three of those parameters.
23:50The prevalence of these autonomously
23:52functioning nodules varies according to
23:54the geographical area and the amount
23:56of iodine intake in that country.
23:58But in the general population,
23:59it's estimated that the prevalence
24:01ranges from 2 1/2 to 4 1/2%,
24:03and surgery and radioactive iodine
24:05therapy represent the standard
24:06of care for this condition.
24:08So, so far,
24:09the literature shows that RFA
24:10normalizes thyroid function
24:11in about half of these cases,
24:13so roughly 50% of patients who
24:15undergo our RF ablation of autonomous,
24:17autonomously functioning thyroid nodules.
24:20I have resolution of the hyperthyroidism
24:22and it goes up to 80% with smaller nodules,
24:25those less than 3 centimeters.
24:27This is associated with a significant
24:30non nodule volume reduction after
24:32about two years of evaluation
24:33from the time of treatment and it
24:35ranges from 68 to 84%.
24:37So RA overall does not seem to
24:39perform quite as well as surgery for
24:42these particular type of nodules,
24:44but still can remain an option
24:45particularly in patients who are
24:47not surgical candidates or who are
24:48a little bit reluctant to undergo.
24:50Surgery for hyperthyroidism.
24:55So briefly, I want to talk about a
24:57few other non-surgical alternatives
24:59to radiofrequency ablation of thyroid
25:02nodules and there are about three
25:04or four that have been looked into.
25:06So as I mentioned earlier,
25:08percutaneous ethanol injection,
25:09so treatment options for symptomatic
25:12benign cysts include needle aspiration,
25:15minimally invasive techniques
25:16or surgical resection.
25:17And with needle aspiration,
25:19the recurrence rates are very high
25:20and that's because you never ablate
25:22the actual cells that are lining that
25:24sys that are secreting the fluid.
25:26So patients get aspirated and sometimes
25:27they have resolution of symptoms
25:29that last you know for months,
25:31maybe even years or so.
25:32But more often than not those
25:34symptoms recur fairly quickly
25:35and then they're left with what?
25:37To do with those recurrent symptoms,
25:38do you subject them to surgery,
25:39do they kind of just deal with the
25:42compressive symptoms and this is
25:43where the role of RFA has kind of
25:45come into play and and also other
25:47interventions like ethanol injection?
25:50So a study at the Mayo Clinic
25:52evaluated the safety and efficacy
25:54of Perth and percutaneous ethanol
25:57injection for thyroid cyst and
25:58they looked at about 20 patients
26:00who had cystic thyroid nodules.
26:02Eight of them had purely cystic nodules
26:04and the other twelve had a complex 60
26:06nodule where over 50% of the nodule
26:08cystic and at two years follow up,
26:10a median of two years follow up.
26:11Almost 94% of patients were asymptomatic
26:14and 70% had at least a 50% reduction in
26:17volume and 50% reduction at six months.
26:20After a blade of procedures is
26:22considered an effective treatment.
26:25So in terms of safety,
26:26four patients had mild temporary
26:28side effects and most of it was
26:30pain at the injection site or
26:32mild bleeding into the cyst.
26:33And so these researchers overall
26:36concluded that ethanol ablation was
26:38safe and effective for patients
26:39with symptomatic thyroid cysts
26:41and is actually the preferred
26:43non-surgical treatment for the
26:44treatment of cystic thyroid nodules.
26:48So although ethanol ablation is very
26:50effective in treating cystic thyroid nodules
26:53is much less effective for solid nodules,
26:55and that's where laser ablation
26:57or other thermal ablative
26:58therapies kind of come into play.
26:59So laser ablation with ND YAG is a thermal
27:02ablation method that's better suited
27:04for treatment of solid thyroid nodules.
27:06The layers are is actually an
27:08acronym for light amplified
27:10stimulated emission of radiation.
27:11It was first described
27:13by Pacella back in 2004,
27:14and the procedure involves inserting
27:162 to 3 spinal needles into a nodule.
27:19The ultrasound guidance,
27:20this does not involve a moving
27:22shot technique.
27:23So once you have those needles injected,
27:25that is going to be the location
27:26of where they remain and then laser
27:28fibers are then positioned through
27:30those needles to allow for the
27:32ND YAG power for watts in between
27:3515 to 2000 joules per treatment.
27:38The ablation needle is typically
27:39placed within the thyroid nodule
27:41along its craniocaudal axis and then
27:43the fibers are exposed to a depth
27:45of about 5 millimeters beyond the
27:46the needle tip and that kind of.
27:49As shown here. Umm.
27:52So there's highly echogenic or
27:56echogenic area that results from
27:57the tissue heating and vaporizing
27:59during the laser firing.
28:00And then you see on colored Doppler they
28:04images obtained from laser illumination.
28:06So after final ablation,
28:08laser marks are seen as anechoic
28:11spots representing cavitation caused
28:13by tissue vaporization and then the
28:15surrounded by a kind of a hyperechoic rim.
28:17A coagulation zone is demonstrated
28:20as this hypoechoic area separated
28:22by rim of viable. This year.
28:26Pepini and his group in a randomized study
28:28of 200 patients compared laser ablation
28:30and clinical observation in patients
28:33with benign thyroid nodules and they
28:35demonstrated a significant and persistent
28:37reduction in the volume of the laser
28:39treated nodules compared to controls.
28:40And this also was associated with
28:42improvement in the local symptoms
28:44with no change in thyroid function.
28:46So in this study,
28:47a single laser therapy session with two
28:50fibers induced a significant volume
28:52reduction greater than 50% and the
28:55improvement of local symptoms in the
28:57vast majority of these solid nodules.
28:59After the treatment,
29:00the volume reduction was progressive
29:01until 12 months and remain stable
29:03out to three years.
29:04And there's only a small minority,
29:06less than 5% of patients that that
29:10had a parcel regrowth usually
29:12around that marginal area.
29:13So the efficacy of radiofrequency ablation
29:15appears to be just slightly superior to
29:18that of laser ablation and the advert
29:20adverse effects are somewhat fewer.
29:22So they're pretty comparable
29:24but the slight but beneficial.
29:28Findings are RFA are thought to be
29:30attributed to the fact that we use a
29:33moving shot technique with RF ablation.
29:35So there's more area of that nodule
29:37that actually can be ablated as
29:39opposed to just the the lasers
29:40sitting in that same spot on the
29:42laser needles sitting in the same
29:44spot for the laser therapy.
29:51Microwave ablation is another thermal
29:53technique that's used as a newer 1,
29:56and it relies on the generation of this
29:59electromagnetic field with wavelengths
30:00between point O3 and 30 centimeters and a
30:03frequency between 900 and 2500 megahertz,
30:05and this causes oscillation of
30:07polarized ions, specifically water.
30:09This oscillation then creates friction and
30:12then increases the local field temperature.
30:15So because an electromagnetic field is
30:16used instead of an electrical current,
30:18the electrical conduction
30:19conduction is not necessary.
30:21So the thermal spread is not as
30:23impeded by things like char or heat
30:25sink as with the RFA technique.
30:27A needle like antenna similarly isn't is
30:29used to propagate the current and multiple
30:31antenna can be used together to cause
30:33an exponential increase in the amount of
30:35heating that occurs within the nodule.
30:38So microwave ablation offers the
30:40ability to deliver more thermal
30:41energy in a shorter time,
30:43and this results in a higher
30:45final tissue temperature.
30:46So this reduction in treatment
30:47time can be more valuable when
30:49you're treating larger tumors.
30:50But because the anatomy of the
30:52central neck is very compact,
30:53it's also possible that these
30:55factors represent some disadvantages.
30:56So rapid heating that is less
30:58responsive to heat sink can explain
31:00some complications described in
31:01some early series of microwave
31:03ablation of thyroid nodules.
31:04There's a lot more heat
31:06generated and it dissipates.
31:08Much more slowly than with
31:09the other techniques.
31:14The aim of a a a study by Wu was to
31:17define the effectiveness and safety of
31:19percutaneous microwave ablation for
31:21benign thyroid nodules after one session.
31:23So in this study, a total of 121
31:26benign thyroid nodules in 100
31:27patients who were your thyroid.
31:29They underwent microwave ablation at a
31:32single institution between 2014 and 2015,
31:34and this was performed with an internally
31:37cooled antenna under local anesthesia.
31:39The volume of the nodule,
31:40the cosmetic score and symptom
31:41score were compared before and
31:43after the procedure and the volume.
31:44Production rate was also calculated,
31:46side effects and complications were
31:48recorded and what we see is that there
31:51was a continuous decline in the volume
31:54reduction rate after microwave ablation
31:56and the volume rates at 369 and 12
32:00months were 577077 and 85 respectively.
32:07The most current or recent
32:10technique that's being used is
32:12high intensity focused ultrasound.
32:14So this is a a more unique noninvasive
32:17modality that uses sound waves as a carrier
32:19to target specific lesions of focus.
32:21High intensity ultrasound transfer
32:23sufficient energy to induce this
32:25coagulative necrosis through
32:27thermal and mechanical injury,
32:28and the thermal effect is achieved
32:31by the conversion of the energy
32:33energy generated by intense
32:34tissue vibration and this this.
32:36Vibration kind of turns into frictional
32:39heat absorption within within a focal
32:41target area creates high temperatures
32:43locally and then immediate cell
32:45death occurs once temperatures
32:46exceed 55 to 60 degrees Celsius.
32:48So at this temperature water within
32:50the tissue vaporizes and micro bubbles
32:52begin to form and it's this micro
32:54bubble expansion and then collapse
32:56it leads to mechanical damage and
32:58hemorrhage within nearby cells.
32:59So with this technique it's an
33:01emerging emerging treatment option
33:03for thyroid nodules,
33:04but a key component in challenge
33:06to this particular.
33:07Technique is the delivery of energy
33:09to a small area without causing a
33:11significant damage to intervening
33:12and surrounding structures.
33:14So similar to white microwave ablation,
33:16you have higher heat energy
33:18generated and a slower resolution
33:20of that heat which can lead to
33:22higher complication rates.
33:26So although Haifu is a promising
33:28form of ablation in the short term,
33:29the medium to long term outcomes
33:31following as a single treatment
33:33are not well established.
33:35And to date the only study that has
33:37reported on medium to long term efficacy
33:40with this treatment was performed by Lang.
33:43And in that study there was a total
33:45of 108 patients who underwent this
33:47high food treatment and were fall
33:50for two years and at the two year
33:52follow-up time period fewer than
33:542/3 of the patients had smaller.
33:56Volume then at the 12 month time point
33:58and then an additional 5th of nodules
34:00actually had a small increase in volume
34:02compared to that 12 month time point.
34:09So as I mentioned earlier,
34:10the first reported treatment of thyroid
34:14nodules by the RFA technique occurred
34:16inside South Korea back in 2002.
34:18And you know, although RA techniques
34:20have been steadily gaining acceptance
34:21in the United States, I'm sorry,
34:23in Europe and Asia for over 20 years now,
34:26the United States has been a little bit
34:28more slow to to adopt these techniques.
34:30The fact that the FDA did not approve
34:32the use of RFA for soft tissue masses
34:35or thyroid nodules until February of
34:372018 probably contributed to this.
34:39Delay in the adoption process
34:40here in the United States,
34:41along with the pandemic,
34:43also causing some delays in
34:45developing this practice.
34:46So although these advantages are well
34:49documented in International series,
34:50there's still a paucity of data
34:52from the United States experience.
34:55This will likely change over the next
34:57few months because several institutions
34:58in the United States are now publishing
35:00their outcomes from their early
35:02experience with RFA of thyroid nodules.
35:08So currently there are 13 established
35:10RFA programs in the United States
35:11and over the next several months,
35:13at least 24 additional programs
35:15are expected to develop,
35:17which is going to greatly increase
35:18access to patients here who are
35:20interested in undergoing a a less
35:22invasive procedure than surgery.
35:28So the first US experience with thyroid RFA,
35:31it was a retrospective review of
35:3314 patients out of the Mayo Clinic.
35:35And so these patients had solid thyroid
35:38nodules that were treated with a
35:40single RFA procedure from December 1st,
35:432013 through October of 2016.
35:45All patients either had declined surgery
35:47or were poor surgical candidates.
35:49The thyroid nodules were benign
35:51on fine needle aspiration.
35:52They were enlarging or causing
35:54compressive symptoms and they were
35:56at least three centimeters in size.
35:58All right. Nodule volume,
36:00compressive symptoms and cosmetic
36:02surgery concerns were evaluated and
36:04the medium volume reduction induced
36:05by the RFA technique was 44%,
36:07down from from 24 milliliters
36:09all the way down to 14.
36:12Medium follow up was about nine months
36:14and maximum results were noted to be
36:16achieved at the six month time point.
36:18So these researchers found that
36:19RFA did not negatively impact
36:21thyroid function and in fact,
36:23in the one patient who has subclinical
36:25hyperthyroidism due to a toxic adenoma,
36:27that patient had normalization
36:29of their thyroid function.
36:30Four months after the ablation procedure,
36:33so further compressive symptoms
36:34resolved in eight of 12 patients
36:36or 67% and improved in the other
36:39four and cosmetic concerns improved
36:41in all all all 12 patients.
36:43So the procedure had no sustained
36:45complications and the authors
36:46concluded that RFA of the nine
36:48large thyroid nodules performed
36:49similarly to reports internationally,
36:51which was encouraging.
36:55The next study occurred out
36:57of Columbia University by two
36:59experienced into convergence,
37:01Doctor Jennifer Cohen,
37:02Doctor James Lee and they wrote in
37:05their experience of 16 patients since
37:07starting their RFA program back in 2019.
37:10So most of these patients had
37:12benign thyroid FA biopsies and
37:15with compressive symptoms.
37:16But additionally there were two patients
37:19who had toxic nodules and one patient
37:21with a recurrent metastatic thyroid cancer.
37:24So these authors.
37:25Reported that all patients
37:26tolerated the procedure well with
37:28just minimal procedural pain and
37:30no long term complications.
37:31At one month follow up the mean
37:33volume reduction was 50% / 50%.
37:35And additionally both patients who had
37:37toxic nodules had one month follow
37:40up and were found to be youth thyroid
37:42and all patients who had undergone
37:443 month follow up also had normal
37:47TSH levels indicating youth thyroid
37:48status and those patients as well.
37:50So again the preliminary U.S.
37:51data is has been comparable
37:54to that experienced.
37:55Internationally.
37:59Next, there was a study to evaluate
38:02the safety and efficacy of RA.
38:05In patients who had indeterminate nodules.
38:10And so this was a retrospective
38:12retrospective single center study
38:14and this was a 53 patients who under
38:17an RF a total of 58 thyroid nodules.
38:19The reduction in volume,
38:21cosmetic and symptomatic improvement as
38:22well as the effect on thyroid function
38:24and complications were assessed.
38:26And once again the medium
38:27reduction volume was over 50%,
38:29it was 70% after a median follow-up
38:31of over 100 days and with significant
38:34symptomatic and cosmetic improvement
38:35in all cases and compared to larger
38:38nodules these authors noted that.
38:40Smaller nodules had greater volume
38:42reduction and improved TSH in autonomously
38:45functioning thyroid nodules and also
38:47there was no effect on the TSH levels
38:50in the non-toxic thyroid nodules.
38:52There were no major complications.
38:54Importantly,
38:54there was one patient who had self
38:56limited local bleeding and another
38:58had a transient voice change
38:59that resolved after six months.
39:01So again these authors concluded that
39:02RA is a safe and efficacious treatment
39:04option for both symptomatic non
39:06functioning and functioning thyroid nodules.
39:11And then lastly, more recently there's
39:13been a study out of Tulane to look
39:16at indeterminate nodules which are
39:18vast majority of nodules that we see.
39:21So these nodules have either their
39:24Bethesda type three or four,
39:26so 178 patients who had either
39:29benign nodules, so Beth Bethesda,
39:31Bethesda two or less or indeterminate,
39:33but that's a three or four on F and
39:35A were included and patients in the
39:38benign and indeterminate cohorts
39:40had similar thyroid nodule volume.
39:42And reduction rates for 65 and 64%.
39:45So no significant differences between
39:47completely benign thyroid nodules and
39:49these indeterminate thyroid nodules.
39:51There were a total of three cases of
39:53dysphonia reported that resolved.
39:54And so this was the first study to
39:56really look at indetermined not
39:58clearly benign nodules,
39:59not clearly malignant nodules,
40:01but indeterminate thyroid nodules
40:03and found that they're comparable
40:05to benign thyroid nodules in terms
40:07of the efficacy.
40:08So this was the first first
40:10North American analysis comparing
40:11benign and indeterminate nodules,
40:13and suggested that RA is a promising
40:15modality for the management of
40:17indeterminate thyroid nodules.
40:21The most common indications for our
40:23phase still remains treatment of
40:25benign disease both non functional
40:27and autonomously functioning.
40:28But there's potential expansion
40:29of the indications for RFA that
40:31they're being investigated.
40:32So currently there's only two institutions,
40:34institutions here that are recruiting
40:36patients for clinical trials in the
40:38United States evaluating the safety
40:39and efficacy of RFA for the treatment
40:41of low wit risk well differentiated
40:43papillary thyroid cancers and
40:44that's the Mayo Clinic in Columbia.
40:46And thus far there's only two US
40:48institutions that have used RA to
40:50treat recurrent thyroid cancer.
40:51Being Columbia and Oregon Health
40:53and Sciences University,
40:55so current knowledge of the efficacy
40:56of RFA for the treatment of thyroid
40:58cancer is still limited and largely
41:01comes from our international experience.
41:03Recently NCCN guideline from the
41:05indicate that RFA can be considered
41:07in the management of recurrent thyroid
41:10cancer particularly if patients are
41:12a high kind of surgical risk and
41:15in fact RFA has actually been used
41:17in for this specific indication
41:19in Southeast Asia and Europe.
41:22So back in 2014 back again looked
41:24at patients who had undergone RFA
41:26for local regional recurrent PTC
41:28and the inclusion criteria were
41:31no evidence of metastasis.
41:32But beyond the neck no more than four
41:36areas of tumor confirm recurrence
41:38by ultrasound guided F and A and
41:40a thyroglobulin measurement on
41:41needle washed out.
41:43So more than a six month follow up
41:44period was needed in surgery was not
41:46feasible or was refused by the patient.
41:48And so in this case there were 61
41:51recurrent tumors in a total of 39.
41:52Patients and the main follow-up
41:54duration was about 26 months.
41:56These researchers found that tumor
41:58volume decreased significantly from
42:00.2 milliliters before ablation
42:01to .02 afterwards.
42:03And the overall complication was complication
42:05rate was relatively low at under 8%.
42:09So these authors also concluded that
42:11RFA can effectively control local
42:13regional recurrent papillary thyroid
42:15cancer without life threatening
42:17complications and select patients.
42:19And then in a follow-up study,
42:20the same group reviewed 29 patients who
42:23had undergone RA for recurrent PTC and
42:25they followed them for at least five years.
42:28They looked at the change in size on
42:31ultrasound and thyroglobulin levels
42:33for at the one month follow up 3/6
42:35and 12 months and then every 6 to 12
42:37months after that one year time point.
42:39And so any complications identified during
42:41the follow up period were also reported.
42:43The mean follow-up duration was
42:45was eighty months and tumor volume
42:47decreased significantly from .2.
42:495 to .01 at the final evaluation
42:51and so the mean volume reduction
42:54was over 99 Percent.
42:5542 of the 46 treated tumors actually
42:58had completely disappeared by the
43:00final evaluation on ultrasound.
43:01And the mean thyroglobulin level
43:04decreased from 2.55 to 0.75,
43:06equating to a biochemical remission
43:08rate of 51%.
43:10And so importantly,
43:11there were no delayed complications
43:12associated with RA after it
43:14was followed for five years.
43:19In terms of future directions
43:20and of using this technique,
43:22there's a lot of interest in treating
43:24primary thyroid carcinomas and that's
43:26because the global incidence of PTC has
43:28been increasing over the past several
43:30decades and particularly for micro PTC's,
43:32those that are less than a centimeter.
43:34It's been largely attributed to
43:35the detection and diagnosis of
43:37smaller tumors on ultrasound,
43:38mostly T1 tumors,
43:40so meaning less than two centimeters,
43:42but they are further subdivided into
43:44T1A less than one centimeter or T1B
43:47between one and 2 centimeters, so these T.
43:49Tumors generally have a favorable
43:51prognosis and a low mortality rate.
43:53So for T1A tumors that don't
43:55have any evidence of extra
43:57thyroidal extension or lymph,
43:58Noma testis or distant metastasis,
44:00conservative management such as active
44:02surveillance has been recommended,
44:04but consensus hasn't been reached
44:06on on that specific protocol of
44:09how to surveil on these patients.
44:11All right.
44:12Lobectomy without a prophylactic
44:13central neck dissection has been
44:15touted as the preferred treatment
44:17for this subset of small tumors
44:19and active surveillance is also
44:20recommended as a new conservative
44:22management for the T1B lesions that
44:24are between one to two centimeters.
44:26The problem with that is that there's
44:27not a lot of evidence on active
44:29surveillance of these particular tumors.
44:30So then you're subjecting patients
44:32to either a thyroid lobectomy for
44:34a small tumor or surveillance with,
44:35you know,
44:36really no good information about the
44:38long term outcomes of surveilling
44:40these type of tumors.
44:41So as such,
44:42RA has been considered as an alternative
44:44to the active surveillance or thyroid
44:46lobectomy for these T1B lesions.
44:51A recent study just published this year
44:53sought to compare the clinical outcomes
44:55of between thyroid lobectomy and RFA for
44:58the treatment of these T1B lesions and
44:59they had a pretty long term follow up.
45:02So there were 1500 patients who
45:05underwent surgery and 156 who chose RFA.
45:09And of those after exclusion criteria,
45:1191 patients who underwent RFA and
45:14192 patients were treated with a
45:16thyroid lobectomy and they were
45:18included in this study for comparison.
45:20So the RFA procedure was performed by
45:22two experienced US physicians who had
45:25more than five years experience in
45:27performing RFA and all RFA patients
45:29underwent a single session procedure.
45:31During the follow up,
45:32there were no significant differences
45:34found in terms of local tumor progression,
45:37lymph node metastasis,
45:38recurrent tumor or persistent tumor
45:40in the RA treated group or the
45:43thyroid lobectomy group.
45:44Recurrence free survival rates were
45:45noted at one in four years and
45:48they were 98 and 95% in the RFA
45:51group and 97 and 96% in the thyroid
45:54lobectomy group respectively.
45:55So this was an important study that
45:58revealed comparable results between
46:00thyroid lobectomy and RF ablation of
46:02a T1 thyroid cancer and it suggests
46:04that RFA may have a role in the
46:06management of these tumors.
46:10So as RFA and other thermal
46:12ablation techniques continue to
46:13expand in the United States,
46:15undoubtedly its role in the management
46:17of thyroid disease for both online
46:18and malignant conditions will need to
46:20be re examined and and considered.
46:22There are several societies currently and
46:24organizations that have begun this process,
46:26including the American Thyroid Association,
46:28American Association of Endocrine Surgeons,
46:30American Head and Neck Society and the
46:32Society of Interventional Radiologists.
46:34And the emerging experience from the
46:36United States is certainly going to
46:37contribute to the literature and to what
46:39we know about the treatment of these nodules.
46:41And hopefully we'll be consolidated with
46:43the international experience so that we
46:45can formulate some recommendation and
46:46guidelines for the safe implementation
46:48implementation of this technique to
46:49our patients here in the United States.
46:54So thank you very much for your
46:55time and I'm open to questions.
47:05Thanks Courtney. There any questions?
47:08I think maybe maybe let me start it off.
47:11You know obviously this is great
47:13and very exciting and thank
47:14you for sharing all the data.
47:16You know, two things. So number one,
47:18maybe just from an anatomical standpoint,
47:19you know when we're doing surgeries we
47:21always worry about the recurrent laryngeal
47:23nerve or all the vasculature around it.
47:25And conceivably if you're putting a very hot
47:27sort of radio frequency in that same zone,
47:29you know, we worry about cautery
47:31getting too close to it.
47:32So how do you kind of reconcile that?
47:34And then I think secondly,
47:35maybe can you speak a little
47:37bit about are there biomarkers?
47:39That'll help us identify the three cohorts,
47:41you know,
47:42the patients that can just be watched,
47:44patients that should have some sort of
47:46radio frequency ablation and patients
47:47that should actually have surgery
47:49or something more that may help
47:51guide this because you know any new
47:52technology has this worry of indication
47:55creep or overuse of the technology
47:57or lack of safety for patients.
47:59And so how are you thinking about it
48:01and maybe speak a little bit about Yale
48:02and how do you think we'll implement that?
48:04Yes. So to answer the first question,
48:06yes, of course, you know the the most.
48:09Significant and complication after
48:11treatment of thyroid nodules surgically
48:13with radiation or with any type of
48:15percutaneous treatments is going to be
48:17injury to the recurrent laryngeal nerve.
48:19And so the best way to avoid
48:20that is to always identify where
48:22your needle tip is located.
48:23So that's why it's important to
48:25have real time ultrasound guidance.
48:27And you know the the way you enter
48:28the nodule is less important as to
48:30identifying where that needle tip is
48:32and understanding that the ablation
48:33zone is going to be 3 to 5 millimeters
48:35beyond the tip of that lesion, right.
48:37So sometimes as.
48:38You as you know as surgeons we always
48:41try and be better and best right,
48:43but sometimes we have to take a foot
48:45off the pedal little bit and recognize
48:47that it's better to leave a smaller
48:49ablation area that may be remain
48:52unabated as opposed to causing an injury.
48:55And again you know greater than 50%
48:57reduction in volume is significant and
48:59as considered an effective treatment.
49:01So you can kind of come off of the
49:02border of that nodule and still be
49:04confident that at the six month
49:05time point you're going to have at
49:07least that 50% reduction in volume.
49:09The most important thing is that
49:10the patients.
49:11Feel that their cosmetic or compressive
49:13symptoms have resolved and also
49:15you can live to fight another day.
49:17And and so appropriate patient
49:18education is important to let them
49:20know that sometimes it may require
49:21more than one ablation procedure.
49:23But again it's like going in,
49:25I'm oversimplifying it,
49:26but it's similar to going in for
49:29a needle biopsy.
49:30You know obviously a bit more
49:31complex and and a bit more risk.
49:33But if you explain that thoroughly
49:35to the patient,
49:35I think that's the safest way to
49:37kind of stay safe and also just
49:38keeping an eye on that needle tip
49:40regardless of which way you enter.
49:42The thyroid and the needle.
49:43And then your second question
49:44was talking about how can we we
49:46always think about this too,
49:47so how do we know which?
49:49Thyroid cancers are going to be
49:51bad players as opposed to others.
49:53And I think that we we just don't know,
49:55right.
49:56We we think we have an idea we'll see.
49:58And so that's why even with
50:00tirade evaluation of thyroid,
50:02ultrasound nodules will say that if
50:03it's a tie rods one or two lesion,
50:06we treat that like it's benign.
50:07We don't have to worry about it.
50:08There's sometimes nodules that are
50:10less than a centimeter and they
50:11don't meet criteria for biopsy,
50:12but they have some characteristics
50:14like microcalcifications that put
50:15them up to like a tyrant four or
50:17five and what do we do with those.
50:18So sometimes some patients.
50:20Those those nodules biopsied and they
50:21turned out to be a papillary thyroid cancer.
50:23Other times people more strictly
50:25follow that criteria and they
50:26don't biopsy, they they observe it you
50:28know for another three to six months and
50:30re biopsy and find that those nodules
50:32either have cancer or they do not.
50:34You know I just think that we just need more.
50:38Experience in looking at these nodules,
50:40observing them over time.
50:41You have to observe the Natural
50:43History of them. But that means,
50:44you know, without intervention really.
50:45And so that it's very it's harder, I think,
50:48in the United States to not do something
50:50both for the patient and for their provider.
50:53I've seen plenty of cases where I've taken
50:55out a 1 centimeter or less small thyroid
50:57cancer patient never had a recurrence.
50:59They're happy and fine.
51:00There have been cases where they've had
51:02to be on thyroid hormone and then I've
51:04seen cases where a small nodule where I
51:06was planning to just do a lobectomy on.
51:09Because it was less than a centimeter,
51:10but then that patient presents with
51:12a palpable or clinically relevant
51:15lateral neck disease,
51:16lymphadenopathy.
51:16So despite it being a small lesion
51:18that had escaped to the lateral
51:20neck and that patient needs a
51:22maximally invasive type of procedure.
51:24So I think we just need more time
51:26and experience and and and and
51:27biomarkers to try and determine
51:29which ones are the bad players,
51:30can we predict them in advance and
51:31to date I don't think we have a
51:33very good way of predicting that.
51:46So that that last that last
51:48study that you talked about was
51:50pretty was kind of a teaser.
51:52Do you think that it's going to
51:54be equivalent or are you going to
51:56start offering the RFA for your for
51:59your patients with thyroid cancer?
52:02And the other part of that was that
52:04there were originally over 1000 patients
52:06that were eligible for that study but
52:09ended up comparing only about 190
52:11some and so is there really just a
52:14certain subset of of thyroid cancers?
52:16That that could be addressed by by RFA.
52:20Great talk. Thank you. Thanks.
52:22So, yes, so very good questions.
52:24I think there's a lot that we don't know
52:26about how best to implement this, right.
52:29So I think the guidelines to date and
52:30the experience worldwide has largely
52:32been for benign thyroid nodule.
52:34So I think here in the US,
52:35we're becoming more comfortable with saying,
52:37OK, this is an appropriate potential
52:39intervention for benign thyroid nodules,
52:40right.
52:41And and the literature supports that,
52:43what we don't have and in the case
52:45of recurrences or in patients who
52:47would not qualify for surgery
52:48because of other comorbidities, OK.
52:50Yeah, here's another thing we can offer.
52:52Without just sitting and knowing that
52:53it's there and potentially going to,
52:55you know, cause some problems.
52:56So what we're trying to define and decide is,
52:59is this an effective treatment
53:01for these small PTC's,
53:03which is the question of the day.
53:04And if I had that answer, probably,
53:05you know, I wouldn't be here right now,
53:07right.
53:07So I think it's going to have
53:10to involve a lot of education,
53:13a lot of experience on the part
53:14of the provider who's doing this
53:16intervention and comfort level.
53:17So, you know,
53:18the best way to have an effective
53:20implementation of a new program is.
53:22To really pick the ideal candidates, right.
53:25So you want lesions that are about 2
53:26centimeters or so, so not too small,
53:28so that you'll damage some surrounding
53:30healthy tissue,
53:31not too large that you'll have
53:32an ineffective outcome,
53:33but just to kind of perfect size.
53:35And you want to start with benign
53:37thyroid nodules so that you can get
53:39an effective improvement in symptoms,
53:40I think no matter what, even if I take out.
53:45UH-1 centimeter thyroid cancer by doing
53:47a lobectomy or even a total thyroidectomy,
53:49there's still no guarantee that that
53:51patient will never have a recurrence.
53:52We feel pretty strongly that they won't.
53:55But if there was,
53:56you know,
53:56single cells in transit that just
53:58wasn't detected on ultrasound,
53:59eventually they're going to show themselves.
54:01And we see that time and time again.
54:02We see it when we do a thyroid
54:04lobectomy for a small thyroid cancer
54:05and then those patients are under
54:07surveillance with you all as the primary
54:09care and endocrinologist and three,
54:11six months, two years down the line.
54:13OK, I see a little tired 4 lesion.
54:15In the in the remaining lobe
54:17and then that turns into OK,
54:18there's another focus of cancer or there's a
54:20single lymph node here that looks concerning.
54:22So I think there's no way to guarantee
54:24that cancer will not come back and I think
54:26patients have to understand that regardless,
54:28regardless of the intervention that you use.
54:30But to kind of more specifically
54:32answer your question,
54:33I think ultimately that would be my
54:34goal to be able to treat these small PTC
54:37because I do think that it's overkill.
54:39So many years ago when I
54:40first started here in 2013,
54:42we were doing a total thyroidectomy for our
54:44one centimeter thyroid cancer routinely.
54:45Total correctly, central neck dissection.
54:47And then you know,
54:49the American Association of Endocrine
54:50Surgeons and other organizations said OK,
54:52is this overkill because we're putting
54:54so many patients on lifelong thyroid
54:56hormone supplementation for cancer,
54:57that's likely not going to kill them.
54:59You know, it requires some treatment,
55:01but it's not going to kill them.
55:02So then we kind of took a step back
55:04and and revised our guidelines to say
55:06that a nodule up to 4 centimeters
55:08can be successfully treated with
55:09a thyroid lobectomy.
55:10Now I can tell you from the surgeon side,
55:12many of us are reluctant to have a 4
55:14centimeter thyroid nodule and just.
55:16To a lobectomy on those nodules
55:18because the normal dimensions of a
55:19thyroid gland or thyroid lobe is
55:21anywhere from 4 to 6 centimeters.
55:23So over 2/3 of the volume
55:24of that lobe is cancer.
55:26And I think that's, you know,
55:28not appropriate in my personal opinion,
55:302 centimeters or less reasonable.
55:33So you know.
55:35But with that,
55:36there's still always the chance
55:38of recurrence.
55:38I I do think that as we get more
55:41comfortable and effective in performing
55:43the RF ablation for the benign,
55:45then there's this.
55:46Opportunity to kind of deal with.
55:47So the next phase will be like
55:49these indeterminate nodules, right,
55:50dealing with the indeterminate nodules.
55:51And then ultimately,
55:52yeah,
55:52I think the goal would be for
55:54these very small lesions ablating
55:56those lesions and then following
55:57them over time and making sure
55:59that we are continuing to follow
56:00those patients over time.
56:01So that they do if they do present
56:03with you know locally advanced
56:05disease that they also still are
56:07able to get effective treatment.
56:08And I think that's important thing
56:10to note too is that surgery is
56:11never off the table in the majority
56:13of cases even if you have another
56:14intervention before then similar to.
56:16Patients who undergo radioactive
56:17iodine therapy for Graves' disease,
56:19you know, makes the surgery tougher,
56:21but if that, if those if that fails,
56:24those patients would still go on to
56:25surgery to treat their Graves' disease.
56:37Actually, Gibson, are there any
56:39specific training guidelines in order
56:40to be able to do this procedure?
56:42So that is being worked on by multiple
56:44medical societies and because of the
56:47people who are performing these procedures
56:49come from very varied backgrounds.
56:51Do you have medical endocrinologists?
56:52You have interventional
56:53radiologists and you have surgeons?
56:55And so there's a different experience
56:57that each one of us has undergone.
56:59And so we're trying to kind of coordinate
57:01and figure out what's the best way to
57:03get that experience so to keep it.
57:04Safer patients.
57:05So one, you definitely need to
57:07have experience and comfort
57:08in performing ultrasound.
57:09So that is universal that needs to happen.
57:11You don't necessarily have to
57:13have a experience in performing
57:14a fine needle aspiration.
57:16Biopsies is helpful I think to have
57:18that experience but it's not required.
57:19But you are going to need some
57:21sort of formal training either on
57:23cadaver models or an observership
57:25afterwards in observing a real
57:28live RFA ablation procedures.
57:31There is a surgeon in Brazil who.
57:35Prior to the pandemic was actually
57:37allowing people to come on site
57:39and Brazil and to observe and then
57:41perform RFA ablation and his patients.
57:43But again,
57:43that is not something that is going to
57:45be widely accepted in the United States,
57:47right.
57:47So we're going to be reduced to one
57:50getting ample experience in ultrasound
57:52performance and then you know,
57:53experience with cat cadaver
57:56and observerships.
57:58I think that is going to be kind
57:59of the standard moving forward.
58:03Great. Well, thank you everyone.
58:04I think it's it's at the hour
58:05and thanks Doctor Gibson
58:06again. Thank you.