Radiofrequency ablation of thyroid nodules: current indications and future considerations

Transcript

• 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.