Latest / Behind The Knife: The Surgery Podcast / Operative Standards for Cancer Surgery Series: Papillary Thyroid Cancer
Transcript
- Final BTK Thyroid Episode === [00:00:00] Hello and welcome to the New Behind the Knife miniseries on the operative standards for Cancer Surgery Manuals developed through the American College of Surgeons Cancer Research programs, operative standards for cancer surgery. Volumes one, two, and three offer concrete evidence-based recommendations on cancer surgery techniques critical to achieving optimal outcomes. These standards cover 15 distinct disease sites with standards for additional disease. Sites currently in progress and select recommendations have been incorporated into the operative standards or incorporated into the 2020 Commission on Cancer Accreditation standards. My name is Jack Sample, and I'm a surgical resident at Mayo Clinic Rochester, and a member of the Education Committee for the Cancer Surgery Standards Programs. And I'm joined by Dr. Tracy Wang and Dr. Vlad Nichi. And along with other members of our committee, we're launching this new miniseries to help spread the word about the operative standards and to discuss each of the requirements in rationale. Today we're gonna be discussing one of the operative standards for thyroid cancer.[00:01:00] To help with this discussion today, we're lucky enough to be joined by experts in the field of endocrine surgery, Dr. Elizabeth Grubbs and Dr. David Hughes. Dr. Grubbs is a professor of surgical oncology at MD Anderson, where she specializes in thyroid, parathyroid, and adrenal gland cancer, and Dr. Hughes is a clinical associate professor at the University of Michigan and a board certified endocrine surgeon specializing in the management of thyroid, parathyroid and adrenal gland disorders. Dr. Grubbs and Dr. Hughes, thank you so much for joining us. The operative standards for thyroid cancer were published in the second volume of the operative standards for cancer surgery. The thyroid section was primarily focused on the preoperative and intraoperative aspects of the evaluation and treatment of patients with biopsy proven papillary thyroid carcinoma, or PTC greater than or equal to one centimeter. This included critical technical elements for oncologic components of thyroid cancer surgery, and recommendations for documentation in the operative [00:02:00] report using synoptic format. In this section, important aspects of PTC management are highlighted, including modifications to the A JCC cancer staging system, the development of recurrent risk stratification system and preoperative elements used to guide surgical planning and management. Section also covers the critical technical elements when performing a thyroidectomy for PTC, including preservation of the parathyroid glands and the management of recurrent al nerve, as well as how to perform both a central and lateral compartment dissection. The key questions for this section also focused on the discussion and summarization of data surrounding total thyroidectomy and thyroid lobectomy for the treatment of low risk PTC. And indications for central compartment lymph node dissection. For the sake of today's behind the Knife podcast episode, we'll be focusing on the decision making regarding the extent of initial thyroidectomy. So we'll start with the first question for Dr. Grubbs, and I can [00:03:00] personally attest that this is an area of confusion for surgical trainees. Whether preparing for endocrine surgical rotations, or when studying for the app site every year, the updated guidelines recommend that either lobectomy or total thyroidectomy are acceptable for PTC tumors, one to four centimeters without extra thyroidal extension or lymph node metastasis. In your practice, what are key considerations you make during the preoperative evaluation of a patient with PTC that may influence you towards a thyroid lobectomy versus total thyroidectomy? So, thanks Jack so much and, and really happy to be here and be part of this important discussion. So. Okay, so low versus total for a thyroid cancer, less than four centimeters. And you're right, it can be confusing because the data really says that for many cancers that are low risk, otherwise a lobectomy or a total thyroidectomy is [00:04:00] appropriate. But I wanna say the key word there, being low risk. And there are some things that you can understand preoperatively to help you know whether it truly is, uh, gonna be more acting like a low risk cancer versus one that has a higher risk for recurrence and therefore probably deserves. A, a more complete operation in the form of a total thyroidectomy. So what can you use preoperatively to help you make that decision? Well, when the person walks in the door, you are going to talk to them, elicit some, some symptoms that, that, that are important, that key sn to, uh, do we have concerns? Um, and then you're gonna do some preoperative studies that are gonna help you as well, determine that. Dr. Groves, if I may really quick how may someone define one of these lesions as, uh, low risk? One of the things that we think about when we think about low risk. Is that, that the the tumor itself, no matter what the size it is, has not left the [00:05:00] thyroid and started to invade other surrounding structures. Things like, um, we think a lot about that recurrent laryngeal nerve that is right next to the thyroid and intimately involved with it is all of us that do thyroid cancer, no. Only too well, we think about the trachea. We think a little bit about the esophagus, even though that's often less involved. And then you also think about anteriorly with those strap muscles. So these are all the areas that surround the thyroid and that a thyroid tumor could choose to grow into. Okay. Dr. Grubbs, you just mentioned some features of a PTC tumor that are more consistent with an invasive lesion, and these are things that we may observe on preoperative ultrasound or in the or, but um, how can we assess a patient's symptoms to determine if they have a low risk cancer based on their clinical presentation? So, when a person comes in, we ask them things about their voice. Have they noticed changes in voice? Have they had change in the caliber? Do they experience more [00:06:00] hoarseness? We ask 'em about their swallowing. Really the key for us, the big one, is pain on swallowing. That gives you a real concern of could there be involvement with, um, full thickness of the esophagus. My, I have a patient that truly has that I, I'm gonna be, have a little bit more concern that there could be some of that invasion that is happening and that would no matter what the size of the, the nodule, even if it's under four centimeters, I would be concerned it could be higher risk and I wouldn't wanna put it in that low risk category and say that we could just do a lobe. We also wanna feel that neck. And we wanna feel not just the thyroid itself. 'cause sometimes we can feel a thyroid and we can feel a little cancer and, and it's nice and mobile and it moves when they swallow and you're like, Ugh, this guy's not stuck to anything. And sometimes you feel a neck and that it, it's a very firm, very kind of socked in feeling and that gives you a higher concern that it maybe has started to grow roots around it. So that helps you. And then the other thing that you can do is feel for [00:07:00] lymph nodes. Sometimes in the central ME, even though that can be a little bit harder 'cause that thyroid's in the way and certainly in the lateral neck. If you have concerning palpable lymph nodes, that's something that is also gonna get your, your, your, um, concern up that there could be metastatic lymph nodes that are large enough that I can feel them with my, my hands. Those are things that are probably leaving the realm of low risk thyroid cancer, where you could consider doing a lobe versus a total thyroidectomy and you really wouldn't make that choice then. Great. So you have a patient in clinic and you've elicited your history and performed a physical exam and are able to palpate a mass on the left side of their neck. Uh, what imaging studies are you gonna use next for your preoperative workup? Fortunately, we have other studies, imaging studies that can help us. We're always, we're gonna, our go-to is always gonna be the ultrasound. And so that's a great preoperative, um, modality that we have. And I would, I would say that really we like ultrasound.[00:08:00] As the, the go-to uh, imaging modality to start with in that setting, we're not just gonna look at the thyroid, but we're gonna look at the thyroid and the lymph node basins, both in the central neck, what we can see in and in the lateral neck. That's a really important preoperative uh, evaluation that we talk a lot about in the operative standards. With the thyroid yourself, with the ultrasound, you can start to get an idea whether you think that there is involvement of the surrounding structures. You can't see a good plane between the trachea, you can't see, um, a good a plane anteriorly with the strap muscles. We'll talk a little bit about the strap muscles uh, later on and, and how important we think those are at. But, but you can start to get an idea. Do you think that this tumor is actually invading outside of the thyroid? Same with lymph nodes, you can look for for concerning, um, metastatic lymph nodes. Within the ultrasound. This is really gonna be helpful in those lateral necks where, um, ultrasound is a beautiful way to see whether there are concerning [00:09:00] lymph nodes that are there. There are, uh, lymph nodes that are concerning for metastasis. We would usually talk about interrogating those with a biopsy, along with getting a biopsy of the primary tumor itself. And then in the central neck you may be able to see metastatic nodes. We, I always talk about it with patients that sometimes that thyroid makes a little bit of a blind spot, so you don't see it as well, but look for it. Dr. Grubbs, what are your thoughts on the role of a CT scan in your preoperative workup? I've read things like CT imaging should be deferred or not be used in the preoperative setting because of the potential future use of radioactive iodine. I also would say that if on my imaging both symptoms that patients have and the imaging that I find in ultrasound sometimes prompts me to get additional imaging in the, in terms of a, a CT scan because that can be additive in those settings, I sometimes, I think the CT scan does a better job of helping describe whether there's more infiltration, especially of the [00:10:00] trachea. And also the esophagus. Um, so if an individual either has an enlarged, uh, um, cancer that looks concerning on ultrasound, I'll get more information from the ct. Or that patient came in and had really, um, had hoarseness or had that really burned nodule sometimes that's when I'll also get the CT as well, because I think that's additive to the ultrasound. So that's the imaging part that, that really helps me understand that if, if for me, if there's lateral metastatic disease or, and, and a lot of times if there's central metastatic disease, uh, or if there's real infiltration into the trachea or the esophagus, that's when I know this is gonna be a more advanced cancer and that lobectomy is less of, of an option for me. Yeah, Dr. Grabs, I, I, I completely agree that ultrasound is so, so key. Uh, and if you have the capacity to do your own ultrasound as a surgeon, I find that very, very helpful. Um, it helps you kind of map out the [00:11:00] lymph nodes that are positive, uh, which lymph node basins you need to dissect. Uh, you did mention the central versus the lateral neck. Sometimes that can be a little confusing. Uh, so the central neck lymph nodes are typically the level six lymph nodes. Uh, those are lymph nodes that go from the hyoid bone cranley down to where the denominate artery crosses the front of the trachea. Coddly, uh, the lateral borders are the common carotid arteries, and then the posterior borders gonna be that pre vertebral fascia over the top of the, uh, spine. Um, and you wanna make sure you remove all those if, uh, the uh, metastatic lymph nodes present in that ips lateral side of the tumor. Most patients, if they have lateral neck lymph nodes, uh, that are involved are also gonna have central neck lymph nodes involved on that same side. So if you're, if you're doing a lateral neck dissection from metastatic lymph nodes, make sure you get that central neck on that same side, uh, while you're removing that tumor, obviously in the thumb fluid. So, I agree with all of that, and I, I think also when we, when we're going back to this idea of. [00:12:00] Of preoperative evaluation and trying to decide when you can do a lobe versus a total thyroid. I think the other things that I think about besides you know, potential invasion outside of the thyroid and lymph node involvement, which makes me think this is gonna be potentially more a, a, a thyroid cancer that's higher risk for recurrence. And where I think a total thyroidectomy, we start to think along those lines because. The idea of potential radioactive iodine and using that might become into the discussion. I think the other things that we, I, I think about is, okay, what about what's in, if I was potentially gonna do a lobectomy, what's in that other lobe? You know, is there, are there things within that other lobe that make me say that continuing to watch it would not be the best idea? Um, do I need to biopsy anything in that other lobe? Um, that it doesn't have the known cancer within it? To, to, to rule that out. The history of the [00:13:00] patient. Do they have a history of radiation to the neck? Um, usually we think about that history. You know, several decades before that would really increase your risk of having a thyroid cancer. So, um, you know, a asking if they have a history of ionizing radiation, um, once in a while about once every eight years I'll get someone that was downwind of Chernobyl. So it's always worth keeping that in the back of your mind, but more you're also thinking about. Radiation from either, um, an older generation might have it from, they were radiated as a child. They, they, when they were a baby, when they had their thymus radiated, um, a radiation for acne, uh, was done. And that would be people more in their fifties to sixties to seventies now. Um, and then, um, radiation for other head and neck tumors or any lymphomas that would've involved the neck as well. If they have that, you know, that that's an increased environmental risk for having thyroid cancer. So you might consider saying, well, because of this [00:14:00] exposure we, we might consider removing the entire thyroid. Yeah. I think when getting these patients histories we often think about those exposures you mentioned, such as childhood radiation or environmental. But at least speaking for myself here, we often overlook family history. So can you speak a little bit more about how this may influence your decision making? Um, when considering a thyroid lobectomy versus a total thyroidectomy for PTC, Family history is an interesting one as well. You know, we talk about with well differentiated thyroid cancer, which are your papillary, uh, thyroid cancers, follicular in your oncotic that there can be a family component. To these non medullary thyroid cancers. And we usually talk about that as if you have at least, what are we calling it? Three first degree relatives that, um, also have one of these thyroid cancers, then you might consider, um. You might consider, uh, a total thyroidectomy in that setting because we think you are at increased risk ha of [00:15:00] having a hereditary component to it, and that means potentially multifocal. And then I think the last really, really important thing is what does the patient want? Um, and that's a huge discussion that we have. There are some patients that I know Dave can attest as well, that never want to even consider. Um, the risk of ha of another operation or considering that they could have a cancer within the remaining lobe and they want a total thyroidectomy because they, their quality of life will be challenged by just even the thought of that. And they're, they're, I, I kind of put them in what I call my maximalist group. And, and that's okay, you know, for, for them, if I can do this safely. And the total thyroidectomy is right for them. We had that discussion much more likely in my practice is individuals that are more minimalist and are like, what is the minimal amount that, that I can do at for this and have the same outcome? And for them, they really enjoy the, the thought and joy might be a strong word. They really like [00:16:00] the idea of being able to keep some of their own thyroid, um, and having that own their own endogenous thyroid hormone. So one, one thing I usually tell my residents when they're trying to decide if they need a total or a lobe is try to think about the end. So if they're gonna need radioactive iodine therapy they should probably get a total thyroidectomy. So think about the indications for radioactive iodine. It's lymph node metastasis. Extra choroidal extension, uh, tumor bigger than four centimeters, that's a little bit debatable. Or if they have some kind of high risk variant to papillary thyroid cancer, you'll only be able to figure that on the, on the final pathology. But if you think they're gonna need redact iodine based on their initial clinical presentation, you should do a total thyroidectomy. One very quick remark before we move on. Um, if you'll, uh, if you'll allow me, it's, um, many patients, specifically female have underlined sometimes subclinical Hashi model and, um.[00:17:00] It's, um, very unlikely at, at least you, the, the experts you'll tell us. But it's very unlikely that we can guarantee that even successful and pathologic proven low risk papular thyroid cancer may render them pill independent. That's the only reason we'll. Thyroid tissue behind. There is no other reason as, uh, Dr. Grab said, you'll wonder, do you biopsy something? Do you follow? Is there cancer there? Which is not unheard of. Even in small nodules, you never know. But, um, hashimo thyroiditis, especially in, in, in women, over age of 50 is very prevalent. Just, uh, just a quick note. That's a really good point. You know, we talk about this in terms of, um. You know, when we talk about, and I know we're not talking about this today, but observing small thyroid cancers and one of the contraindications for observing is when you've got thyroiditis and you don't feel like you really have a [00:18:00] good understanding of, of visualizing, you know exactly the modules within the thyroid. And so I think that's something you can talk to patients about. You know, do we feel like that we're really getting a good view of that contralateral load? I think the other thing you bring up, which is a really good point, is patient expectation. Correct. Um, about are they going to, you know, sometimes we talk about doing a lobectomy if all things are equal. It's a low risk thyroid cancer, you're not planning on giving radioactive iodine. You know, if I keep, if I have half my thyroid in place, then I won't need to be on thyroid hormone replacement. Right. And the challenge there is obviously sometimes that we give additional thyroid therapy in the form of thyroid hormone suppression as. You know, treatment for the cancer. And so I always am sure to remind patients that just because we only take out a lobe doesn't mean we're not gonna re recommend thyroid hormone. But I do find that. That there [00:19:00] is still value to having sometimes their own thyroid hormone, even if we're gonna supplement it, then being completely thyroid hormone dependent. And so those are the, you know, some of the dis, especially with my young women, I, you know, and I know we there, the, the, the, um, studies haven't really panned out to show us very well about quality of life with LO in total. But just, um, having done this you know, a couple of years, it's like I. It, you, you start to have these, these these observations. We somewhat covered it. Uh, Dr. Uh mentioned that there have been several studies now increasing, uh, volume information and, and studies that show that, um, there is really no significant statistical difference, um, that will, you know, render disease-free survival, uh, benefit between. Thyroid lobectomy versus St. Thyroidectomy thyroidectomy for low risk [00:20:00] thyroid cancer. But I, uh, wanted to ask you guys, um, it, let's say Doc Dr. Hughes, let's say that, uh, you are operating on a 45 years old, uh, woman with 2.5 centimeter papillary cancer that has been biopsy proven. What would, uh, a a and you are planning for thought, uh, for thyroid lobectomy, what would be the intraoperative finding? Maybe actively looking for them or, or just that will appear that will change your decision making conversion from a lobectomy to either a total thyroidectomy correct. And then, uh, either with or without a lymph node dissection. Yes. Yeah, I tried. The best thing you can do is avoid surprises. Um, make sure you get good imaging before the surgery. Uh, make sure that ultrasound can really evaluate those things. If you do get in there and you see some extraoral extension of that tumor, if it's anterior and just into the strap muscles, most of the time you can just remove a small island of the [00:21:00] strap muscles along with the tumor and be able to get a negative margin. There's a few studies that show that the strap muscle invasion really doesn't necessarily, uh, equate to worse outcomes. It's a little bit different. If it's a posterior extension, it's grown into either the esophagus, the tracheal, or the recurrent limbal nerve. Then you want to obviously try to preserve those structures as much as possible. If you have a functional recurrent nerve prior to surgery, uh, and there's invasion of that tumor into the nerve, uh, you should do everything you possibly can to try to preserve function of that nerve, even if it requires leaving a microscopically positive margin on the nerve. Uh, if the nerve is already out. Prior to surgery and there is extraoral extension into that nerve, uh, sacrificing the nerve, taking a negative margin is perfectly adequate. So I think that extra throat extension posteriorly is a, is a, a more likely surprise because the ultrasound, uh, there can be a blind spot caused by shadowing. Um, and that's something that you won't know until you're end there with surgery. If you're leaving a, a positive [00:22:00] margin on the nerve to preserve it, uh, that patient probably would benefit from radioactive iodine and to convert to a total thyroidectomy for that patient. The cervical lymph nodes, you will see some central neck lymph nodes. When you do a thyroid lobectomy or total thyroidectomy those lymph nodes will look abnormal. A lot of times they'll have some either cystic changes, they'll have a little bit of a blue color to them, uh, depending on what the primary tumor looks like. Uh, using frozen sections very has great you know, sensitivity for presence of lymph node metastasis. Uh, if you got lymph node metastasis in the central neck, uh, especially if it's visible to the, to the naked eye, uh, you should probably convert to a total and then perform a formal central neck dissection, at least IPS laterally, uh, if not contral laterally for a patient like that. I agree completely. I think you know, the one thing that, to pick up on what Dave was saying last and. You know, we, we often have the, the thought process of what is the right amount of, of operating sometimes in the setting. And you know, I think [00:23:00] in the setting where you have known ipsilateral disease, a lot of times I will think to myself, I, I should do a bilateral central neck in this setting. I also have to weigh this against what are the risks of doing that more aggressive central neck on the contralateral side from the, the primary cancer. And that's where I really kind of have to take stock. You know where I am in the case. Okay? How do my four parathyroids look, right? If I feel that? Uh, that I, the ipsilateral side was that right side. And, and I, I just, well, let's blame the disease. It had nothing to do with the surgeon. Those two parathyroids look terrible. Couldn't have saved to 'em, not, no. The best surgeon in the world. But if they don't look good, and I go to the other side, and I know that, and I don't have any, you know, grossly concerning lymph nodes on that contralateral side. And I know I really, in this, I need to save a [00:24:00] parathyroid. I might choose in this case. Because those parathyroids are, are, you know, I, I know that, that I have a higher chance of, of, of having hypoparathyroidism. If, if I hurt these last two remaining parathyroids, I may decide in this particular case to say I'm gonna be less aggressive. Versus if on that ins later side I was amazing. And again, now it's the surgeons who saved those parathyroids and they looked great, then I might be more aggressive on that contralateral side. So, you know, you're constantly in this operation kind of recalibrating, where am I? You know, there's always a fork in the road and it's like, which way has more benefit? And, and, and sometimes, you know, you have wiggle room that, um, that you can, can make some of those decisions. Sometimes you don't. Sometimes you have bilateral central neck, large nodal metastasis that you need to remove. And, and, and you're gonna have to take more. You're gonna have to take more risk in terms of doing more dissection, which by [00:25:00] definition, um, you know, puts those parathyroids at, at greater risk. But, but those are, you know, conversations that you're had. Those, those are things that are case by case that you just can't make grand, grand, um, you know, observations that, that apply to everyone. I, I, I think, um, I, I, in my practice, I also do the same thing, like really weighing the risk interoperatively and, uh, seeing, I mean, honestly how the superior look and if it's, um, the, the lower parathyroids, um, like in the thyroid temic ligament, not always can see them actually. At least I not always identify them really clearly with lymph nodes, uh, surrounding them. So it's a really technically challenging part of the procedure. Yeah. Thanks Dr. Grubbs and Dr. Hughes, if I can just chime in. So do you, assuming you have a Unifocal thyroid nodule, nothing contralateral. Do you ever, like, what are, do you ever [00:26:00] say, Hey, we're gonna, there's a need to do a total thyroidectomy here. Does size play a role into it? Or, you know, where are you in that camp, uh, in that spectrum of, of making that decision right now? Yeah. I, I, I think you've got a four centimeter cancer. That's obviously inside the thyroid gland. Everything else looks completely normal. Um, it is a patient decision. I think, um, I think it's important to counsel them that their outcomes will probably not be drastically different. If you do a lobectomy or total their life might be a little bit different. Need a total, you're gonna obviously have to take thyroid medication every day. Um, the rates of needing thyroid medication after just the lobectomy vary pretty widely based on the patient factors. You know what, what you, what TSH you treat with a thyroid medication versus not. Uh, but there's a significant risk they need to take thyroid medication long term anyway. The total thyroid thyroidectomy does expose both recurrent ral nerves. It is gonna slightly increase the risk of nerve injury. And obviously hypoparathyroidism only happens in total thyroidectomy. Um, it doesn't happen if you do a [00:27:00] initial lobectomy and they never had the other parathyroid plans disturbed. So going all over, all those things with the patient preoperatively, I think will help make the best decision for them. You know, I think we do know that there is. Uh, information that the larger the, the cancer, the more concern there is for for risk of recurrence. And so you might consider, you know, doing in a more extensive operation. And so I, I will say that when I have a 3.8 centimeter thyroid cancer it gives me a little bit of pause, right? And that's where having discussions with patients prior about what their. About expectations and what their goals are is helpful. You know, again, if I've got if I've got a 30-year-old female who's very, very motivated to save her contralateral lobe and understands that, um, we may be going back for additional surgery in the future with a [00:28:00] completion. Um, you know, that's different than my 78-year-old or that's like, I, I never want like, do what you gotta do, but you know that this is it. You got one shot. So I, I think you, you kind of have to take some of that into to consideration as well, you know? Again, it, that one to four range is kind of a toughie, right? That's a big range for thyroid cancers. And, and I, I think that, you know, they don't all fit into, to one bucket. And you do have to think, you know, you do wanna think through that. I think the other thing as well, and, um, I didn't say this during the preoperative part, but a re reminder, you're always in this as a partner with your endocrinologist usually. And so if you work with an endocrinologist that tends to like to, um. That that is, is more RAI forward in how they treat their patients. You wanna have those discussions with them before you operate because what you don't want is the patient coming back to you and saying. [00:29:00] Dr. Jones said you needed to take my other lobe out. 'cause they're definitely gonna give RAI, you know, have that discussion ahead of time, uh, really understand, um, with your, your, your, your clinical partners how you each work so that you can, can have some of that. And so there's not confusion, um, with the patient after the fact. Better to go ahead and, and have all that discussion ahead of time. Excellent. Uh, Dr. Grubbs and Dr. Hughes, thank you so much for joining us today and sharing your technical expertise, uh, surrounding the field of thyroid cancer surgery. Thank you guys. Appreciate it. Uh, this was a really great discussion regarding the clinical questions that we often encounter, particularly for surgical trainees like myself. And I hope that you know, this discussion will help reinforce some of those really important evidence-driven oncologic considerations that we encounter. Highly appreciate it. If you're interested in learning more about the operative standards for cancer surgery, check out the Cancer Surgery Standards Program website, which will be linked in the show notes. Thank you again for joining us and catch upcoming episodes in the coming months regarding more operative [00:30:00] techniques for cancer surgery and dominate the day. Dominate it man.