Update Course Rewind: Thoracotomy vs VATS for Lung Metastases

If you missed our annual pediatric surgery update course, don't worry. We're going to summarize our favorite sessions right here on this podcast. In today's episode, it's a battle between thoracotomy and VATS or video assisted thorascopic surgery, specifically for lung metastasis. Most pediatric surgeons probably already have opinions about this, but we are here to discuss the two techniques with pros and cons. And hopefully we'll give you a little more insight into the surgical management of pulmonary metastasis and osteosarcoma. I'm Rod Gerardo. And I'm Ellen Cisco. We are research residents at Cincinnati Children's Hospital. And this is the Stay Current in Pediatric Surgery Podcast. So a 16 year old uh kid comes to clinic. Um, he has a lot of pain from his left tibia. Um you get an x-ray and you see this lesion. Everyone, that was Dr. Roshni Dasgupta. She is a pediatric surgeon at Cincinnati Children's Hospital Medical Center and she's going to be explaining this through a case. In the next step, they get a bone biopsy and it shows osteoblastic osteosarcoma, which is basically a type of bone cancer that usually develops in the osteoblast cells that form bone. It happens most often in children, adolescents and young adults. The most common primary site is in the long bones in the leg, like in his case in the tibia. And the most common site of metastatic disease is in the lung. In fact, about 20% of patients already have lung metastasis by the time of diagnosis and that's usually picked up on staging chest CT. In this chest CT, we see three small nodules on the right side, um measuring 2 to 6 millimeters, and then there's a sort of non-specific nodule um on the left side. He then undergoes his four cycles of chemotherapy, he goes to orthopedics, has his limb salvage procedure, get another cat scan and um the CT scan is unchanged. So the same number of nodules on both the right and the left side. Okay, then what's the role for a metastatectomy? I mean, does it make a difference? Should we even bother doing surgery on the lungs for this? About 40% of patients you can get a durable cure response after 5 years if you have complete metastatic site clearance. So you can make these patients long-term survivors. Um obviously the less mets you have, the better outcome you do. So patients with solitary nodules do better, but if you are able to surgically resect all metastatic tumor sites, independent positive prognostic factor and it does affect overall survival not just disease recurrence. Do small nodules matter? Our data actually from one of our P serve studies shows that even at the size of 1 millimeter, you can get about 60% of 1 millimeter nodules contained malignant disease. This is in a group of patients with metastatic osteosarcoma. Obviously the bigger the nodule is the more likely you're going to have malignancy, but all the way down to 1 millimeter, you will see tumor. Even 1 millimeter? Wow. Okay, that's important to consider. Let's move on. We got a lot to learn here. The next question is, if we think that removing these nodules will have some overall survival advantage and we want to do something about them, how do you approach the lung nodules? Historically, thoracotomy has really been standard of care. Why? Because we can use our fingers and hands and feel the tiny little grains of sand. You will find about 30 to 40% more lung nodules with your fingers and looking than you actually find on cat scan, even with our special MIP scanning and our like thin cut CT scans. All right, it seems like hands are very important to check for any nodules that may have been missed by radiology. But hands are not the only helpers. We also have indocyanine green or ICG to help us diagnose these nodules. ICG is a die used in a variety of diagnostic and therapeutic procedures. Is there any role for ICG in these cases? We can use ICG with thoracotomy and you can sometimes find the deeper nodules. One of the issues with ICG is depth of penetration. So when you are open, it's a little bit easier to use ICG for some of those deeper nodules. So these are very good reasons to do a thoracotomy, Ellen. I mean, why isn't it our first choice or our best choice? Great question, Rod. It is obviously more invasive than other alternatives and there's longer length of stay. Also sometimes it's just technically more difficult and we're not really sure that removing those tiny little 1 millim nodules actually gives you a survival advantage. Of course, keep in mind that if we prefer not to do a thoracotomy or we literally can't do a thoracotomy. The other option, it's a video assisted thorascopic surgery, also known as a VATS. So when do we choose VATS and why do we prefer that over thoracotomy? Well, it's minimally invasive, it's a shorter length of stay. Often when you go back in for a repeat thoracoscopy, you don't have the same adhesions, it's not as stuck, you can actually get in there pretty well. Okay, so that seems so much more beneficial for patients and for surgeons, so why don't we just do VATS for everyone all the time. We often need to have some sort of localization process. You need to have good interventional radiology. Also there is some limitation on how many nodules you might be able to take out. Often with thoracotomy, you can take out 15 to 20 nodules. But with thoracoscopy, it's a little more limited as to how many you can actually find and localize. What about disease free recurrence? For patients who underwent a thoracotomy versus a thorascopia. There is a multi-institution study including 200 patients with metastatic osteosarcoma, which is the largest study that has ever been done. And that study, they looked at the outcomes between open resection and thorascopia. Um which really tells you that in oligo metastatic disease, meaning that patients who have less than four nodules on each side, there was no difference in terms of mortality. So if you look at these survival curves, they're pretty much exactly the same, which means we don't know the answer between which is the right operation. You know, sort of from a cancer surgeon perspective, you're like I need to get all the tumor out all the time, but when you actually look at the data, maybe those small little nodules that you're feeling with the grain of sand don't actually make that much difference and we don't know. This our our conclusion from the study was that um they have com comparable outcomes and we really don't know what the right answer is. There was definitely significant selection bias, um institutional selection bias and you know, patients were not going to get a thorascopia for if they had a bunch you know, a lot of nodules. So um that just tells us that we need to learn more. I still have some questions. Please help me, Dr. Dasgupta. What about chemotherapy? I mean, would that help for a one to two millimeter nodule? Can that help them shrink or regress? Basically what we think about at which point do you address metastatic disease? It's after four cycles of chemotherapy and often if these nodules are still residual, you're not going to see any change. I know we can't know right now which is superior to the other. But is it possible to at least use thorascopia for bilateral lung mets? I mean, is that a thing or is that just me putting a lot of hope into some less invasive way to get these nodules out. There are so many ways to do this, right? You could do a median sternotomy, you could do staged thoracotomies, you could do bilateral thorascopies and I think the practice is so varied and we don't know what the right answer is. Most people, I'd say the practice is is that they do staged staged procedures, particularly if they're thoracotomies um between four and six weeks apart to allow a cycle of chemotherapy in between. Okay, so here's Dr. Steve Rossenberg from Rocky Mountain Hospital for children. He's going to talk about some different scenarios and how to approach them. I'm very happy to see these these studies have finally come out because we actually did reported on our data almost 20 years ago. But survival didn't change when you had only three to four nodules on a side and the argument about that you needed to put your hand in to feel all the granules, then you automatically should do a bilateral thoracotomies because this is a systemic disease. It's not a unilateral disease. So it's it's unreasonable to presume and and we can only see 1 or 2 millimeter nodules now even with the best CTs and then you still miss some. So there's no question that tumor clearing is is improved survival, but there are ones that you can feel and not see and there were ones that you can't feel. Um and so we do sequential monitoring and surveillance, but if if there's only three to four nodules on a side and they're applicable to thorascopia, that's how we go just to reduce the morbidity. And if it's bilateral, we'll do it bilateral. Well said Dr. Rothenberg. We still got a lot to figure out. Now here's our boss, Dr. Todd Ponsky. He's a pediatric surgeon at Cincinnati Children's Hospital Medical Center. He's going to share some of his thoughts, some of his expectations on the future of techniques to remove these lung nodules. We may have to find non surgical methods. I think Cyberknife, that's happening in every other solid organ, things like that are going to be a future for for for localizing, using fiducials and just zapping these lesions without surgery. Dr. Dasgupta shared with us that the children's oncology group is actually starting a study to answer this very question and they should be starting enrollment towards the end of this year or early next year. So, if you're not already involved and are interested, contact Dr. Dasgupta. So there you have it. Our 2021 update course session on thoracotomy versus VATS for lung metastasis. If you love this content, be sure to like and subscribe to our YouTube channel. If you're listening to the audio version of this podcast, please leave us a rating and a review. And be sure to download the Stay Current in Pediatric Surgery app. It's in the Apple App Store and in the Google Play Store. But until next time. I'm Rod. And I'm Ellen. And remember knowledge should be free.