OK, I'm going to go through 10 challenges to overcome for vertebral augmentation in cancer patients. These are, as I essentially gave myself this topic, I realized for me, as I progressed through my early career developing these procedures and my skill set, I really found 10 challenges to overcome. And so I'm just going to go through them pretty basically. I put some goals and some objectives, mainly for those in the audience that might want to review these after the presentation, and for me to focus on what I hope you get out of my presentation. And really, the first thing I always think about is for treating bone pain in cancer patients, it's really two types of pain. There's that mechanical pain. That's really from instability. There's some type of either structural instability in the bone itself or in the attachment ligaments and tendons. Or there's a resting positional pain, and that's really the second source of pain is from a tumor-associated inflammation, the tumor volume causing periosteal stretching and compression on surrounding structures. So really, for vertebral augmentation, we're really dealing mainly with mechanical pain. There's some component with the resting and positional pain. So challenge number one, convincing your referring provider that this is a good idea. That certainly is the number one challenge. So for me, I use the existing data in the IR literature. I inform the patient and family members, and they're often the best advocates for this type of procedure. I had to possess the technical skills, so I had to develop those. And I had to have ready access to good imaging equipment. And I had to consider, did I have access to CT for more challenging cases? And that was very critical in the early stages of my development, because the cases that came to me were the ones that the anesthesiologist did not want to do. So I needed that CT access. Challenge two is treating all involved levels. And often, we deal with either cancer patients or patients without cancer and osteoporotic fractures. Patients will have multiple vertebral compression fractures. So identifying levels that need to be treated requires a good physical exam, really good imaging, recent imaging, identifying the etiology. Is this cancer-related? Is it age-related, osteoporosis? Is this malignant? And then consider the treatment plan. And each one of us works in a different environment. In my environment, I'm perfectly comfortable treating multiple levels at the same time. But in other environments and reimbursement patterns, we might need to treat one or two levels at a time or change our treatment for different reasons based on our referring providers. So I put, for your review later on, some articles that, if you're interested, you can look them up in how you approach these different challenges. Challenge number three is upper thoracic spine fractures. And that's where, really, a lot of the referrals I got initially were for these upper thoracic compression fractures, either pathologic or osteoporotic. And these are the ones that are very challenging to do under fluoroscopy because the shoulders will get in the way on the lateral view. And so having access to CT all of a sudden opens up a whole new arena for you. And you get a new referral pattern set up. And that leads to other easier cases down the road. So in each of these points, I put some items there. Having that CT access, now you can deal with planar fractures. And I put an example here that's kind of your typical planar fracture. I've treated ones that are more like a pancake, even, and they work out just great. And really, it's understanding the patients, understanding the referral provider, understanding this is a chronic issue for them, and pain is their major factor in their daily life. So having that CT access and that technical ability, now you can treat those planar lesions. So challenge number three was these posterior vertebral body, excuse me, five, posterior vertebral body defects. And I'm going through these challenges. And if you do end up reviewing my presentation afterwards, they're really in order of increasing challenge, if you will. So this is really challenge number five. It gets much more advanced and much more challenging as these defects become bigger and bigger. And this is an example from, I think, my second year out of fellowship that I had to do. And you start thinking about different ways you approach these. You have different devices that you can use, and we'll get into a little bit later. But understanding it's possible, and there are different resources in the literature to help you do that, and understanding the complications and planning for those complications. Next is creating a working relationship with radiation oncology. And that is certainly a big challenge. And a symbiotic relationship is really, I found it works the best. They certainly have a lot of post-radiation issues that you can help them out with. So this was an example of a cervical verteroplasty for post-radiation osteonecrosis. And the radiation oncologists were very glad that I was able to help them here. And that led to other treatments there. And then moving on, then adding on ablation or embolization for local tumor control. And there are a lot of different ways you can do this. And unfortunately, I can change the photo. But essentially, the helpful situations will be large tumors, tumors that are encroaching upon that posterior vertebral body area, oligometastasis, and then that resting pain I was talking about where you have tumor pushing that periosteum and causing pain in the surrounding areas there. So you have different types of tools. Predominantly, it's RFA. But you can also employ cryoablation and or add in embolization. Next, we have a lot of vertebral implants that have really gained a lot of popularity in the last few years. You have expandable devices. And I list a few of those. Each one has an advantage and a disadvantage. You have this renewed interest in middle column support. And there are new devices and new techniques that are coming out. And I list a few of them. And then I listed some helpful situations when you have extensive lytic destruction and you're really worried about cement leakage or cement alone not being able to join the pieces you need joined. Sclerotic bone where cement might not be enough there. High risk for cement leakage. And there's a lot of new literature out there. It's very exciting. And the devices are very exciting to use. Again, example, big lytic collision defect. And I wasn't sure what the cement would do in that area. Showing another couple different devices here. A peak implant. And that's really for that middle column support. That's very important in some situations. Expandable devices give you new options there for kyphoplasty or cement retention. And then cement containment. Again, you can use those devices to contain cement. Inner spinal spacers, I added that because it's a different type of treatment. It's not specifically for vertebral body compression fractures. But I sometimes see there's a secondary effect there. You'll get spinal canal stenosis related to those fractures. And so having that option for expandable devices, interspinal spacers, is kind of a new exciting frontier that can be very helpful for patients that end up getting secondary lower extremity weakness from spinal canal stenosis related to the fractures. Again, cannulated screws to hold together very sclerotic cancer fragments there that otherwise cement would not be beneficial. And here's another example in the S1 area where just injecting cement might not be enough there and you might get cement leakage. And lastly, I put up this article about the safe type of option where it's a stent screw assisted internal fixation. Again, a lot of new exciting options out there to be explored. Challenge number nine, cervical vertebral augmentation. If you want to tackle that, you can do it under fluoroscopy or CT. I tend to like having a CT now because I have ready access to it, so it's easy for me to get in there. I put a few of these articles about putting in stents and screws in there and different techniques. It's not terribly challenging, and all of you have the skills to do this. It's just a little, when you do it the first time, it's a little concerning and different. This is one of my older examples, I think, from my first year outside of fellowship. And then challenge number 10 is really considering alternatives to PMMA in rare situations. And there are a lot of different types of bone cement out there, a lot of different other types of bone graft substitutes and potential to do embolization. And so really, the challenge here is understanding when to do what and talking with referring providers how it will work out and how it will pan out. So I put a few articles there if you're interested in looking at that. And here's an example of mine for an aggressive hemangioma that I treated with alcohol embolization. And again, it was a discussion with the neurosurgeon and back and forth, and that's what we settled on. It worked fantastically well. So those are the 10 challenges that I found as I developed my bone practice at MD Anderson. And just to review, you have them all there on one page. Thank you. Topic of my talk is microwave osseous tumor ablation. So we know that about 1.9 million patients are diagnosed with cancer in the US every year, and about 609,000 will die annually. And that really translates to about almost 1,700 deaths per day that is related to cancer. Globally, cancer is killing about 9.9 million people in 2019. That's more than malaria, TB, and HIV combined. Cancer is going to be the leading cause of death in the next 20 to 30 years, and it already is in about 91 countries around the world. Osseous metastatic disease is a common presentation of cancer, and about 70% of the patients will develop bone metastasis at some point. So there will be a stage four phenomenon in these patients. And spine is overall the third most common site of metastasis after lung and liver. The common locations are about 70% of these metastases are found in the thoracic spine, particularly from T4 to T7. 20% are found in the lumbar spine, and about 10% are found in the cervical spine. More than 50% of the patients with spinal metastases have several levels of involvement. Sometimes we do see isolated epidural involvement without any osseous enhancement. And once you see that on an MRI, we should be thinking about lymphoma or renal cell carcinoma. So the three types of metastasis that is routinely encountered in bone is lytic metastasis, a mixed-density metastasis, and a blastic metastasis. More common to see the lytic and the mixed variety than the blastic mets. When a patient is diagnosed with stage four metastatic disease with osseous metastasis, these are the modalities of treatment that are available to the patient. If it's unstable spine, then surgery is done followed by radiation. Radiation oncologists do SPRT for oligometastatic disease and diffuse radiation for extensive diffusely metastatic disease. Medical oncology is available with all the chemotherapy, the bisphosphonate therapies. And now, radiology also is in the picture with vertebral augmentation primarily for cranial relief. And now we are doing these ablations of the spine tumors, especially if there is oligometastatic disease. And then pain palliation also is done with the use of certain injections and blocks. So image-guided ablation of the osseous tumors is rapidly being recognized now as a minimally invasive technique, which is a very good, effective, adjunct, and sometimes even alternative to conventional therapies. And we all know the conventional therapies are mostly radiation therapy, be it SBRT or EBCT, chemotherapy, especially for diffusing metastatic disease with the use of narcotic analgesia, surgery for unstable spine in patients with quadricompression. So what are the real indications for doing osseous metastatic ablation? It's severe back pain with ongoing compression, persistent pain even after a patient has completed radiation therapy, radio-resistant tumors such as sarcomas, melanomas, and renal cell carcinomas. Patient has reached the maximum radiation dose, but is still complaining of pain. Certain patients develop radiotoxicity with ongoing pain. Certain patients have metal suppression because of the medical treatment that has been received and the radiation therapy. And certain patients sometimes refuse radiation therapy completely because they have had radiation therapy previously for their primary tumors and had a bad experience, and they're refusing radiation to outrun this time. Treatment goals, of course, this is a stage four disease, so pain treatment is the main goal of treatment. Local regional control of the disease, especially if it's only a metastatic disease, reduction in the overall tumor burden, and especially if we are doing ablation in a weight-bearing bone, we have to make sure that we do good cement augmentation of that bone. So as the name suggests, there are thermal ablations, which is application of heat or cold to the tumor and cause tumor destruction. As compared to the surgery, we reduce morbidity and mortality. Procedural costs are significantly less than surgery. We are always under image guidance, and we know we are within the tumors when we are treating them. So usually this is done as an outpatient procedure. Patient goes home the same day. Everything remains on the table. Patient can have surgery, patient can have radiation, patient can have medical oncology treatment. So it is synergistic with all other treatment modalities. And it's a good procedure, which once learned by an individual, can, with repeatedly good outcomes, attainable with this procedure. The thermal ablation modalities that are available right now are radiofrequency ablation, cryoablation, microwave ablation, and now the MRI-guided focused ultrasound which uses acoustic energy and which is almost non-invasive completely. I will be talking more about the microwave ablation. So microwave refers really to the use of electromagnetic waves for causing tumor destruction by use of these antennas whose frequencies range between 900 to 2,500 megahertz. They usually cause a flip of the hydrogen atom of the water molecule about 2.5 billion times per second which leads to frictional heat and that heat leads to cellular death via coagulative necrosis. Why microwave? Because microwave leads to a consistently high inter-tumoral temperature and this can be both an advantage as well as a disadvantage at some time. You can get larger tumor ablation volumes, faster ablation times. You can use multiple applicators at the same time. There is significantly less heat sink effect compared to radiofrequency ablation. So you can use this in mixed density and blasting metastasis. Blasting metastasis are also done very well with this electromagnetic waves. No electric electricity is involved and no grounding pads are needed. As I said, decreased bone impedance so we can use it for sclerotic and mixed density metastasis. There are multiple papers that have come out with the use of microwave ablation in spine tumors. So it's a modality that is increasing now both in bone as well as in soft tissue ablations. There are multiple systems that are available in the market now, about nine of them. I particularly use a system that has low frequency for bone ablation compared to the high frequency because the tumor can go up real fast with a high frequency probe compared to the low frequency probes. We've kind of already talked about the heat sink effect of tissue contraction and the properties available. A good way, hopefully in future, we'll have thermal imaging available and we can really see our burn areas as we are burning real time. We'll look at the tumors and we'll know the temperature within the kill zone and as the temperature drops out to the periphery of the kill zone. For right now, people have been doing the DCE color-coded T1-weighted images and this is a good example of that. Here you can see the slitted mass shows the footprint on the DCE. And after ablation, you can see the peripheral rim of reactionary treatment granulation tissue and the main tissue is being destroyed. So just an example that I have, L3 metastasis, you can see, we went in, we did the ablation and then we did the cementation. This is a follow-up MRI. As you can see, the treated level has no enhancement. There's another metastasis developed in this patient. This is a DCE MRI. This is the arterial phase. This is a delayed phase. So this is the metastasis at the lower level, at the treated level, there was no activity. The patient did really very well post-treatment at six months also. Another patient with RCC metastasis. You can see here, we went in, we ablated, put cement in there. This is a six months, almost six months follow-up MRI. Patient did really well. This is a 24-month MRI that we obtained on this patient and this little bit of epidural disease has completely gone. The cement is in there very nicely and there's no extension. The ablation zone is quite stable. Thank you. So my talk is about 3-H between cementoplasty and screw fixation. I will first discuss fracture stabilization using these two kind of technique and then I will discuss preventive consolidation for patient with bone metastasis. So let's start with bone fracture. As you know, it's quite frequent in cancer patient. It can be pathological fracture or bone insufficiency fracture and both of them are responsible for mechanical pain and the key, if we want to palliate this patient, is to provide stabilization of the fracture line. There are several options for this. The first one, of course, is a bed rest and wait. There are also external fixation such as plaster and corset and different kind of surgical external fixation but usually the fracture healing is delayed by the tumor cells itself that destroy the bone and also by ongoing treatment such as chemotherapy or local radiotherapy. Cementoplasty is a very effective technique for this purpose. It provide palliation of fracture because cement acts as glue and sticks the fracture fragments. It provide a very significant pain reduction, especially in vertebral compression fracture with a small amount of cement. Cementoplasty is very effective for compression fractures because there are low fracture mobility in this kind of fracture and because there are usually no fracture gap. However, for fracture like shear fracture or even worse, extension fractures, there is a high mobility of the fracture line and also sometimes a fracture gap that make cementoplasty sometimes ineffective because we cannot glue the fragment and with complication because there are leakage through the fracture gap. In such a fracture, we need to perform an inter-fragmentary compression using cannulated compression screw. Look at this case. There is a huge shear fracture with a large gap. We won't inject cement here. It won't be effective and we will have some leakage. So we stabilize the fracture using screw and we achieve a huge decrease of the pain and a fracture healing here at one month. Of course, to have a strong compression, you have to have a strong anchorage in the bone in order to avoid this kind of loosening of the screw. So the technique here is the internal cemented screw, meaning that we enter a strong cortical, we go through the fracture and we have an anchorage of the tip of the screw within the cement that we have injected immediately before. Similarly, even in compression fracture when we have this kind of large gap, we won't have any leakage using screw because the cement that we will inject is in the distal fragment and the screw is used to compress the fracture. So it's very simple procedure. This is a kind of screw. We have here a fracture, pathological or not. We go with an 8-gauge needle through the fracture line and we will inject the cement not in the fracture but in the distal part, in the distal fragment. So we inject the cement. Then this cement will be helpful for the anchorage. We insert a Kirschner wire, we remove the 8-gauge and we advance our cannulated screw over the guide pine across the fracture line and within the cement that we have injected immediately before and before its consolidation. So this is very effective. We have demonstrated in 100 consecutive cancer patients suffering from pathological pelvic fracture that it decreases the pain and the opioid equivalent dose at one month. It can be also done outside of the pelvis. This is a case of a fracture of the pedicles. We inject cement first in the vertebra in order to have a consolidation and then we insert the screw through the pedicles inside the cement to have the stabilization of the pedicles. There is another location for the sternum. We perform a screw fixation with cement to stabilize this painful fracture. Now let's move to the preventive consolidation interest. Cement is highly resistant to compression solicitation. So when we inject cement in a lytic metastasis, it will be very effective for compression stresses like in vertebroplasty. So cement is very appropriate for this kind of stresses. However, it is not ideal for white-bearing bones where extension and shearing stresses are predominant. Here, the addition of a metallic screw provides a necessary resistance to torsion and shearing stresses. It is intended to bridge the weakness area of bone due to the lytic metastasis. Again, we want to have an anchorage of the screw using cementoplasties that we inject first. Then we remove the needle to insert a Kirchner wire, and we advance the screw within the cement across the lytic area. Here is a case. This is a large lytic metastasis of the sacrum. We won't inject cement here because it's probably not the best option for good consolidation, and also because if we inject cement, we will have some leakage in the foraminum and have some complication. So we go through a puncture of S1 and S2. Then we inject cement in the normal bone, so no risk of leakage, and then we advance the screw in the cement across the lytic metastasis. This is for S2. We do the same for S1, injection of cement, and then we advance the screw within the cement across the lytic metastasis. And this is the kind of consolidation that we can have. We have evaluated this kind of strategy in 50 consecutive patients suffering from 54 lytic metastases over five centimeters in the pelvis. And after two years followed, we have only one fracture, so this means a long-term consolidation of 98%. Interestingly, it has been evaluated in this study. This is a biomechanical evaluation of three distinct type of percutaneous consolidation procedure in 20 composite MEPEV with Harrington type 3 asperiacetabular lesion. And as you can see, the addition, this is a cementoplasty alone, screw fixation alone are fixed, meaning association with cement and screw compared to the control group. And you can see that the addition of pelvic screws over cementoplasty significantly improve the pelvis load-bearing strength. So when you have this kind of case, of course, for this you have to perform a fixed procedure, cement and screw. But what about this one? They are not so big, is cement enough? What we are doing now for this is we perform a cemented pin. We perform cement and we reinforce the cement with this kind of metallic pin. Very easy procedure, very similar to cement. We puncture here through the iliac crest, we inject cement in the iliac metastasis. And in the middle of the procedure, we insert the pin inside the cement. And because it is thinner than the lumen of the needle, we can continue injecting around the pin. There are two metastasis, so we insert the first one and then we do the same, a second one in the posterior. So here is a kind of consolidation that you can have with an 11-gauge needle only. We use this kind of procedure also for tricky cases. This is a large metastasis where we plan to perform a fixed procedure. So we have this trajectory across the metastasis. We inject the cement for the anchorage. And you can see a second track where we inject cement inside the lytic metastasis and we reinforce the cement with our pin. So we have here both cemented pin and cemented screw. And here is the final result. With two puncture, a very strong consolidation of this metastasis with something that we call the X-bridging technique, dedicated for this kind of lytic metastasis, more anterior acetabular region. Here is another case, screw, cemented screw and cemented pin. For more posterior lytic area, we perform the T-bridging, again with a screw and a pin and cement. So my conclusions are that cementoplasty is effective for palliation and consolidation, of course, but better result are obtained in compression fracture because there are low fracture mobility and no fracture gap. Cement then provide resistance to a mechanical solicitation other than compression and diffusion is not predictable. On the other side, cemented screw and cemented pin appear to be the best choice for percutaneous treatment for palliation and also for consolidation. It is highly predictable, it provide a compression of the fracture line, especially for the cemented screw. And cement provide, of course, a resistance to compression stresses, but the addition of metallic screw or pin provide the necessary resistance to torsion and shearing stresses. Thank you. My task for the next 10 minutes is to present to you ways of collaboration between interventional and radiation oncologists. Actually, both fields of medicine, they share common names and common origin. Both fields, they use sophisticated imaging equipment in order to provide local tumor control to provide curative or palliative treatments, aiming to ask less distraction as possible for the normal parenchyma. They share also common origins. For many years, they used to work together, most commonly in the radiology department. After the 50s, both disciplines start taking separate pathways and in certain specific countries nowadays, they are totally different disciplines of medicine. However, with the advancements in the field of interventional oncology, now we do have some overlap concerning the indications for treatment between interventional and radiation oncologists. And if we want to speak about collaboration, I'm pretty convinced that if we collaborate with radiation oncologists, this will give advances and advantages to cancer patients, to the healthcare system, and last but not least, to the hospital itself. We can collaborate on strategic field, and this is more general. We can work together to provide solutions in the need for data to incorporate clinical responsibility into our curriculum and to provide quality assurance of services. Specifically for MSK, we can combine treatments in the search of an improved outcome. We can offer interventional radiology techniques in order to enable patients to undergo radiation therapy. And last but not least, we can provide solutions to radiation therapy-related complications. Starting with the need for data, it's no secret that in developed countries, the investment in health is under scrutiny. And the decision for placing more money on the table will be based on serious data, focusing upon cost-effectiveness of one technique, and of course the impact that the therapy will have on everyday life of the patient. Concerning publications, both disciplines today, they share a lot of papers. We have papers describing technical parameters, providing outcomes in terms of safety and efficacy. But if we want to compare one technique with the other, we don't have a lot of randomized comparative trials. Most probably, this is because these trials, they cost a lot of money. And in most of the cases, they end up with heterogeneous cohort of patients which seriously limits the validity of the conclusion. So what we actually need is a data collection by means of well-constructed, sophisticated registries. And I guess that societies are moving towards that pathway in order to provide and define evidence-based criteria for choosing or combining between interventional and radiation oncology therapies. This criteria, most probably, they will include lesions characteristics, proximity of vulnerable structures to the therapeutic zone, the status of the affected organ, and last but not least, they should take into account the patient's choice. If we move to clinical responsibility, my personal feeling is that we are doing better than radiation oncologists. Both of us, we work and participate in MDT meetings, but radiation interventional oncologists, they work better in providing optimum care and assume primary clinical responsibility. There's a clear need for the scientific societies to try and provide the basis for incorporating knowledge of basic aspects of oncology into the training curriculum. We should facilitate the assumption of full clinical responsibility, and we should be responsible for the follow-up of our patients. Last but not least, we need to be able to provide quality assurance of our services. At the moment, we are using sophisticated equipments. We have sophisticated programs of quality assurance, but what we need to move from the liver and other parts of the body to MSK is the use of navigation systems or verification softwares, everything that will increase the automation of our services. Just to give you a clinical example, this is a young patient with an osteoid, osteoma in the spine. It was in a peculiar location close to the foramen. We used a CT-compatible navigation system with a fiducial placed in the patient. We did use this system in order to increase the accuracy of our approach, and at the same time to reduce the radiation dose to the patient, because we needed a lesser number of scans in order to approach the lesion. And you can see our needle inside the nidus, and coaxially we inserted the radiofrequency electrodes and proceeded to ablation. Specifically for the spine and ablation and vertebral augmentation techniques nowadays, we do have therapeutic algorithms by multidisciplinary working groups, clearly trying to define the place and the position of ablation and vertebral augmentation techniques in the treatment of cancer patients with spine metastatic disease. However, what I would love to have is prior to ablation to be able in the spine and in the peripheral skeleton to design my ablation zone, to have data about how large this will be. And ideally, I would love to be paid for that in a similar way that radiation oncologists are being paid, at least in Greece. Moving on from strategic to clinical field, we know the disadvantages of radiation oncology for local tumor control. This includes the limitations by cumulative radiation tolerance of nearby organs. Radiation oncology is limited on specific tumor histologies, and it is dependent by oxygen for cytotoxicity. On the other hand, for pain palliation, the results of radiation therapy are moderate. Even if you combine complete and partial pain responses, the success rate is around 60%. Ablation does way better than 60% for pain reduction. So what we need is to learn from radiation oncologists how they communicate their success to the media, to the physicians of other disciplines, to patients themselves. For the last decade, we do have data that if we combine radiation therapy with ablation, we end up with a significantly better pain reduction effect, which comes earlier in the follow-up course, and it lasts longer than if you treat the patient with a single technique. Specifically for the spine, if you have lesions in dangerous locations, such as the posterior wall or close to the vertebral foramen or inside the vertebral pedicle, if you treat these lesions with one technique, no matter if this is radiation therapy or ablation, most probably you will end up with a moderate success. If you combine, however, ablation with radiation therapy, your efficacy rate will be higher, and this is true not only for metastatic lesions in the spine of various pathologic substrate, but this is also true for patients with multiple myeloma, and you can treat them with triple combination techniques, which is the common practice at the moment. That means radiation therapy, ablation, and of course vertebral augmentation in order to avoid post-treatment pathologic fractures. If we move from the spine to peripheral skeleton, this is a recent systematic review, including three studies, 92 patients who underwent combined approaches for metastatic lesions in the peripheral skeleton. The authors support that they provide scarce data that these combined approaches are safe and efficacious. However, if you see in this systematic review, you will see that there is a wide variation, first of all, on the time interval between one therapy and the other, and second of all, on which therapy precedes the other. If we are speaking about local tumor control, I guess that performing the two therapies, post-radiation therapy and ablation, close together, it will be okay. If we are speaking about pain palliation, my personal feeling is that if you don't have significant pain reduction after three to four weeks post-radiation therapy or post-ablation, you should proceed with the second arm of the treatment. However, keep in mind that if you have a soft tissue lesion or if you have a bone lesion with excess of soft tissue, if you apply these two therapies close together, most probably you could end up with over-exaggeration of the pain, which will be temporary, but it will be there simply because you will have over-inflammation due to the combined treatment. We can also offer interventional radiology techniques in order to enable patients to undergo radiation therapy, that apart from biopsy, we can offer vertebral augmentation techniques in order to treat a painful site and allow, thus, the patients to lay comfortably on the radiation therapy table. Last but not least, we can treat radiation therapy-related complications. The most common complication seems to be pain. This pain can be postural during radiation therapy because patients are required to remain stationary for extended time periods. You can have pain which is related to radiation therapy inflammation or toxicity, or you can even have delayed neuropathic pain due to radiation therapy. For this last case, percutaneous neuralysis is a great technique for pain reduction in patients suffering from neuropathic pain. Do not forget that with augmentation techniques, we can treat pathologic fractures, which are really common after radiation therapy, since the technique does not improve stability. On the contrary, it weakens adjacent bone with an effect on pathologic fracture. We do have, right now, evidence reporting that SBRT is responsible for an 11% of pathologic fractures in the peripheral skeleton. This rate goes over 33% if we speak about the spine, and approximately two-thirds of these fractures, they occur within the first four months after radiation therapy. This is a paper 10 years ago from the Heeres brothers. One brother is a radiation oncologist, the other is a neurointerventionalist. They have evaluated 201 cases of patients with cancer and metastatic fractures, and they concluded that you can combine radiation therapy with vertebral augmentation techniques in order to significantly reduce the chance of pathologic fractures. Closing up, I don't know if we do something good or something bad in Athens, but the truth is that we share a common department with the radiation oncologists. We have one head of the department. We are very happy about that, most probably because he's always a radiologist, but the truth is that we share the same facility. We share the same staff for outpatient clinics and the same world support for inpatients. As already said in my presentation, I'm pretty convinced that if we work together with radiation oncologists, this will provide great benefits to cancer patients. It will provide advantages to the healthcare system and to the hospital. This collaboration, I think it's undeniable that we need it specifically on the clinical field, but in the strategic field, which form we'll take, still it's debatable, but I'm pretty convinced that it should be an honest and equal approach. Thank you very much. Well, finally, we'll finish with myself here to talk about what Dr. Yevich challenged me with was talking about new technical digital tools for MSK intervention. This is really thought-provoking in terms of where we can go in terms of treatment of patients. So I'll talk a little bit about what you might consider in your practice with mixed reality opportunities. I'll talk a little bit about artificial intelligence in a practical way and how we've implemented it in our practice partially. A little bit about where ablation planning's going, some imaging advances that might offer opportunities for complex treatments, and a little bit of where simulation can go. I think as a reference, the Medtronic Stealth System I think is a good anchor in terms of how you look at how mixed realities might go forward. Clearly, you acquire a volume, reference that to an external marker, and use cameras to stay in that volume with index devices for placement. Big efforts in this by Medtronic clearly in terms of interventional spine. There's new systems coming forward that can take away or maybe change how we approach this using this mixed reality approach. This is one system that has FDA approval by Novorad called OpenSight. And here, optical markers are placed on the skin as a reference, and then that brings in the 3D volume. Here, a breast biopsy is being set up. And using basically a optical headset, you can use this as a reference for placement. Here you can see CT image data's been merged into that visual field for placement of a cryo device to treat a lytic metastasis in the spine. These were all generously provided by Dr. Gibby. But I think it shows you can take what is presented on a screen into a headset with this sort of approach, again, using these markers on the skin. Another system also that's coming into the spine intervention world. It's pretty similar to how the Medtronic system works. Again, this is a custom headset. Again, an anchor is placed here on the spinous process. And then in the headset, you have a stereo view of what is presented, left eye and right eye, with a clear headset. And again, using index systems. It's conceptually the same as what the Medtronic Stealth System offers, but now delivered in a more ergonomic way for surgeons as it's being used now. And you can also do this percutaneously. It's interesting, if you look, a group in China has actually taken this to another level, I think. And they bring segmentation into the environment so that you have a more limited and more useful view, potentially, and then use the HoloLens for visualization. And here, they're treating compression fractures that have a cleft, and they target the cleft in the fracture. The difference here is they do first segmentation. And then you can see that this is, again, presented to the operator in terms of the different colors for the lumbar spine. And then you can target these different areas. Now you have an indexed way and know where you're going in terms of placement of devices with the headset. They've looked as to whether or not there's an advantage with this. It's interesting, if you compare mixed reality in terms of time for a procedure in their hands, it was faster to do these with the mixed reality system. Fluoroscopy times clearly about half. And so in this early experience, I think this is a good way to approach how you might be able to take advantage of this, and particularly reducing time with fluoroscopy. The Philips team has developed a different approach to this where they put cameras in the fluoroscopic head. And then these cameras are used over the body to figure out where you are in that volume. And now the images are presented onto the screen. How this looks, first is you put visual markers on the skin, these are then indexed so you have a reference and you can bring the volume into the planning system. And then this looks upside down, but this is what the camera sees. So you have a four-view look at the body. One of these is a trocar. And here you can see that it's targeted down a particular line. And the camera, at different angles, sees that same device placed into the skin and makes sure that you have a good 3D targeting approach for placement of a device like this into a pedicle. And then, as you see on the screen now, what your target is, so you can see your targeting particular pedicle. You can see the line of trajectory referenced visually with the optical system. And whether or not you can place it in here and you can use then step-on fluoro for a quick check. So it's pretty rapid translation between an augmented reality system, really, and fluoroscopy. Similar to how this was studied, this again is now placement of devices, trocars. You compare what you can do with the augmented reality system versus fluoroscopy, they found fluoroscopy was faster. It's a limited number of patients and I think early experience. But even with this, taking longer, the amount of fluoroscopy that was used was much less. And the dose for the operator was less. So it's an opportunity to reduce dose for both the operator and the patient. And again, early experience. And I think as this gets more developed, you'd be able to probably improve the procedural time as well. So that's mixed reality coming into, I think, the interventional suite. Let me just briefly cover what AI might offer in terms of dose reduction. Clearly this is not an MSK, but it's easier to see in the liver. This is an AI model that we've deployed into our practice. So if you look at 100% dose versus denoise, and I'll amplify this so you can see it a little bit more clearly. You can actually acquire lower dose imaging, do the noise reduction, 50% dose, and even 25% dose reduction, and then apply denoising. What's interesting is if you compare full dose imaging that you would acquire without any artificial intelligence applied, and compare it to the noisy 25% dose image, and now we're gonna put noise reduction AI applied to this. And you can see that the quality of that image, as long as you stay above the photon starvation level, is actually better than the 100% dose level. So for those procedures where a lot of imaging is done, this offers a great opportunity to reduce dose for these procedures. So it's a significant dose reduction with preserved and even enhanced signal-to-noise, really, after artificial intelligence is applied. What's it look like procedurally? Here you can see a probe that's placed into the iliac bone. Original imaging on the left, and denoised imaging on the right. And you can see, it's much easier to see the edge of the ice ball once this denoising algorithm's applied. So good visualization. And this is deployed in our practice. We use it every day. We've run about 25,000 images through this model. And it's delivered to our imaging station within about five seconds. So you can do it practically. Next phase of this is really to go from denoising imaging to denoising with artifact. And here, our team, Chris Favaz and Andrea Ferraro, have developed a metal artifact reduction AI system. Here you can see the original imaging on top. And below, what happens when you apply artificial intelligence to these imaging. You get rid of a lot of blooming and streak artifact. And we'll just follow across one ice ball generation here, comparing the upper images, which are the original imaging, denoised below. And here, you get a little bit lower. What's neat is, as you try to look back where the ice ball is, as you get closer and closer to these artifacts, it's much more conspicuous with the denoising, or the metal artifact reduction applied. That attenuation difference is there. It's just masked by the artifact. And so that has a great opportunity for conspicuity. Another potential way to go about this is to use differences in imaging. And here, our groups looked at whether or not dual energy CT has a benefit for intervention in the spine, particularly so you can visualize ice in bone. If you don't know how dual source energy imaging works, this is a real simple way of looking at it. If you look at two different types of materials, say bone and soft tissue, they have different attenuation values at a particular energy. If you go to a different source energy, you can see a difference in that attenuation factor, and then you can identify the element. And so as a result, what you can do is subtract the bone. So these are the virtual non-calcium images with cryoprobes placed in there. What does it offer? I'll show you a couple of examples of how this looks. This is done in a experimental way. And so here we can see that these virtual non-calcium images show that you can actually see the ice in the bone. If you look above, you basically can't see it. You can extrapolate, but you can't see it. These were done in a cadaver, so don't be too alarmed by the fact that it's getting into the canal. But here, posterior spinous process. Ice ball is visualized. And here you can see quite easily where that ice ball is. And again, compared to the top image, where it's very difficult to see. If you look at a coronal image in the lumbar spine, here again, probes in here, you can see with pretty good conspicuity, the ice in the bone. And that's quite often a challenge when you're doing these complex ablations in the spine or other bone. There's also some work that's being done in terms of more planning and simulation. We've looked at whether or not we can simulate ice. And here, comparing what we would segment by hand versus what the predicted zero degree line would be. And the difference, which is actually quite small and actually better with the prediction than what we can do manually. So there's good opportunities coming forward, at least for cryoblation in terms of planning. So pretty accurate simulation. Mixed reality may have some opportunity in terms of determining how you should approach an ablation. And this strong team put together a proposal of how this might actually work using mixed reality again. And here, what they're doing is placing cryoprobes through index markers to see how you might be able to put these. Clearly, you're not gonna plan a procedure this way, but I think it shows you that that potential is there and potentially a way to train or communicate how you're trying to approach a procedure. So in conclusion, there's new tools largely coming out of the operative environment for device placement. I think you can see that artificial intelligence is actually here and something that you can deploy and practice and it does enable more complex MSK ablation. At least you can see better. Ablation planning is still emerging and I think it needs to develop further. But I think there's some exciting new things coming forward for interventional oncology in terms of new digital tools. So thank you.

vertebral augmentation

cancer patients

healthcare providers

CT imaging

vertebral stabilization

radiation oncology

thermal ablation

interventional collaboration

AI in MSK interventions