V/Q scan. We use MAA for IV and I did not add D.T.P.A in the aerosol form. Indication. Pulmonary embolism for pre-surgical testing or the patient is unable to have a CAT scan
with contrast because either they're allergic to the iodinated contrast or they have a decreased eGFR. V/Q scan has two components, the ventilation, which has aerosol dose of 40 millicuries and then a perfusion dose IV of five millicuries. Sorry, going back, actually those are the containers
that we use to carry those doses. Ventilation, patient either gets an oral, disposable oral mouthpiece or often disposable mask on their face and it can, the radioactive isotope can be infused with either air or oxygen depending on patient's need.
Patient is told to take nice, deep breath through their mouth, not through their nose. We want them to take deep breaths through their mouth for about two to three minutes until the isotope is all gone, and this part is done all by technologist and then they scan them for about 20 minutes.
Those are ventilation pictures. Where the isotope is, you can see all the darkness, because if there's a PE, it won't travel further. It wouldn't travel because there is a clot. The isotope cannot infuse. Perfusion, that's where the nurse comes in.
You confirm the patient, you confirm the allergies, and you inject. Now MAA is always only injected in peripheral IV, central line, because MAA is very concentrated, so if we inject in central line, including PIC lines or Medi-Ports, it can cause a PE.
We don't really want to do that to the patient. Patient is instructed to take deep, even breaths, so when I come in as I'm putting in an IV or assessing their IV if they have one, I usually talk to them about that time period, and I talk, give them the education
that I will be injecting the radioactive isotope, I will be flushing it with two to three normal saline depending on what kind of IV excess it is and varieties and if it has an extension or not. And I want you to do yoga breathing for me. 'Cause I've had patient who have literally
hyperventilated on me, thinking that they're helping me. Yoga breathing is my term, I really love it. Nice, deep, even breaths and it also helps with the stress. Once you're done, just remember to tell them to breath normally, not, don't tell them stop breathing. Done that, didn't go very well.
- [Audience] Don't tell them to hold their breath. - Yeah, so just breath normally. This is the perfusion picture. As per a doctor's, I'm gonna step up here, it didn't prefuse, stop right up here, so they actually found that PE there
because the isotope did not travel to the full lungs. There was a little PE, so it didn't actually trans. - [Audience] Seeing the black in this case is a good thing? - Yes. - [Audience] 'Cause that means it perfuses correctly. - This is another picture.
It's a perfusion. The darkened areas are where it's not going through the isotope. Yeah. Okay so this is another case where the CT was normal, the doctors were still not sure,
they sent it to us, the ventilation scan went great, the pictures looked great. Then, perfusion scan, you can see the little, a big area, that's darkened, the isotope did not go. Right, the colors are amazing. Contraindication.
Patients who are unable to follow instructions, that could be because of altered mental status or sedation. Patients who are in too much pain because they will not hold still for the scan. And pulmonary hypertension. A regular MAA is 0.5 million particles.
It consists of 0.5 million particles. For pulmonary hypertension, we can only inject up to 100, 250,000 particles. If you use 0.5 million particle, a regular MAA dose, you can cause capillary blockage causing a cardiac arrest right there on the scanner.
Not something we do need. We have had patients who are elderly. We do not know their history or they are unsure, so it's always great to have a doctor in the room while you are injecting, just to be on the safe side and we have had that, especially later in the evening,
when we don't have as much help. V/Q scan, this was one where we weren't sure. Actually the lower pictures are of a patient who was in a lot of pain. Upper pictures are normal. As you can see, you don't know if you're seeing
an angel or vulture. Depends on the patient, right? Or the person who's looking at it. Patient kept moving, instead of breathing in through the mouth, they gasped, and they, the radioactive isotope
went into their stomach and we could see esophagus and the stomach and it was just not a happy scan. It's always great to make sure your patient is comfortable before you start doing all of these procedures with them.
And you kinda see in, in real time, in fluoro, this is at the same point and time, but from different projections
that these different contours actually project differently based on how the detector is rotated, so that you can kind of have, in a real time feedback as to where the edges of your intended ablation or cement fill are.
And sometimes again, and this can be very hard to tell, using just fluoroscopy in a pelvis or a bone that's had extensive destruction. Where you don't have good cortico kind of markers under fluoroscopy. Registration is really a key to all this,
and a big part of where the technologist come into play. This is really the process of aligning one data set with another. There's different ways you can do this. Two dimensional, three dimensional,
or three dimensional, three dimensional registration. What this allows you to do is potentially draw those objects of overlays on a separate 3D data set, so maybe a pre-procedural imaging study that has contrast, where you can actually see your targets a little bit clearer.
And then be able to fuse or register this with you know, real time, time of procedure, cone-beam CT. So that you can kind of then stack and fuse those objects that you've drawn on a more detailed study before.
Point overlay is pretty simple. Again drawn on cross sectional imaging. These are just specific points. Can mark bone cortex.
You can mark kind of ablation probe stations if you're doing multiple overlapping ablation zones. Again this can be very helpful when, perhaps in a tumor case where there's been some bone destruction, you don't have good bony fluoroscopic landmarks that you might have in a normal patient.
Polyline overlay is kind of a similar technique. It's basically drawing a curvilinear line, again on a cross sectional imaging. And this is for more curvilinear structures such as perhaps marking nerves or neuroforamina. Estimating ablation zones,
marking out portal veins or other targets that you might use for even non MSK procedures. These are just a couple examples of this. You can kind of see a schematic representation on the left of what an ablations zone might look like. Also, some examples on the right of marking out a
sciatic nerve particularly, and then down on the right side, it's a little bit hard to see, but some green kind of cross hair point marks, just in terms of where you're gonna pull back your ablation probe along the path.
There just kinda different ways that you can utilize these, you know, these tools. These are examples again of the kind of curvilinear marking of neuroforamina. Whether it's ablation or cementation or such. That these are maybe structures
that you wanna know where they are under fluoro and stay away from.
This particular patient had significant improvement, did have some diarrhea, but demonstrated significant improvement after that block. This is an actual patient that we treated several years ago. 55 year old woman, she was very cathectic. She was in the end stages of her life
and she had pancreatic cancer. She had an abdominal wall met that was actually invading into her liver and she had severe epigastric pain and constipation. Her ECOG status was poor and she was on a lot of narcotic medications.
She had one of these metastases resected and her pain had come back immediately. You can see just anterior to the liver, there's this soft tissue mass that's invading into the liver. She has multiple liver metastases and her pancreatic cancer
is invading into her celiac plexus. So using a combination of what Nick has talked about and these nerve blocks, as an interventionalist, we can offer multiple things to these patients to improve their outcomes. I'm a huge fan of ultrasound, so I use ultrasound
to guide my needles as often as possible. I'm using a glove because I'm gonna end up doing cryoablation in the near field of that metastasis that I showed you. On the image on the right hand side, you can see the cryoprobe going down
into the shadowing cryoablation defect. It's treating that lesion, but just above that, you can see a horizontal white line, which is actually a needle that I'm injecting saline to keep the skin safe as we're doing the cryoablation. By using the glove with the saline in it,
I can actually use that as a standoff pad to sort of see that skin and make sure that the cryo energy and that ablation zone is not coming up into the skin. Just a nice technique with ultrasound, very simple. And then, at the same time, while I'm doing the cryoablation just lateral to that,
I'm taking an ultrasound guided approach and dropping a needle down in front of the aorta and doing that celiac plexus block and neurolysis at the same time. So the patient gets the ablation for pain control and they get the neurolysis for pain control
and had significant improvement in their pain. You can see there the cryo defect. We delivered the alcohol to perform the neurolysis and the patient had significant improvement for a while. Ultimately, her pain recurred, but she then ended up going to hospice and passing.
We definitely offered her improved pain control and quality of life for at least a short period.
We've talked a little bit or touched on some of the traditional blocks, Demetrius has kind of run through some of those, so I won't be covering those. But the concept is that basically you put your needle
in the space, you inject a little contrast to make sure you're in a safe position and then you give a combination of lidocaine and a longer acting agent like bupivacaine with a steroid and then that's the block. Once you've done that and diagnosed that that's actually
addressed the problem and is addressing the pain, you can then move on to the neurolysis and ablation where you're sort of more permanently blocking that. We started incorporating some of the more complex sympathetic blocks into our practice which really, many of the pain specialists out there
shy away from because they're much more heavily reliant on imaging and that's where we shine, and that's where you all come in to help us to use the guidance techniques that William talked about to sort of get us to some of these more difficult places to reach.
But I'm really gonna focus on percutaneous ablation because it's particularly well suited to this application, minimally invasive for these potentially frail and elderly patients,
as well as high kill rate with tumors of many different histologies. So when we're choosing, this is the technique, so how do we do it? If we were facing a metastasis in the scapula like this, we can treat it with heat,
radiofrequency, or microwave ablation, or we can treat it with cryoablation, extreme cold temperatures, extreme cold or extreme heat, they'll both kill the tumor. How do we decide? Well, if we compare cryoablation versus microwave ablation
or radiofrequency ablation, ease of use, the heat-based therapies are certainly easier to use. They're generally faster, so the procedure duration is quite a bit shorter, but the energy transmission into bone is better with cryoablation.
It'll go through the cortex, whereas heat is limited in that regard. The predictability of the ablation zone, the cryoablation. As you can see in that scapular picture, we can actually see the edge of the ablation with several different modalities, CTMR and ultrasound.
Our ability to monitor that ablation then and prevent it from escaping into adjacent collateral structures. And then the ablation zone size, we can usually treat a larger area with cryoablation, and patient tolerance, their pain scores are generally less
after a cryoablation than a heat-based therapy. So in general, most of us who are treating for local tumor control would use cryoablation. These factors are a little less true these days where there are newer bipolar radiofrequency devices that are designed specifically for bone
so have better ability to control tumors within these sites.
We're gonna talk about image guided blocks for pain syndromes. The goals of these blocks are often to reduce narcotic requirements, manage acute pain crises, and what we've learned is that the autonomic nervous system contributes significantly to many pain syndromes.
We'll talk about some neuro blocks, neurolysis, and nerve ablations. When we talk about neurolysis and nerve ablations, what we're trying to do rather than a block which is just a temporary fix and control of pain, we now wanna try to make it at least semi-permanent
to give that patient some time to allow them to ramp down their narcotics, maybe have an improved quality of life. The agents that we use for neurolysis are alcohol and phenol, but more recently, we're starting to use both thermal ablation,
pulsed RF ablation, and cryoablation.
So needle guidance is one of the main tools that we use. This is basically a straight line overlay.
Distinct starting and ending points. We draw this again on cross sectional imaging. Automatically, you can align the C-arm to the, to kind of align with the path that you've drawn, in either a bullseye line of sight orientation, or also a kind of tangential view.
And really you can use this for anything that has straight line geometry. Bone trocars, cement cannulae, ablation probes, screws, temperature probes, hydrodissection needles, anything that more or less is straight line geometry. Just a couple examples of this.
On the right side you can see an example of bullseye needle guidance orientation, and then a more tangential view from the side of the same pathway, so that you can have real time kind of overlay guidance of needle placement as you rotate the II, with a detector,
back and forth real time. And one of the benefits of this is to be able to achieve placements within narrow corridors. Example on the left is placing a screw through a scapular body, which
you know, is pretty thin with a narrow corridor, but this really facilitates placement in this circumstance.
- [Nick] Good morning everyone. My name's Nick Kurup, I'm from Mayo Clinic. And I'd just like to thank Kristin and the leadership for inviting me to speak. I'm gonna be talking about bone ablation for local tumor control, and these are my disclosures, research stuff,
and writing about this subject. So I'm mostly gonna focus on the why. Why do we do bone ablation for local tumor control and I'll talk about a rationale for focal therapy in these patients, a little bit about technique,
and then some evidence supporting ablation for these patients. So there's been an evolution in our understanding of patients with metastatic disease. Starting in the late 1800s with Dr Halsted, he described the orderly and contiguous understanding
of metastatic spread in the case of breast cancer. So the primary tumor moving through the lymphatics to the lymph nodes before spreading systemically. And he used this as justification for patients undergoing mastectomy or radiation therapy to the breast.
Another understanding of metastatic disease is that it's always widely disseminated. So if we have a patient like this that has a melanoma metastasis to the liver, if we only had more sensitive imaging techniques could really see what's going on,
we would see that there's not only the single metastasis, but really a host of other metastases, and these patients all have micrometastasis, cats out of the bag, there's nothing to do focally for these patients.
So is there any cellular or biologic basis for this understanding? Well over the last couple of decades really, there's been a lot of scientific study into tumors on a genomic basis.
And we find that tumors really have a lot of heterogeneity. So this clump of cells that are multicolored here represent the tumor and really, we see that the metastases that develop from this to the brain, liver, and lungs, and spread from different parts of that tumor.
And each of these parts of the tumor may develop different mutations. And even the tumors that spread, like that green metastasis to the liver, then may develop further mutations that allow it to spread further.
And so if we find patients who have a limited amount of metastatic spread, potentially those patients have a single mutation as a more homogeneous tumor. In which case, we could potentially have a therapeutic window in which we can
prevent them from having spread elsewhere. So if we take this example, patient who has a colon cancer and the colon cancer had spread to the liver, those metastases then develop further mutations that spread to the lung and the bone and then the bone metastasis further spreads to the brain,
we could potentially, if we find a patient who only has a liver metastasis and a bone metastasis, if we actually treat those areas focally potentially we can limit their metastatic progression, improve survival.
Now, to become resilient and manage stress if you're in IR this is not something you can do by taking a 20 minute meditation break for yourself and typically by the time you're done with your day, your weekend,
you're coming home and there's a life too so just focusing on yourself and working really hard on meditation may not do the trick because there are other people around you who very much determine how your day goes. And we've published just last year in the JVIR
where we looked, well what happens if a patient walks in the door and they have this really negative affect. I'm getting more and more intrigued by the whole issue of mood contagion and if you look at that the people who come in like that, they actually
have more adverse events, they get about three times the amount of drugs and if you just look at anxious people it's those persons who come in and they look at you with these big, fearful eyes and they tell you I'm gonna die today,
how is that going to affect you? They are gonna experience more pain and above all, their procedures are gonna take much, much longer. The good news though is, what we've found out in this IR room with the multiple players
where there is one person feeding off the stress of the other it is enough to actually just relax one person and with that you can break this cycle. Yeah and then we have relatives that may make some pertinent remarks there
and there was actually a pretty cute study done by a NICU team where they randomized and had a simulated relative say something as kind as, oh if I would have known that you're doing here like third world medicine I would have brought my relative somewhere else.
Just something that pushes all your buttons and they found out that this whole team suddenly couldn't work as well anymore. Now it's not that easy to change what other people do but, you know, you're within this whole setup,
you may be the manager of your division or you have a manager whom you have to report to and there's a lot of other things that goes through your head. I mean this morning you heard about MACRA is in full swing, payment big time depends on it
and the satisfaction ratings and yes, you do wanna retain your staff because you need to have happy staff otherwise your patient's not gonna be happy either.
When we're treating these tumors for local tumor control we're really aggressive in ablating them. So we have a rib metastasis here, and we won't just put one probe in it and call it a day. We have to make sure that we have adequate cold temperatures surrounding the entire tumor with margin
to make sure that we can provide a long-lasting effect for these patients, rather than this case in which patient has a spinal metastasis, we put one probe in part of it and leave a little corner of tumor
when our goal is local tumor control that's not really adequate. And local recurrence really matters so in this study this is one example study of a patient who had surgical replacement of renal cell carcinoma, bone metastases.
And in this study they show that threefold higher hazard ratio of death in patients who develop local tumor recurrence at the site of the resection. So if we can, extrapolating that surgical data to ablation we wanna make sure we get that local control.
Unfortunately as we treat aggressively we are more at risk for developing complications. In this large metastasis that's in the supra-acetabulum here we try to be very cautious that we don't actually have that ice ball encroach upon the femoral head,
as opposed to this equally large metastasis in the supra-acetabulum where we actually have the ice that if you extrapolate those into that femoral head and then several months later the patient develops femoral head collapse and fracture, and their pain recurs.
So let's just talk briefly about the evidence and I'll use metastatic renal cell carcinoma as a model case. Different tumor histologies will have different evidence and different studies to support them. So in this case of a patient who has a right renal mass
and develop this renal metastasis and we ablate that with the ice ball you can see very well. So does this oligometastatic state even occur in renal cell carcinoma met, patients? Well, it does. Most patients actually present
with limited metastatic disease. More than half the patients, when they present with metastases, have just a single site of disease, and that proportion actually increases as patients age. So the patients who are the most elderly,
the most frail, the least suited to surgery, actually are the most likely to have a single site of disease to treat. Is there a survival benefit from surgery if we extrapolate those data? Well, if patients have a wide or radical surgical resection
as opposed to a marginal, they're just pinning that metastasis, those patients do better who have a wide radical surgery. And if patients at the end of their surgery actually are free of disease, they don't have other sites of metastasis,
if we can actually treat all of their disease, they live longer.
So what about if patients have more than just one renal cell carcinoma metastasis? What if they have multiple. So in this study from my institution,
the urology team looked at patients who had all of their tumors resected as opposed to patients who had any of their tumors resected compared to those who had none of them resected. And there was a survival benefit for each of those patients. And these authors wrote a really nice statement
I like in this scenario. And they said limited data exists on the outcomes of these types of patients, and we believe this may result in an unnecessary therapeutic anilism, whereby patients who have multiple lesions
are excluded from an aggressive approach. They're just put onto systemic therapy or comfort care. And why is the literature limited in this case? It's due to the morbidity of surgical resection. So really ablation in these minimally invasive IR techniques provide an opportunity to help this patient population.
But it's really key to pay attention during
you know, your procedure. Patient movement during the procedure leads to misregistration of the overlay objects. And inaccurate needle placement. And so you really have to kind of periodically verify this registration and alignment.
This an example just from a case where you can see that the overlay is off from the actual fluoroscopic image. Which means that all of the objects that are tied to that overlay are also gonna be off.
And so while the needle guidance and the advanced imaging can be helpful, you do have to kind of pay attention as a proceduralist to what you're doing, and whether it makes sense fluoroscopically. So you can see here that this
bullseye orientation needle guidance placement is really not exactly where it needs to be. It really should be shifted over a little bit more, into this AP corridor. So registration becomes kind of a iterative process during cases.
I'll be talking about MAG 3 renal scan. It can use furosemide and captopril. We don't use captopril as much at MSK. I've only used it twice in the two and a half, three years I've been there. I'll just quickly touch on it.
We use captopril to diagnose either renovascular hypertension or renal stenosis. Again, we don't use it as much. Furosemide is our choice of drug that we use. GFR scan that uses D.T.P.A in IV form. Renal scan MAG 3.
This was, when I put it off, Vera went like, "Is this an infection control slide?" It is not an infection control slide. It's just, I though it was really cute, because-- - [Audience] Are those supposed to be kidneys? - Yes, these are two kidneys.
One is kinda healthy, and the second is very sick, and that's what sometimes you find in the renal scans, that one kidney is working great and the second is just, I don't know, feeling all that hot. Indications. For perfusion and, renal perfusion and function,
renal obstruction, renal trauma, or renovascular hypertension. Renal scan is done in three parts, pre-procedure, peri and post, and I'll go over each one of them. Pre-procedure we try to hydrate our patients
with one liter of water as quickly as they can tolerate. If the patient has any contraindication to that much fluid, our doctors change the order for the fluids. Pediatric, the hydration is done on the pediatric floor by their doctors, and the dose is based on BSA. Initial blood pressure is needed on all of our patients
who are going through the renal scan. Again, education, I like to educate my patients before I start doing anything so that they know what we are doing. Most of the patients, as I'm talking to them, that yes, we will be placing an IV,
I would like you to use the restroom before you go on to the scanner. We will be injecting you under the scanner. And someone will take pictures for about 20 minutes before I come in and inject lasix or furosemide. They cannot move after I inject 40 milligrams
of IV furosemide for about 20 minutes. At that point, I offer them a brief. I try not to call it a diaper, because, I mean, come on, how many adults here wants to listen to the fact that, "Hey do you guys wanna wear a diaper?"
- [Audience] Are you hydrating them orally? - Orally. If they can take it, then definitely orally. Another nurse actually calls the diaper a disposable underwear. - Oh, I like that. - Yeah, right?
Education, because as an adult, if I go for a scan, if someone tells me, "Hey, there's a diaper, please wear it," I would not like it. It's just letting them know why you're giving it to them. They don't have to use it, it's just in case,
it's to protect them, because they will not be able to move for about 20 minutes after the furosemide injection. At that point, it might be 40 minutes. They've already had a liter of water in them. Even then, I always tell my patients,
even when you're wearing a brief, we would still want you to hold it. Because it they do void, or if they have an accident, it creates a background radioactive isotope imaging in the scanner, it can get on the scan, and we would rather just avoid all of that.
I'm pretty sure most patients wants to go home in their own clothes, so that's really important. Just in case. Truthfully most of my adult patients opt to wear it. Renal scan for peri-procedure, again, this is a flow study,
so you're talking with a nuclear medicine technologist. Nurse and the technologist have to be on the same page, ready when you inject. So you confirm with the technologist, are you ready, the scanner is in the right place, one, two, three, go.
You inject your dose eight millicuries, and then you flush it with about 50 to 60 milliliters of normal saline. After that, 20 minutes of imaging, the nurse can usually leave, come back in 20 minutes, inject 40 milligrams of furosemide,
which can be based, it can be increased if the createnine is higher. And then flush it with another 10 milliliter of saline. Leave, they do another 20 minutes of pictures, stop, the patient gets off the scanner, uses the bathroom, comes back
for another five minute picture to make sure the bladder did empty out. These are the imaging. As you can see, there's a really cool, and this is as you're injecting the isotope and the saline. It just gives that picture.
See, going back to my kidney slide, we have left kidney that's pretty healthy and the right kidney is not doing so hot. Actually that darkened area up there is the kidney not able to eliminate all of the urine so it's holding on to the isotope.
20 minutes later, as you can see in the end, lasix is given and slowly they're gonna clear out. Post-procedure, you assess the patient, you get another blood pressure, because you really don't want them to tank. I'll make sure they're all great,
the blood pressure is good, you gave them furosemide. Also, assessing, another assessment, that's really important is their ability to ambulate. You don't ask them, "Do you think you can walk fine? "You think you feel safe?" Walk with them for that initial thing,
for the initial walk to the bathroom or to the hallway because I know that if I really have to go, I'm probably not looking very far. (mumbles). You do not want the patient to fall. So just make sure that they are able
to ambulate independently and you're walking with them. You're not just letting them walk by themselves right after the scan.
For Technetium, sulfur colloid, there are patients who have sulfa allergies, and they are really worried that they might just have an allergic reaction to this
because they hear sulfur. I have talked to the doctors as well as our pharmacists, and they have said that it's possible but not probable given that the rate of, chance of an allergy to sulfur colloid is less than 10%. We have injected patients who have sulfa allergies
without pre-medicating them without any problems, but you always know those patients were highly anxious, or they pretty much, they give you a full blown allergic reaction to anything, so you can discuss with their MD and give them Benadryl 25 milligrams PO.
This is the technique under CT guidance. This was an actual patient who had chronic pain in the left shoulder with arm pain. This diagnostic block is to determine whether there is a sympathetic component.
You bring your needle down, avoiding the carotid and sometimes you do have to pass through the jugular vein, but that's okay because you're using a small needle. And then as we're getting closer to the spine at the T1 level you also have to avoid the vertebral artery. So we bring the needle down and we basically dock the needle
just lateral to the esophagus at the junction between the rib head and the T1 vertebral body and that's exactly where the stellate ganglion lives. We inject a little contrast to make sure that we're not intervascular, and then the lidocaine and bupivacaine mixture.
Patients often get immediate relief on the table. This patient did well with this block. We've had several patients that have undergone this block for hot flashes and have had improvement in their symptoms. We've had some failures, but this is one that is not often offered and can really help
in some of these complex pain patients.
Segmentation or volumetric overlay is basically overlaying either a shaded volume or a contour of a volume. The edges of the overlay volume can kind of be tangential to whichever orientation of the detector,
as it changes in real time. Again, drawn on the cross sectional CT data, using kind of segmentation type software. The use of this is really to mark a volume, or kind of a curvilinear surface. So you can either use this as to mark target volumes
that you're intending to ablate or cavities that you're intending to fill with cement. But you can also mark areas that you want to stay away from. Particularly in say the joint space, or the acetabulum or such. So this is an example, kind of on the left,
of you know, two different areas, volumetric areas kind of segmented out on the cross sectional data and how this looks on the three dimensional volumetric model on the right. So the yellow would be kinda this area of tumor, and destruction in the bone that we're intending to fill,
and the red being the actual joint space itself, that we wanna stay out of.
However, in 1995 Drs. Welchselbaum and Hellman
wrote an opinion paper called Oligometastases and then rewrote on this subject in 2011 about the concept of oligometastasis, and they really described this as a distinct state in which tumors have an intermediate metastatic potential. So these patients have a limited number
and site of metastases, and these are variably defined in the literature, but usually people will say up to five metastases. And in these patients it makes sense to do focal therapy rather than systemic therapy. These patients do not have all of the changes
that are required to have distant metastatic spread.
So what are the focal therapies we could use?
Well surgery's been used for years, and there's certainly clinical evidence for this in a number of scenarios. Pts who have colorectal metastases to the liver. They undergo a partial liver resection and they live longer. They are long-term survivors from that.
Same thing with resection of lung metastases, even adrenal metastases. Radiation therapy is certainly used for this in certain areas, particularly of the spine. Embolization is certainly used as a local regional therapy
for metastatic disease, particularly into the liver, and currently it's being used in patients who have more than oligometastasis, several metastases. Focus ultrasound is being used, it's really in the experimental stage now for actually developing local control,
not just in the uterine fibroid here or benign tumor, but in bone metastases.
The celiac plexus block is one that is much better known and I think you probably have all experienced this in your practices, but the celiac plexus block and neurolysis is for the treatment of intractable epigastric pain, most often in pancreatic cancer,
but it can also be in patients who have liver masses or have biliary dilatation and have biliary tubes placed and are having pain related to their biliary tree. But it's also used for intractable nausea and vomiting. If you have somebody who has profound nausea and vomiting and is not responding to normal medications,
a celiac plexus block and neurolysis can improve that. The permanent block blocks the sympathetics and allows the parasympathetic system to start working unopposed, so it actually can improve gastric emptying, which is why we think it improves the nausea and vomiting.
It can improve GI motility, so it can actually improve patients' appetite. The only sort of danger to this block and neurolysis is that it can cause diarrhea by having that parasympathetic system working in overdrive without the sympathetics to balance,
that you can actually develop diarrhea.
And it's a big case where, or a big example where the technologist can add a lot of value and help out a lot. So just a case example that kind of ties together. This was a 53 year old male. He's doing pretty good, except he kinda had
some progressive right hip pain for a few months, but was still walking and able to kind of do most things. Was diagnosed with myeloma. And this was his CT scan, kind of a coronal projection. You can see this large lytic destructive lesion
over his right acetabulum. With extensive kind of bony dehiscence and thinning of the cortex throughout. And so this was the plan to stabilize this. And help his pain from kind of a combined augmented screw, cement and screw approach.
These were the needle paths, and the screw paths that we used on pre-procedural imaging. You can kind of see representations of these here. So again it gives you a good idea of where these screws are gonna go, and in the case of the bottom right image
through a narrow corridor, this really allows us to achieve that. Using this live kind of overlay needle guidance. Several of these screws were placed. Again, up on the I guess top left, you can see this narrow ramus corridor,
that this kind of allows us to find. So again, just kind of more examples of how this case progressed. Registration is a key part again. This was the segmentation that I showed you earlier. And then kind of used this in real time
as we filled this entire area with cement. Again, given the bony destruction, at least the kind of posterior aspect of it was extremely difficult to see. Just under fluoroscopy, and I think without this nice contouring of our target lesion,
in cases that we've had, you know, previously, we would have stopped a lot earlier, thinking that we'd filled it. Whereas here we have kind of that confidence that there's a little bit more to go, a little bit more to fill.
So you can kinda see it, as this goes on, we are able to fill most of the target volume. And this was kind of the completion, you can kinda see that these are screws, and then the cement area here, kind of reforming almost the acetabulum roof.
So he did well, so this was all done percutaneously. He basically had three Band-aids from his three different screw entry sites. And was weight bearing within two hours. Afterwards, he underwent radiation therapy. He was on systemic therapy.
He's starting a Zometa for his kind of overall bone health, and he really doesn't have any specific right hip pain. And the biggest thing for him was that he was able to kind of move on to his systemic therapy and radiation therapy almost immediately afterwards. So a really good outcome, and one that I think that
without a lot of these advanced imaging techniques, we either wouldn't have been able to accomplish or probably would not have been able to provide as much structural reinforcement as we were.
So when we're doing this technique, what do we need before we get started? We need adequate preprocedural imaging. So if we're seeing this tumor that's in a bit of a scary location in the proximal femur,
sometimes if we treat that too aggressively that can fracture, but this looks like it's isolated into the medullary cavity. But these patients have multiple imaging modalities and these help. So if we have functional imaging, in this case a PET scan,
we can see it's actually a bilobe lesion that actually is a little bit higher than we might just suspect from the CT alone. And so when we're ablating we make sure to cover that entire territory when we're in this indication
of trying to locally control that disease. Likewise, if we have a patient like this who has sclerotic metastases, prostate or breast cancer, they've been treated. It's a little bit hard to know which of these are actually active disease.
Have they already been treated? Because they'll look like this for the rest of their life. And we do a PET scan and we actually see there's really only one tumor that has FDG uptake or choline uptake and is actually active disease, and so we actually target that tumor.
- So this was born out of the idea that there were some patients who come to us with a positive physical exam or problems on dialysis, bleeding after dialysis, high pressures, low flows, that still have normal fistulograms. And as our nephrology colleagues teach us, each time you give a patient some contrast,
you lose some renal function that they maintain, even those patients who are on dialysis have some renal function. And constantly giving them contrasts is generally not a good thing. So we all know that intimal hyperplasia
is the Achilles Heel of dialysis access. We try to do surveillance. Debbie talked about the one minute check and how effective dialysis is. Has good sensitivity on good specificity, but poor sensitivity in determining
dialysis access problems. There are other measured parameters that we can use which have good specificity and a little better sensitivity. But what about ultrasound? What about using ultrasound as a surveillance tool and how do you use it?
Well the DOQI guidelines, the first ones, not the ones that are coming out, I guess, talked about different ways to assess dialysis access. And one of the ways, obviously, was using duplex ultrasound. Access flows that are less than 600
or if they're high flows with greater than 20% decrease, those are things that should stimulate a further look for clinical stenosis. Even the IACAVAL recommendations do, indeed, talk about volume flow and looking at volume flow. So is it volume flow?
Or is it velocity that we want to look at? And in our hands, it's been a very, very challenging subject and those of you who are involved with Vasculef probably have the same thing. Medicare has determined that dialysis shouldn't, dialysis access should not be surveilled with ultrasound.
It's not medically necessary unless you have a specific reason for looking at the dialysis access, you can't simply surveil as much as you do a bypass graft despite the work that's been done with bypass graft showing how intervening on a failing graft
is better than a failed graft. There was a good meta-analysis done a few years ago looking at all these different studies that have come out, looking at velocity versus volume. And in that study, their conclusion, unfortunately, is that it's really difficult to tell you
what you should use as volume versus velocity. The problem with it is this. And it becomes, and I'll show you towards the end, is a simple math problem that calculating volume flows is simply a product of area and velocity. In terms of area, you have to measure the luminal diameter,
and then you take the luminal diameter, and you calculate the area. Well area, we all remember, is pi r squared. So you now divide the diameter in half and then you square it. So I don't know about you,
but whenever I measure something on the ultrasound machine, you know, I could be off by half a millimeter, or even a millimeter. Well when you're talking about a four, five millimeter vessel, that's 10, 20% difference.
Now you square that and you've got a big difference. So it's important to use the longitudinal view when you're measuring diameter. Always measure it if you can. It peaks distally, and obviously try to measure it in an non-aneurysmal area.
Well, you know, I'm sure your patients are the same as mine. This is what some of our patients look like. Not many, but this is kind of an exaggerated point to make the point. There's tortuosity, there's aneurysms,
and the vein diameter varies along the length of the access that presents challenges. Well what about velocity? Well, I think most of us realize that a velocity between 100 to 300 is probably normal. A velocity that's over 500, in this case is about 600,
is probably abnormal, and probably represents a stenosis, right? Well, wait a minute, not necessarily. You have to look at the fluid dynamic model of this, and look at what we're actually looking at. This flow is very different.
This is not like any, not like a bypass graft. You've got flow taking a 180 degree turn at the anastomosis. Isn't that going to give you increased turbulence? Isn't that going to change your velocity? Some of the flow dynamic principles that are important
to understand when looking at this is that the difference between plug and laminar flow. Plug flow is where every bit is moving at the same velocity, the same point from top to bottom. But we know that's not true. We know that within vessels, for the most part,
we have laminar flow. So flow along the walls tends to be a little bit less than flow in the middle. That presents a problem for us. And then when you get into the aneurysmal section, and you've got turbulent flow,
then all bets are off there. So it's important, when you take your sample volume, you take it across the whole vessel. And then you get into something called the Time-Averaged mean velocity which is a term that's used in the ultrasound literature.
But it basically talks about making sure that your sample volume is as wide as it can be. You have to make sure that your angle is as normal in 60 degrees because once you get above 60 degrees, you start to throw it off.
So again, you've now got angulation of the anastomosis and then the compliance of a vein and a graft differs from the artery. So we use the two, we multiply it, and we come up with the volume flow. Well, people have said you should use a straight segment
of the graft to measure that. Five centimeters away from the anastomosis, or any major branches. Some people have actually suggested just using a brachial artery to assess that. Well the problems in dialysis access
is there are branches and bifurcations, pseudoaneurysms, occlusions, et cetera. I don't know about you, but if I have a AV graft, I can measure the volume flow at different points in the graft to get different numbers. How is that possible?
Absolutely not possible. You've got a tube with no branches that should be the same at the beginning and the end of the graft. But again, it becomes a simple math problem. The area that you're calculating is half the diameter squared.
So there's definitely measurement area with the electronic calipers. The velocity, you've got sampling error, you've got the anatomy, which distorts velocity, and then you've got the angle with which it is taken. So when you start multiplying all this,
you've got a big reason for variations in flow. We looked at 82 patients in our study. We double blinded it. We used a fistulagram as the gold standard. The duplex flow was calculated at three different spots. Duplex velocity at five different spots.
And then the diameters and aneurysmal areas were noted. This is the data. And basically, what it showed, was something totally non-significant. We really couldn't say anything about it. It was a trend toward lower flows,
how the gradients (mumbles) anastomosis, but nothing we could say. So as you all know, you can't really prove the null hypothesis. I'm not here to tell you to use one or use the other, I don't think that volume flow is something that
we can use as a predictor of success or failure, really. So in conclusion, what we found, is that Debbie Brow is right. Clinical examinations probably still the best technique. Look for abnormalities on dialysis. What's the use of duplex ultrasound in dialysis or patients?
And I think we're going to hear that in the next speaker. But probably good for vein mapping. Definitely good for vein mapping, arterial inflow, and maybe predicting maturation. Thank you very much.
So we've looked at our experience in treating musculoskeletal limited metastatic disease for complete remission, and we looked at 52 metastases in 40 patients. A quarter of them were renal cell in this case. Had about two years followup,
and 87% were able to achieve local tumor control. And these patients live a long time. The median survival of these patients was almost four years with two years survival of 84% with acceptable complication rate. We looked at specifically in renal cell carcinoma,
treating those in multiple different sites. And you know, most of these patients did have locations in bone and soft tissue. So if we used those data to say is there evidence to support this? Well, in these 82 tumors the recurrence
resurvival was very high in 94%, and the patient's overall survival 83% were still alive two years later. In our local tumor control about 88% with an acceptable complication rate. So it is possible to treat these patients
and continue to have them live a long time without systemic therapy. Others have certainly looked at this. This is a group in Detroit that's looked at the same thing, renal cell carcinoma metastasis ablation, and they found the same thing,
median survival over two years in this group. And they actually did a little bit of a cost analysis and said what's the estimated cost even if we have to ablate these people twice and their cost per life year gained was $26,000, which is very reasonable
and compares favorably to systemic therapy, these patients who are put on systemic therapy, the cost is 30 to 45,000 in their study. I've seen estimates over $60,000 for a year. So it's certainly reasonable to do that. This is a busy chart that just shows
that there's a lot of evidence for treating musculoskeletal tumors for local tumor control for a variety of histologies from lung cancer to renal cell cancer to a mixed populations, and breast cancer, whether it's in the spine or other areas in the bone,
a variety of ablation modalities, cryoablation versus heat and the local tumor control rates are reasonable, 70 to 98% depending on the patient population we're looking at. And these data have been compelling enough that the National Cancer Care Network's guidelines
had been revised for patients with stage four renal cell carcinoma. Now that if they are not surgical candidates, ablative techniques in these metastases should be considered.
The stellate ganglion is one of the higher blocks and it's actually probably one of the more difficult blocks. Many of the pain specialists will do these blind which I think is kind of amazing,
considering you have the vertebral artery, you have the carotid artery, you have the esophagus in the vicinity, and so this is a block that I think should definitely be done under image guidance. There have been papers showing that when done under CT guidance, that there's a much greater accuracy
and success with this block. The stellate ganglion block is used to treat complex regional pain syndromes in the upper extremities, like reflex sympathetic dystrophy, hyperhidrosis. So if you have patients who have heavy sweating in the hands, you can use this block to address that.
It's also been used for refractory angina, which I thought was interesting. Phantom limb pain in patients that have had amputations of their upper extremity. Herpes zoster, as well as pain in the head and neck. This block also is used in Raynaud's syndrome
in a scleroderma, it's used in vasospasm syndromes, in patients that are post traumatic or have experienced frost bite, or have embolic syndromes in the upper extremity. And again, intractable angina is one that I actually learned when I was reading about this talk.
One of the indications that is not well known is the use of the stellate ganglion block for hot flashes in the setting of breast cancer. Many of these patients are on tamoxifen and other types of agents that can cause intense hot flashes and a stellate ganglion block can actually
improve those symptoms.
So in conclusion, recent fluoroscopic software advances enable these various forms of,
ends up kind of being augmented fluoroscopy. The points, lines, volumes, really you can apply these in a lot of different creative ways. Dataset registration, verification is critical. Advanced imaging ends up being trusting the computer. And so a knowledgeable technologist is really invaluable
in terms of making sure that things are done correctly from the workstation standpoint and the registration as a case kind of goes along. So, thanks for your attention.
So now we move from a potential case like this
where the patient has a large renal mass and a metastasis into their left femur, and that patient underwent a surgical resection here, replacement of that, a big operation for a patient with metastatic disease, now we take a similar kind of patient
with a left renal cell carcinoma and has two metastases, one in a rib and a small one in the acetabular region. And they undergo the nephrectomy and then ablation of these two areas. That may be the new model.
This is a super busy diagram, but basically this looks at both the somatic nerves and the autonomic system. I don't think we have a laser, unfortunately. Basically the autonomic system innervates the liver, the gallbladder, the stomach, and the upper epigastrium,
but also innervates the large and small intestine. And then as we move down from top to bottom into the lower sympathetic chain, there's innervation of the kidneys, of the uterus, ovaries, scrotum, the urinary bladder, and the perineum. So, in thinking about it that way,
we then can understand where we're gonna target our blocks based on where the pain syndrome is.
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