Transcription:
Biopsies, Ports, and Other Tools Interventional Radiologists Bring to Cancer Care

Dr. John Leonard:  Welcome to Weill Cornell Medicine CancerCast, conversations about new developments in medicine, cancer care and research. I am your host, Dr. John Leonard. And today, we will be talking about biopsies, ports and other tools that interventional radiologists bring to cancer care. My guest today is Dr. Bradley Pua, who's an interventional radiologist at Weill Cornell Medicine and New York Presbyterian Hospital. We'll get in a little bit to what interventional radiology is. But one thing I can say is that it's a rapidly evolving field that's at the forefront of minimally invasive techniques for patient care.

Dr. Pua and his colleagues perform a variety of procedures including biopsies, port placements, vascular access, and tumor ablations as well as many other things that fall into the course of routine cancer care. And I know many patients in our audience and family members know a bit about some of these procedures and we thought it would be a great opportunity to bring you in, Brad, and talk about what's involved in some of these and maybe demystify it a little bit for patients. So thanks so much for joining us today.

Dr. Brad Pua: Thank you, Dr. Leonard, for the introduction and the invitation. I think that it's always great to be able to share what it is that we do. And to be frank about it, and even explaining what international radiologists are is always something that's even very difficult amongst my own family members. So I'm glad for the opportunity.

Dr. John Leonard: Well, great. when people think of radiologists, they often think of people sitting in a dark room, looking at pictures and then issuing reports. And while that's probably a little bit of what you do and what many radiologists do and it's obviously essential to cancer screening and patient care in many different venues, but it seems to me like an interventional radiologist is kind of a special category of radiologists. So maybe if you could give our audience little bit of a sense of kind of what is an interventional radiologist. It'd be interesting to know how you found yourself heading in this area amongst all the areas of specialization within your field.

Dr. Brad Pua: So interventional radiology is a fairly new field, as you said. And you know, to be Frank with you, I wasn't even aware of the field when I was in medical school in the early 2000s. The history of it is quite interesting. There was a physician, his name is Charles Dotter. In fact, he actually trained and practiced at Cornell way back when. And what he did was he realized that when he saw people with narrowings in arteries that were feeding the legs causing pain, he could actually put a small tube in to actually open up those narrowings. And that was what started the field of interventional radiology.

So the basis of interventional radiology is to harness our parent sort of discipline, radiology, utilization of the traditional imaging, what we would consider traditional imaging, such as CAT scan, x-ray, ultrasound, MRI, to actually look into the body in a different way to actually perform therapies.

So for me, I started out in surgical residency and, you know, was always fascinated by the human anatomy and kind of the ability to deliver hands-on care using most up-to-date techniques and devices and technological advancements. So IR is really a more minimally invasive means to treat disease much like a surgeon would treat diseases, but without the prolonged hospital stay or large incisions.

So by and large, the limitation of surgery is visualization and, you know, surgeons make these incisions or place cameras such as in laparoscopic and endoscopic surgery so that we can all see what we're doing. Interventional radiologists, because of the training and radiology, we see anatomy differently. We see the anatomy through real-time CT, through x-ray, through ultrasound, through MRI. So we can perform the same functions without these large incisions or with any incisions.

I also grew up in the era of Star Trek, so I kind of think about how you can diagnose and treat things without incisions. And what got me excited about this field in the middle of surgical residency was the ability to contribute to something like this. So, you know, I think this type of therapy and evolution of medicine is continuing towards smaller incisions, if any, and with shorter or no hospital stay. And this also allows us to not only optimize outcomes, but the entire patient experience. So for me, this was a natural thing.

Dr. John Leonard: So there are a number of different sorts of areas and procedures that you and your colleagues help patients with. And one of the big areas, and we'll get to several of the others, because I think it's good for people to kind of hear about the different things that you all bring to the table, which obviously in many cases make a big difference for patients.

One area is biopsies and patients that I see, and I see lymphoma patients, but there are many other cancer patients and their caregivers and loved ones that listen, biopsies are always a part of cancer care, either making the diagnosis or part of the treatment. And people are used to surgical biopsies or in some cases, you know, surgical procedures where one is removing the tumor to not only make the diagnosis, but provide some therapy.

But you perform a variety of different biopsies that are often smaller than surgical biopsies. So maybe if you could talk a little bit about how you approach these situations when a patient is referred for a potential biopsy. Obviously, they've probably already had a scan of some sort or imaging that says that there's target to go after, so to speak. But you all have a number of different options. Can you tell us a little bit about what those are and what the patient can expect if they're being referred for a biopsy?

Dr. Brad Pua: So, like you stated, traditional biopsy really is taking a tissue for us to make a better diagnosis of what we're seeing. And I think unfortunately even with several strides and advancements in our imaging techniques, such as, PET scanning, CT scanning MRI, oftentimes we sometimes just don't know what we're dealing with. So that's where a biopsy comes in to actually take the tissue so that we can make a confident diagnosis to guide therapy and also perhaps to bank the tissue to look into unique genetic makeups still allow more advance therapies.

So, when I get referred a patient for a biopsy, the first thing I do is look at the imaging to see, you know, "Am I adding anything? Will my performing this biopsy, you know, given it's a small risk, but there are risks none the less in any procedure, am I adding anything to the overall value?" And if so, then I start to look a little deeper into is this biopsy safe? And what imaging modality or what do I have in my imaging armamentarium should I be using to actually best get to this target?

So we have a couple of different imaging modalities that we potentially use to help us get to targets. The most common are either ultrasound or CAT scan guidance. And the way we decide between the two is sort of going back to the primary tenet of doing the least amount of harm to a patient. So we often would try to do procedures under ultrasound guidance if we can.

The reason for that is an ultrasound biopsy is actually performed in real time. So I'll have the needle in one hand and the ultrasound probe in the other. So I see the needle at all times as relation to the target. And an ultrasound, because it actually uses sound waves to create the images much like radar sonar, we're not actually delivering any radiation to our patient while we're actually imaging them for the biopsy.

So just in general then, if I am asked to perform a biopsy, I'll always say, "Well, can I do this with ultrasound?" If not, that's when I'll look for something else. So the limitation of ultrasound is that it can't really penetrate tissue that deeply. And you only really see about five to six centimeters in. And it also can't see through air or bone. Therefore, if a target is behind bone or bowel, in lung or is very deep, then we often will end up using CT guidance.

Dr. John Leonard: Typically, what type of anesthesia does a patient have? That's always one person's question. "How much pain am I going to have? And how does that work?" I know it depends a lot on the site and the location, but typically how is that handled?

Dr. Brad Pua: The vast majority of our biopsies are performed under local anesthesia. And with some, they are performed with conscious sedation much like the medications when you would expect when you go for your routine colonoscopy. In general, we actually, if a person can tolerate it, try to keep a patient as awake as possible while keeping them very comfortable. A lot of that has to do with the fact that, depending upon the site of the target, we may ask for some participation in terms of holding their breath. We're doing certain maneuvers to help allow us to gain access more safely. But you know, the primary objective though is to make sure that the person is as comfortable as possible throughout the process.

Limiting the amount of anesthesia is also a sort of a risk and benefit calculation we take into account. The biopsy is fairly low risk. So the more anesthesia we give someone, or even utilizing general anesthesia or anesthesia requiring a breathing tube, is often more risks than it is worth the biopsy. So it's really much a conversation with the patient and the other specialists involved.

Dr. John Leonard: So the size of the needle, and I presume most of the time you're using a needle, I mean, what do patients expect with that? And I think most people would assume the smaller the needle, the less pain, but maybe the less material you get. The bigger the needle, the more risk, the more pain, but the more material you get. How do you kind of balance out those parts of deciding how you're going to approach an individual patient?

Dr. Brad Pua: So there are really two major techniques we use to obtain biopsy. Something called a fine-needle aspiration and another term, core biopsy. A fine needle aspiration refers to us passing a very tiny needle into a lesion and to actually scrape cells so that we can see what it is. A core biopsy is actually taking large pieces of tissue. And so that not only can we see what the cells are made out of or what the tissue is made out of, but we can see the architecture.

And so depending upon what the suspicion is of the lesion, and that's in discussion with the referring provider, as well as looking at the images ourselves and making a radiologic assessment, it kind of guides the size of needles that we would use.

But by and large, we will use as large of a needle as possible for entry. So there is technique that we term coaxial technique. So we use a large needle to go into the lesion to make one puncture through the skin and whatever other structures. And through that needle, we will take multiple aspirates first to confirm that we are in the right place. And if it is necessary to take more for additional diagnosis, for more tissue, for cellular architecture, for molecular studies or even for banking, we'll take more.

One advantage that we have is that we also work in a concerted effort with our cytopathologists. So when I do take a sample, I actually take the sample in real-time to our cytopathologist in the adjacent room. We look at it under a microscope. It's not to make a diagnosis, but what we do is we look at it to make an assessment as to whether or not we have enough to make a diagnosis and if we do need to then subsequently go and either put a larger needle in or take the core biopsies.

The reason we don't just take core biopsies in every patient though, which is the natural next question, is that does confer slightly increased risks of bleeding. So we try to play that risk-benefit game.

Dr. John Leonard: So it sounds like for most scenarios, the main risks are bleeding, infection and pain. Is that kind of the main concern generally speaking? And in my experience, those tend to be pretty low, at least what I see in my patient population. Of course, I'm sure it depends on the individual circumstances.

Dr. Brad Pua: Yes, they're generally pretty low and, yes, they are by and large, site bleeding. Generally speaking, it does stop with some manual compression. Infection is exceedingly rare. And it's also very organ-specific. So say someone comes in for a lung biopsy, the lung functionally is a big bag of air, so there are very site-specific risks. So for lung, for instance, the lungs could collapse. So it just depends on where you are.

A common question I actually get from a lot of patients is, what are the chances that in you putting a needle in to, say, a tumor, when you're taking the needle out, do the cells of the tumor actually seed the track of the needle? So tumor track seeding. That's actually exceedingly rare and almost unheard of. But I bring that up because it is, in fact, a very common question I get asked.

Dr. John Leonard: So I want to move now to ports and IV lines, that type of device is very important for patients getting cancer treatment, particularly because of the nature of many therapies that are given intravenously. The fact that certain chemotherapy drugs in particular can damage the veins and so you need to have very good intravenous access to protect the veins and manage those issues. Sometimes the. devices are used to draw blood. So maybe can you give our audience a sense of the different types of devices? I know that people have heard of ports, they've heard of PICC lines, but if you can describe the different types of devices that your team is involved with and maybe what's involved with placing them and the pros and cons of the major types of those. I think that would be helpful because this affects so many different patients receiving cancer treatment.

Dr. Brad Pua: So I guess to start with, I think probably the listeners are very comfortable with the term intravenous or IV, which is a  catheter that gets placed through a vein that you can see. And through that, you can potentially deliver therapies, deliver fluids, and occasionally take blood.

The next step up is something we call a PICC line. It's spelled P-I-C-C. It’s an acronym for peripherally-inserted central catheter. And so really, we'd like to consider it just a very long IV. It's placed under ultrasound guidance. And this catheter itself actually goes in from one of the veins in the arm and is long enough to actually snake into one of the main vessels, right above the heart, the superior vena cava, which is the main vein that drains the head and neck and the arms.

And so through this line, we can actually give materials that potentially could cause more damage to the smaller veins, such as chemotherapy, certain antibiotics. These lines can also stay in much longer than an intravenous. Most intravenous lines, typically you'd like to replace every three to five days for infectious risks. PICC lines can stay in for a few months and if taken care of properly, can probably stay in longer. One other advantage of a PICC line is that you can draw blood from it in addition to giving the more caustic medications and/or even intravenous nutrition.

A PICC line is just like an intravenous in the sense that, once you are done utilizing it, we can actually just take it out, take whatever sticker or even stitch that maybe holding it in place, you cut the stitch and you pull it out and you hold some pressure. So it's just much like an intravenous in that way.

The next step up would be larger bore lines. So much like a PICC line, but if we need to give medications at a faster rate or take medications or even pull cells at a faster rate, then we may be asked to place what we call tunneled central lines or central lines. And those often, the lines are large enough that we can't fit them in one of the veins in the arms. So we will place them in one of the veins in the neck or the chest.

They function much like a PICC line. They end in the same place as a PICC line. And their life expectancy in terms of length that you can keep one in without malfunction or clotting or infection is the same as a PICC line. They're a little more involved in the sense that, if we were asked to take one out, it is a small minor procedure to actually remove it. It's not about cutting a stitch. A lot of these actually have a little cuff in them that's buried underneath the skin to hold it in place, so it doesn't inadvertently fall out. So we would need to take that cuff out. So it's a small 10, 15 minute procedure under local anesthesia to get out.

A step up from that is something we call a totally implanted venous access device or more commonly known as a port. I think that this is almost the Cadillac of all central access. What it is, it's a plastic with some metal, but mostly plastic device about the size of a quarter. And it gets implanted underneath the skin a couple of centimeters below the collarbone. And connected to that device is a small catheter that gets snaked into one of the veins in the neck and subsequently gets fed down into that major vein, the superior vena cava, right above the heart.

Now, this entire system is actually completely underneath the skin, which is a major difference between the other two I've just discussed. Because it is completely underneath the skin, once the skin is healed, it allows patients to resume a lot of activities that you would otherwise be limited by with something exposed. So patients can sit in hot tubs, go swimming without much limitation because everything is underneath the skin.

What's nice about this device is that the port itself that's underneath the skin in the chest has a silicone disc that can be felt by any provider, typically say a chemotherapy nurse, and that disc is actually accessed with a needle through the skin to allow us now access to the deep vein. This will allow us to give therapy, potentially draw some blood on certain occasions, even give contrast in very high rate for CAT scans.

This device is rated for the life of the therapy. So it is rated for several hundreds thousands of uses, can stay in for a couple of years, assuming you're constantly maintaining it and using it. And once you're done with the therapy, you would come back for a same-day procedure, so I would take this out under local anesthesia through the same incision.

Dr. John Leonard: So I think the take home messages around ports lines are really that you have to tailor it to the nature of the treatment that the patient's getting, the length of time they're going to get it, what it needs to be for and also the patient's individual situation. I remember I had a patient a while ago, who we talked about putting a port in and she was an avid target shooter, shotguns, and that was a big point of discussion of holding the shotgun near where her port would be. And so we went round and round on how to manage that. So, I think that's a good reminder to patients, at least when you can be flexible to think about what you can do to help them preserve their other activities which are obviously important to them.

Another area that you and your team are involved with are what people call stents and the concept of a patient having an obstruction of either their bile duct or their ureter blocking their urinary drainage. Can you briefly tell us a little bit about, and I'm sure there are other types that I'm not mentioning, catheters of some sort or another that go into space near the lung? But generally, how does that work in these sorts of scenarios where patients have a blockage or have fluid that are causing them difficulty and how can this be helpful?

Dr. Brad Pua: So, I guess I placed that in the general category of tubes drains and, like you said, stents. Unfortunately, with cancer, it often manifests itself with compression of normal structure. So I guess, depending upon what it's compressing, we may be asked to relieve this obstruction by bypassing it or alleviating the obstruction itself.

So, I guess one of the examples you brought up would be, say there's an obstruction of the ureter. So, I guess take for instance if somebody had a cancer of the bladder, the bladder being an organ that collects urine produced by the kidneys and the kidneys being connected to the bladder by the tubes called the ureters. If someone had a cancer in that area and compress the ureter, you would now have backup of the urine up into the kidneys which could reduce its function cause the urine or fluid to become infected. In a scenario like this, we're often asked then to either place a tube through the skin, directly into the kidney to allow the urine to drain into a bag in the more acute setting.

So say in an infected setting, to allow the infection to heal and then subsequently actually sort of treat the underlying cause, which is the compression. So we treat the underlying cause by now going through that same access through the skin and placing either generally plastic stents, but in some scenarios, metallic stents, to actually open the ureter back up to allow the normal flow of urine down.

So this kind of concept can be done in many different places. It can be done in blood vessels if the cancer is compressing a blood vessels. It can be done in the biliary tree if the cancer happens to be in liver compressing normal flow of bile. So it just really depends on the situation.

Dr. John Leonard: So another category is the concept of ablations. And maybe you could just spend a minute telling us about what's involved in that area. It seems to me like that tends to be mostly issues with the liver and certain tumors of the liver. I know there are also embolizations, but maybe just give our audience a sense of some of those areas.

Dr. Brad Pua: So, I guess what we've discussed thus far is I guess what we, IRs, interventional radiologists, would consider what we do for support or supportive procedures. So, a fair amount of my practice is involved with therapeutic procedures, so procedures where we're directly affecting cancer care through treating the cancer itself or treating the sequelae of cancer.

So I kind of would categorize it that way whether or not I'm training the primary or metastatic cancer, or I would be palliating certain complications of the cancers. So, for the directed therapies of primary or metastatic or secondary cancers, we have two main sort of techniques that we have in our armamentarium, either transarterial embolization or percutaneous thermal ablation.

Transarterial embolization refers to us treating tumors by attacking the blood vessels that feed them. That's usually accomplished by us passing a small IV into an artery in the groin or the wrist and passing a catheter through this IV under x-ray guidance into the blood vessels to supply the tumor. And then through this catheter, we're able to either block off the blood supply to the tumor by injecting these plastic particles that actually block it off, or actually deliver chemotherapy or high-dose radiation by using these plastic particles as a delivery mechanism. So I think that if one were to do say a Google search of these terms such as bland embolization, chemoembolization, radioembolization all refer to that same general concept.

And these procedures, as with most procedures done in interventional radiology, are done on an ambulatory or a same-day discharge basis. And depending upon the tumor type and what we're treating often confer very similar effectiveness rates and success rates to even surgery, which may require increased hospital length of stay or hospital days in the hospital.

I think another strategy would be the percutaneous thermal ablation. And what that is it's much like a biopsy where we, under CAT scan guidance, actually take a needle and place it into the tumor. But instead of actually taking tissue, the needle is hooked up to a machine that either can freeze a tumor or heat a tumor and kill the tumor on site.

And the way we decide between them all is really based upon the tumor type and just how vascular the tumor is. So we do a lot of assessments as to the best type of therapy is. There are also combination therapies we could potentially offer where we actually would do both.

Now, I think that the laundry list of ways we're involved in cancer care is pretty vast. But I think probably one other thing I would mention that's very worthwhile for us is our involvement in palliation of cancer pain. So we can often use these percutaneous or thermal ablative techniques to actually treat the areas that are causing pain from cancer. And it really does go a long way in improving quality of life.

Dr. John Leonard: So you've talked about how the field is a relatively new one and thanks for pointing out last area, which is obviously very important in many situations. I know you and your team do research and this is a rapidly evolving field. Are there any other areas on the horizon that you're excited about that may offer a new dimension with respect to what you can provide to patients?

Dr. Brad Pua: You know, a lot of the exciting things happening are speaking to just how well we interact on a medical, sort of societal institutional level with one another and sharing our best practices and best techniques. So there are a lot of things where we're trying to see whether or not any of these techniques can aid immunotherapies or chemotherapies. So that's one active areas that we're looking into.

Another is to continue to improve upon our already minimally invasive means of treatment. You know, a lot of the things that we talked about today still require needlestick. I'd like to get us to really to the point of what we talked about earlier, which is the Star Trek, where we're actually not using needles at all.

One of the techniques that were already utilizing in prostate cancer care and bone tumor care is something called high-frequency ultrasound, where under MRI guidance. We use very high intensity ultrasound through the skin without any incision and we concentrate the ultrasound beam into one area of the body and we burn it without any effects on the outside. So to me, that's actually even a step above what high dose radiation therapy would do partially because ultrasound does not utilize radiation. So that's a potential advantage. There's a lot of exciting things, but I think that's really one of them.

Dr. John Leonard: So before we wrap up, I wanted to ask you what kind of message you have for our patient. One of the different areas of interventional radiology is the patient may not actually meet the specialist very long before the procedure and so it's maybe a little bit of a black box sometimes. And you've done a lot to kind of demystify it, but what advice would you say for patients to kind of be more comfortable or messages would you give patients who are potentially undergoing one of these procedures as they think about what's to come?

Dr. Brad Pua: That's a great point. I think that in us trying to limit the number for visits patients have to different providers, often for the more simple and supportive procedures such as the biopsies and the central access and or the line access, we will be meeting patients for the first time the morning of. And so, think oftentimes we're able to answer all the questions and make patients very comfortable with what they're about to undergo, certainly in concert with the referring primary treatment provider.

But, you know, I think that if patient were to have any questions, there's certain things that most practices including ours will do. One is our nurses often reach out a couple of days before the procedure, not only to go over pre-procedure instructions, but also to answer any questions about the procedure.

In addition, we will offer patients, now in the days of video visits and phone consultations, any consultations to go over the procedure itself for these sort of more simple supportive procedures. All complex procedures, patients just like you with a surgeon or any other provider would see us in consult before the procedure to go over the details of those procedures. And really, the idea behind it is to make the entire experience as streamlined as possible, and to make sure that everyone involved is as informed as possible.

Dr. John Leonard: Well, thanks very much for talking with us today. I think one of the things that your discussion points have highlighted is the importance of cancer care at a multidisciplinary center where you can get high-level expertise, not only in interventional radiology, but other areas. And you also get the benefits of a multidisciplinary team so that you can have various providers kind of all looking at a patient situation, question, therapy, diagnosis, and really bring to bear the best of all specialties and the right intervention, the right technique, the right approach for each patient's individual situation. And I think your expertise and what you all bring to the table is very helpful and central to many patients' situations and make a big difference. So thanks so much for sharing your insights with us today.

Dr. Brad Pua: No, thank you very much for the invitation and the opportunity.

Dr. John Leonard: So I would like to invite our audience to download, subscribe, rate, and review CancerCast on Apple podcasts, Google podcasts or online at WeillCornell.org. We also encourage you to write to us at CancerCast@med.Cornell.edu with questions, comments, and topics you'd like to see us cover in more depth in the future.

That's it for CancerCast, conversations about new developments in medicine, cancer care and research. I'm Dr. John Leonard. Thanks for tuning in.