Hi, this is Elliot Fishman and welcome to our latest podcast. This is going to be on the evaluation of the patient with known renal cell carcinoma and the patterns of tumor recurrence. So, what we're going to do in this study is really look at how we evaluate a patient who's had renal cell carcinoma. Maybe they've had a nephrectomy, maybe they've had a partial nephrectomy, maybe they've had ablation. We're going to understand how we follow them, and what are the patterns of typical recurrence. CT is the gold standard and the primary imaging modality used for postoperative surveillance. It's good at detecting lesions whether it's in the lungs or the mediastinum, in the liver or the pancreas or adrenal, in the native kidney where the mass was initially if it was a partial nephrectomy, or the contralateral kidney, or to bowel, or any place else. The intensity and frequency of CT surveillance are strictly risk-stratified based on the tumor's initial stage and surgical outcomes.

So, just some magic numbers. Renal cell carcinoma is the most common adult malignancy of the kidney, accounting for approximately 2% of adult malignancies and 4% of new cancer cases in the US every year. Therapy will vary. In the old days, everyone had a nephrectomy. Now, that's rare. We have ablative therapy, we have RF ablation, we have cryotherapy, microwave is gaining popularity. We have anti-angiogenic therapy for patients with more extensive disease. We do partial nephrectomies, we do total nephrectomies. Survival rates for metastatic renal cell have increased. And again, using imaging for early detection will indeed benefit patients.

Just some SEER data from the NCI. The survival, five years of pancreatic cancer�remember, pancreatic cancer has 11% five-year survival, renal cancer has a 78.6% survival. And that's, of course, because most tumors or many tumors are picked up at an early stage and surgical resection is very successful in these patients. If you look at the estimated number of new cases in the US this past year was over 80,000, with an estimated deaths of about 14,000. We said that 78.6% of patients will survive five years, and those numbers are increasing, particularly as immunotherapy is coming along.

In terms of survival, it's really a stage thing. If you're localized, 93%. If you have distant mets, it's 19%. So, again, early detection is the key. Now, of course, presentation can range from hematuria, which is about 40% of cases, and that's the classic gross hematuria. But it can be flank pain, back pain, weight loss, or the metastasis like a bone lesion being the presentation.

We mentioned that surveillance is based on risk level. The AUA and the NCCN both have fairly common ideas. Low risk, that means low-stage tumor, baseline CT at 3 to 12 months, then annually for 3 years, often optional or alternating with ultrasound after that. Moderate risk: chest, abdomen every 6 months for 2 to 3 years, then annually for 5 years. And high risk, you know, the higher-stage tumors, CT every 3 to 6 months for 2 years and every 6 to 12 months for 5 years, and the patients will still be followed after 5 years. So, again, low, moderate, and high risk will have different follow-ups. Since 80% of the recurrences occur within the first 2 to 3 years, when you look at that chart, it's front-loaded so that we can catch early metastatic disease.

Now, the goals of a follow-up scan for renal cell carcinoma: we want to look for local recurrence in the renal bed or in the kidney if there was a partial nephrectomy or an ablation-like study. We want to look at the contralateral kidney for possibly additional sites of tumor, either metastasis or synchronous tumors. We then want to look at the entire abdomen: look at the liver and spleen, look at the adrenal, pancreas, the bowel as well as the stomach. We also want to look carefully at the chest for lung metastasis and the mediastinum because nodes are not uncommon. And, of course, we'll be looking at soft tissue and bone, since metastasis can go there. And we'll be looking at nodal disease: nodal spread in the para-aortic region, mediastinum, pelvis are all indeed possibilities.

So, the goal of the follow-up scan is to look for spread. And again, we look at the entire scan. We see mets to the stomach, we see mets to the bowel, we see mets to the heart, we see mets to the skin. And, of course, at some point, you'll also be doing, depending on the specific stage of tumor, imaging of the brain. It typically is going to be MR, but metastasis from renal cell, especially clear cell renal cell carcinoma, would indeed go to the brain.

Now, what's our protocol, you ask? Well, we don't routinely do non-contrast scans; I think in this scenario, they add very little. We then do three-phase study with arterial phase from the chest through the pelvis. Remember, the majority of cases are clear cell renal cell carcinoma, and they're typically hypervascular. With papillary, which make up about 10% to 15%, the vascularity is less, of course, and typically they're hypovascular, but we'll still do the multiple phases. We'll do the chest through the pelvis and bladder, and then we'll do venous phase from diaphragm to symphysis, and delayed phase from the mid-liver through the pelvis so that we can get a good look at the kidneys in the excretory phase, look at the renal pelvis, look at the ureters, look at the calyces. I review the images looking at the axial and multi-planar. I'll also routinely look at MIP and volume-rendered images. And you'll see in this talk when I show you cases, some of the cases I'm going to show a lot of images just to give you a feel about the importance of the phase of acquisition and how we look at the data.

Now, there are pitfalls. Metastases from clear cell are usually vascular, and so if you don't do arterial phase imaging, you're going to miss them. I often look at outside CT scans, we all do, and not to be critical, but often a single phase, maybe a venous phase or a late venous excretory phase is done. Well, you're going to miss a lot of lesions-liver, contralateral kidney, pancreas, and other areas-if you do not get arterial phase imaging. In terms of injection rate, we're going with about 100 to 120 cc of contrast, injected ideally at 5 cc's a second.

Now, if the patient did have a transitional cell carcinoma, which is not what we'll be discussing here, our delays are usually a little bit longer, 5 to 6 minutes. But with a clear cell or a papillary or a chromophobe, we are going to go at about 4 to 5 minutes. I don't like getting late scans because then the contrast is very dense, you get all sorts of beam-hardening artifact, and it makes it very hard to pick up smaller lesions.

So, let's look at a case. This was a routine follow-up of renal cell carcinoma patient with right nephrectomy. When you look quickly, there is a lesion, we're not sure of its significance, but it's in the upper pole of the left kidney. When you look really hard, because I know the answer, look over here in the liver, 1 cm, hard to see. Look at the adrenal, a little density there. But are you going to call that? Well, the person who read this at first did not call it. And they did not call anything in the pancreas, but I admit I don't see anything in the pancreas on these venous phase images.

So, what exactly am I missing? Is there something in the liver? Is there something in the adrenal? What's going on in that patient's left kidney? Well, with arterial phase, let's look at the venous against arterial. This low density is this vascular metastasis. This is an adrenal metastasis, and this is a vascular renal cell carcinoma which washes out. Okay? Liver, adrenal, and the kidney. Well, then you look at the pancreas. We don't see anything on the venous, but look here: multiple metastases. Yes, this was in a renal cell lecture, and you weren't missing the right kidney, you could say a neuroendocrine tumor, and you'd be right. But in this case, this is metastasis to the pancreas, but you missed it.

Again, the lesion in the upper pole of the left kidney has poor margins, it's soft tissue density, and if this is your only image, you have to be concerned. Yes, it could be a high-density cyst, but you'd want to look at the old scans. This is a great example of a patient developing a met to the kidney, but it's easier to see on the arterial than the venous phase because you know it's vascular. And again, liver and pancreas. Look at the liver lesions, right? Look at the adrenal lesion in the right adrenal gland, and look at that vascular lesion in the patient's left kidney, all very nicely shown.

And again, more metastasis in the pancreas, more liver lesions. And I'm going to keep going and show you the adrenal and the liver. None of these lesions is more than 15 millimeters, and that's the point. When lesions are vascular, you can pick them up when they're small, but if you're not doing the right phase, which means you didn't do arterial phase, you're going to miss these lesions, and the patient will not be treated in a timely fashion. This becomes very, very important. I like this adrenal metastasis, it's a centimeter or less. We talk about adrenal mets, they do occur from renal cell, but they're usually larger, and in this case, it was really small.

And again, metastasis to the pancreas can be solitary or can be multiple, and I'll show you a number of cases of both of those. The MIP imaging really shows you the liver lesions very nicely, including several additional small lesions seen here and here, in addition to the larger lesion. Here's the pancreatic lesions again. And here it is on the arterial phase, and again, looking at that lesion in the left kidney, very clearly another site of tumor. The patient will be treated with chemotherapy, the patient will also get a partial left nephrectomy. So, again, multiple sites of disease in a single patient. This also makes the point to remind you about not having satisfaction of search. Oh, you saw the liver but you didn't see the pancreas, or you saw the adrenal but not the liver. You need to see all of the lesions in order to manage the patient correctly.

Here's some cinematic renderings. There's the pancreatic lesions, there's the liver lesion very nicely, there's the textural changes and there are the liver lesions. Here they are again on the coronal images, nicely circled. And of course, there's the adrenal lesion and then the pancreatic lesions. So, whether you're using the axials or the coronals, the MIP or the volume rendering, the volume rendering or the cinematic rendering, you're able to see all of the lesions in question. But again, you need to look very carefully, and in this case, once I see some lesions, I will look more carefully at the bowel, I'll look at the stomach, we look everywhere because when you have multiple sites of disease, you're more likely to have additional sites as well. So, it becomes very, very important. And again, the volume rendering showing you some of those lesions very nicely documented. And here's just a change in the cinematic rendering to accentuate the kidney, the renal vein, the celiac, GDA, and the metastasis. So, again, looking at all of those possible lesions really gives you a feel about the importance of protocol. And I show this case to start off with making the point that if you don't do the study correctly, you're not going to pick up the metastasis.

Now, in this patient, we had liver lesions. Liver lesions from clear cell are very vascular. Here's another example of multiple liver lesions from 1.5 centimeters to about 4 centimeters. You can see, again, some additional lesions including in the lung. So, liver and lung in this patient. Splenic lesions are rare, but they do occur, but I don't see one here. And again, the washout. These lesions are very vascular with clear cell renal cell carcinoma. Lesions can be very vascular, but wash out very quickly. If you only had the venous phase, I think you still would call liver metastasis because these lesions are cystic but have enhancement around it. You're not going to call it a simple cyst, it doesn't look like hemangioma or anything else, but we would surely say that it's much easier to look at the arterial phase imaging and make the correct diagnosis. But again, I want you to recognize that if you only had the venous, you recognize that those are metastasis and you go from there.

Another patient, clear cell renal cell carcinoma, and the patient now has a metastasis to the right adrenal gland. There's also metastasis on the surface of the spleen, right there. And again, mets to the adrenal gland. Renal cell carcinoma, clear cell, wherever the mets go, the mets are going to be vascular in most cases when you have arterial phase imaging, nicely shown here. And, of course, same patient, there's implants on the patient's duodenum, there's implants on the liver, there's implants on the omentum. So, a range of implants on the omentum. Again, very vascular. So, you can see that the patterns of disease, multiple sites of disease, some typical, some atypical, but you need to see them all.

There's mets in the pelvis, pushing on the bladder, very vascular. And again, bladder, omentum, very clearly shown. So, again, the importance of the arterial phase, why we scan the entire abdomen and pelvis with arterial phase in clear cell, because it's not just the kidney, it's not just the liver, it's not just the adrenal, it's not the pancreas, it's the omentum, the pelvis, the bowel, it's everywhere we need to be looking.

And again, this case, we had the bowel. There's also pancreas involved, right? Pancreas and adrenal and liver, multi-organ involvement and omentum. Omental lesions are fairly uncommon, bowel in general is fairly uncommon, but we do see a reasonable number of cases, so you need to look very, very carefully at that. Same patient, when I show you the MIP, now look at how those lesions with bowel and omentum stand out on the right side of the image. Here it is again. Look at those lesions, and you see more lesions, right? Here's the adrenal, but look at all of these implants on small bowel, as well as on omentum, as well as in mesentery. Image on your left is a MIP showing that, image on your right is volume rendering, also accentuating the lesion in the patient's pelvis. And again, here's that pelvic lesion with volume rendering, multiple metastases, here's the MIP imaging. So, a combination of volume rendering and MIP. In this case, both work very nicely. In some cases, one will be better than the other. When lesions are small and very vascular, MIP does an amazingly good job. When lesions involve organs and texture changes, then volume rendering is often going to be better.

So, again, a beautiful example of metastasis to bowel, as well as to pancreas, as well as to liver. So, again, here is the same patient with those lesions and the feeding vessels on the cinematic rendering. Just a really, really elegant case.

So, what else? I mentioned bowel. Let's do this: let's take a break right here, come back, and let's look at some other patterns of metastasis after say a five-minute break. See you in five minutes.