The Value of CT Scans in Chronic Lymphocytic Leukemia


Transcript:William G. Wierda, MD, PhD: I think another important topic in terms of evaluating patients for chemoimmunotherapy, or who have been treated with chemoimmunotherapy, is the issue of CAT scans. For years, we weren't doing CAT scans to evaluate patients. Now we're doing a lot of them because the clinical trials that we're doing are requiring them. I wonder if anybody would like to comment on what they feel is the value of the data that's generated from the CAT scans and what your thoughts are on it.

Thomas J. Kipps, MD, PhD: Don't get me started.

William G. Wierda, MD, PhD: Yeah, please.

Alessandra Ferrajoli, MD: He's from California, so.

Thomas J. Kipps, MD, PhD: CT scans are overused. And I remember seeing a patient who was from the Beverly Hills area of Los Angeles. And he brought, with his first clinic visit, a stack of CT scans where he had them almost every three months. And you could almost flip them and get a movie. And I actually advised him to get away from the radiology paparazzi. The problem with CT scans is that oftentimes we're allowing the radiologist to do our work for us.

The good thing about CLL is that the lymph node enlargement is generalized. If you feel lymph nodes that are enlarged in the neck or under the arms, then it's typically the enlargement that you have elsewhere in the body—with a few exceptions. I think that if your clinical exam gives rise to some concern about an abnormality, then, of course, getting a CT scan makes sense. But to do it as a routine for monitoring patients is now overused and is exposing our patients to unnecessary radiation exposure.

Unfortunately, some of the CT scanners may not be as well calibrated as others. And so we have to be concerned about the amount of radiation dose that patients may receive at certain centers. That's a big concern of mine.

Susan M. O’Brien, MD: I think it's a really good point. I do understand, to some extent, why we need them in trials, particularly if it's a trial where data are going to the FDA, right? Because you need an independent review, and the independent review has got to have something to review. And they're not going to be able to review your physical exam. So, I get it there. But I couldn't agree with you more: outside of a clinical trial, I see many patients that have routine CAT scans at certain intervals, and there's completely no point to it. Because, as you just said, if you don't feel anything and they don't have any cervical or axillary, you know, does that mean there's no abdominal nodes? Well there could be some, but who cares? So, it doesn't really matter.

Thomas J. Kipps, MD, PhD: This has been assessed in the Cooperative Group trials and also in the German CLL Study Group. They assessed the question: if they got CT scans versus not, do they change their designation of how they did over the long term? It's very difficult to see an outcome difference. So one has to worry about what the value of the CT scan is in the setting of good clinical monitoring by a thoughtful physician who's able to examine the patient thoroughly.

Richard R. Furman, MD: One of the additional factors that I think really has to be taken into account, and I couldn't agree with the both of you more, is that now that our CLL patients have options beyond chemotherapy, their longevity is going to dramatically increase. Radiation tends to have a late effect, and now our patients have a future to be thinking about. And so, I really think doing away with CT scans as much as possible is certainly important. And there's tremendous overuse of PET scanning, which is really not necessarily more radiation, but it's the idea that, unless you suspect someone has Richter's transformation, a PET scan doesn't really add a lot to the care of the patient. And it really is just unnecessary radiation.

Thomas J. Kipps, MD, PhD: Yeah, I agree with Dr. Furman. I think a lot of this is a carryover from treating patients with lymphoma or other cancers, other than CLL. The PET scan uptake is pretty nondescript and very low, unless you're suspecting a patient has the Richter's transformation. That's the only indication I would see for getting a PET scan.

Alessandra Ferrajoli, MD: And in that setting, we may want to remind the practicing oncologists that if there is suspicion for Richter’s transformation and a PET CT is done, then the highest uptake is the one where we should try to obtain histological confirmation on Richter.

Richard R. Furman, MD: Absolutely.

Alessandra Ferrajoli, MD: And one more, based on our experience, that is very important is that the histological confirmation is done through either an excisional biopsy or a tumor biopsy and not a simple fine needle aspiration. That often is not sufficient in the majority of the cases to make a diagnosis of Richter's transformation.

Susan M. O’Brien, MD: Okay, I remember you published on it. And when you looked at this, there were surprises, right? Other diagnoses-like infections that had nothing to do with transformation?

Alessandra Ferrajoli, MD: Correct.

Richard R. Furman, MD: And then something that I think we may need to think about in the future, and the numbers are too small to really collect meaningful data. But just like in the HIV population, as the advent of heart therapy increased the number of Hodgkin's disease and diminished the number of diffuse large B-cell lymphoma, I have started to see an uptake in the number of Richter's transformations that are Hodgkin's and not large cell lymphomas. So certainly, that dramatically changes how you would manage the case and the clinical outcome.

Transcript Edited for Clarity

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