Risk Assessment in Follicular Lymphoma

Transcript:Ian W. Flinn, MD, PhD: Ajay, that takes us to thinking about prognosis and how we risk stratify patients. There are a variety of instruments that have been developed. They’re often used in clinical trials. Are they using them in clinical practice? What about other things such as PET [positron emission tomography] scanning? How do you incorporate this into your assessment of patients’ risk?

Ajay K. Gopal, MD, FACP: This is one of the challenges we face with follicular lymphoma, trying to accurately predict who’s going to do poorly and who’s going to do well and then using that information to make treatment decisions. I’ll start by emphasizing that we don’t yet know how to use those tools to decide who gets a more intensive therapy. There are a variety of prognostic scoring systems from the FLIPI [Follicular Lymphoma International Prognostic Index], as you mentioned, which is kind of cumbersome, you’ve got to count out nodal areas, to the FLIPI2, which really focuses on beta-2 microglobulin and bulk of disease. There’s also an m7-FLIPI, which puts a genetic signature plus the FLIPI score, which is a little better at predicting which patients are going to fall under that very high-risk category. But that’s not something that we can easily routinely do. It is a challenge though; we don’t yet know how to use those tools to decide which patient gets which therapy, or even which patient to initiate therapy on if they’re asymptomatic.

Ian W. Flinn, MD, PhD: What about PET scanning? Do you think that helps? Do you get PET scans on everybody? What do you do with the information? Are you using it pre and post treatment?

Ajay K. Gopal, MD, FACP: That’s another excellent questions. There’s controversial data with PET scanning. I typically do get a PET scan if I’m going to start therapy. We also use it when we’re trying to sort out whether a patient might have transformation before we start. I often use it to guide biopsy. But in terms of the data as to whether a PET scan will predict outcome, they’re differing results. There are 2 abstracts from this meeting, 1 looking at metabolic tumor volume, which suggested that it was not predictive of outcome, and then a second one looking at SUV [standardized uptake value] which suggested it was. So I think the data are still a bit controversial as to using PET scan to predict outcome, but I think it is useful as a baseline study.

Ian W. Flinn, MD, PhD: Nathan, are you getting PET scans on everyone pretreatment or the majority of people?

Nathan H. Fowler, MD: Yes. I agree with Ajay’s comments. It’s extremely valuable, especially at diagnosis. I found it will guide biopsies. And if you go after the hottest nodes, sometimes you’ll pick up an occult transformation. So it’s very sensitive; 97% of patients who have follicular will have a hot PET, and it’s extremely useful. Also you know I find that there are occasionally sites of extra nodal disease that will not get picked up on CT [computed tomography] and are seen on PET. So yes, I do use it pretty much all the time in baseline.

Ian W. Flinn, MD, PhD: We talked about PET scanning on the front end. We were trying to figure out where to take patients and things like that. But how about afterwards, are you getting PET scans routinely after someone completes therapy, at what interval and any problems with that?

Nathan H. Fowler, MD: In my practice, I really like PETs for follicular lymphoma, again, because they’re positive if patients have disease. They can have false-positives, but generally I think with a good clinical exam and history you can rule out what is positive. I mean if patients come in with a cold or the flu and they have hot nodes in the hilum, it’s probably not relapsed lymphoma. And so I find that at least in our hands with a good nuclear medicine physician and a good understanding of what’s happening with the patient, we don’t have a whole lot of false-positives.

In current practice it’s very rare to get a PET without a CT at the same time. Most centers now are on PET/CTs. And so when I think about they’re getting radiation exposure to the patient, it’s the same whether you get a CT or a CT/PET. And the cost, at least in our center, is fairly similar. Now most payers will not agree to PET imaging as surveillance, or in a certain timespan. But my opinion, if you’re going to get a CT, I don’t have any doubts about including a PET because it adds additional information that I can use or not use, depending on the clinical picture.

Transcript edited for clarity.