Bruce Cheson, MD: The GELF criteria were initially developed to identify patients who had so-called bulky disease, and they included not only disease-related symptoms and organ compromise but also the specific size of tumor recommendations: 3 lymph nodes of at least 3 cm or 1 lymph node of at least 7 cm. We now use the GELF criteria to identify patients with follicular lymphoma and other indolent lymphomas who need to be treated and identify others who might be able to be managed from a watch-and-wait perspective. So, that’s where it has transformed over the years, from being just “What is bulky disease?” to “Who needs to be treated?”

Anas Younes, MD: When a patient is diagnosed with follicular lymphoma, the most important thing is to establish the stage. This is usually done through CT scans and a bone marrow biopsy. Most recently, we incorporated PET functional imaging because you may pick up sites that were not picked up by CT scan, but more importantly, you can pick up a highly active site by PET scan that would have otherwise looked like a normal, enlarged lymph node by CT scan. This is important because if you’re staging a patient, you find multiple lymph nodes above and below the diaphragm, and one of them has a very high SUV—which is a measure that we use to determine how functionally active the lymph node is—this may give you a hint that there may be an active histologic transformation from follicular lymphoma to a more aggressive subtype, like diffuse large B-cell lymphoma. This tells you that you should put the needle there to obtain tissue biopsy and then rule out an active transformation, because this can make a difference in treatment choices. So, if you stage a patient—the patient has follicular lymphoma and you decide that they have a low tumor burden by the GELF criteria—and you want to put the patient on active surveillance, I think it’s important to repeat functional imaging before you start therapy to decide whether there is a transformation or not. Because this can play an important role in selecting what type of regimen you would use.

Bruce Cheson, MD: Patients who have low tumor volume—do not have disease-related symptoms, effusions, or any other of the stigmata of the GELF criteria—can just be most often “watched and waited” with careful management and close observation, but without the need to be treated. It’s when the disease looks like it’s growing, when symptoms start to appear, that discussions need to be initiated as to when it is time to treat. That’s when discussions need to be initiated as to when is the time to start treatment, and with which treatment modality.

Transcript Edited for Clarity