ASCO: Pros/Cons of Follow-Up Imaging in Lymphoma

Kenneth R. Carson, MD

As part of our coverage of the 2014 American Society of Clinical Oncology (ASCO) Annual Meeting, Cancer Network is speaking today with Kenneth Carson, MD, assistant professor of medicine in the division of oncology at Washington University School of Medicine in St. Louis. On Sunday, June 1, Dr. Carson will serve as the chair for an Education Session titled “Follow-Up Imaging in Lymphoma: A Debate on Its Use.”

-Interviewed by Leah Lawrence

Cancer Network: Dr. Carson, imaging is frequently used as a form of follow-up in patients with cancer. Why is there a debate about its use in lymphoma?

Dr. Carson: At this time we don’t know that follow-up imaging after curative-intent treatment for patients with lymphoma is actually improving their overall outcomes, and there are concerns that are valid that the radiation associated with follow-up imaging may be causing long-term harms.

Cancer Network: What then do the current treatment guidelines recommend as it relates to follow-up imaging in lymphoma?

Dr. Carson: It depends upon the subtype of lymphoma. For the most common form of non-Hodgkin lymphoma, diffuse large B-cell lymphoma, the guidelines in the United States recommend imaging up to every 6 months for 2 years after completion of therapy, while the guidelines in Canada and Europe are quite different, recommending much less imaging.

Cancer Network: If imaging was not used, how else are relapses detected in these patients?

Dr. Carson: Studies have shown that the majority of relapses are detected by clinical symptoms or physical exam findings that would be seen in the clinic by oncology providers.

Cancer Network: What are some of the arguments that are in support of follow-up imaging?

Dr. Carson: There is some evidence that patients who have relapse detected by imaging maybe have earlier-stage disease that may contribute to better long-term outcomes with salvage therapy.

Cancer Network: In contrast, what are some of the arguments against follow-up imaging?

Dr. Carson: One of the biggest arguments against follow-up imaging is the concern about the long-term risks associated with the radiation that is used in those diagnostic procedures. This could increase long-term risk of secondary malignancies, and this is particularly important in patients who have been treated with curative intent, such as patients with aggressive non-Hodgkin lymphoma.

Cancer Network: In your opinion, what needs to happen to draw more definitive conclusions about the use of follow-up imaging in patients with lymphoma?

Dr. Carson: In an ideal world, we would perform a large randomized trial to look at the risks and benefits of follow-up imaging, though this would be a very expensive and very long trial, and it is unlikely that it will ever be performed. In the near-term, enhancing our understanding will likely involve using observational databases that will assess the long-term outcomes of patients who have relapse detected with and without surveillance imaging.

Cancer Network: Thank you, Dr. Carson, for speaking with us today about follow-up imaging in lymphoma.

Dr. Carson: You’re welcome.