Changes in Imaging Surveillance of Diffuse Large B-Cell Lymphoma Survivors after Publication of the American Society of Hematology Choosing Wisely® Recommendations
Authors: Durani Urshila , Asante Dennis , Heien Herbert C , Thompson Carrie A. , Halfdanarson Thorvardur R. , Peethambaram Prema , Quevedo J. Fernando , Villasboas Jose C , Go Ronald S. 
Published: October 2019

Abstract
Introduction:
The role of surveillance imaging in diffuse large B-cell lymphoma (DLBCL) after treatment with curative intent is debated. In 2013, the American Society of Hematology (ASH) Choosing Wisely® campaign (Hicks LK, et al. Blood 2013) released a recommendation to "limit surveillance CT scans in asymptomatic patients following curative-intent treatment for aggressive lymphoma." This was based on previous studies demonstrating a lack of survival benefit as well as a significant impact on the patient in terms of cost, anxiety, incidental findings and radiation exposure. Similar findings have been described regarding the use of PET imaging, especially in low risk patients. We aimed to study the changes in practice patterns of surveillance imaging for DLBCL survivors treated with curative intent before and after the publication of the ASH Choosing Wisely® campaign.
Methods:
Administrative claims data from a large U.S commercial insurance database (OptumLabs Data Warehouse) were used to retrospectively identify adult patients with an incident diagnosis of DLBCL between 2008 and 2016 and at least one year of follow-up. We excluded those who did not receive treatment with curative intent: RCHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) x 6 cycles or RCHOP x 3-5 cycles plus radiation. Patients were also excluded if they had a co-existing or second cancer, or if they received any chemotherapy/radiation during their surveillance period, as to exclude anyone with a recurrence of their lymphoma. The surveillance period started 90 days after the last chemotherapy or radiation and continued for the duration of follow-up. Surveillance imaging was defined as any PET, PET-CT, CT chest, CT abdomen, and/or CT pelvis. To examine trends over time, three time periods were defined: 2008-2010, 2011-2013 and 2014-2016. The Cochran Armitage test was used to test the trend hypothesis.
Results:
A total of 1,472 patients were included. Cohort characteristics by time period are described in Table 1. Surveillance imaging frequency decreased from 84% in Year 1 of surveillance to 43% in Year 5 (Figure 1). Overall, surveillance imaging during the first 3 surveillance years significantly decreased over the three time periods (Figure 2) (P<0.01 for Years 1 and 2, P=0.04 for Year 3). Imaging surveillance for the first two years of surveillance did not significantly decrease from 2008-2010 to 2011-2013 (P>0.05), but significantly decreased from 2011-2013 to 2014-2016 (P<0.01). Of the groups that received imaging surveillance during year 1, the median number of scans during the first year was 2 (inter-quartile range, 1-2) and did not significantly change over time. In addition, PET/PET-CT surveillance decreased from 49% in Year 1 to <10% in Year 5. PET/PET-CT also decreased over the three time periods, from 62% (2008-2010) to 48% (2011-2013) to 43% (2014-2016) during the first year of surveillance and 40% to 31% to 25% during the second year. Younger age (<65 years versus ≥65 years) was associated with higher imaging utilization (86% versus 81%, respectively), and specifically PET/PET-CT utilization (55% versus 43%, respectively), during the first year of surveillance. However, race (white versus non-white) did not significantly affect imaging (85% versus 83%) or PET utilization (50% versus 47%) during the first year of surveillance.
Conclusions:
Our study demonstrates that the rate of surveillance CT and PET imaging in DLBCL patients treated with curative intent decreased significantly in the years after the publication of the ASH Choosing Wisely® campaign. However, over half of the DLBCL patients diagnosed in 2014-2016 continued to undergo surveillance imaging, indicating either incomplete guideline dissemination or ongoing debate regarding optimal surveillance practice. Future studies are necessary to determine whether such a decline in surveillance imaging is sustained and to examine factors (patient, provider, and payer) associated with surveillance imaging in DLBCL.

Disclosures
No relevant conflicts of interest to declare.