Purpose — The use of surveillance computed tomography (CT) imaging in patients with diffuse large B-cell lymphoma (DLBCL) in remission is neither effective nor cost-effective. The American Society of Hematology (ASH) Choosing Wisely (CW) campaign, in particular, emphasizes the lack of benefit beyond 2-years of completion of therapy. We sought to describe the real-world practice of surveillance imaging.
Methods — We used population-based health system administrative databases from Ontario, Canada. We studied a cohort of all adult patients ≥18 with DLBCL who received rituximab (R) with CHOP between 2004-2012. We defined an index date of 2-years after the last dose of RCHOP as the time frame beyond which surveillance imaging would be inappropriate. The cumulative incidence of receiving CT scans after the index date represented the primary outcome of interest.
Results — The cohort consisted of 2,401 patients treated with RCHOP during the study period. The cumulative incidence reached 52.5% (50.4%-54.6%) by 3 years of follow-up. On multivariable analysis, patients with more comorbidities and within certain geographic regions within the province were noted to have increased CT scanning. The cumulative incidence appeared to decrease over the study follow-up period (from 62.4% in 2006 to 48.0% in 2014 p<0.001).
Conclusion — During a timeframe in which surveillance imaging is deemed unnecessary by the CW campaign, the practice remains excessive. Regional variations in CT scanning suggest that local practice patterns can be targeted to reduce imaging. A recent decline in scanning may reflect a broadening appreciation for the evidence against surveillance or uptake of the CW campaign.