The use of surveillance computed tomography (CT) imaging in patients with diffuse large B-cell lymphoma in remission is neither effective nor cost-effective. The American Society of Hematology 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.Patients and Methods
We used population-based health system administrative databases from Ontario, Canada. We studied a cohort of all adult patients ≥ 18 years with diffuse large B-cell lymphoma who received rituximab (R) with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) between 2004 and 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 2401 patients treated with RCHOP during the study period. The cumulative incidence reached 52.5% (range, 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 < .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.Micro-Abstract
Population-based administrative databases from Ontario, Canada were used to study the real-world practice of CT imaging in patients with diffuse large B-cell lymphoma in remission. The cumulative incidence of CT imaging two years after curative systemic therapy reached 53% over the following 3 years. During a period in which surveillance is deemed unnecessary by the Choosing Wisely campaign, the practice remains excessive.