High rates of surveillance imaging for treated diffuse large B-cell lymphoma: findings from a large national database.

We aimed to characterize surveillance imaging and circumstances of relapse for patients with diffuse large B-cell lymphoma (DLBCL) in the National Comprehensive Cancer Network Non-Hodgkin's Lymphoma Outcomes Database, a prospective cohort study collecting clinical and outcome data at seven comprehensive cancer centers. Patients presenting with newly diagnosed DLBCL in remission ≥3 months after initial therapy and who had accrued 2 years of follow-up were eligible for analysis (n = 625). The median number of imaging studies was 2.5/year (institutional range 0.5-3.5, p < 0.0001); 48.4% received only dedicated computed tomography (CT) scans, 14.6% received only positron emission tomography (PET)-inclusive modalities, 32.8% received a combination and 4.2% received no imaging. Among all eligible patients, 50 (8.0%) experienced relapse, and approximately one-quarter of subclinical relapses were detected through routine imaging. Our results suggest that despite limited data regarding its effect on outcomes, surveillance imaging is prevalent in DLBCL, and a majority of patients receive PET scans at some point during follow-up.