Impact of routine surveillance imaging on the outcomes of patients with diffuse large B-cell lymphoma following autologous hematopoietic cell transplantation

Abstract Background For patients with relapsed or refractory DLBCL, autologous hematopoietic cell transplantation (auto-HCT) is commonly employed. After auto-HCT, DLBCL patients are often monitored with surveillance imaging. However, there is little evidence to support this practice. Patients and Methods We performed a multi-center retrospective study of DLBCL patients who underwent auto-HCT (n=160), achieved CR post-transplant, and then underwent surveillance imaging. Of these, only 45 patients relapsed after day +100 post auto-HCT, with relapse detected by routine imaging in 32 (71%) and relapse detected clinically in 13 (29%). Results Baseline patient characteristics were similar between the two groups. Comparing the radiographic and clinically detected relapse groups, the median time from diagnosis to auto-HCT (389 days versus 621 days, p=0.06) and median follow-up after auto-HCT (2464 days versus 1593 days p=0.60) were similar. The median time to relapse post auto-HCT was 191 days in radiographically detected relapses compared to 492 days in clinically detected relapses (p=0.35), and median post-relapse survival was 359 days in such patients compared to 123 days in patients with clinically detected relapse group (p=0.36). However, the median post-transplant overall survival was not significantly different for patients with relapse detected by routine imaging versus relapse detected clinically (643 vs. 586 days, p=0.68). Conclusion In conclusion, a majority (71%) of DLBCL relapses after auto-HCT are detected by routine surveillance imaging. Overall there appears to be limited utility for routine imaging post auto-HCT except in select cases where earlier detection and salvage with allogeneic HCT is a potential option.