Surveillance Imaging after Autologous Hematopoietic Cell Transplantation Predicts Survival in Patients with Diffuse Large B Cell Lymphoma

Abstract

The utility of surveillance imaging after autologous hematopoietic cell transplantation (AHCT) in relapsed/refractory diffuse large B cell lymphoma (DLBCL) remains unclear. The purpose of this study was to determine whether surveillance imaging predicts survival after AHCT. At the University of Minnesota, serial imaging for early relapse detection has been used prospectively for all consecutive AHCT recipients treated since 2010. The present analysis included 91 AHCT recipients with DLBCL who underwent ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG-PET) scan at day +100 post-AHCT. ¹⁸F-FDG-PET parameters included the Deauville (D) 5-point scale, peak standardized uptake values (SUV_max), total legion glycolysis (TLG), and total metabolic tumor volume (TMTV). Survival of patients with clinically symptomatic versus asymptomatic radiographically detected relapsed DLBCL after AHCT was compared. Sixty patients experienced relapse; 35% was detected on day +100 surveillance PET scan. 5-year overall survival (OS) by ¹⁸F-FDG-PET scan at day +100 post-AHCT was significantly lower in D4 and D5 patients (37%; 95% confidence interval [CI], 14% to 100% versus 25%; 95% CI, 43% to 89%) compared with patients with D1 and D2 (62%; 95% CI, 43% to 89% versus 62%; 95% CI, 46% to 84%). TLG and TMTV were not prognostic. SUV_max at day +100 varied from 1.5 (D1) to 17.9 (D5). In multivariate analysis, only SUV_max was predictive of relapse and OS; mortality increased 1.8-fold with each SUV_max doubling (hazard ratio [HR], 1.8; 95% CI, 1.3 to 2.3; P < .01). At a median follow-up of 3.3 years (range, 1 to 12 years), lymphoma-related mortality was 1.8-fold higher among patients whose relapse was detected clinically (symptomatic) versus radiographically on surveillance scan (HR, 1.8; 95% CI, .9 to 3.4; P = .08). In patients with relapsed/refractory DLBCL, a routine PET imaging at day +100 post-AHCT detects asymptomatic relapse and high SUV_max identifies patients with poor expected survival of less than 1 year. Identifying this high-risk cohort can potentially highlight patients who might benefit from preemptive interventions to prevent or delay relapse.

Keywords: Autologous hematopoietic cell transplantation; Deauville score; Diffuse large B cell lymphoma; PET; Surveillance.