Work

Surveillance PET 100 Days after Autologous Hematopoietic Cell Transplantation Identifies Diffuse Large B Cell Lymphoma Patients with Extremely Poor Survival

Year: 2019

Type: article

Abstract: Introduction The utility of surveillance imaging following auto-HCT in relapsed/refractory DLBCL remains unclear. Imaging is costly and exposes patients to radiation. Novel interventions are now available for patients relapsing after auto-HCT making early disease recognition crucial to intervene prior to clinical progression. We analyzed a cohort of auto-HCT recipients who were uniformly monitored with surveillance (18)F-FDG-PET CT at day 100 (Interquartile range (IQR): 97-103 days) post-HCT. Objectives We explored the PET parameters including Deauville (D) and total metabolic tumor volume (TMTV) as predictors of relapse and survival after auto-HCT. In addition, we assessed outcomes of patients with clinically versus radiographically detected relapsed DLBCL after auto-HCT. Methods/Results We included 131 DLBCL patients (median age 56 years) with available day 100 PET scan treated with auto-HCT between 2006-2016. Median follow-up was 3.3 years. Five-year cumulative incidence of relapse after auto-HCT was 50%, (95%CI 39 to 59) and overall survival (OS) was 51% (95% CI 41 to 63). Twelve (9%) relapsed prior to day 100 and 91 patients underwent surveillance PET/CT imaging at day 100. At time of surveillance re-staging most patients' scores were D1 (22%) or D2 (55%) and 21 (23%) had a D≥3. Patients with D5 (n=12) had higher TMTV (137 cm 3 ) compared to D4 (n=9, TMTV 12.5 cm 3 ). 5-year OS in post-HCT D4 and D5 were only 37% (95%CI=14 to 100) and 25% (95%CI=43 to 89), respectively, whereas those with post-transplant D1 and D2 both had 5-year OS of 62%. Median survival in years for D1, D2, D4 and D5 were 6.0, 6.8, 4.7, and 1.2, respectively. Risk of death was 4 times higher in D5 patients relative to D1 (HR 4.10, 95%CI =1.56 to 10.77; p ≤ 0.01). The hazard ratio for death following relapse was 2-fold higher (HR 1.8 [95% CI 0.9 to 3.4]; p=0.08) if relapse was detected clinically versus only radiographically over a median follow-up time period of 3.3 years. Conclusion In patients with relapsed/refractory DLBCL, PET scan D5 in day 100 post-HCT PET is associated with extremely poor survival ∼ 1 year. Identifying this high-risk cohort can potentially highlight patients that might benefit from cell therapy or other rescue treatment strategies.

Source: Transplantation and Cellular Therapy

DOI: 10.1016/j.bbmt.2018.12.834