Survival following allogeneic haematopoietic cell transplantation after non-myeloablative conditioning depends on day 100 PET scan in patients with lymphoma

A. Jaspers, P. Fosse, N. Withofs, M. Lejeune, E. Willems, K. Hafraoui, R. Hustinx, F. Baron, Y. Beguin

Author address: 

CHU of Liège (Liège, BE)

Abstract: 

Background: PET scan is increasingly used in the follow-up of lymphoma patients (pts). Whereas several studies addressed the question of the impact of PET positivity after autologous transplantation on transplantation outcomes, very few have been performed after allogeneic hematopoietic cell transplantation (Allo-HCT). This is the aim of the current retrospective study. Methods: We analyzed data from 50 lymphoma pts who underwent an allo-HCT after non-myeloablative conditioning. The diagnoses were Hodgkin’s lymphoma (n=8) and non-Hodgkin’s lymphoma (n=42). PET scans were scheduled on days 100,180 and 365 and then yearly for a total of 5 years. Results: Day 100 PET scans were not performed in 5 patients. Among the remaining 45 patients, 20 (44.4%) presented hypermetabolic lesions, including 9 patients (20%) with lesions evocative of lymphoma.1-year overall survival (OS) (Figure 1) was lower in patients with typical lymphoma lesions than for those whose PET scan was negative or positive for infectious/ infl ammatory reasons (44% vs 85%, p=0.0013). Figure 1 : OS according to 1st PET scan on day 100 (0=complete response, 1=infl ammatory/infectious, 2=probably infl ammatory/ infectious, 3=residual disease, 4=progression or new lymphomatous lesion, 5=suspicion of other neoplasia). During follow-up, twenty pts (44.4%) never presented hypermetabolic lesions after transplant and 25 (55.6%) had at least one abnormal PET scan. Among the 25 patients, only 9 (20%) had probable/proven lymphoma: 3 residual diseases, 5 relapses and 1 non-biopsy proven progression. Two others pts (4.4%) presented another neoplasia (1 lung cancer and 1 lung PTLD). The 14 remaining pts (31.1%) had suspicious lesions at one of the follow-up PET scans, but none of these proved to be a relapse. Biopsies were performed in 6 of these cases, including 2 lymph node (1 normal and 1 lymphoid hyperplasia), 2 lung (1 normal and 1 aspergillosis) and 2 gastro-intestinal (1 normal and 1 Graft-versus-Host disease) biopsies. For 6 pts, imaging studies were normal or demonstrated infectious or infl ammatory disorders. The last 2 pts were thought to relapse based on both PET and CT scans, refused biopsies, but then their lesions regressed spontaneously. Conclusion: A positive PET scan on day 100 post-transplant is predictive of poorer OS. However, there is a noteworthy incidence of false-positive PET scans after non-myeloablative alloHCT. We therefore recommend that every suspicious lesion should be explored by CT scan and/or biopsy
2012

abstract No: 

P1087

Full conference title: 

Annual Meeting of the EBMT, 38th
    • EBMT 38th (2012)