Total body irradiation compared with BEAM: Long-term outcomes of peripheral blood autologous stem cell transplantation for non-Hodgkin's lymphoma

Abstract

Purpose: The optimal preparative regimen for non-Hodgkin's lymphoma patients undergoing autologous peripheral blood stem cell transplantation (PBSCT) is unknown. We compared a total body irradiation (TBI)-based regimen with a chemotherapy-alone regimen.

Methods and materials: A retrospective cohort study was performed at a Canadian cancer center. The TBI regimen consisted of cyclophosphamide, etoposide, and TBI 12 Gy in six fractions (CY/E/TBI). The chemotherapy-alone regimen consisted of carmustine, etoposide, cytarabine, and melphalan (BEAM). We compared the acute and long-term toxicities, disease relapse-free survival, and overall survival (OS).

Results: Of 73 patients, 26 received CY/E/TBI and 47 received BEAM. The median follow-up for the CY/E/TBI group was 12.0 years and for the BEAM group was 7.3 years. After PBSCT, no differences in acute toxicity were seen between the two groups. The 5-year disease relapse-free survival rate was 50.0% and 50.7% in the CY/E/TBI and BEAM groups, respectively (p = .808). The 5-year OS rate was 53.9% and 63.8% for the CY/E/TBI and BEAM groups, respectivey (p = .492). The univariate analysis results indicated that patients with Stage IV, with chemotherapy-resistant disease, and who had received PBSCT before 2000 had inferior OS. A three-way categorical analysis revealed that transplantation before 2000, rather than the conditioning regimen, was a more important predictive factor of long-term outcome (p = .034).

Conclusion: A 12-Gy TBI-based conditioning regimen for PBSCT for non-Hodgkin's lymphoma resulted in disease relapse-free survival and OS similar to that after BEAM. PBSCT before 2000, and not the conditioning regimen, was an important predictor of long-term outcomes. TBI was not associated with more acute toxicity or pneumonitis. We found no indication that the TBI regimen was inferior or superior to BEAM.