Total body irradiation before allogeneic bone marrow transplantation: Is more dose better?

Purpose: This study was performed to retrospectively assess the potential influence of total-body irradiation (TBI) dose on overall survival in patients undergoing allogeneic bone-marrow transplants (BMT) for hematologic malignancies. Methods and Materials: Between October 1984 and December 1996, 116 patients were conditioned with high-dose chemotherapy and fractionated TBI before allogeneic BMT. The median age was 34 years (range 3-60), The TBI dose was given in 6 fractions, twice-a-day, over 3 days before BMT, The total dose was 10 Gy in 24 patients, 12 Gy in 66 patients, and 13.5 GS in 26 patients. Results: TBI dose was inversely correlated with overall survival. Five-year survival was 62% for patients conditioned with 10 Gy, 55% for patients conditioned with 12 Gy, and 46% for patients conditioned with 13.5 Gy. Age at BMT was also independently correlated with survival, with the best outcome for patients < 40 years old. Conclusion: A TBI dose (fractionated) > 10 Gf may not necessarily be associated with a better outcome in patients undergoing allogeneic bone-marrow transplant for hematologic malignancies. (C) 2001 Elsevier Science Inc.