In the 1980s, using a cyclophosphamide/TBI (Cy/TBI) ablative regimen resulted in a disease-free survival of 30-40% in patients with high-risk MDS.23 In an effort to study if further intensification of the conditioning regimen would improve the outcome, busulfan was added to this regimen and compared with historical controls using Cy/TBI alone. The results showed that there was a decrease in relapse risk, but no significant difference in survival with significantly more NRM (68% vs 36%).24 From these early studies it appears that further intensification of the conditioning regimen is not a solution to improve the outcome in this disease. In the setting of unrelated matched donor transplants it has been shown that use of non-TBI-based conditioning regimens (Bu/Cy) is associated with improved outcomes both in the low- and high-risk MDS groups.16 Overall, there has been a move toward the use of non-TBI-based conditioning regimens for allogeneic SCT in MDS. Oral busulfan with pharmacologic targeting and intravenous busulfan reduce the incidence of RRT and NRM and improve transplant outcomes.1625 26 Recent data published by Deeg et al. using targeted busulfan levels with cyclophosphamide have shown promising results even in an older patient population with low- and high-risk MDS.8 The data from some of the largest series using myeloablative regimens are summarized in Table 42.2.
Was this article helpful?