Reduced-dose versus standard-dose total body irradiation before allogeneic haematopoietic stem cell transplantation in adults with acute lymphoblastic leukaemia
In brief
Standard 12 Gy TBI increases non-relapse mortality fivefold without reducing relapse
In a retrospective series of 101 adults with acute lymphoblastic leukaemia undergoing first allogeneic stem-cell transplant, a conventional 12 Gy total-body irradiation regimen was linked to about six times higher non-relapse mortality compared with an 8 Gy dose, while relapse incidence was unchanged. Adjusted analyses suggest lower-dose TBI may be safer, but prospective studies are required.
- Journal
- British journal of haematology (Q1)
- Published
- 15 September 2026
- Study design
- Prospective / inception cohort
- Evidence level
- Level 2, Moderate (CEBM 2b)
- Authors
- Isabella Gruber, Matthias Edinger, Hendrik Poeck, Elisabeth Meedt, Ernst Holler, Wolfgang Herr, et al.
- PMID
- 42740588
- DOI
- 10.1111/bjh.70835
Why clinicians should know about it
- Picked for Hematology (paper of the day, 16 September 2026): Reduced‑dose TBI vs standard in ALL transplant conditioning
Abstract
Comparative data on reduced-dose (8 Gy) versus standard-dose (12 Gy) total body irradiation (TBI) before allogeneic haematopoietic stem cell transplantation (allo-HSCT) for adults with acute lymphoblastic leukaemia (ALL) remain limited. We retrospectively analysed 101 adults undergoing first allo-HSCT between 1999 and 2024 after 8 Gy or 12 Gy fractionated TBI-based conditioning. Relapse and non-relapse mortality (NRM) were analysed using multivariable Fine-Gray models. Median follow-up was 8.1 years. Although the 8 Gy cohort was older, had greater comorbidity burden and a higher-risk disease profile, unadjusted NRM, relapse incidence and overall survival did not differ between groups. In multivariable analyses, 12 Gy TBI was associated with increased NRM (sub-distribution hazard ratio 5.97, 95% confidence interval [CI] 1.77-20.15; p = 0.004) without evidence of reduced relapse incidence. The association between 12 Gy TBI and higher NRM was consistent across sensitivity analyses, including adjustment for transplant year and conditioning regimen, cause-specific Cox regression and propensity score overlap weighting. The association of 12 Gy TBI with inferior overall survival in the multivariable model was not confirmed after overlap weighting. Consistent pre-transplant measurable residual disease data were unavailable, limiting adjustment for this prognostic factor. These findings support prospective evaluation of reduced-dose TBI in selected adults with ALL.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.