title: Low-dose fractionated total body irradiation (TBI) adversely affects prognosis of patients with leukemia receiving an HLA-matched allogeneic bone marrow transplant from an unrelated donor (UD-BMT).
abstract: The optimal total body irradiation (TBI) regimen for unrelated donor bone marrow transplant (UD-BMT) is unknown. In the present study we analyze the outcomes of two different TBI regimens used in our center for patients with leukemia undergoing an UD-BMT. Between January 1994 and August 2001, 99 consecutive UD-BMT patients entered this comparative study. The conditioning regimen consisted of cyclophosphamide, 120 mg/kg followed by TBI on days -3, -2 and -1. Forty-six patients received TBI 12 Gy (2 Gy, twice a day) in six fractions (HF-TBI) and 53 patients received TBI 9.90 Gy (3.30 Gy per day) fractionated over 3 days (F-TBI). End-points were transplanted-related mortality (TRM), leukemia relapse rate (LRR) and overall survival (OS). At median follow-up of 22 months (58 months for HF-TBI and 17 for F-TBI, respectively), 60 patients were alive (32 in HF-TBI sub-group and 28 in F-TBI one). The actuarial 5-year TRM was 31% for HF-TBI and 41% for F-TBI (P = 0.1), whereas the 5-year LRR was 13% for HF-TBI and 31% for F-TBI (P = 0.04). The actuarial 5-year OS was 68% for patients treated with HF-TBI and 51% for those treated with F-TBI (P = 0.02). At multivariate analysis F-TBI schedule emerged as an adverse predictor for OS (P = 0.04) and LRR (P = 0.03). These data indicate that a lower total dose of TBI appears significantly less effective in leukemia eradication and associated with worse overall survival when compared with a higher dose of radiation.
authors.affiliation: UO Oncologia Radioterapica, Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Corvò
authors.forename: T
authors.initials: T
authors.lastname: Lamparelli
authors.forename: B
authors.initials: B
authors.lastname: Bruno
authors.forename: S
authors.initials: S
authors.lastname: Barra
authors.forename: M T
authors.initials: MT
authors.lastname: Van Lint
authors.forename: V
authors.initials: V
authors.lastname: Vitale
authors.forename: A
authors.initials: A
authors.lastname: Bacigalupo
mesh_terms: D000293:Adolescent; D000328:Adult; D016026:Bone Marrow Transplantation / Q000276:immunology / Q000401:mortality*; D019583:Dose Fractionation, Radiation; D005260:Female; D006650:Histocompatibility Testing; D006801:Humans; D007938:Leukemia / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012008:Recurrence; D012189:Retrospective Studies; D016019:Survival Analysis; D014019:Tissue Donors; D019172:Transplantation Conditioning / Q000379:methods; D014184:Transplantation, Homologous; D014185:Transplantation, Isogeneic; D014916:Whole-Body Irradiation / Q000379:methods / Q000401:mortality*