title: Helical tomotherapy targeting total bone marrow after total body irradiation for patients with relapsed acute leukemia undergoing an allogeneic stem cell transplant.
abstract: OBJECTIVE
  To report our clinical experience in planning and delivering total marrow irradiation (TMI) after total body irradiation (TBI) in patients with relapsed acute leukemia undergoing an allogeneic stem-cell transplant (SCT).
  
  
  METHODS
  Patients received conventional TBI as 2 Gy BID/day for 3 days boosted the next day by TMI (2 Gy in a single fraction) and followed by cyclophosphamide (Cy) 60 mg/kg for 2 days. While TBI was delivered with linear accelerator, TMI was performed with helical tomotherapy (HT).
  
  
  RESULTS
  Fifteen patients were treated from July 2009 till May 2010, ten with acute myeloid leukemia, and five with acute lymphoid leukemia. At the time of radiotherapy eight patients were in relapse and seven in second or third complete remission (CR) after relapse. The donor was a matched sibling in 7 cases and an unrelated donor in 8 cases. Median organ-at-risk dose reduction with TMI ranged from 30% to 65% with the largest reduction (-50%-65%) achieved for brain, larynx, liver, lungs and kidneys. Target areas (bone marrow sites and spleen in selected cases) were irradiated with an optimal conformity and an excellent homogeneity. Follow-up is short ranging from 180 to 510 days (median 310 days). However, tolerance was not different from a conventional TBI-Cy. All patients treated with TBI/TMI reached CR after SCT. Three patients have died (2 for severe GvHD, 1 for infection) and 2 patients showed relapsed leukemia. Twelve patients are alive with ten survivors in clinical remission of disease.
  
  
  CONCLUSIONS
  This study confirms the clinical feasibility of using HT to deliver TMI as selective dose boost modality after TBI. For patients with advanced leukemia targeted TMI after TBI may be a novel approach to increase radiation dose with low risk of severe toxicity.
authors.affiliation: Department of Radiation Oncology, University of Genoa and National Cancer Research Institute, Largo R. Benzi 10, Genoa, Italy. renzo.corvo@unige.it
authors.forename: Renzo
authors.initials: R
authors.lastname: Corvò
authors.forename: Michele
authors.initials: M
authors.lastname: Zeverino
authors.forename: Stefano
authors.initials: S
authors.lastname: Vagge
authors.forename: Stefano
authors.initials: S
authors.lastname: Agostinelli
authors.forename: Salvina
authors.initials: S
authors.lastname: Barra
authors.forename: Gianni
authors.initials: G
authors.lastname: Taccini
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Van Lint
authors.forename: Francesco
authors.initials: F
authors.lastname: Frassoni
authors.forename: Andrea
authors.initials: A
authors.lastname: Bacigalupo
mesh_terms: D000293:Adolescent; D000328:Adult; D001853:Bone Marrow; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000628:therapy*; D011874:Radiometry; D011880:Radiotherapy Planning, Computer-Assisted; D012008:Recurrence; D033581:Stem Cell Transplantation; D036542:Tomography, Spiral Computed; D016896:Treatment Outcome; D014916:Whole-Body Irradiation; D055815:Young Adult