title: Extreme heterogeneity of myeloablative total body irradiation techniques in clinical practice: a survey of the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation.
abstract: BACKGROUND
  Total body irradiation (TBI) is widely used for conditioning before hematopoietic cell transplantation. Its efficacy and toxicity may depend on many methodological aspects. The goal of the current study was to explore current clinical practice in this field.
  
  
  METHODS
  A questionnaire was sent to all centers collaborating in the European Group for Blood and Marrow Transplantation and included 19 questions regarding various aspects of TBI. A total of 56 centers from 23 countries responded.
  
  
  RESULTS
  All centers differed with regard to at least 1 answer. The total maximum dose of TBI used for myeloablative transplantation ranged from 8 grays (Gy) to 14.4 Gy, whereas the dose per fraction was 1.65 Gy to 8 Gy. A total of 16 dose/fractionation modalities were identified. The dose rate ranged from 2.25 centigrays to 37.5 centigrays per minute. The treatment unit was linear accelerator (LINAC) (91%) or cobalt unit (9%). Beams (photons) used for LINAC were reported to range from 6 to 25 megavolts. The most frequent technique used for irradiation was "patient in 1 field," in which 2 fields and 2 patient positions per fraction are used (64%). In 41% of centers, patients were immobilized during TBI. Approximately 93% of centers used in vivo dosimetry with accepted discrepancies between the planned and measured doses of 1.5% to 10%. In 84% of centers, the lungs were shielded during irradiation. The maximum accepted dose for the lungs was 6 Gy to 14.4 Gy.
  
  
  CONCLUSIONS
  TBI is an extremely heterogeneous treatment modality. The findings of the current study should warrant caution in the interpretation of clinical studies involving TBI. Further investigation is needed to evaluate how methodological differences influence outcome. Efforts to standardize the method should be considered.
authors.affiliation: Department of Bone Marrow Transplantation and Onco-Hematology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Gliwice, Poland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Giebel
authors.forename: Leszek
authors.initials: L
authors.lastname: Miszczyk
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Slosarek
authors.forename: Leila
authors.initials: L
authors.lastname: Moukhtari
authors.forename: Fabio
authors.initials: F
authors.lastname: Ciceri
authors.forename: Jordi
authors.initials: J
authors.lastname: Esteve
authors.forename: Norbert-Claude
authors.initials: NC
authors.lastname: Gorin
authors.forename: Myriam
authors.initials: M
authors.lastname: Labopin
authors.forename: Arnon
authors.initials: A
authors.lastname: Nagler
authors.forename: Christoph
authors.initials: C
authors.lastname: Schmid
authors.forename: Mohamad
authors.initials: M
authors.lastname: Mohty
mesh_terms: D019583:Dose Fractionation, Radiation; D005060:Europe; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007951:Leukemia, Myeloid / Q000628:therapy*; D010818:Practice Patterns, Physicians'; D011874:Radiometry; D011795:Surveys and Questionnaires; D019172:Transplantation Conditioning / Q000379:methods*; D014916:Whole-Body Irradiation / Q000379:methods*
keywords: hematopoietic stem cell transplantation; radiation dosimetry; radiotherapy dose; radiotherapy fractionation; total body irradiation