title: Total body irradiation with volumetric modulated arc therapy: Dosimetric data and first clinical experience.
abstract: BACKGROUND
  To implement total body irradiation (TBI) using volumetric modulated arc therapy (VMAT). We applied the Varian RapidArc™ software to calculate and optimize the dose distribution. Emphasis was placed on applying a homogenous dose to the PTV and on reducing the dose to the lungs.
  
  
  METHODS
  From July 2013 to July 2014 seven patients with leukaemia were planned and treated with a VMAT-based TBI-technique with photon energy of 6 MV. The overall planning target volume (PTV), comprising the whole body, had to be split into 8 segments with a subsequent multi-isocentric planning. In a first step a dose optimization of each single segment was performed. In a second step all these elements were calculated in one overall dose-plan, considering particular constraints and weighting factors, to achieve the final total body dose distribution. The quality assurance comprised the verification of the irradiation plans via ArcCheck™ (Sun Nuclear), followed by in vivo dosimetry via dosimeters (MOSFETs) on the patient.
  
  
  RESULTS
  The time requirements for treatment planning were high: contouring took 5-6 h, optimization and dose calculation 25-30 h and quality assurance 6-8 h. The couch-time per fraction was 2 h on day one, decreasing to around 1.5 h for the following fractions, including patient information, time for arc positioning, patient positioning verification, mounting of the MOSFETs and irradiation. The mean lung dose was decreased to at least 80 % of the planned total body dose and in the central parts to 50 %. In two cases we additionally pursued a dose reduction of 30 to 50 % in a pre-irradiated brain and in renal insufficiency. All high dose areas were outside the lungs and other OARs. The planned dose was in line with the measured dose via MOSFETs: in the axilla the mean difference between calculated and measured dose was 3.6 % (range 1.1-6.8 %), and for the wrist/hip-inguinal region it was 4.3 % (range 1.1-8.1 %).
  
  
  CONCLUSIONS
  TBI with VMAT provides the benefit of satisfactory dose distribution within the PTV, while selectively reducing the dose to the lungs and, if necessary, in other organs. Planning time, however, is extensive.
authors.affiliation: Department of Radiation Oncology, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, 4010, Linz, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Springer
authors.affiliation: Department of Radiation Oncology, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, 4010, Linz, Austria. josef.hammer@bhs.at.
authors.forename: Josef
authors.identifier: http://orcid.org/0000-0002-2116-830X
authors.initials: J
authors.lastname: Hammer
authors.affiliation: Department of Radiation Oncology, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, 4010, Linz, Austria.
authors.forename: Erwin
authors.initials: E
authors.lastname: Winkler
authors.affiliation: Department of Radiation Oncology, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, 4010, Linz, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Track
authors.affiliation: Department of Radiation Oncology, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, 4010, Linz, Austria.
authors.forename: Roswitha
authors.initials: R
authors.lastname: Huppert
authors.affiliation: Internal Department I - Hematology with Stem Cell Transplantation, Hemostaseology and Medical Oncology, Krankenhaus der Elisabethinen Linz, Linz, Austria.|Division of Medical Oncology, University of Washington, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Böhm
authors.affiliation: Internal Department I - Hematology with Stem Cell Transplantation, Hemostaseology and Medical Oncology, Krankenhaus der Elisabethinen Linz, Linz, Austria.
authors.forename: Hedwig
authors.initials: H
authors.lastname: Kasparu
authors.affiliation: Internal Department I - Hematology with Stem Cell Transplantation, Hemostaseology and Medical Oncology, Krankenhaus der Elisabethinen Linz, Linz, Austria.|Medical Faculty, Johannes Kepler University, Linz, Austria.
authors.forename: Ansgar
authors.initials: A
authors.lastname: Weltermann
authors.affiliation: Internal Medicine I - Medical Oncology, Hematology and Gastroenterology, Krankenhaus der Barmherzigen Schwestern Linz, Linz, Austria.
authors.forename: Gregor
authors.initials: G
authors.lastname: Aschauer
authors.affiliation: Internal Medicine I - Medical Oncology, Hematology and Gastroenterology, Krankenhaus der Barmherzigen Schwestern Linz, Linz, Austria.|Medical Faculty, Johannes Kepler University, Linz, Austria.
authors.forename: Andreas L
authors.initials: AL
authors.lastname: Petzer
authors.affiliation: Department of Radiation Oncology, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, 4010, Linz, Austria.
authors.forename: Ernst
authors.initials: E
authors.lastname: Putz
authors.affiliation: Department of Radiation Oncology, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, 4010, Linz, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Altenburger
authors.affiliation: Department of Radiation Oncology, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, 4010, Linz, Austria.
authors.forename: Rainer
authors.initials: R
authors.lastname: Gruber
authors.affiliation: Department of Radiation Oncology, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, 4010, Linz, Austria.
authors.forename: Karin
authors.initials: K
authors.lastname: Moser
authors.affiliation: Department of Radiation Oncology, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, 4010, Linz, Austria.
authors.forename: Karin
authors.initials: K
authors.lastname: Wiesauer
authors.affiliation: Department of Radiation Oncology, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, 4010, Linz, Austria.|Medical Faculty, Johannes Kepler University, Linz, Austria.
authors.forename: Hans
authors.initials: H
authors.lastname: Geinitz
mesh_terms: D000328:Adult; D006801:Humans; D007938:Leukemia / Q000532:radiotherapy; D008175:Lung Neoplasms / Q000532:radiotherapy*; D016399:Lymphoma, T-Cell / Q000628:therapy; D008875:Middle Aged; D058958:Organs at Risk / Q000528:radiation effects; D056888:Patient Positioning; D011785:Quality Assurance, Health Care; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012984:Software; D033581:Stem Cell Transplantation / Q000379:methods; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D014916:Whole-Body Irradiation / Q000379:methods*; D055815:Young Adult
keywords: Dose homogenising; Dose sparing; Leukaemia; Organs at risk (OAR); Total body irradiation (TBI); Total marrow irradiation (TMI); Volumetric modulated arc therapy (VMAT)