Arc therapy for total body irradiation--a robust novel treatment technique for standard treatment rooms.
OBJECTIVE
We developed a simple and robust total body irradiation (TBI) method for standard treatment rooms that obviates the need for patient translation devices.


METHODS
Two generic arcs with rectangular segments for a patient thickness of 16 and 20 cm (arc16/arc20) were generated. An analytical fit was performed to determine the weights of the arc segments depending on patient thickness and gantry angle. Stability and absolute dose for both arcs were measured using EBT3 films in a range of solid water slab phantom thicknesses. Additionally ionization chamber measurements were performed every 10 cm at a source surface distance (SSD) of ∼ 200 cm.


RESULTS
The measured standard deviation for arc16 is ± 3% with a flatness ⩽ 9.0%. Arc20 had a standard deviation of ± 3% with a flatness ⩽ 7.3% for all measured thicknesses. The theoretical curves proved to be accurate for the prediction of the segment weightings for the two arcs. In vivo measurements for the first 22 clinical patients showed a dose deviation of less than 3%.


CONCLUSIONS
Arc therapy is a convenient and stable method for TBI. This cost-effective approach has been introduced clinically, obviating the need for field patches and to physically move the patient.
Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany; Department of Radiation Oncology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany. Electronic address: anika.jahnke@medma.uni-heidelberg.de.
Anika
A
Jahnke
Department of Radiation Oncology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.
Lennart
L
Jahnke
Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany; Department of Radiation Oncology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.
Flavia
F
Molina-Duran
Department of Radiation Oncology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.
Michael
M
Ehmann
Department of Radiation Oncology, Klinikum der Ludwig-Maximilians-Unversität München, Germany.
Steffi
S
Kantz
Department of Radiation Oncology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.
Volker
V
Steil
Department of Radiation Oncology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.
Frederik
F
Wenz
Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.
Gerhard
G
Glatting
Department of Radiation Oncology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.
Frank
F
Lohr
Department of Radiation Oncology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.
Martin
M
Polednik
D006801:Humans; D008168:Lung / Q000528:radiation effects; D019047:Phantoms, Imaging; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D014916:Whole-Body Irradiation / Q000379:methods*
Arc therapy; TBI; Total body irradiation