Christopher W Schneider1, Wayne D Newhauser1,2, Lydia J Wilson1, Uwe Schneider3,4, Robert Kaderka5, Saveta Miljanić6, Željka Knežević6, Liliana Stolarcyzk7, Marco Durante8, Roger M Harrison9. 1. Department of Physics and Astronomy, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, LA, 70803-4001, USA. 2. Mary Bird Perkins Cancer Center, 4950 Essen Lane, Baton Rouge, LA, 70809, USA. 3. Faculty of Science, University of Zürich, Winterthurerstrasse 260, 8057, Zürich, Switzerland. 4. Institute for Radiotherapy, Hirslanden Medical Center, Rain 34, 5000, Aarau, Switzerland. 5. GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt, 64291, Germany. 6. Ruder Bošković Institute, Radiation Chemistry and Dosimetry Laboratory, Bijenićka 54, HR-10000, Zagreb, Croatia. 7. Bronowice Cyclotron Centre, Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342, Krakow, Poland. 8. Trento Institute for Fundamental Physics and Applications (TIFPA), National Institute of Nuclear Physics (INFN), University of Trento, Via Sommarive 14, 38123 Povo, Trento, Italy. 9. Faculty of Medical Sciences, University of Newcastle, Newcastle-upon-Tyne, NE2 4HH, UK.
Abstract
PURPOSE: To develop a simple model of therapeutic and stray absorbed dose for a variety of treatment machines and techniques without relying on proprietary machine-specific parameters. METHODS: Dosimetry measurements conducted in this study and from the literature were used to develop an analytical model of absorbed dose from a variety of treatment machines and techniques in the 6 to 25 MV interval. A modified one-dimensional gamma-index analysis was performed to evaluate dosimetric accuracy of the model on an independent dataset consisting of measured dose profiles from seven treatment units spanning four manufacturers. RESULTS: The average difference between the calculated and measured absorbed dose values was 9.9% for those datasets on which the model was trained. Additionally, these results indicate that the model can provide accurate calculations of both therapeutic and stray radiation dose from a wide variety of radiotherapy units and techniques. CONCLUSIONS: We have developed a simple analytical model of absorbed dose from external beam radiotherapy treatments in the 6 to 25 MV beam energy range. The model has been tested on measured data from multiple treatment machines and techniques, and is broadly applicable to contemporary external beam radiation therapy.
PURPOSE: To develop a simple model of therapeutic and stray absorbed dose for a variety of treatment machines and techniques without relying on proprietary machine-specific parameters. METHODS: Dosimetry measurements conducted in this study and from the literature were used to develop an analytical model of absorbed dose from a variety of treatment machines and techniques in the 6 to 25 MV interval. A modified one-dimensional gamma-index analysis was performed to evaluate dosimetric accuracy of the model on an independent dataset consisting of measured dose profiles from seven treatment units spanning four manufacturers. RESULTS: The average difference between the calculated and measured absorbed dose values was 9.9% for those datasets on which the model was trained. Additionally, these results indicate that the model can provide accurate calculations of both therapeutic and stray radiation dose from a wide variety of radiotherapy units and techniques. CONCLUSIONS: We have developed a simple analytical model of absorbed dose from external beam radiotherapy treatments in the 6 to 25 MV beam energy range. The model has been tested on measured data from multiple treatment machines and techniques, and is broadly applicable to contemporary external beam radiation therapy.