A descriptive and broadly applicable model of therapeutic and stray absorbed dose from 6 to 25 MV photon beams. Issue 7 (1st June 2017)

• Record Type: Journal Article
• Authors: Schneider, Christopher W.; Newhauser, Wayne D.; Wilson, Lydia J.; Schneider, Uwe; Kaderka, Robert; Miljanić, Saveta; Knežević, Željka; Stolarcyzk, Liliana; Durante, Marco; Harrison, Roger M.
• Is Part Of: Medical physics. Volume 44:Issue 7(2017)
• Page Start: 3805
• Page End: 3814
• Publication Date: 2017-06-01
• Subjects: absorbed dose -- analytical model -- external beam radiotherapy -- out‐of‐field dose; Medical physics -- Periodicals; Medical physics; Geneeskunde; Natuurkunde; Toepassingen; Biophysics; Periodicals; Periodicals; Electronic journals; 610.153
• DOI: 10.1002/mp.12286
• Languages: English
• ISSNs: 0094-2405

Abstract

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.