title: Characteristic features of a high-energy x-ray spectra estimation method based on the Waggener iterative perturbation principle.
abstract: We have redeveloped a high-energy x-ray spectra estimation method reported by Iwasaki et al. [A. Iwasaki, H. Matsutani, M. Kubota, A. Fujimori, K. Suzaki, and Y. Abe, Radiat. Phys. Chem. 67, 81-91 (2003)]. The method is based on the iterative perturbation principle to minimize differences between measured and calculated transmission curves, originally proposed by Waggener et al. [R. G. Waggener, M. M. Blough, J. A. Terry, D. Chen, N. E. Lee, S. Zhang, and W. D. McDavid, Med. Phys. 26, 1269-1278 (1999)]. The method can estimate spectra applicable for media at least from water to lead using only about ten energy bins. Estimating spectra of 4-15 MV x-ray beams from a linear accelerator, we describe characteristic features of the method with regard to parameters including the prespectrum, number of transmission measurements, number of energy bins, energy bin widths, and artifactual bipeaked spectrum production.
authors.affiliation: School of Health Sciences, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan. akira@cc.hirosaki-u.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Iwasaki
authors.forename: Mamoru
authors.initials: M
authors.lastname: Kubota
authors.forename: Junichi
authors.initials: J
authors.lastname: Hirota
authors.forename: Akira
authors.initials: A
authors.lastname: Fujimori
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Suzaki
authors.forename: Masahiko
authors.initials: M
authors.lastname: Aoki
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Abe
mesh_terms: D000465:Algorithms; D009716:Numerical Analysis, Computer-Assisted; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013052:Spectrometry, X-Ray Emission / Q000379:methods*; D014965:X-Rays