Technical note: Heterogeneity dose calculation accuracy in IMRT: study of five commercial treatment planning systems using an anthropomorphic thorax phantom.
The purpose of this study was to determine the accuracy of five commonly used intensity-modulated radiation therapy (IMRT) treatment planning systems (TPSs), 3 using convolution superposition algorithms or the analytical anisotropic algorithm (CSA/AAAs) and 2 using pencil beam algorithms (PBAs), in calculating the absorbed dose within a low-density, heterogeneous region when compared with measurements made in an anthropomorphic thorax phantom. The dose predicted in the target center met the test criteria (5% of the dose normalization point or 3 mm distance to agreement) for all TPSs tested; however, at the tumor-lung interface and at the peripheral lung in the vicinity of the tumor, the CSA/AAAs performed better than the PBAs (85% and 50%, respectively, of pixels meeting the 5%/3-mm test criteria), and thus should be used to determine dose in heterogeneous regions.
Davidson
Scott E
SE
Department of Radiation Physics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA. sedavids@mdanderson.org
Popple
Richard A
RA
Ibbott
Geoffrey S
GS
Followill
David S
DS
D000465:Algorithms; D016880:Anisotropy; D004867:Equipment Design; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D019047:Phantoms, Imaging; D017785:Photons; D011786:Quality Control; D013902:Radiography, Thoracic / Q000379:methods* / Q000592:standards*; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods* / Q000592:standards*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods* / Q000592:standards*; D015203:Reproducibility of Results; D013899:Thoracic Neoplasms / Q000532:radiotherapy*