The complexity of the solution space and time was analyzed by taking into account depletion process and the characteristics of the backtracking algorithm. Through analysis and comparison of several kinds of searching algorithms, the backtracking algorithm was selected to establish and calculate the linear chains in searching process using depth first search (DFS) method, forming an algorithm which can solve the depletion problem adaptively and with high fidelity. To confirm the calculation precision and efficiency, the algorithm which can cover all the reaction paths and search the paths automatically according to the problem description and precision restrictions should be found. Every possible reaction path of the nuclide must be considered during the linear chain establishment process. The density, activity and decay heat of every nuclide in the chain then can be calculated by analytical solutions. Wu Mingyu Wang Shixi Yang Yong Zhang Qiang Yang Jiayinīased on the theory of linear chain method for analytical depletion calculations, the burnup matrix is decoupled by the divide and conquer strategy and the linear chain with Markov characteristic is formed. This is primarily because of the ability of Monte Carlo algorithms to implicitly account for tissue heterogeneities, density scaling functions and/or effective depth correction factors are not required.Īpplication of backtracking algorithm to depletion calculations The Monte Carlo dose calculation algorithm for CyberKnife provides more accurate dose distribution calculations in regions of lateral electron disequilibrium than commercially available model-based algorithms.
In general, the gamma analysis comparisons for the other algorithms were <95%.
In each phantom irradiation, the Monte Carlo predictions resulted in gamma analysis comparisons >97%, using acceptance criteria of 3% dose and 3-mm distance to agreement. The Monte Carlo algorithm provided the most accurate comparison between planned and measured dose distributions. The phantom accommodated slabs of varying density comparisons between planned and measured dose distributions were accomplished with radiochromic film. A heterogeneous slab phantom was used to evaluate the accuracy of several commercially available dose calculation algorithms, including Monte Carlo dose calculation for CyberKnife, Analytical Anisotropic Algorithm and Pencil Beam convolution for the Eclipse planning system, and convolution-superposition for the Xio planning system. This enhanced accuracy is particularly evident in regions of lateral scatter disequilibrium, which can develop during treatments incorporating small field sizes and low-density tissue. Monte Carlo dose calculation algorithms have the potential for greater accuracy than traditional model-based algorithms. Sharma, Subhash Ott, Joseph Williams, Jamone Dickow, Danny
International Nuclear Information System (INIS) Dose Calculation Accuracy of the Monte Carlo Algorithm for CyberKnife Compared with Other Commercially Available Dose Calculation Algorithms
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