Dosimetry parameters calculation of two commercial iodine brachytherapy sources using SMARTEPANTS with EPDL97 library.

AIM: Simulating Many Accumulative Rutherford Trajectories Electron Photon and Neutral Transport Solver (SMARTEPANTS) is a discrete ordinates S N Boltzmann/Spencer-Lewis solver that was developed during 1988-1993 by William Filippone and his students. The code calculates particle fluxes, leakage currents as well as energy and charge deposition for coupled electron/photon in x-y-z geometries both in forward and in adjoin modes. Originally, SMARTEPANTS was designed to utilize CEPXS cross-section library for shielding calculation in satellite electronics. The aim of this study was to adapt SMARTEPANTS to use a new photon cross-section library from Evaluated Photon Data Library, 1997 version (EPDL97) for intravascular brachytherapy (125)Isimulations. MATERIALS AND METHODS: A MATLAB (MathworkNatick, Massachusetts) program was written to generate an updated multigroup-Legendre cross-section from EPDL97. The new library was confirmed by simulating intravascular brachytherapy Best® Model 2301 and Intersource (125)I dosimetry parameters using SMARTEPANTS with different energy groups (g), Legendre moments (L) and discrete ordinate orders (S). RESULTS: The dosimetry parameters for these sources were tabulated and compared with the data given by AAPM TG-43 and other reports. The computation time for producing TG-43 parameters was about 29.4 min in case of g = 20, L = 7 and S = 16. CONCLUSION: The good agreement between the results of this study and previous reports and high computational speed suggest that SMARTEPANTS could be extended to a real-time treatment planning system for (125)I brachytherapy treatments.

Solving radiative transfer problems in highly heterogeneous media via domain decomposition and convergence acceleration techniques.

This paper deals with finding accurate solutions for photon transport problems in highly heterogeneous media fastly, efficiently and with modest memory resources. We propose an extended version of the analytical discrete ordinates method, coupled with domain decomposition-derived algorithms and non-linear convergence acceleration techniques. Numerical performances are evaluated using a challenging case study available in the literature. A study of accuracy versus computational time and memory requirements is reported for transport calculations that are relevant for remote sensing applications.