Parameterization of brachytherapy source phase space file for Monte Carlo-based clinical brachytherapy dose calculation

Phys Med Biol. 2014 Jan 20;59(2):455-64. doi: 10.1088/0031-9155/59/2/455. Epub 2013 Dec 30.

Abstract

A common approach to implementing the Monte Carlo method for the calculation of brachytherapy radiation dose deposition is to use a phase space file containing information on particles emitted from a brachytherapy source. However, the loading of the phase space file during the dose calculation consumes a large amount of computer random access memory, imposing a higher requirement for computer hardware. In this study, we propose a method to parameterize the information (e.g., particle location, direction and energy) stored in the phase space file by using several probability distributions. This method was implemented for dose calculations of a commercial Ir-192 high dose rate source. Dose calculation accuracy of the parameterized source was compared to the results observed using the full phase space file in a simple water phantom and in a clinical breast cancer case. The results showed the parameterized source at a size of 200 kB was as accurate as the phase space file represented source of 1.1 GB. By using the parameterized source representation, a compact Monte Carlo job can be designed, which allows an easy setup for parallel computing in brachytherapy planning.

MeSH terms

  • Brachytherapy / methods*
  • Breast Neoplasms / radiotherapy
  • Humans
  • Monte Carlo Method*
  • Phantoms, Imaging
  • Radiation Dosage*
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted / methods*