Use of a radial projection to reduce the statistical uncertainty of spot lateral profiles generated by Monte Carlo simulation

Xiaoning Ding, Wei Liu, Jiajian Shen, Aman Anand, Joshua B. Stoker, Yanle Hu, Martin Bues

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Monte Carlo (MC) simulation has been used to generate commissioning data for the beam modeling of treatment planning system (TPS). We have developed a method called radial projection (RP) for postprocessing of MC-simulation-generated data. We used the RP method to reduce the statistical uncertainty of the lateral profile of proton pencil beams with axial symmetry. The RP method takes advantage of the axial symmetry of dose distribution to use the mean value of multiple independent scores as the representative score. Using the mean as the representative value rather than any individual score results in substantial reduction in statistical uncertainty. Herein, we present the concept and step-by-step implementation of the RP method, as well as show the advantage of the RP method over conventional measurement methods for generating lateral profile. Lateral profiles generated by both methods were compared to demonstrate the uncertainty reduction qualitatively, and standard error comparison was performed to demonstrate the reduction quantitatively. The comparisons showed that statistical uncertainty was reduced substantially by the RP method. Using the RP method to postprocess MC data, the corresponding MC simulation time was reduced by a factor of 10 without quality reduction in the generated result from the MC data. We concluded that the RP method is an effective technique to increase MC simulation efficiency for generating lateral profiles for axially symmetric pencil beams.

Original languageEnglish (US)
Pages (from-to)88-96
Number of pages9
JournalJournal of applied clinical medical physics
Issue number6
StatePublished - Nov 2017


  • Beam modeling data
  • Lateral profile
  • Monte Carlo simulation
  • Proton spot scanning therapy
  • Statistical uncertainty reduction

ASJC Scopus subject areas

  • Radiation
  • Instrumentation
  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'Use of a radial projection to reduce the statistical uncertainty of spot lateral profiles generated by Monte Carlo simulation'. Together they form a unique fingerprint.

Cite this