An efficient dose calculation strategy for intensity modulated proton therapy.

Area of Science:

• Medical physics
• Radiation oncology
• Computational biology

Background:

• Intensity-modulated proton therapy (IMPT) offers improved radiotherapy efficacy.
• IMPT optimization is computationally intensive, especially for large tumors.
• Existing methods face challenges with speed and memory demands.

Purpose of the Study:

• To develop a computationally efficient strategy for IMPT optimization.
• To reduce the time and memory requirements for IMPT planning.
• To maintain dose distribution accuracy during optimization.

Main Methods:

• A two-level iterative dose calculation strategy was proposed.
• Dose contributions were separated into major and minor components using threshold parameters.
• Inner iterations updated doses based on major contributions; outer iterations refined with full contributions.

Main Results:

• The proposed strategy achieved nearly identical dose distributions compared to full matrix optimization.
• Computing time was reduced by at least a factor of 3.
• Internal memory requirements were reduced by a factor of 10 or more.

Conclusions:

• The developed strategy accelerates IMPT optimization while minimizing memory usage.
• This approach can enhance other optimization tasks, like beam angle selection.
• The method shows potential for improving clinical IMPT treatment planning, particularly for complex cases.