Optimization of rotational arc station parameter optimized radiation therapy.

Area of Science:

• Radiation Oncology
• Medical Physics
• Computational Biology

Background:

• Volumetric Modulated Arc Therapy (VMAT) is a standard in radiation therapy.
• Optimization of treatment planning is crucial for improving plan quality and delivery efficiency.

Purpose of the Study:

• To develop a fast optimization method for Station Parameter Optimized Radiation Therapy (SPORT).
• To demonstrate SPORT's capability to match VMAT in plan quality and delivery efficiency.
• To evaluate SPORT using three clinical cases across different disease sites.

Main Methods:

• SPORT divides angular space into 180 station points (SPs) with candidate apertures determined by a column generation algorithm.
• A state-of-the-art GPU-based solver optimizes aperture weights using stochastic gradient descent to avoid local minima.
• The optimization process iterates, reoptimizing aperture weights to achieve further plan improvements.

Main Results:

• SPORT demonstrated marked dosimetric improvements across prostate, head and neck, and brain cancer cases.
• Significant reductions in dose to organs at risk were observed, e.g., 22% decrease in rectal volume for prostate.
• Treatment times were shortened by up to ~1 minute per case compared to VMAT.

Conclusions:

• SPORT presents an intriguing alternative treatment modality with superior dosimetric quality and delivery efficiency.
• The widespread adoption of digital linear accelerators supports SPORT's potential to enhance patient care.