Shortening treatment time in robotic radiosurgery using a novel node reduction technique

Area of Science:

• Medical Physics
• Radiation Oncology
• Robotics in Medicine

Background:

• Robotic radiosurgery offers precise radiation delivery.
• Treatment planning time is a significant factor in overall treatment duration.
• Optimizing the number of beam positions (nodes) can reduce treatment time.

Purpose of the Study:

• To develop and evaluate a node reduction technique for robotic radiosurgery.
• To decrease the treatment time per fraction by creating more time-efficient treatment plans.
• To assess the impact of node reduction on treatment plan parameters and quality.

Main Methods:

• Integrated node reduction into an in-house inverse planning algorithm.
• Employed iterative inverse optimization, excluding low-contribution node positions.
• Generated and compared treatment plans with and without node reduction for various cancer cases.

Main Results:

• Achieved an average 77% reduction in node positions.
• Reduced fraction durations by 25% on average (18%-40% range).
• Observed minimal changes in dose distributions and effectively restricted low-dose regions.

Conclusions:

• Node reduction considerably shortens robotic radiosurgery treatment times.
• This optimization yields minimal changes in dosimetrical plan quality.
• Additional constraints are necessary to ensure low-dose conformality and manage skin dose.