Comprehensive 4D robustness evaluation for pencil beam scanned proton plans

Area of Science:

• Radiation oncology
• Medical physics
• Cancer treatment

Background:

• Moving targets in the thorax present dosimetric challenges for pencil beam scanned proton therapy (PBS-PT).
• Current PBS-PT facilities face limitations in treating these dynamic targets due to motion-induced uncertainties.
• Clinical benefits of PBS-PT for moving targets necessitate robust treatment planning solutions.

Purpose of the Study:

• To develop and evaluate a novel method for assessing uncertainties in PBS-PT for moving targets.
• To enable robust plan optimization and guide motion mitigation strategies in clinical practice.
• To facilitate the expansion of PBS-PT indications to include thoracic moving targets.

Main Methods:

• Development of the 4D robustness evaluation method (4DREM).
• Realistic and efficient assessment of potential events impacting PBS-PT treatments in the thorax.
• Application of 4DREM in large patient cohorts, including lung and esophageal cancer.

Main Results:

• The 4DREM provides a realistic and efficient assessment of motion-related dosimetric uncertainties in PBS-PT.
• The method is applicable to large patient cohorts, demonstrating its clinical utility.
• Illustrates practical approaches for triggering robustness settings and selecting motion mitigation techniques.

Conclusions:

• The 4DREM is a crucial tool for addressing dosimetric uncertainties in PBS-PT for moving targets.
• This method will support the clinical implementation of PBS-PT for thoracic cancers with moving targets.
• Enables optimization of treatment plans and selection of appropriate motion management strategies for improved patient outcomes.