Image guided particle therapy in CNAO room 2: implementation and clinical validation

Area of Science:

• Medical Physics
• Radiotherapy Technology
• Image-Guided Interventions

Background:

• Accurate patient positioning is critical for effective particle therapy.
• Existing setup verification methods can be time-consuming and may not achieve the highest precision.
• The Centro Nazionale di Adroterapia Oncologica (CNAO) sought to enhance its treatment delivery accuracy.

Purpose of the Study:

• To implement and evaluate a novel image-guided system for patient setup in particle therapy.
• To achieve sub-millimeter accuracy in patient positioning for proton and carbon ion treatments.
• To automate setup error compensation using robotic systems.

Main Methods:

• Development and installation of a robotic in-room imaging system at CNAO.
• Utilizing 2D/3D registration from kV-images and 3D/3D alignment from cone beam CT.
• Transferring six degrees-of-freedom correction vectors to a robotic patient positioning system.
• Validation using rigid and anthropomorphic phantoms, and preliminary clinical patient data.

Main Results:

• Sub-millimeter residual errors in absolute positioning of rigid phantoms were achieved.
• Sub-millimeter and sub-degree positioning accuracy demonstrated with anthropomorphic phantoms.
• Automated setup error compensation resulted in high precision patient alignment.
• Preliminary clinical results in 10 patients showed promising performance.

Conclusions:

• The novel image-guided system significantly enhances patient setup accuracy in particle therapy.
• The in-house developed system offers high customization and clinical performance comparable to commercial solutions.
• This technology has the potential to improve treatment outcomes in proton and carbon ion therapy.