Lung ion-fluoroscopy Guided Hadron therapy: LIGHT concept and proof-of-principle

Area of Science:

• Medical Physics
• Radiation Oncology
• Image-Guided Therapy

Background:

• Lung cancer radiotherapy faces challenges with tumor motion during treatment.
• Current motion mitigation techniques like rescanning can lead to suboptimal dose delivery.
• Advanced imaging and gating strategies are needed for precise tumor targeting.

Purpose of the Study:

• To provide proof-of-concept for real-time ion imaging and treatment gating in lung cancer radiotherapy.
• To evaluate the accuracy and feasibility of the LIGHT system using 3D range modulators.
• To compare the dosimetric benefits of this advanced image guidance against standard clinical practices.

Main Methods:

• A plastic scintillator-based portal ion radiography detector was used for real-time tumor motion tracking in a mock lung phantom.
• Treatment gating was investigated using triggers from the ion radiography detector.
• A simulated study compared the dosimetric outcomes of the LIGHT system with rescanning.

Main Results:

• The ion radiography detector achieved 0.1mm accuracy in tracking tumor motion.
• Imaging dose was approximately one-third of comparable X-ray fluoroscopy methods.
• Simulated treatment showed high target coverage (D_95% of 98-99.2%) with the LIGHT system.

Conclusions:

• The LIGHT system offers a promising approach for mitigating tumor motion in radiotherapy.
• Real-time ion imaging and 3D range modulators can enable precise, motion-managed lung cancer treatment.
• This technique shows potential for improving dose delivery and exploring future FLASH radiotherapy methods.