Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy

Area of Science:

• Radiation Oncology
• Medical Imaging
• Cancer Treatment

Background:

• Stereotactic ablative body radiation therapy (SBRT) for extracranial targets carries risks of normal tissue injury and tumor miss.
• Accurate targeting of moving tumors is challenging due to respiratory and cardiac motion.

Purpose of the Study:

• To describe a novel SBRT platform designed for high-precision treatment of moving extracranial tumors.
• To detail the technological advancements enabling accurate tumor targeting and dose delivery.

Main Methods:

• A first-of-its-kind SBRT platform utilizing real-time imaging and tumor tracking.
• Dual-diagnostic kV x-ray units for stereoscopic feedback of intrafraction tumor movement.
• Image-guided feedback controlling a gimbaled radiation accelerator with pan-and-tilt action.
• Robot-driven gantry pivots for versatile beam angles and advanced software for 6D positioning.
• Integration of respiration-correlated CT and (18)F-FDG PET imaging for enhanced tumor contouring.

Main Results:

• The platform achieves sub-millimeter accuracy (0.4 mm at isocenter) in irradiating cancer targets.
• Enables precise steering of radiation dose to tumors while reducing exposure to surrounding normal tissues.
• Enhanced tumor contouring using multimodal imaging reduces the likelihood of physical tumor miss.

Conclusions:

• This advanced SBRT platform offers a solution for precise treatment of moving extracranial tumors.
• The technology enhances treatment accuracy, minimizes normal tissue toxicity, and reduces the risk of tumor miss.
• New radiation plans are presented for treating moving lung tumors with improved efficacy and safety.