Computerized optimization of multiple isocentres in stereotactic convergent beam irradiation

Area of Science:

• Medical Physics
• Radiation Oncology
• Computational Imaging

Background:

• Conventional radiation therapy planning relies on time-consuming, experience-based trial-and-error methods.
• Optimizing beam parameters like target point positions and collimator sizes is crucial for effective cancer treatment.

Purpose of the Study:

• To develop and present a fully computerized method for determining and optimizing treatment parameters in convergent beam irradiation.
• To reduce the significant time investment associated with conventional interactive planning methods.

Main Methods:

• Utilized CT or MR scans for defining target volumes and organs at risk.
• Implemented an automated initial configuration generation followed by program-driven optimization of target point positions and collimator diameters.
• Employed a fast approximate dose calculation method for convergent beam irradiation to enhance optimization speed.

Main Results:

• The optimization process aims to closely approximate a prescribed dose at the target surface.
• Successfully minimized dose peaks within the target volume and spared surrounding healthy tissues and organs at risk.
• Demonstrated the procedure's success in several clinical cases involving up to six target points.

Conclusions:

• The computerized method significantly reduces treatment planning time compared to conventional approaches.
• This approach enables precise dose delivery to the target while effectively sparing organs at risk.
• The method shows promise for applications such as calculating leaf positions for micromultileaf collimator irradiation.