Characterization of Cherenkov imaging parameters and positional constraints on an O-ring linear accelerator

Area of Science:

• Medical Physics
• Radiation Oncology
• Imaging Technology

Background:

• Introduction of Cherenkov imaging technology to the Halcyon O-ring linear accelerator platform.
• Need to demonstrate imaging feasibility and optimize camera placement for this new application.

Purpose of the Study:

• To demonstrate the feasibility of Cherenkov imaging on the Halcyon platform.
• To optimize camera placement for Cherenkov imaging on the Halcyon.
• To compare imaging metrics with the TrueBeam platform.

Main Methods:

• Acquired Cherenkov image frames using triggering data for simple beams on the Halcyon.
• Compared analyzed metrics with those from the TrueBeam platform.
• Performed 3D rendering of patient treatment plans to assess visibility from various camera positions.

Main Results:

• Cherenkov imaging systems are compatible with Halcyon's pulse timing, enhancing signal-to-noise.
• Optimal camera placement is treatment-site dependent, within a biconical visibility zone around the isocenter.
• Highest median visibility for right breast plans (80.33% front, 68.49% rear); lowest for head and neck (26.44% front, 38.18% rear).

Conclusions:

• Presents the first formal camera positional analysis for Cherenkov imaging on any platform, serving as a template for others.
• Confirms Cherenkov imaging parameters require no changes for optimal Halcyon imaging.
• Provides a framework for expanding optical imaging systems reliant on line-of-sight visibility.