Performance of an improved first generation optical CT scanner for 3D dosimetry

Area of Science:

• Medical Physics
• Radiation Oncology
• Dosimetry

Background:

• The OCTOPUS system is a first-generation optical CT scanner used for 3D dosimetry.
• Optimizing scanning time and data acquisition is crucial for clinical implementation of 3D dosimetry.
• PRESAGE dosimeters are suitable for 3D dose verification in radiation therapy.

Purpose of the Study:

• To analyze the performance of a modified 3D dosimetry optical scanner.
• To evaluate the impact of a new Labview control panel on scanning efficiency and data acquisition.
• To compare the dose distribution accuracy of the modified scanner with the original OCTOPUS system and treatment planning systems.

Main Methods:

• A modified 3D optical scanner based on the OCTOPUS system was developed.
• A custom Labview user control panel was implemented for enhanced mechanical control and data acquisition.
• PRESAGE dosimeters were used for dose measurements.
• Scanning time, mechanical integrity, and optical density distribution were evaluated.

Main Results:

• The total scanning time was reduced from 8 hours to approximately 2 hours.
• The functional performance, including mechanical integrity and data acquisition uncertainty, was assessed.
• Agreement between the modified scanner and treatment plans was comparable to that of the original OCTOPUS system.

Conclusions:

• The modified 3D dosimetry optical scanner offers a significant reduction in scanning time.
• The system demonstrates comparable accuracy to the first-generation OCTOPUS scanner for dose distribution.
• The developed Labview control panel enhances flexibility and efficiency in 3D dosimetry measurements.