Isocentric rotational performance of the Elekta Precise Table studied using a USB-microscope.

Area of Science:

• Medical Physics
• Radiation Oncology

Background:

• Accurate patient positioning is critical in radiation therapy.
• The performance of treatment tables affects dose delivery precision.

Purpose of the Study:

• To investigate the isocentric three-dimensional performance of the Elekta Precise Table.
• To develop and validate a new elastic model for the treatment table.
• To propose a method for optimal table positioning relative to the accelerator.

Main Methods:

• A pointer attached to the radiation head and a USB-microscope on the treatment tabletop were used for precise measurements.
• Table performance was mapped under various angles and load conditions.
• A new elastic model was developed and validated using six geometric and elastic parameters calculated via linear least squares fitting.

Main Results:

• The USB-microscope achieved a measurement resolution of 0.01 mm.
• The developed elastic model accurately described table performance, with minor deviations attributed to backlash.
• A novel method for optimal table positioning was presented.

Conclusions:

• The study provides a detailed performance analysis of the Elekta Precise Table.
• Incorporating geometric and elastic models into the dose planning system is recommended to eliminate systematic errors and enhance positioning accuracy.