Improvement of patient localization repeatability using a light-section based optical surface guidance system in a...

Area of Science:

• Radiation Oncology
• Medical Physics
• Image-Guided Therapy

Background:

• Surface-guided radiotherapy (SGRT) is crucial for patient positioning and monitoring during radiation therapy.
• Accurate patient localization is essential for effective and safe radiotherapy delivery.

Purpose of the Study:

• To evaluate the impact of surface guidance on the repeatability of patient localization.
• To identify specific conditions leading to high positional errors in radiotherapy.

Main Methods:

• A comparative study involving 20 patients: 10 with VOXELAN (VXLN group) and 10 without (non-VXLN group).
• Defined 12 regions of interest (ROIs) across patients to assess misalignment.
• Utilized 13 ROIs specifically at the isocenter for detailed analysis.

Main Results:

• The VOXELAN system demonstrated comparable translational positional errors to the non-VXLN group across all ROIs.
• VXLN group showed a mean longitudinal translational error of approximately 0.1mm, with the largest standard deviation in this direction.
• While VXLN group had large longitudinal standard deviations, vertical and lateral standard deviations were small, indicating reduced rotational errors.

Conclusions:

• Surface guidance, particularly with systems like VOXELAN, effectively reduces body twist and rotation, complementing image-guided radiotherapy.
• VOXELAN offers rapid detection of positioning errors without additional radiation exposure.
• The system is a valuable tool for pre-positioning in radiotherapy, enhancing accuracy and safety.