Simulation-free cone beam CT-based online adaptive radiotherapy for metastatic spinal cord compression

Area of Science:

• Radiotherapy
• Medical Imaging
• Oncology

Background:

• Simulation-free radiotherapy planning using diagnostic CT reduces patient burden.
• Online adaptive radiotherapy (oART) guided by cone-beam CT (CBCT) enhances treatment efficiency.
• Metastatic spinal cord compression (MSCC) requires timely and effective radiotherapy.

Purpose of the Study:

• To evaluate the feasibility and time efficiency of different simulation-free oART workflows for MSCC patients.
• To identify the optimal workflow for clinical implementation.
• To compare supervised and unsupervised, rigid and deformable image registration methods.

Main Methods:

• Retrospective analysis of diagnostic CT and CBCT scans from MSCC patients.
• Emulation of four simulation-free oART workflows: DefSup, DefUn, RigSup, RigUn.
• Evaluation based on segmentation quality, dose distribution accuracy, and time consumption.

Main Results:

• The Deformable Supervised (DefSup) workflow demonstrated superior accuracy in segmentation and dose distribution.
• DefSup achieved a median time consumption of 6.57 minutes, indicating clinical suitability.
• 120 simulation-free oART emulations were performed across 27 MSCC patients.

Conclusions:

• The DefSup workflow is the most optimal and safe for clinical implementation in MSCC patients.
• Successful treatment of the first MSCC patient using the DefSup workflow validates its clinical utility.
• Simulation-free oART offers a more efficient radiotherapy workflow.