Eliminating computed tomography imaging artifacts through 3D printed radiotherapy head supports

Area of Science:

• Medical Physics
• Radiotherapy Technology
• Biomedical Engineering

Background:

• Computed tomography (CT) artifacts from immobilization devices like headrests can compromise radiotherapy accuracy.
• Standard headrests can introduce artifacts affecting volume definition and dosimetry in brain radiotherapy.

Purpose of the Study:

• To reduce CT artifacts caused by standard radiotherapy headrests.
• To design and prototype a custom head support to mitigate these artifacts.

Main Methods:

• Utilized fused deposition modeling (FDM) 3D printing with polylactic acid (PLA) to create custom head supports.
• Acquired CT scans of water and anthropomorphic head phantoms on supports with straight and curved designs.
• Compared CT imaging of a 3D printed prototype with a standard headrest.

Main Results:

• Straight edges and infill patterns in headrest supports caused dark streaks (CT artifacts) due to the exponential edge-gradient effect (EEGE).
• Artifacts were eliminated when headrest supports featured a combination of curved edges and infill patterns.

Conclusions:

• Incorporating artifact-attenuating design elements is crucial for immobilization accessories used in CT scanners.
• 3D printing is a valuable tool for prototyping radiotherapy accessories and addressing clinical challenges.