Three-Dimensional Printing Chitosan-Based Bolus Used for Radiotherapy.

Area of Science:

• Biomaterials Science
• Radiotherapy Physics
• Biomedical Engineering

Background:

• Commercial radiotherapy boluses struggle to conform to irregular skin surfaces, causing air gaps and inaccurate radiation dosing.
• Customized bolus fabrication is crucial for effective radiotherapy of superficial lesions on areas like the scalp, nose, and ear.

Purpose of the Study:

• To develop a photocurable chitosan-based bioink for digital light processing (DLP) 3D printing of patient-specific radiotherapy boluses.
• To investigate the properties and efficacy of the 3D printed bolus for improved radiotherapy applications.

Main Methods:

• Chitosan was methacrylated to create a photosensitive bioink (CHI-MA) using methacrylic anhydride.
• Photosensitive crosslinkers of varying molecular weights were incorporated to modulate hydrogel properties.
• Digital Light Processing (DLP) 3D printing was used to fabricate complex bolus structures.

Main Results:

• The CHI-MA bioink demonstrated tunable photocuring efficiency and mechanical properties.
• 3D printed CHI-MA hydrogels exhibited good biocompatibility, flexibility, and structural stability.
• A 3D printed nose bolus showed excellent fit on a model and a desirable radiotherapy effect.

Conclusions:

• DLP 3D printing of CHI-MA bioink offers a promising method for creating customized radiotherapy boluses.
• This approach addresses the limitations of commercial boluses by ensuring conformal contact and accurate dose delivery.
• The developed bioink holds potential for improving radiotherapy treatment of superficial lesions.