Individual 3D-printed fixation masks for radiotherapy: first clinical experiences

Area of Science:

• Medical Physics
• Radiation Oncology
• Biomedical Engineering

Background:

• Conventional thermoplastic masks are standard for patient immobilization in radiation therapy.
• Advancements in additive manufacturing offer potential for personalized medical devices.
• Optimizing patient positioning is crucial for effective radiation delivery and minimizing off-target dose.

Purpose of the Study:

• To assess the clinical feasibility of 3D-printed fixation masks for whole brain radiation therapy.
• To compare the positioning accuracy of 3D-printed masks against established thermoplastic mask systems.
• To evaluate the reliability and reproducibility of 3D-printed masks in a routine clinical workflow.

Main Methods:

• Six patients underwent whole brain radiotherapy utilizing custom 3D-printed fixation masks.
• Daily image guidance and position correction were implemented before each treatment fraction.
• Interfractional position correction vectors were compared to historical data from patients treated with standard thermoplastic masks (head-only and head-and-neck).

Main Results:

• The experimental cohort using 3D-printed masks exhibited mean systematic errors ranging from 0.59 to 2.10 mm.
• These error ranges were comparable to those observed in control groups using thermoplastic masks (0.18-0.68 mm and 0.34-2.96 mm).
• The results suggest 3D-printed masks are a viable alternative to current thermoplastic systems.

Conclusions:

• Individually 3D-printed masks provide reliable and reproducible interfractional positioning accuracy for whole brain irradiation in clinical practice.
• These findings support the use of 3D-printed masks as a feasible alternative to thermoplastic systems.
• Further research is recommended for smaller target volumes and other anatomical regions before widespread adoption.