Cost-effective immobilization for whole brain radiation therapy

Area of Science:

• Radiation Oncology
• Medical Physics
• Biomedical Engineering

Background:

• Standard immobilization masks (e.g., thermoplastic masks) are crucial for precise radiation delivery in whole-brain radiotherapy.
• However, these masks can be costly and uncomfortable for some patients, particularly in resource-limited settings.
• Exploring low-cost, effective alternatives is essential for improving accessibility and patient comfort.

Purpose of the Study:

• To evaluate the inter- and intra-fraction motion associated with a low-cost tape immobilization technique.
• To compare the setup reproducibility of tape immobilization with traditional thermoplastic masks for whole-brain treatments.
• To assess the feasibility of tape immobilization for patients unable to tolerate standard masks or in settings with limited resources.

Main Methods:

• Eight healthy volunteers underwent setup reproducibility assessments using two tape immobilization techniques (one-strip and two-strip).
• Inter-fraction reproducibility was measured by positioning volunteers five times per technique.
• Intra-fraction reproducibility was assessed using 5-minute video recordings of anterior and lateral positions.
• An in-house software analyzed photographic and video data to quantify setup variations.

Main Results:

• The maximum intra-fraction displacement observed was 2.8 mm, increasing with time on the treatment table.
• The maximum inter-fraction range of positions was 5.4 mm.
• Both one-strip and two-strip tape immobilization techniques demonstrated motion magnitudes comparable to thermoplastic masks.
• Setup reproducibility was found to be similar between the tape and thermoplastic mask methods.

Conclusions:

• Tape-based immobilization techniques provide economical and effective alternatives to thermoplastic masks for whole-brain radiotherapy.
• These methods offer comparable setup reproducibility, making them suitable for resource-limited clinical environments.
• Tape immobilization is a practical option for patients who cannot tolerate conventional immobilization masks.