A Study of Feasibility for Reusing Thermoplastic Masks - Toward a Green Environment

This study evaluated the feasibility of reusing thermoplastic masks in radiation oncology to reduce environmental waste and financial costs.

The study conducted from July 2024 to December 2024 involved 70 thermoplastic masks across three types: 3-clamp brain masks, 5-clamp head-and-neck masks, and 4-clamp chest/abdomen/pelvis masks. Measurements of fresh masks were compared to those after molding and re-flattening post-treatment. Dimensions were recorded in superior-inferior (SI) and lateral directions at specific anatomical levels.

The 3-clamp brain thermoplastic cast expanded 46% ± 7% in SI directions postmolding. Width increased by 63% ± 16% (chin) and 75% ± 10% (forehead). Re-flattened casts showed 25% ± 4% SI reduction and 19% ± 8% (chin) and 26% ± 5% (forehead) contraction in width. The 5-clamp head-and-neck thermoplastic cast expanded 16% ± 3% SI postmolding, with width expansion of 54% ± 15% (chest), 62% ± 10% (forehead), and 66% ± 5% (chin). Re-flattened casts showed 6% ± 3% SI expansion and 26% ± 5.5%, 40% ± 16%, and 37% ± 17% width enlargement at chest, chin, and forehead levels, respectively. The 4-clamp chest/abdomen/pelvis thermoplastic casts expanded 3% ± 5% (SI) in 26 casts and contracted by 7.5% ± 2.5% in 2 casts postmolding.

Thermoplastic masks demonstrated acceptable dimensional changes while reusing, with consistent structural integrity and minimal compromise in functionality. Single reuse could significantly reduce costs and waste, particularly in resource-limited settings, making this practice a viable option for sustainable health care.