title: Polymethylmethacrylate blocking trays. The effects of repeated usage.
abstract: Sheets of polymethylmethacrylate (Lucite), which are commonly used to hold low-melting-point alloy blocks for radiation therapy treatments, are frequently recycled; subsequently, they generally contain a substantial number of holes. Experiments which have been performed to measure the deflection of these plates under a load indicate that, even with many holes drilled through the plates, their strength is not diminished significantly.
mesh_terms: D008768:Methylmethacrylates / Q000528:radiation effects; D013679:Technology, Radiologic; D013718:Tensile Strength
chemical_list: D008768:Methylmethacrylates