Couchtops and overlays
An overlay lays on top of the cradle, existing support frame and/or spine of a CT, simulator or LINAC. For LINACS, an overlay will still result in the need to rotate the table in order to avoid the beam passing through the underlying steel support.
A couchtop replaces the steel support system of the LINAC with a carbon fibre support system, eliminating the need for a table rotation. An indexed overlay is necessary for a CT to ensurthat your positioning devices are in the correct location from room to room. These overlays are lightweight and can easily be removed between uses on a non-dedicated CT.
Carbon fibre couchtops
Carbon fibre couchtops provide both a radiation-friendly treatment surface and indexing capabilities. These couchtops have exchangeable panels, you can choose between a solid (foam core with a carbon fibre outer layer), tangential or a grid surface for your treatment.
Some couchtops and overlays come with additional treatment panels and accessories such as Type-S head extension and Posifix IMRT baseplates.