1974: MCP 70 Technology for creating radiation shields rapidly : MCP introduced a rapid system , simple and effective ,afor producing individual shielding blocks for patient radiotherapy treatment. The advantages , compared to existing methods of producing shields: 6-8 hour turn-around of exact shields, in house , increased patient comfort through more exact, individual , treatment . Low investment cost for equipment . Re-useable alloy materials. No hand finishing of blocks.
Up until the MCP Technology was introduced, shielding blocks were produced very slowly in external foundries using lead, which was cast into sand moulds . The MCP process also replaced the method of placing large ad hoc pieces of lead under the energy source to create patient shield.
The MCP 70 Technology was later adopted as the standard process throughout Europe for producing, rapid , accurate shielding blocks for patient radiotherapy.
The MCP 70 Process for creating Radiotherapy Shields rapidly:
Using a marker pen the area to be treated is drawn on the X-ray film. A block of Styrodur foam is placed in the cutting equipment between the light box and the source.
The heated cutting wire hanging from the top of the equipment (source)and using the magnifying glass; is guided around the marked area on the X-ray film to cut out the shape in Styrodur.
The cut out Styrodur piece is placed in a metal casting frame and held down and fastened with a clamp to stop it floating when the MCP70 Alloy is cast around it from the melting tank supplied.
The MCP 70 Alloy has unique properties. The melting temperature is exactly 70
degrees , compared to lead with 327 degrees C ,and after use can be reclaimed either in hot water or in the melting tank supplied.
After cooling - approximately 6-8 hours , the Styrodur piece is removed from the alloy block – no finishing required.
The alloy shield is positioned between the Linac. source and the patient.