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The Simulator:

     The simulator looks like the machines used for therapy and, as the name suggests, behaves in the same way except that it does not generate high energy X-rays. As previously mentioned it is essential that the patient is positioned very accurately on the apparatus for each session and the mask is the primary means of accomplishing this. Tiny metal markers are embedded in the surface of the mask as reference points and, once the patient is in place, final adjustments are made using laser beam generators attached to the fabric of the room. Another reference point is made on the patient by applying a single dot tattoo ( a permanent souvenir ) in the middle of the chest.

     The light generated by the simulator illuminates the same areas that will be exposed to the X-rays and is used to verify the instructions given to the apparatus. In some cases it is necessary to protect part of the area that would be exposed to the radiation so,  lead blocks were placed in front of the beam to create shadows protecting the vulnerable areas. Various markings were made on the mask to assist the radiographers later when treatment began, and X-ray pictures were taken as a record of the positioning. The actual therapy was delivered in two phases which each required a separate session on the simulator.

     The first simulator session lasted about  forty five minutes and was the longest period I spent with the mask in place. After this there was only one more task to complete before treatment was scheduled to begin.