@jeffmarc, as others have mentioned, a radiation simulation appointment is the appointment to set up the radiation treatment. During simulation, your radiation therapy team will help you find a comfortable position. You must lie still during treatment, so being comfortable is important.

You'll lie down on the same type of table that will be used during your treatment. Cushions and props will help hold you in the right placement. Next, the radiation therapy team marks the place on the body that will get the radiation. This might be done with a marker or with small permanent tattoos.

@johnw22, sometimes the time between simulation and actual treatment begin will be short (a few days) or longer, as in your situation, (a few weeks). This is likely due to scheduling of the equipment and number of patients. The simulation will not have to be repeated. What type of radiation will you have?