A patient is treated on the 6 MV linear accelerator treatmen…

A patient is treated on the 6 MV linear accelerator treatment machine at 100 cm SAD.  The treatment SSD is 90 cm.  The prescription states that a dose of 4000 cGy is to be delivered to a depth of 10 cm in 20 fractions with an AP/PA treatment field arrangement.  If the patient’s spinal cord lies at a depth of 6 cm beneath the patient’s posterior skin surface, what is the depth to the spinal cord from the anterior skin surface?

A patient’s prescription requires a total of 180 cGy to be d…

A patient’s prescription requires a total of 180 cGy to be delivered per day to equally weighted to POP fields (Parallel Opposed Ports).  The treatment time to deliver 100 cGy is 2.15 minutes.  What treatment time must be delivered to each field to follow the prescription?