Problem:
1. If the dose in air at 200cm is 50cGy, what is the dose in the air at 400cm?
2. Calculate the number of MU required to deliver 100cGy at isocenter to a depth of Dmax for a 10x10 cm field in a TMR setup.
Hint: the linac is typically calibrated to deliver 1cGy per 1 MU at dmax with 10x10cm field size TMR: TMR: 1 at Dmax TMR: 0.75 at 10cm depth Answer choices: A. 100MU B. 151 MU C. 133 MU