# TG-43 Practice Problems

A NASI MED3633 ^{103}Pd source with measured air kerma strength of 40.218 U is used for a brachytherapy treatment.
What is the dose rate in water, in cGy/hr, at a point located at a radial distance of 4.0 cm and a polar angle
of 80^{o}? Use the line source approximation, for a source of 0.42 cm active length.
(Hint: Use Figure 1 and the geometric definition of the dot product)

**All values, unless stated within the problem, should be obtained using the TG-43 updated report.