Solutio in silico

TG-43 Practice Problems

A NASI MED3631-A/M 125I source with measured air kerma strength of 45.994 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 67o? 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)

Figure 1

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

cGy/hr