Theoretical evaluation of dose distributions in water about models 6711 and 6702 125I seeds

The distribution of absorbed dose about models 6711 and 6702 125I seeds in water has been calculated from first principles using the Monte Carlo method. Dose is calculated as a function of angle with respect to the transverse seed bisector for distances from the seed center ranging from 0.1 to 7.5 cm. The computed results are compared to measured data. A truncated Fourier series is used to describe the Monte Carlo data in terms of a small number of coefficients, facilitating accurate and efficient dose calculations for clinical treatment planning.