High-energy photon primary and scatter dose calculation in water using primary collision kerma as a parameter

A new method is proposed for calculating high-energy photon primary and scatter dose in a semi-infinite or finite water phantom. Both primary and scatter dose calculations are performed using primary water collision kerma as a parameter. The primary and the scatter dose are each separated into forward and backward components. Zero-area tissue-maximum ratios (TMRs) are used for the primary dose calculation and revised scatter-maximum ratios (SMRs) for the scatter dose calculation.