This chapter is an extension of Chapter 5 in which a Monte Carlo generated scatter LSF [also referred to as the dose spread function (DSF) by Boone (2009)] was used as a kernel in a convolution-based model to generate an analytic equation describing the peak dose f(0) of an axial dose profile f(z) as a function of primary beam width a, including both wide cone beams and narrow fan beams (where a is the z-collimator aperture projected at isocenter). The interest in the peak dose f(0) is due to the fact that it was shown in Chapter 5 to be the logical (and unique) choice for a stationary phantom cone beam (SCBCT) dose-descriptor consistent with the CTDI-based dose used in conventional CT. AAPM Report 111 (AAPM 2010) likewise recommends using f(0) for stationary phantom CT.