Figure 4.

Dose profile data for 15 MV photon beam calculated by MC code versus measurement data $(\text{SSD}\hspace{0.17em}=\hspace{0.17em}100)$. The curves (a), (b), and (c) correspond to $6\hspace{0.17em}\times \hspace{0.17em}6,\hspace{0.17em}10\hspace{0.17em}\times \hspace{0.17em}10$, and $18\times 18\hspace{0.17em}{\text{cm}}^2$ field sizes, respectively. Dose profiles for 5, 10, and 20 cm depths are plotted in each part of (a), (b), and (c), respectively. For more clarification, the data for 5 and 10 cm depths are scaled 0.8 and 0.9 respectively.