Figure 7.

Scatter plot showing ratios of maximum point dose to rib; dose to $<1\hspace{0.17em}\text{cc}$, $<5\hspace{0.17em}\text{cc}$, and $<10\hspace{0.17em}\text{cc}$ of ribs calculated by PB‐hete and XVMC algorithms. For the identical beam geometry, MLC margins, and same number of MUs, the PB‐hete algorithm overestimated maximum rib point dose, dose to $<1\hspace{0.17em}\text{cc}$, $<5\hspace{0.17em}\text{cc}$, and $<10\hspace{0.17em}\text{cc}$ of ribs by 5%, 3%, 3%, and 3%, on average, respectively, compared to XVMC.