Figure 5.

The P‐values for one active and inactive sources present for ${\hspace{0.17em}}^{125}\mathrm{I}$ (a) and ${\hspace{0.17em}}^{192}\mathrm{I}\mathrm{r}$ (b) at line $\mathrm{Z}=2\text{cm}$. The positions of inactive sources are shown with different symbols. For inactive source positions at $(0,0.5,-0.5),(0,0,-0.5),(0,-0.5,-0.5),(0,-0.5,0)$ or $(0,-\mathrm{o}.5,0.5)$, the corresponding P‐values in any voxel are unity. The P‐values for inactive seed positions at $\mathrm{Z}>2\hspace{0.17em}\mathrm{c}\mathrm{m}$ are also unity. If the radiation path is intersected by the inactive seeds, those inactive seeds have effect on the P‐values. The P‐values statistic accuracy is better for ${\hspace{0.17em}}^{192}\mathrm{I}\mathrm{r}$ than the ${\hspace{0.17em}}^{125}\mathrm{I}$, especially for further distances due to higher photon scattering contributions. The MC uncertainties are at most 2%.