Figure 1.
Structural diagram of the Ir-192 source and its stainless steel outer cover.
Figure 2.
Structural model of Henschke applicator for Ir-192 source for MCNP calculation, visualized by MCNPX Visual Editor.
Figure 3.
Diagram of the setup for simulating dose variation caused by imprecision of measurement-position MCNPX tally spheres are placed at different distances from the source.
Positive/negative signs indicate positions away from or close to the source, respectively.
Figure 4.
(a) Ratios of F6 and *F8 tally dose of MCNPX calculation for the presence of Ir-192 in the water phantom. (b) Comparison of MCNPX-calculated and previously reported results for the Ir-192 radial dose function. (c) Comparison of MCNPX-calculated and previously reported results for the Ir-192anisotropy function. (d) Comparison of dose distribution in water with the presence of the tandem for the ionization-chamber-measured value (I.C.), treatment-planning system value (TPS), and MCNPX-calculated value.
Figure 5.
Relative dose differences in water with the presence of the tandem.
(a) MCNPX-calculated value versus treatment-planning value, (b) MCNPX-calculated value versus ionization-chamber-measured value, and (c) treatment-planning value versus ionization-chamber-measured value.
Figure 6.
The ratio of dose with the presence of the ovoid and with the presence of the tandem.
Figure 7.
Photograph showing the internal structure of the ovoid of the Henschke applicator.
Table 1.
Dose variation caused by measurement-position errors, calculated by MCNPX (1σ<1.5%).