Monte Carlo calculation of dosimetry parameters for the IR08‐ brachytherapy source

Abstract

There are no statistical significant dosimetric differences among the three seed orientations in this study (i.e., ideal, vertical, and diagonal). However, the observed differences between the calculated and measured values could be explained by the measurement uncertainty and the configuration of the resin beads within the capsule and capsule orientation.

Monte Carlo calculations and experimental measurements of the TG‐43U1‐recommended dosimetric parameters of 125I (Model IR‐Seed2) brachytherapy source

“…The phantom size in this simulation was comparable with the experimental setup (i.e., $30\hspace{0.17em}\text{cm}\times 30\hspace{0.17em}\text{cm}\times 15\hspace{0.17em}\text{cm}$). The composition of the Plexiglas was H, 8%; C, 60%; and O, 32%, with a mass density of 1.19 g/cm 3 (14) . To calculate its dosimetric parameters, the seed was simulated in the center of the phantom and the simulations were performed for radial distances of r = 0.1, 0.2, …, 7 cm away from the source and at polar angles relative to the longitudinal axis of the seed from 0° to 90° with 5° increments.…”

Dosimetric Characteristics of the Brachytherapy Sources Based on Monte Carlo Method

“…Table 2 shows the calculated dose rate constant for the IR-103 Pd seed (Saidi et al, 2010), new 103 Pd source (Rivard et al, 2004b) and the calculated and measured values of Λ, for NASI model MED3633 and Theragenics model 200 sources (Rivard et al, 2004b). The Monte Carlo calculated values of geometry function in this example for three orientations are shown in Table 3(a), (c) and (d).…”

“…This example presents Monte Carlo (MC) simulation results for the dosimetry parameters of the IR-103 Pd seed (Saidi et al, 2010). Dose distributions in this example were simulated with the MCNP5 Monte Carlo (MC) radiation transport code published by Los Alamos National Laboratory (mcnpgreen.lanl.gov/index.html., 2008) and the MCPLIB04 photon cross-section library is based on the ENDF/B-VI data (BNL.…”

“…(Saidi et al, 2010) with the MED3633 and Theragenics model 200 sources (Rivard et al, 2004a) at the distance of 5 cm.…”

“…As the beads are free to move within the titanium capsule, their location can vary with seed orientations. Saidi et al (2010), simulated three geometric models of the seed, ideal, vertical and diagonal, as shown in Figure 2 The dose rate constant for the 103 Pd seed was calculated by using the Equation (3). Due to the low energy of the photons from 103 Pd, it was assumed in the Monte Carlo calculations all electrons generated by the photon collisions are absorbed locally, so dose is equal to kerma at all points of interest (Sadeghi et al, 2008b).…”