Background: Iodine brachytherapy sources with
low photon energies have been widely used in
treating cancerous tumors. Dosimetric parameters of
brachytherapy sources should be determined
according to AAPM TG-43U1 recommendations
before clinical use. Monte Carlo codes are reliable
tools in calculation of these parameters for brachytherapy
sources. Materials and Methods: Dosimetric
parameters (dose rate constant, radial dose function,
and anisotropy function) of two I-125 brachytherapy
sources (models LS-1 and Intersource) were
calculated with MCNP4C Monte Carlo code following
task group #43 (TG-43U1) recommendations of
American Assossiation of Physicists in Medicine. The
simulations were done inside a spherical water
phantom because of its tissue equivalent properties.
The Monte Carlo simulations for radial dose function
were performed at distances ranging from 0.25 to 10
cm from the source center. The anisotropy functions
F(r, θ), for both sources, were calculated at distances
of 1, 2, 3, 5 and 7 cm from the source center for
angles ranging from 15 to 90 degree. Results: The
results of the Monte Carlo simulation indicated a
dose rate constant of 0.952 cGyh -1U-1 and 0.986
cGyh -1U-1 for models LS-1 and Intersource,
respectively. The tabulated data and fifth order
polynomial coefficients for radial dose functions
along the source are described in this paper. The
results indicated that the anisotropy in dose
distribution increased along the source axis.
Conclusion: The obtained results were in good agreement
with measurements and calculations of other
investigators, using other Monte Carlo codes. Iran. J.
Radiat. Res., 2010 7 (4): 217-222
Zehtabian M, Faghihi R, Sina S. Comparison of dosimetry parameters of two commercially available Iodine brachytherapy seeds using Monte Carlo calculations. Int J Radiat Res 2010; 7 (4) :217-222 URL: http://ijrr.com/article-1-582-en.html