Document Type: Original Paper
Assistant Professor, Physics Dept., School of Sciences, Sabzevar Tarbiat Moallem University, Sabzevar, Iran
Introduction: 90 Sr/ 90 Y source has been used for the intravascular brachytherapy to prevent coronary
restenosis in the patients who have undergone angioplasty. The aim of this research is to determine the
dose distribution of 90 Sr/ 90 Y source in a water phantom.
Materials and Methods: In the present work, MCNP code has been applied to calculate the dose
distribution around a 3 cm length of 90 Sr/ 90 Y source in a 30×30×30 cm 3 water phantom. Also, the exact
geometry of the source has been used in this simulation. Tally *F8:e which is suitable for beta ray
dosimetry has been evaluated with less than %5 relative error in a sphere having 0.2 mm radius.
Results: The isodose curve for 10, 20, 40, and 90% depth dose (PDD) were derived based on the
calculated dose curves along the parallel and perpendicular axis to the source.
Discussion and Conclusion: The results obtained in this work are in a good agreement with the
experimental result published by Buckley et al. and the International Atomic Energy Agency (IAEA)
report in a water phantom. Therefore, the result of this research can be used in the intravascular