Evaluation of dosimetric parameters of some common 32P sources wire used for intravascular brachytherapy by using Monte Carlo code FLUKA

Background: Brachytherapy is one of the effective types of radiation therapy which is widely used to treat cancer. In this technique, radioactive source is placed directly inside or next to the target tissue. Brachytherapy is divided into different kind. Intravascular brachytherapy is one of the most common types of the brachytherapy, which is safe and feasible as a short-term treatment for patients with recurrent drug-eluting stent in-stent restenosis. In this method, ionizing radiation (beta emitter radionuclides such as 32P) is placed inside arteries after angioplasty, stent insertion, or bypass grafts may prevent narrowing of the arteries or grafts.Methods: In this paper, by introducing different 32P sources wire (three sources) which is used in the intravascular brachytherapy, we describe their dosimetric parameters by using the FLUKA Monte Carlo code. The dosimetric parameters were performed within the water and polystyrene phantoms.Results:The parameters included dose rate along the transverse axis, dose rates normalized to the dose rate at the reference point, and radial dose functions were evaluated for the different 32P intravascular brachytherapy source wires based on the AAPM TG-60 protocol.We validate our simulations by using the previous published data, which is performed by different codes such as MCNP, EGSnrs, and PENELOPE. We also presented effect of the catheter on the dosimetric parameters. validate Our results for three sources show that in first source, the maximum error related to the dose rate is 7.77% compared to the PENELOPE code. In second source, dose rate at the reference point was calculated to be0.1241 GyS-1mCi-1, for FLUKA, and 0.1311 GyS-1mCi-1 for EGSnrs. In third source, the error range for dose rate for FLUKA in comparison with MCNPX, EGSnrs, PENELOPE and CYLTRAN codes, was between 0 and 4%.Conclusion: Our simulation results shows that FLUKA code can begood used for beta emitter sources and can help to accurately estimate the dose around these sources, that dates can be used in clinical treatment.

Keywords:

Dosimetry , Brachytherapy , 32P , Monte Carlo simulation , FLUKA code