Simulate And Study The Dosimetric Parameters Of ¹⁰³Pd Brachytherapy Source

In recent years, as medical standards are being raised and the development ofnuclear science and technology, we can implante the radioactive sources in the tumorof human body tissue directly, to treatment of cancer. This method in the clinicaltreatment of intracranial tumors, nasopharyngeal cancer, pancreatic cancer andprostate cancer, etc. are very good, better than radiation therapy in vitro. Currently themost commonly used implantation of radioactive in the human tissue is 125I and ¹⁰³Pd.Because the dose distribution of radioactive sources implanted in the human tissuedetermine the effects of treatment, so the calculation of dosimetric parameters is veryimportan before clinical application.In this paper,we simulate and study the dosimetric param of model 200 ¹⁰³Pdwith the help of Monte Carlo MCNP 4C program.Calculated the Dose-rateconstant,Radial dose function,2D anisotropy function and the Isodose distributioncurve,we compared the results obtained with the recommended values of TheAmerican Association of Physicists in Medicine in the Task Group No.43 Report,Thecontrast is slight.Such as the value of Dose-rate constant is 0.663cGy·h-1·U-1, And itsrelative error is 3.42%; according to the calculation of the dose rate distribution in theXY plane 15mm×15mm we drawn the isodose distribution curve,and are consistentwith related research, in the range of 0.1 10cm we calculated the Radial dosefunction , the results showed that the calculation error is small near the source ,andcalculation error from range of 5% to 10%when thedistance is 7 to10cm;Finally,calculated the 2D anisotropy function in the range of 00 900 ,compared with the recommended in the Task Group No. 43 Report average error is4%.This paper also fit the Radial dose function and Anisotropy function and obtainedpractical empirical formula , fitting coefficient also reached 98%. Sum that, we use theMonte Carlo MCNP 4C program Simulate and Study the model 200 ¹⁰³Pd, the resultsobtained are reliable, can be used for clinical reference.