Purpose: To perform dosimetric study of 142Pr microspheres for the use as a possible choice of radionuclide in microsphere brachytherapy of nonresectable hepatic tumor for faster dose delivery and facilitated dosimetry for quality assurance. Methods and Materials: Dose distributions of 142Pr and 90Y microspheres within hepatic tumors and blood vessels were calculated using MCNPX2.6 Monte Carlo code. The biological effective doses (BEDs) for 142Pr and 90Y microspheres were calculated and compared using the linear-quadratic model. Results: Dose distributions due to beta particles were similar for both 142Pr and 90Y. Total initial activity required to achieve the same total dose of 150Gy at 2cm from the center of the tumor was 0.662 GBq and 0.191 GBq for 142Pr and 90Y, respectively. For α/β ratio equal to 10Gy, calculated BED values were 301.0 and 194.7 for 142Pr and 90Y, respectively, considering a total physical dose of 150Gy. Conclusions: Total dose delivery and dose distributions for both 142Pr and 90Y within tumors and blood vessels were obtained and compared. Shorter half-life of 142Pr is an advantage, enabling a faster dose delivery. The higher BED found for 142Pr implies potential improvement in the treatment effectiveness. 142Pr showed to be an attractive option for applications in microsphere brachytherapy.
Bibliographical noteFunding Information:
Financial disclosure/Conflict of interest: The first and corresponding authors acknowledge the support from a Ralph E. Powe Junior Faculty Enhancement Award provided by Oak Ridge Associated Universities .
- Hepatic tumors
- Microsphere brachytherapy
- Monte Carlo simulation