Praseodymium-142 microspheres for brachytherapy of nonresectable hepatic tumors.
OBJECTIVE
To perform dosimetric study of (142)Pr 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
Dose distributions of (142)Pr and (90)Y microspheres within hepatic tumors and blood vessels were calculated using MCNPX2.6 Monte Carlo code. The biological effective doses (BEDs) for (142)Pr and (90)Y microspheres were calculated and compared using the linear-quadratic model.


RESULTS
Dose distributions due to beta particles were similar for both (142)Pr and (90)Y. Total initial activity required to achieve the same total dose of 150 Gy at 2 cm from the center of the tumor was 0.662 GBq and 0.191 GBq for (142)Pr and (90)Y, respectively. For α/β ratio equal to 10 Gy, calculated BED values were 301.0 and 194.7 for (142)Pr and (90)Y, respectively, considering a total physical dose of 150 Gy.


CONCLUSIONS
Total dose delivery and dose distributions for both (142)Pr and (90)Y within tumors and blood vessels were obtained and compared. Shorter half-life of (142)Pr is an advantage, enabling a faster dose delivery. The higher BED found for (142)Pr implies potential improvement in the treatment effectiveness. (142)Pr showed to be an attractive option for applications in microsphere brachytherapy.
Department of Physics, East Carolina University, Greenville, NC.
Maria Clara M
MC
Ferreira
Tarun K
TK
Podder
Karl H
KH
Rasmussen
Jae W
JW
Jung
D000328:Adult; D001918:Brachytherapy / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis / Q000532:radiotherapy*; D008863:Microspheres; D008962:Models, Theoretical; D009367:Neoplasm Staging; D011221:Praseodymium / Q000627:therapeutic use*; D011868:Radioisotopes / Q000627:therapeutic use*; D011874:Radiometry / Q000379:methods; D011879:Radiotherapy Dosage
D011868:Radioisotopes; D011221:Praseodymium
Hepatic tumors; Microsphere brachytherapy; Monte Carlo simulation; Praseodymium-142