A dosimetric research on radioactive 125I seed plane implantation / 介入放射学杂志

ABSTRACT

Objective To explore the dosimetric effects of the same number and activity of radioactive 125I seeds in different plane arrangements. Methods Simulated 9 distribution modes using 9 125I seeds were designed by three- dimensional treatment planning system (3D- TPS), and the isodose curves of 60 Gy, 80Gy, 130 Gy, 145 Gy and 200 Gy were obtained. The areas enclosed by the isodose curves, the longer and shorter radius of these isodose curves and the medical cost per unit area were calculated with the professional image analysis software. Results Obvious differences in areas enclosed by the isodose curves, the longer and shorter radius of these isodose curves and the medical cost per unit area existed between each other among the nine different distribution modes of 9 125I seeds. The distribution modes that had the maximum areas enclosed by 60 Gy, 80 Gy, 130 Gy, 145 Gy and 200 Gy isodose curves were x1.5y1.5, x1y1.5, x1y1, x1y1 and x0.5y1, respectively, with the corresponding areas of 1 583.86 mm2, 1 146.03 mm2, 768.30 mm2, 621.85 mm2 and 480.97 mm2, respectively. Conclusion The peripheral dose and the therapeutic efficacy are significantly influenced by the arrangement of 125I seeds when the same number and activity of the seeds are used. The dose distributions are more homogeneous when the maximum areas enclosed by the isodose curves are obtained.