肺癌三维适形放射治疗脊髓受照射剂量

摘要

In plan of three dimensional conformal radiotherapy for lung cancer, to analysis physical dose and the corresponding biological dose of actual irradiated for spinal cord. Methods: To measure diameter of cross-sectional for spinal cord by the use of TPS tools, the use of TPS dose volume histogram, dose volume histogram form tool for calculating the minimum physical dose, maximum physical dose and average physical dose of spinal cord; the use of cross-sectional dose distribution spinal cord for calculating the irradiation physical dose. This paper studies irradiation physical dose and the corresponding biological dose. Results: The diameter of cross-sectional of Spinal cord PRV in 16 mm～19 mm range;Spinal cord accept is non-uniform irradiation with three dimensional conformal radiotherapy for lung cancer, PRV cross-sectional exposure dose of irradiated spinal cord is not identical, irradiation physical dose of spinal cord is greater than the corresponding biological dose. Conclusions: Irradiation dose of spinal cord three dimensional conformal radiotherapy for lung cancer and its subject according to PRV cross-section related to the scope, PRV cross-sectional exposure dose of irradiated spinal cord is not identical, physical dose of maximum point for spinal cord, does not represent Irradiation dose of the whole PRV cross section with the spinal cord.%目的:在肺癌三维适形放疗计划中,分析脊髓的实际受照射的物理剂量及相应的生物剂量.方法:利用TPS的测量工具测量脊髓PRV横截面的直径；利用TPS的剂量-体积直方图、剂量-体积直方表等工具计算脊髓的最小物理剂量、最大物理剂量及平均物理剂量；利用横断面的剂量分布计算脊髓的受照射物理剂量.研究分析脊髓受照射的物理剂量及相应的生物剂量.结果:脊髓PRV横截面的直径在16.0 mm～19.0 mm范围内；肺癌三维适形放疗脊髓接受的是非均匀照射,受照射脊髓的PRV横截面受照射剂量不相同,脊髓的受照射的物理剂量大于相应的生物剂量.结论:肺癌三维适形放疗脊髓的受照射剂量与其受照PRV横截面范围有关,受照射脊髓的PRV横截面受照射剂量不相同,脊髓最大剂量点的物理剂量,并不代表脊髓整个PRV横截面的受量.