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目的:使用治疗计划系统(TPS)探讨相邻射野的衔接。方法:模拟相邻两照射野X线SSD照射,治疗深度5cm时,使用不同射野边长和射野间距,测得剂量测量点(两射野中点体表下2.5、5.0、7.5、10、12.5cm深度)剂量。结果:体表下5cm测量所得与理论值相对照,偏差为0.46%-8.51%,体表下2.5cm最低剂量仅为79.37cGy,剂量最高点出现在体表下10cm,达到123.33cGy,分析重建后矢状位剂量分布图可见随着射野的增大,剂量的冷热区也随着增大。结论:在使用X线相邻两照射野X线SSD照射时,尤其是射野较大时,可能造成肿瘤剂量的不足以及肿瘤深处正常组织受量的超量。
Objective: To explore the interface between adjacent fields using a treatment planning system (TPS). Methods: X-ray SSD was used to simulate the adjacent two radiation fields. When the depth of treatment was 5 cm, the distance between the two sides and the distance between the two fields were measured. The dose measurement points (2.5, 5.0, 7.5, 12.5 cm depth) dose. Results: Compared with the theoretical value, the deviation of the 5cm body surface measurement was 0.46% -8.51%, the lowest 2.5cm body surface dose was only 79.37cGy, the highest dose appeared in the body surface under 10cm, reaching 123.33cGy, the analysis and reconstruction Posterior sagittal dose distribution can be seen with the increase of the radiation field, the dosage of hot and cold zone also increases. CONCLUSIONS: When X-ray SSDs are used to irradiate adjacent two radiation fields, especially when the radiation field is large, the insufficiency of tumor dose and the excessive amount of normal tissue deep in the tumor may be caused.