Objective Pre-use dosimetric veriifcation of 3D TPS (Three-Dimensional Treatment Planning System) was performed in the department so as to verify its effectiveness and security in the clinical application under normal conditions. Methods Dosimetric veriifcation of the absolute dose was carried out to calculate the absolute dose of POI (Point of Interest) for the water phantom and compare it with the actually measured value. The relative deviation and passing rate for the tests were calculated according to the recommendation of Netherlands Commission on Radiation Dosimetry (NCS). The dosimetric veriifcation of the relative dose was carried out to scan the Mapcheck and solid water so as to import the images to the TPS. The 2D dose distribution at the depth of 5 cm from the surface was calculated and compared with the actually measured result. Then, the passing rate for the tests was calculated according to the standard of AAPM TG119. Results For the dosimetric veriifcation of the absolute dose, the POI whose relative deviation of the absolute dose was less than 1%, 2%, 3%and more than 4%occupied 33%, 84.5%, 95.3%and 2.3%respectively, which were all located in the high dose gradient area within the built-up area. For the dosimetric veriifcation of relative dose, the test whose passing rate was greater than 99%and 98%accounted for 72.2%and 89%respectively with its lowest passing rate being 92.1%. Conclusion The veriifcation result proved the intended effectivity and safety of 3D TPS in its clinical applications under normal conditions, which was worthwhile to be promoted. However, the physician and physicist should be highly aware of dosimetric abnormalities caused by the curved and tongue-and-groove design of leaves, which can lead to unnecessary radiation damage.%目的：对我科三维治疗计划系统（TPS）进行使用前的剂量学验证，以检验该系统在临床正常使用条件下的有效性和安全性。方法首先设计绝对剂量验证测试例，计算水模体中感兴趣点的剂量，并与同一点的实测剂量进行对比，计算相对偏差，按荷兰辐射剂量测量委员会的推荐计算每个测试例的通过率；再设计相对剂量验证测试例，对Mapcheck和固体水进行CT扫描，将CT图像导入TPS，计算表面下5 cm深度处的二维剂量分布，并与实测的剂量分布进行对比，按AAPM TG119标准计算每个测试例的γ通过率。结果绝对剂量验证中，相对偏差在1%以内的兴趣点占33%，相对偏差在2%以内的占84.5%，相对偏差在3%以内的占95.3%，相对偏差超过4%的占2.3%，均位于建成区内，属高剂量梯度区。相对剂量验证中，γ通过率＞99%的测试例占72.2%，γ通过率＞98%的占89%，γ通过率最低为92.1%。结论我科三维治疗计划系统在临床正常使用条件下具有预期的有效性和安全性，可以投入临床应用。但对叶片的端面弧形设计效应和侧面凹凸设计效应引起的剂量学变异现象，物理师和医师必须高度注意，以免造成不必要的放射损伤。
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