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目的:比较先进外照射光子剂量算法(Acuros XB)和各向异性分析算法(AAA)在乳腺癌胸壁放疗中的剂量学差异。方法:随机回顾选取8例由不同放疗医生勾画靶区的术后乳腺癌患者,左侧和右侧各4例,对每个病例分别设计动态调强(IMRT)和容积调强(VMAT)两种放疗计划,动态IMRT计划采用5-7野照射,VMAT计划采用双弧照射。再对每个计划分别采用Acuros XB算法和AAA算法进行剂量计算,比较靶区及危及器官的剂量学差异。结果:Acuros XB算法获得IMRT计划靶区剂量的均匀性与适形度均好于AAA算法(t=3.185、-9.138,P=0.015、0),且健侧肺、脊髓等危及器官的受量低于AAA算法(t=-5.090、-2.520,P=0.001、0.012),但患侧肺、对侧乳腺、皮肤、心脏的受量高于AAA算法(t=-2.500、-4.560、-5.100、-3.010,P=0.041、0.003、0.001、0.002);Acuros XB算法获得的VMAT中治疗靶区剂量的均匀性优于AAA算法(t=0.580,P=0.579),但适形度均比AAA算法差(t=1.290,P=0.237),且脊髓等危及器官的的受量低于AAA算法(t=4.010,P=0.005),但患侧肺、对侧肺、心脏、对侧乳腺、皮肤的受量高于Acuros XB算法(t=6.900、0.350、4.310、-2.500、-2.800,P=0.000、0.740、0.004、0.041、0.026)。大部分差异具有统计学意义。结论:与Acuros XB算法相比,AAA算法低估了在肺、心脏、对侧乳腺等危及器官中的剂量,低估了靶区内的最大剂量,高估了靶区的平均剂量。两种算法的剂量学指标均满足临床要求,均可用于临床治疗。
OBJECTIVE: To compare the dosimetry differences between advanced external irradiation photon dose algorithm (Acuros XB) and anisotropy analysis algorithm (AAA) in chest wall radiotherapy. Methods: Eight patients with postoperative breast cancer were screened by different radiologists. Four cases of left breast and right breast were randomly selected. Dynamic IMRT and VMAT II were designed for each case. Radiotherapy plan, dynamic IMRT plan 5-7 wild irradiation, VMAT plan double-arc irradiation. For each program, Acuros XB algorithm and AAA algorithm were used for dose calculation. Differences in target areas and organs at risk were compared. Results: The dose and the conformality of the target dose obtained by the Acuros XB algorithm were better than those of the AAA algorithm (t = 3.185, -9.138, P = 0.015,0) Lower than the AAA algorithm (t = -5.090, -2.520, P = 0.001,0.012), but the ipsilateral lung, contralateral breast, skin, heart by the AAA algorithm (t = -2.500, -4.560, -5.100 , -3.010, P = 0.041,0.003,0.001,0.002). The uniformity of target dose in VMAT obtained by Acuros XB algorithm was better than AAA algorithm (t = 0.580, P = 0.579) (T = 1.290, P = 0.237). The spinal cord and other organs at risk were lower than the AAA algorithm (t = 4.010, P = 0.005), but the affected lung, contralateral lung, heart, contralateral breast, The skin volume was higher than the Acuros XB algorithm (t = 6.900,0.350, 4.310, -2.500, -2.800, P = 0.000,0.740,0.004,0.041,0.026). Most differences were statistically significant. Conclusion: Compared with Acuros XB algorithm, the AAA algorithm underestimates the dose in endangered organs such as lung, heart and contralateral breast, underestimates the maximum dose in the target area and overestimates the average target dose. The dosimeters of the two algorithms meet the clinical requirements and can be used for clinical treatment.