METHODS: This study included 90 treatment plans after BCS, irradiated in our clinic from January 2012 to August 2016 with TT (n = 30) and 3D-CRT (n = 30), 3DCRT DIBH (n = 30). PTVs were contoured at different time points by different radiation oncologists (> 7). TT was performed with a total dose of 50.4 Gy and a single dose of 1.8 Gy with a simultaneous integrated boost (SIB) to the tumor cavity (TT group). Patients irradiated with 3DCRT/3DCRT DIBH received 50 Gy à 2 Gy and a sequential boost. Contouring of lymph drainage routes was performed retrospectively according to RTOG guidelines.
RESULTS: Average doses (DMean) in axillary lymph node Level I/Level II/Level III were 31.6 Gy/8.43 Gy/2.38 Gy for TT, 24.0 Gy/11.2 Gy/3.97 Gy for 3DCRT and 24.7 Gy/13.3 Gy/5.59 Gy for 3DCRT-DIBH patients. Internal mammary lymph nodes (IMLNs) Dmean were 27.8 Gy (TT), 13.5 Gy (3DCRT), and 18.7 Gy (3DCRT-DIBH). Comparing TT to 3DCRT-DIBH dose varied significantly in all axillary lymph node levels and the IMLNs. Comparing TT to 3DCRT significant dose difference in Level I and IMLNs was observed.
CONCLUSIONS: Dose applied to locoregional lymph drainage pathways varies comparing tomotherapy plans to conventional tangentially arranged fields. Studies are warranted whether dose variations influence loco-regional spread and must have implications for target volume definition guidelines.
方法:本研究包括90个BCS治疗方案,2012年1月至2016年8月在我们的诊所用TT(n=30)和3D-CRT(n=30)照射,3DCRTDIBH(n=30)。PTV在不同的时间点由不同的放射肿瘤学家轮廓化(>7)。TT的总剂量为50.4Gy,单剂量为1.8Gy,同时对肿瘤腔进行整合增强(SIB)(TT组)。接受3DCRT/3DCRTDIBH照射的患者接受50Gyà2Gy并依次加强。根据RTOG指南回顾性地进行了淋巴引流途径的轮廓。
结果:对于TT,腋窝淋巴结I级/II级/III级的平均剂量(DMean)为31.6Gy/8.43Gy/2.38Gy,3DCRT患者为24.0Gy/11.2Gy/3.97Gy,3DCRT-DIBH患者为24.7Gy/13.3Gy/5.59Gy。乳内淋巴结(IMLNs)平均为27.8Gy(TT),13.5Gy(3DCRT),和18.7Gy(3DCRT-DIBH)。比较TT与3DCRT-DIBH剂量在所有腋窝淋巴结水平和IMLN中显着变化。比较TT与3DCRT,在I级和IMLN中观察到显著的剂量差异。
结论:将断层治疗计划与常规切向排列的区域相比,应用于局部淋巴引流途径的剂量各不相同。有必要研究剂量变化是否会影响局部区域传播,并且必须对目标体积定义指南产生影响。