目的:比较混合调强放射治疗(h-IMRT)和体积调强电弧治疗(VMAT)技术在早期乳腺癌(BC)大分割全乳照射(HF-WBI)中的剂量学优缺点。
方法:比较了20例乳腺癌患者的h-IMRT和VMAT计划的剂量分布。该比较包括使用剂量体积直方图(DVH)评估计划目标体积(PTV)和风险器官(OAR)的剂量测定参数。此外,该研究检查了正常组织并发症概率(NTCP),基于不同模型的第二癌症并发症概率(SCCP)和肿瘤控制概率(TCP)。
结果:在两个计划之间发现了显着差异,就机器单位(MU)而言,控制点,95%体积(V95%),剂量均匀性指数(DHI)和一致性指数(CI)。评估II级放射性肺炎和缺血性心脏病导致的心脏死亡的终点。在h-IMRT计划中,与VMAT计划相比,放射性肺炎的NTCP值略低,心脏死亡的NTCP值略高,由Lyman-Kutcher-Burman模型决定.Schneider模型用于预测双肺和对侧乳腺的SCCP。结果表明,h-IMRT计划优于VMAT计划,具有统计学意义。此外,LQ-Poisson模型用于预测PTV的TCP,显示h-IMRT计划优于VMAT计划(P>0.05)。
结论:h-IMRT技术,提供卓越的剂量覆盖和更好的治疗效果,副作用更少,如模型计算,与VMAT技术相比,更适用于HF-WBI。
OBJECTIVE: To compare the dosimetric advantages and disadvantages between hybrid intensity-modulated radiation therapy (h-IMRT) and the volumetric modulated arc therapy (VMAT) technique in hypofractionated whole-breast irradiation (HF-WBI) for early-stage breast cancer (BC).
METHODS: The dose distribution of h-IMRT and VMAT plans was compared in 20 breast cancer patients. This comparison included evaluation of dosimetric parameters using dose volume histograms (DVHs) for the planning target volume (PTV) and organs-at-risk (OARs). Additionally, the study examined the normal tissue complication probability (
NTCP), the second cancer complication probability (SCCP) and the tumor control probability (TCP) based on different models.
RESULTS: Significant differences were detected between the two plans, in terms of Machine units (MUs), the control points, 95 % volume (V95 %), dose homogeneity index (DHI) and conformity index (CI). The endpoint of grade II radiation pneumonitis and cardiac death due to ischemic heart disease were assessed. In h-IMRT plan, the
NTCP values were marginally lower for radiation pneumonitis and slightly higher for cardiac death compared to VMAT plan, as determined by the Lyman-Kutcher-Burman model. The Schneider model was employed to predict the SCCP for both the bilateral lungs and contralateral breast, the results demonstrate that the h-IMRT plan outperforms the VMAT plan, with statistical significance. Additionally, the LQ-Poisson model was employed to forecast the TCP of the PTV, showing that the h-IMRT plan outperformed the VMAT plan (P > 0.05).
CONCLUSIONS: The h-IMRT technique, offering superior dose coverage and better therapeutic efficacy with fewer side effects as calculated by models, is more suitable for HF-WBI compared to the VMAT technique.