4D CT 图像伪影会影响肺和肝转移瘤 SBRT 的局部控制。
4D CT image artifacts affect local control in SBRT of lung and liver metastases.
机构信息
Department of Radiotherapy and Oncology, University Medical Center Hamburg-Eppendorf, Germany; Department of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, Germany.
Department of Radiotherapy and Oncology, University Medical Center Hamburg-Eppendorf, Germany.
出版信息
Radiother Oncol. 2020 Jul;148:229-234. doi: 10.1016/j.radonc.2020.04.006. Epub 2020 Apr 9.
BACKGROUND AND PURPOSE
4D CT images often contain artifacts that are suspected to affect treatment planning quality and clinical outcome of lung and liver SBRT. The present study investigates the correlation between the presence of artifacts in SBRT planning 4D CT data and local metastasis control.
MATERIALS AND METHODS
The study includes 62 patients with 102 metastases (49 in the lung and 53 in the liver), treated between 2012 and 2016 with SBRT for mainly curative intent. For each patient, 10-phase 4D CT images were acquired and used for ITV definition and treatment planning. Follow-up intervals were 3 weeks after treatment and every 3-6 months thereafter. Based on the number and type of image artifacts, a strict rule-based two-class artifact score was introduced and assigned to the individual 4D CT data sets. Correlation between local control and artifact score (consensus rating based on two independent observers) were analyzed using uni- and multivariable Cox proportional hazards models with random effects. Metastatic site, target volume, metastasis motion, breathing irregularity-related measures, and clinical data (chemotherapy prior to SBRT, target dose, treatment fractionation) were considered as covariates.
RESULTS
Local recurrence was observed in 17/102 (17%) metastases. Significant univariable factors for local control were artifact score (severe CT artifacts vs. few CT artifacts; hazard ratio 8.22; 95%-CI 2.04-33.18) and mean patient breathing period (>4.8 s vs. ≤4.8 s; hazard ratio 3.58; 95%-CI 1.18-10.84). Following multivariable analysis, artifact score remained as dominating prognostic factor, although statistically not significant (hazard ratio 10.28; 95%-CI 0.57-184.24).
CONCLUSION
The results support the hypothesis that image artifacts in 4D CT treatment planning data negatively influence clinical outcome in SBRT of lung and liver metastases, underlining the need to account for 4D CT artifacts and improve image quality.
背景与目的
4D CT 图像常存在伪影，这些伪影可能会影响肺部和肝脏 SBRT 的治疗计划质量和临床结果。本研究旨在调查 SBRT 计划 4D CT 数据中伪影的存在与局部转移控制之间的相关性。
材料与方法
本研究纳入了 2012 年至 2016 年间接受 SBRT 治疗的 62 例 102 处转移灶患者（肺部 49 处，肝脏 53 处），主要为根治性治疗。每位患者采集 10 期 4D CT 图像，用于 ITV 定义和治疗计划。治疗后 3 周和此后每 3-6 个月进行随访。基于图像伪影的数量和类型，引入了严格的基于规则的两分类伪影评分，并分配给个体 4D CT 数据集。使用单变量和多变量 Cox 比例风险模型（具有随机效应）分析局部控制与伪影评分（两名独立观察者的共识评分）之间的相关性。考虑了转移灶部位、靶区体积、转移灶运动、与呼吸不规则相关的测量值以及临床数据（SBRT 前的化疗、靶区剂量、治疗分割）作为协变量。
结果
102 处转移灶中有 17 处（17%）出现局部复发。局部控制的单变量显著因素包括伪影评分（严重 CT 伪影与少量 CT 伪影；风险比 8.22；95%CI 2.04-33.18）和平均患者呼吸周期（>4.8 s 与 ≤4.8 s；风险比 3.58；95%CI 1.18-10.84）。多变量分析后，尽管统计学上无显著意义，但伪影评分仍然是主要的预后因素（风险比 10.28；95%CI 0.57-184.24）。
结论
这些结果支持这样一种假设，即 4D CT 治疗计划数据中的图像伪影会对肺部和肝脏转移灶 SBRT 的临床结果产生负面影响，这强调了需要考虑 4D CT 伪影并改善图像质量。
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