Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.
Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.
Clin Breast Cancer. 2018 Oct;18(5):e899-e908. doi: 10.1016/j.clbc.2018.02.009. Epub 2018 Feb 21.
The acceptance of hypofractionated radiotherapy in treating breast cancer in the breast conservation therapy setting has stimulated interest in hypofractionated postmastectomy radiotherapy (PMRT). We assessed national trends and patterns of utilization of hypofractionated PMRT.
Women 18 years of age or older with breast cancer treated with mastectomy and PMRT to the chest wall with or without regional lymph nodes from 2004 to 2014 were identified from the National Cancer Database. A standard fractionation cohort was defined as patients receiving 180 to 200 cGy per fraction to a total dose of 4500 to 7000 cGy over 5 to 7 weeks, and a hypofractionation cohort was defined as those receiving 250 to 400 cGy per fraction to a total dose of 3000 to 6000 cGy over 2 to 5 weeks. Multivariable logistic regression was used to determine factors associated with hypofractionated PMRT use.
We identified 113,981 patients who met study criteria. Overall, hypofractionated PMRT use was low (1.1%) although utilization increased over time (P ≤ .001). Older age, greater comorbidity, further distance from treatment facility, treatment at academic facilities, less extensive disease, and recent treatment year were statistically significant predictors of hypofractionation use compared with standard fractionation. Conversely, breast reconstruction and receipt of chemotherapy were negative predictors.
Because of the absence of high-level evidence to support its use, hypofractionated PMRT was uncommonly utilized in the United States from 2004 to 2014, although a small increase in use was noted over time. Findings from this study might be useful in designing future studies, and might serve as a baseline for evaluation of future changes in practice patterns.
保乳治疗中适形分割放疗技术的应用，激发了人们对乳房切除术后放疗（PMRT）适形分割的兴趣。我们评估了全国范围内应用适形分割 PMRT 的趋势和模式。
从国家癌症数据库中，选取了 2004 年至 2014 年间接受乳房切除术和 PMRT 的 18 岁及以上的乳腺癌患者，放疗靶区包括胸壁和（或）区域淋巴结。标准分割组定义为接受 180 至 200 cGy/次，5 至 7 周内完成总剂量 4500 至 7000 cGy 的患者；适形分割组定义为接受 250 至 400 cGy/次，2 至 5 周内完成总剂量 3000 至 6000 cGy 的患者。多变量逻辑回归用于确定与适形分割 PMRT 应用相关的因素。
我们共纳入 113981 例符合研究标准的患者。虽然整体上适形分割 PMRT 的应用率较低（1.1%），但随着时间的推移，其应用率呈上升趋势（P≤0.001）。与标准分割相比，高龄、合并症较多、距离治疗机构较远、在学术机构接受治疗、疾病范围较局限以及治疗时间较近是接受适形分割的统计学显著预测因素。相反，乳房重建和接受化疗是应用适形分割的负性预测因素。
由于缺乏支持其应用的高级别证据，2004 年至 2014 年期间，适形分割 PMRT 在全美并未广泛应用，尽管其应用率随时间推移略有增加。本研究的结果可能有助于设计未来的研究，并可作为评估未来实践模式变化的基线。
