Department of Radiation Oncology, Stanford University, Stanford, California.
Department of Radiation Oncology, Geisinger Health System, Danville, Pennsylvania; Department of Medical Imaging and Radiation Sciences, Thomas Jefferson University, Philadelphia, Pennsylvania.
Int J Radiat Oncol Biol Phys. 2021 May 1;110(1):112-123. doi: 10.1016/j.ijrobp.2020.11.021. Epub 2021 Jan 27.
We sought to investigate the tumor control probability (TCP) of spinal metastases treated with stereotactic body radiation therapy (SBRT) in 1 to 5 fractions.
PubMed-indexed articles from 1995 to 2018 were eligible for data extraction if they contained SBRT dosimetric details correlated with actuarial 2-year local tumor control rates. Logistic dose-response models of collected data were compared in terms of physical dose and 3-fraction equivalent dose.
Data were extracted from 24 articles with 2619 spinal metastases. Physical dose TCP modeling of 2-year local tumor control from the single-fraction data were compared with data from 2 to 5 fractions, resulting in an estimated α/β = 6 Gy, and this was used to pool data. Acknowledging the uncertainty intrinsic to the data extraction and modeling process, the 90% TCP corresponded to 20 Gy in 1 fraction, 28 Gy in 2 fractions, 33 Gy in 3 fractions, and (with extrapolation) 40 Gy in 5 fractions. The estimated TCP for common fractionation schemes was 82% at 18 Gy, 90% for 20 Gy, and 96% for 24 Gy in a single fraction, 82% for 24 Gy in 2 fractions, and 78% for 27 Gy in 3 fractions.
Spinal SBRT with the most common fractionation schemes yields 2-year estimates of local control of 82% to 96%. Given the heterogeneity in the tumor control estimates extracted from the literature, with variability in reporting of dosimetry data and the definition of and statistical methods of reporting tumor control, care should be taken interpreting the resultant model-based estimates. Depending on the clinical intent, the improved TCP with higher dose regimens should be weighed against the potential risks for greater toxicity. We encourage future reports to provide full dosimetric data correlated with tumor local control to allow future efforts of modeling pooled data.
我们旨在研究 1 至 5 个剂量分割的立体定向体部放射治疗（SBRT）治疗脊柱转移瘤的肿瘤控制概率（TCP）。
从 1995 年至 2018 年，从 PubMed 索引中筛选出符合条件的文章，这些文章必须包含 SBRT 剂量学细节，并与 2 年局部肿瘤控制的累积发生率相关。比较收集数据的物理剂量和 3 个分割等效剂量的逻辑剂量-反应模型。
从 24 篇文章中提取了 2619 例脊柱转移瘤的数据。对单剂量数据 2 年局部肿瘤控制的物理剂量 TCP 模型进行分析，并与 2 至 5 个剂量分割的数据进行比较，得出α/β=6 Gy 的估计值，并对数据进行汇总。考虑到数据提取和建模过程中固有的不确定性，90%的 TCP 相当于 1 个剂量分割的 20 Gy、2 个剂量分割的 28 Gy、3 个剂量分割的 33 Gy，以及（外推）5 个剂量分割的 40 Gy。常见分割方案的估计 TCP 为 1 个剂量分割的 18 Gy 时为 82%，20 Gy 时为 90%，24 Gy 时为 96%，2 个剂量分割的 24 Gy 时为 82%，3 个剂量分割的 27 Gy 时为 78%。
最常见的分割方案的脊柱 SBRT 治疗可获得 82%至 96%的 2 年局部控制率。鉴于从文献中提取的肿瘤控制估计值存在异质性，在报告剂量学数据和报告肿瘤控制的定义和统计方法方面存在差异，在解释由此产生的基于模型的估计值时应谨慎。根据临床意图，应权衡更高剂量方案的 TCP 改善与潜在毒性增加的风险。我们鼓励未来的报告提供与肿瘤局部控制相关的完整剂量学数据，以允许未来对汇总数据进行建模的努力。
