Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, 305-8575, Japan.
Department of Radiation Oncology, Proton Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Radiat Oncol. 2023 Feb 23;18(1):38. doi: 10.1186/s13014-023-02236-1.
High-dose proton beam therapy (PBT) uses excellent dose concentricity based on the unique characteristic termed the Bragg peak. PBT is a highly feasible treatment option that improves survival in select patients with newly diagnosed glioblastoma (GBM). However, selection bias remains an issue in prior studies that evaluated the efficacy of PBT. The aim of the present study was to compare the survival outcomes and toxicities of high-dose PBT and conventional radiation therapy (CRT) using propensity score-matched treatment cohorts.
The analysis included patients with newly diagnosed GBM treated with high-dose PBT of 96.6 Gy (RBE) or CRT of 60 Gy from 2010 to 2020. Propensity score generation and 1:1 matching of patients were performed based on the following covariates: age, sex, tumor location, extent of resection, chemotherapy, immunotherapy, and pre-radiation Karnofsky performance scale score.
From a total of 235 patients, 26 were selected in each group by propensity score matching. The median overall survival (OS) of the PBT group was 28.3 months, while the median OS of the CRT group was 21.2 months. Although acute radiation-related toxicities were equivalent between the PBT and CRT groups, radiation necrosis as a late radiation-related toxicity was observed significantly more frequently in the PBT group.
High-dose PBT provided significant survival benefits for patients with newly diagnosed GBM compared to CRT as shown by propensity score matching analysis. Radiation necrosis remains an issue in high-dose PBT; thus, the establishment of an effective treatment strategy centered on bevacizumab would be essential.
高剂量质子束治疗（PBT）利用独特的布拉格峰特性实现了极好的剂量集中性。PBT 是一种高度可行的治疗选择，可改善特定新发胶质母细胞瘤（GBM）患者的生存。然而，在评估 PBT 疗效的先前研究中，选择偏倚仍然是一个问题。本研究旨在通过倾向评分匹配治疗队列比较高剂量 PBT 和常规放疗（CRT）的生存结果和毒性。
该分析纳入了 2010 年至 2020 年期间接受 96.6Gy（RBE）高剂量 PBT 或 60Gy CRT 治疗的新发 GBM 患者。根据以下协变量进行倾向评分生成和患者 1:1 匹配：年龄、性别、肿瘤位置、切除程度、化疗、免疫治疗和放疗前卡诺夫斯基表现量表评分。
在总共 235 名患者中，通过倾向评分匹配选择了每组 26 名患者。PBT 组的中位总生存期（OS）为 28.3 个月，而 CRT 组的中位 OS 为 21.2 个月。尽管 PBT 和 CRT 组的急性放射性相关毒性相当，但 PBT 组观察到的放射性坏死作为一种迟发性放射性相关毒性明显更为频繁。
与 CRT 相比，倾向评分匹配分析显示高剂量 PBT 为新发 GBM 患者提供了显著的生存获益。高剂量 PBT 仍存在放射性坏死问题；因此，建立以贝伐单抗为中心的有效治疗策略至关重要。
