Kusumawidjaja Grace, Gan Patricia Zhun Hong, Ong Whee Sze, Teyateeti Achiraya, Dankulchai Pittaya, Tan Daniel Yat Harn, Chua Eu Tiong, Chua Kevin Lee Min, Tham Chee Kian, Wong Fuh Yong, Chua Melvin Lee Kiang
Division of Radiation Oncology, National Cancer Centre, Singapore.
Division of Clinical Trials and Epidemiological Sciences, National Cancer Centre, Singapore.
Onco Targets Ther. 2016 Mar 2;9:1115-22. doi: 10.2147/OTT.S96509. eCollection 2016.
Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor with high relapse rate. In this study, we aimed to determine if dose-escalated (DE) radiotherapy improved tumor control and survival in GBM patients.
We conducted a retrospective analysis of 49 and 23 newly-diagnosed histology-proven GBM patients, treated with DE radiotherapy delivered in 70 Gy (2.33 Gy per fraction) and conventional doses (60 Gy), respectively, between 2007 and 2013. Clinical target volumes for 70 and 60 Gy were defined by 0.5 and 2.0 cm expansion of magnetic resonance imaging T1-gadolinium-enhanced tumor/surgical cavity, respectively. Bilateral subventricular zones (SVZ) were contoured on a co-registered pre-treatment magnetic resonance imaging and planning computed tomography dataset as a 5 mm wide structure along the lateral margins of the lateral ventricles. Survival outcomes of both cohorts were compared using log-rank test. Radiation dose to SVZ in the DE cohort was evaluated.
Median follow-up was 13.6 and 15.1 months for the DE- and conventionally-treated cohorts, respectively. Median overall survival (OS) of patients who received DE radiotherapy was 15.2 months (95% confidence interval [CI] =11.0-18.6), while median OS of the latter cohort was 18.4 months (95% CI =12.5-31.4, P=0.253). Univariate analyses of clinical and dosimetric parameters among the DE cohort demonstrated a trend of longer progression-free survival, but not OS, with incremental radiation doses to the ipsilateral SVZ (hazard ratio [HR] =0.95, 95% CI =0.90-1.00, P=0.052) and proportion of ipsilateral SVZ receiving 50 Gy (HR =0.98, 95% CI =0.97-1.00, P=0.017).
DE radiotherapy did not improve survival in patients with GBM. Incorporation of ipsilateral SVZ as a radiotherapy target volume for patients with GBM requires prospective validation.
多形性胶质母细胞瘤（GBM）是最具侵袭性的原发性脑肿瘤，复发率高。在本研究中，我们旨在确定剂量递增（DE）放疗是否能改善GBM患者的肿瘤控制和生存率。
我们对2007年至2013年间分别接受70 Gy（每次分割2.33 Gy）DE放疗和常规剂量（60 Gy）放疗的49例和23例新诊断的经组织学证实的GBM患者进行了回顾性分析。70 Gy和60 Gy的临床靶区分别通过磁共振成像T1加权钆增强肿瘤/手术腔向外扩展0.5 cm和2.0 cm来定义。在配准的治疗前磁共振成像和计划计算机断层扫描数据集上，将双侧脑室下区（SVZ）勾勒为沿侧脑室侧缘5 mm宽的结构。使用对数秩检验比较两个队列的生存结果。评估DE队列中SVZ的辐射剂量。
DE治疗组和常规治疗组的中位随访时间分别为13.6个月和15.1个月。接受DE放疗患者的中位总生存期（OS）为15.2个月（95%置信区间[CI]=11.0-18.6），而后者队列的中位OS为18.4个月（95%CI=12.5-31.4，P=0.253）。DE队列中临床和剂量学参数的单因素分析显示，同侧SVZ辐射剂量增加时，无进展生存期有延长趋势，但总生存期无延长趋势（风险比[HR]=0.95，95%CI=0.90-1.00，P=0.
