Shah Sunny, Gates Kevin, Mallory Chase, Rubens Muni, Maher Ossama M, Niazi Toba N, Khatib Ziad, Kotecha Rupesh, Mehta Minesh P, Hall Matthew D
Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, Florida.
Department of Pediatric Oncology.
Adv Radiat Oncol. 2021 Mar 26;6(4):100691. doi: 10.1016/j.adro.2021.100691. eCollection 2021 Jul-Aug.
Postoperative radiation therapy (RT) is commonly used for World Health Organization grade II-III intracranial ependymoma. Clinicians generally aim to begin RT ≤5 weeks after surgery, but postoperative recovery and need for second look surgery can delay the initiation of adjuvant therapy. On ACNS 0831, patients were required to enroll ≤8 weeks after initial surgery and begin adjuvant therapy within 3 weeks after enrollment. The purpose of this study was to determine the optimal timing of RT after surgery.
The National Cancer Database was queried for patients (aged 1-39 years) with localized World Health Organization grade II-III intracranial ependymoma treated with surgery and postoperative RT. Overall survival (OS) curves were plotted based on RT timing (≤5 weeks, 5-8 weeks, and >8 weeks after surgery) and were compared by log-rank test. Factors associated with OS were identified by multivariate analysis. After 2009, complete data were available on whether patients underwent gross total resection or subtotal resection. Planned subset analysis was performed to examine the effect of RT timing on OS in patients with known extent of resection.
In the final analytical data set of 1043 patients, no difference in 3-year OS was observed in patients who initiated RT ≤5 weeks, 5 to 8 weeks, and >8 weeks after surgery (89.8% vs 89.1% vs 88.4%; = .796). On multivariate analysis, grade III tumors (hazard ratio, 2.752; 95% confidence interval, 1.969-3.846, < .001) and subtotal resection (hazard ratio, 2.253; 95% confidence interval, 1.405-3.611, < .001) were significantly associated with reduced OS. Timing of RT, total RT dose, age, and other factors were not significant. These findings were affirmed in the subset of patients treated between 2010 and 2016, when extent of resection was routinely recorded.
Delayed postoperative RT was not associated with inferior survival in patients with intracranial ependymoma. Delayed RT initiation may be acceptable in patients who require longer postoperative recovery or referral to an appropriate RT center, but should be minimized whenever practical.
术后放射治疗（RT）常用于世界卫生组织二级至三级颅内室管膜瘤。临床医生通常旨在术后≤5周开始进行RT，但术后恢复情况以及二次手术的需求可能会延迟辅助治疗的开始。在ACNS 0831研究中，要求患者在初次手术后≤8周入组，并在入组后3周内开始辅助治疗。本研究的目的是确定术后RT的最佳时机。
查询国家癌症数据库，以获取接受手术及术后RT治疗的1-39岁局限性世界卫生组织二级至三级颅内室管膜瘤患者。根据RT时机（术后≤5周、5-8周和>8周）绘制总生存（OS）曲线，并通过对数秩检验进行比较。通过多因素分析确定与OS相关的因素。2009年后，可获得患者是否接受全切除或次全切除的完整数据。进行计划亚组分析，以研究RT时机对已知切除范围患者OS的影响。
在1043例患者的最终分析数据集中，术后≤5周、5至8周和>8周开始RT的患者，3年OS无差异（89.8%对89.1%对88.4%；P = 0.796）。多因素分析显示，三级肿瘤（风险比，2.752；95%置信区间，1.969-3.846，P < 0.001）和次全切除（风险比，2.253；95%置信区间，1.405-3.611，P < 0.001）与OS降低显著相关。RT时机、总RT剂量、年龄和其他因素不显著。在2010年至2016年接受治疗且常规记录切除范围的患者亚组中，这些结果得到了证实。
颅内室管膜瘤患者术后延迟RT与较差的生存率无关。对于需要更长时间术后恢复或转诊至合适RT中心的患者，延迟RT开始可能是可以接受的，但应在实际可行时尽量缩短延迟时间。
