Department of Radiation Oncology, Stanford University Medical Center, Stanford, California.
Neuro Oncol. 2018 Jul 5;20(8):1133-1141. doi: 10.1093/neuonc/noy001.
Radiation therapy (RT) remains a critical component of multimodality treatment for medulloblastoma. Traditionally, clinicians strive to start RT within 4-5 weeks of surgery, but the optimal timing after surgery remains unclear.
Using the National Cancer Database, we identified pediatric and adolescent patients with medulloblastoma treated with curative-intent surgery, RT, and chemotherapy. Factors associated with early or delayed RT were identified using Pearson chi-squared tests. Overall survival (OS) differences based on RT timing were compared using the Kaplan-Meier estimator with log-rank tests. Patient, tumor, and treatment characteristics associated with OS were analyzed with univariate and multivariate Cox proportional hazards models.
Among the 1338 patients analyzed, early RT (defined as initiation ≤3 wk after surgery) was associated with younger age, M1-3 disease, and subtotal resection. Patients who initiated RT early had decreased 5-year OS compared with patients who initiated RT 3.1-4, 4.1-5, or >5 weeks after surgery (72.5% vs. 80.5%, 79.4%, and 77.8%, respectively; P = 0.019), but there was no significant difference in OS among the latter 3 groups (P = 0.788). On multivariate analysis, early RT versus the 3.1- to 4-week interval was significantly associated with poorer OS (adjusted hazard ratio, 1.72; 95% CI: 1.19-2.48; P = 0.004), while time to RT of >5 weeks but within 90 days of surgery did not adversely impact OS (P = 0.563).
In this large national database analysis, delaying RT within 90 days of surgery was not associated with inferior outcomes. Although clinical judgment remains paramount, postoperative RT timing should allow for healing and the development of an optimal treatment plan.
放射治疗（RT）仍然是治疗髓母细胞瘤的多模式治疗的关键组成部分。传统上，临床医生努力在手术后 4-5 周内开始 RT，但手术后的最佳时机仍不清楚。
使用国家癌症数据库，我们确定了接受根治性手术、RT 和化疗治疗的儿童和青少年髓母细胞瘤患者。使用 Pearson 卡方检验确定与早期或延迟 RT 相关的因素。使用 Kaplan-Meier 估计器和对数秩检验比较基于 RT 时机的总生存（OS）差异。使用单变量和多变量 Cox 比例风险模型分析与 OS 相关的患者、肿瘤和治疗特征。
在分析的 1338 名患者中，早期 RT（定义为起始≤手术后 3 周）与年龄较小、M1-3 疾病和次全切除有关。与手术后 3.1-4 周、4.1-5 周或>5 周开始 RT 的患者相比，早期开始 RT 的患者 5 年 OS 降低（分别为 72.5%、80.5%、79.4%和 77.8%；P=0.019），但后 3 组之间的 OS 无显著差异（P=0.788）。多变量分析显示，与 3.1 至 4 周间隔相比，早期 RT 与较差的 OS 显著相关（调整后的危险比，1.72；95%CI：1.19-2.48；P=0.004），而手术后 90 天内 RT 时间超过但不超过 90 天不会对 OS 产生不利影响（P=0.563）。
在这项大型全国性数据库分析中，手术后 90 天内延迟 RT 与不良结局无关。尽管临床判断仍然至关重要，但术后 RT 时机应允许愈合并制定最佳治疗计划。
