Department of Radiation Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Radiation and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center Johns Hopkins School of Medicine, Baltimore, Maryland.
Int J Radiat Oncol Biol Phys. 2021 Mar 1;109(3):726-735. doi: 10.1016/j.ijrobp.2020.09.049. Epub 2020 Nov 23.
This multi-institutional retrospective study sought to examine the hematologic effects of craniospinal irradiation (CSI) in pediatric patients with medulloblastoma using proton or photon therapy.
Clinical and treatment characteristics were recorded for 97 pediatric patients with medulloblastoma who received CSI without concurrent chemotherapy or with concurrent single-agent vincristine from 2000 to 2017. Groups of 60 and 37 patients underwent treatment with proton-based and photon-based therapy, respectively. Overall survival was determined by Kaplan-Meier curves with log-rank test. Comparisons of blood counts at each timepoint were conducted using multiple t tests with Bonferroni corrections. Univariate and multivariate analyses of time to grade ≥3 hematologic toxicity were performed with Cox regression analyses.
Median age of patients receiving proton and photon CSI was 7.5 years (range, 3.5-22.7 years) and 9.9 years (range, 3.6-19.5 years), respectively. Most patients had a diagnosis of standard risk medulloblastoma, with 86.7% and 89.2% for the proton and photon cohorts, respectively. Median total dose to involved field or whole posterior fossa was 54.0 Gy/Gy relative biological effectiveness (RBE) and median CSI dose was 23.4 Gy/Gy(RBE) (range, 18-36 Gy/Gy[RBE]) for both cohorts. Counts were significantly higher in the proton cohort compared with the photon cohort in weeks 3 to 6 of radiation therapy (RT). Although white blood cell counts did not differ between the 2 cohorts, patients receiving proton RT had significantly higher lymphocyte counts throughout the RT course. Similar results were observed when excluding patients who received vertebral body sparing proton RT or limiting to those receiving 23.4 Gy. Only photon therapy was associated with decreased time to grade ≥3 hematologic toxicity on univariate and multivariable analyses. No difference in overall survival was observed, and lymphopenia did not predict survival.
Patients who receive CSI using proton therapy experience significantly decreased hematologic toxicity compared with those receiving photon therapy.
本多机构回顾性研究旨在探讨质子或光子颅脊髓照射（CSI）治疗儿童髓母细胞瘤的血液学效应。
2000 年至 2017 年间，97 例未接受同期化疗或同期单药长春新碱治疗的髓母细胞瘤患儿接受 CSI 治疗，记录其临床和治疗特征。60 例患儿接受质子治疗，37 例患儿接受光子治疗。采用 Kaplan-Meier 曲线和对数秩检验确定总生存率。采用多重 t 检验和 Bonferroni 校正比较各时间点的血细胞计数。采用 Cox 回归分析进行单因素和多因素分析，以确定发生≥3 级血液学毒性的时间。
接受质子和光子 CSI 的患儿中位年龄分别为 7.5 岁（范围 3.5-22.7 岁）和 9.9 岁（范围 3.6-19.5 岁）。大多数患儿诊断为标准风险髓母细胞瘤，质子组和光子组分别为 86.7%和 89.2%。累及野或全后颅窝的中位总剂量为 54.0 Gy/ 相对生物效应（RBE）Gy，CSI 剂量中位值为 23.4 Gy/ Gy（RBE）（范围 18-36 Gy/ Gy[RBE]），两组间差异无统计学意义。在放射治疗（RT）的第 3 至 6 周，质子组的血细胞计数明显高于光子组。虽然两组间白细胞计数无差异，但接受质子 RT 的患者在整个 RT 过程中淋巴细胞计数明显更高。当排除接受椎体 spared 质子 RT 的患者或仅纳入接受 23.4 Gy 的患者时，也得到了相似的结果。单因素和多因素分析均显示，仅光子治疗与降低≥3 级血液学毒性的时间相关。未观察到总生存率的差异，且淋巴细胞减少与生存无关。
与接受光子治疗的患者相比，接受质子治疗的 CSI 患者血液学毒性明显降低。
