Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL.
Department of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, PA.
Am J Clin Oncol. 2020 May;43(5):356-361. doi: 10.1097/COC.0000000000000675.
The brain is a rare site for sarcoma metastases. Sarcoma's radioresistance also makes standard whole-brain radiotherapy less appealing. We hypothesize that stereotactic radiation techniques (stereotactic radiosurgery [SRS]/stereotactic fractionated radiotherapy [FSRT]) may provide effective local control.
This single-institution retrospective analysis evaluated our experience with linear acceleator-based SRS/FSRT for sarcoma brain metastases. Time to event analysis was estimated via Kaplan-Meier. Univariable/multivariable Cox regression analyses followed to assess the impact of patient and disease characteristics on outcomes.
Between 2003 and 2018, 24 patients were treated with 34 courses of SRS/FSRT to 58 discrete lesions. The median age at first treatment was 57 years (range: 25 to 87 y). Majority of patients had concurrent lung metastases (n=21; 88%), diagnosed spindle cell sarcoma (n=15; 25%) or leiomyosarcoma (n=12; 21%) histology, and were treated with either SRS (n=43; median dose=19 Gy, range: 15 to 24 Gy) or FSRT (n=17; 3/5 fractions, median dose=25 Gy, range: 25 to 35 Gy). With a median follow-up after brain metastasis of 7.3 months, the 6 month/12 month local control, distant brain control, and overall survival of 89%/89%, 59%/34%, and 50%/38%, respectively. All local failures were of primary spindle cell histology (P<0.001), which was associated with poorer distant control (hazard ratio=25.8, 95% confidence interval: 3.1-536.4; P=0.003) on univariable analysis, and OS (hazard ratio=7.1, 95% confidence interval: 2.0-26.1; P=0.003) on multivariable analysis.
This is the largest patient cohort with sarcoma brain metastases treated with SRS/FSRT, it provides durable local control, despite a reputation for radioresistance. Further prospective evidence is required to determine the impact of primary histology on control and survival following brain metastasis diagnosis.
脑是肉瘤转移的罕见部位。肉瘤的放射抗性也使得标准的全脑放疗不太吸引人。我们假设立体定向放射技术（立体定向放射外科[SRS]/立体定向分割放疗[FSRT]）可能提供有效的局部控制。
本单机构回顾性分析评估了我们使用基于线性加速器的 SRS/FSRT 治疗肉瘤脑转移的经验。通过 Kaplan-Meier 估计时间事件分析。随后进行单变量/多变量 Cox 回归分析，以评估患者和疾病特征对结果的影响。
在 2003 年至 2018 年间，24 例患者接受了 34 次 SRS/FSRT 治疗 58 个离散病变。首次治疗时的中位年龄为 57 岁（范围：25 至 87 岁）。大多数患者同时患有肺转移（n=21；88%），诊断为梭形细胞肉瘤（n=15；25%）或平滑肌肉瘤（n=12；21%）组织学，并接受 SRS（n=43；中位剂量=19 Gy，范围：15 至 24 Gy）或 FSRT（n=17；3/5 个分数，中位剂量=25 Gy，范围：25 至 35 Gy）治疗。脑转移后的中位随访时间为 7.3 个月，6 个月/12 个月的局部控制率、远处脑控制率和总生存率分别为 89%/89%、59%/34%和 50%/38%。所有局部失败均为原发性梭形细胞组织学（P<0.001），这与远处控制较差（单变量分析风险比=25.8，95%置信区间：3.1-536.4；P=0.003）和 OS（风险比=7.1，95%置信区间：2.0-26.1；P=0.003）相关。
这是最大的肉瘤脑转移患者队列接受 SRS/FSRT 治疗，尽管放射抗性较大，但仍能提供持久的局部控制。需要进一步的前瞻性证据来确定脑转移诊断后原发组织学对控制和生存的影响。
