Fritz Corinna, Borsky Kim, Stark Luisa S, Tanadini-Lang S, Kroeze Stephanie G C, Krayenbühl Jérôme, Guckenberger Matthias, Andratschke Nicolaus
Department of Radiation Oncology, University Hospital Zurich Zurich, Switzerland.
Front Oncol. 2018 Nov 22;8:551. doi: 10.3389/fonc.2018.00551. eCollection 2018.
Stereotactic radiosurgery (SRS) is the preferred primary treatment option for patients with a limited number of asymptomatic brain metastases. In case of relapse after initial SRS the optimal salvage treatment is not well defined. Within this retrospective analysis, we investigated the feasibility of repeated courses of SRS to defer Whole-Brain Radiation Therapy (WBRT) and aimed to derive prognostic factors for patient selection. From 2014 until 2017, 42 patients with 197 brain metastases have been treated with multiple courses of SRS at our institution. Treatment was delivered as single fraction (18 or 20 Gy) or hypo-fractionated (6 fractions with 5 Gy) radiosurgery. Regular follow-up included clinical examination and contrast-enhanced cMRI at 3-4 months' intervals. Besides clinical and treatment related factors, brain metastasis velocity (BMV) as a newly described clinical prognostic metric was included and calculated between first and second treatment. A median number of 1 lesion (range: 1-13) per course and a median of 2 courses (range: 2-6) per patient were administered resulting in a median of 4 (range: 2-14) metastases treated over time per patient. The median interval between SRS courses was 5.8 months (range: 0.9-35 months). With a median follow-up of 17.4 months (range: 4.6-45.5 months) after the first course of treatment, a local control rate of 84% was observed after 1 year and 67% after 2 years. Median time to out-of-field-brain-failure (OOFBF) was 7 months (95%CI 4-8 months). WBRT as a salvage treatment was eventually required in 7 patients (16.6%). Median overall survival (OS) has not been reached. Grouped by ds-GPA (≤ 2 vs. >2) the survival curves showed a significant split ( = 0.039). OS differed also significantly between BMV-risk groups when grouped into low vs. intermediate/high risk groups ( = 0.025). No grade 4 or 5 acute or late toxicity was observed. In selected patients with relapse after SRS for brain metastases, repeat courses of SRS were safe and minimized the need for rescue WBRT. The innovative, yet easy to calculate metric BMV may facilitate treatment decisions as a prognostic factor for OS.
立体定向放射外科治疗（SRS）是无症状脑转移瘤数量有限患者的首选初始治疗方案。对于初次SRS治疗后复发的情况，最佳挽救治疗方案尚未明确界定。在这项回顾性分析中，我们研究了重复进行SRS疗程以推迟全脑放射治疗（WBRT）的可行性，并旨在得出用于患者选择的预后因素。2014年至2017年期间，我院对42例患有197个脑转移瘤的患者进行了多疗程SRS治疗。治疗采用单次分割（18或20 Gy）或低分割（6次分割，每次5 Gy）放射外科治疗。定期随访包括每隔3 - 4个月进行临床检查和增强磁共振成像（cMRI）。除了临床和治疗相关因素外，还纳入并计算了首次和第二次治疗之间新描述的临床预后指标——脑转移瘤生长速度（BMV）。每个疗程平均治疗1个病灶（范围：1 - 13个），每位患者平均进行2个疗程（范围：2 - 6个），每位患者随时间推移平均治疗4个转移瘤（范围：2 - 14个）。SRS疗程之间的中位间隔时间为5.8个月（范围：0.9 - 35个月）。在首个疗程治疗后，中位随访时间为17.4个月（范围：4.6 - 45.5个月），1年后局部控制率为84%，2年后为67%。野外脑衰竭（OOFBF）的中位时间为7个月（95%置信区间4 - 8个月）。最终有7例患者（16.6%）需要进行WBRT挽救治疗。总体生存（OS）中位数尚未达到。按诊断特异性预后评分（ds - GPA）分组（≤2 vs. >2），生存曲线显示出显著差异（P = 0.039）。当按低风险与中/高风险组对BMV风险组进行分组时，OS也存在显著差异（P = 0.025）。未观察到4级或5级急性或晚期毒性反应。对于选定的SRS治疗后复发的脑转移瘤患者，重复进行SRS疗程是安全的，并最大限度地减少了挽救性WBRT的需求。创新且易于计算的指标BMV作为OS的预后因素可能有助于治疗决策。
