Limon Dror, McSherry Frances, Herndon James, Sampson John, Fecci Peter, Adamson Justus, Wang Zhiheng, Yin Fang-Fang, Floyd Scott, Kirkpatrick John, Kim Grace J
Department of Oncology, Rabin Medical Center, Petah-Tikva, Israel.
Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina.
Adv Radiat Oncol. 2017 Sep 11;2(4):555-563. doi: 10.1016/j.adro.2017.09.002. eCollection 2017 Oct-Dec.
Due to the neurocognitive side effects of whole brain radiation therapy (WBRT), stereotactic radiosurgery (SRS) is being used with increasing frequency. The use of SRS is expanding for patients with multiple (>4) brain metastases (BM). This study summarizes our institutional experience with single-fraction, linear-accelerator-based SRS for multiple BM.
All patients who were treated between January 1, 2013, and September 30, 2015, with single-fraction SRS for ≥4 BM were included in this institutional review board-approved, retrospective, single-institution study. Patients were treated with linear accelerator-based image guided SRS.
A total of 59 patients with ≥4 BM were treated with single-fraction SRS. The median follow-up was 15.2 months, and the median overall survival for the entire cohort was 5.8 months. The median number of treated lesions per patient was 5 (range, 4-23). Per patient, the median planning target volume (PTV) was 4.8 cc (range, 0.7-28.8 cc). The prescribed dose across all 380 BM for the 59 patients ranged from 7 to 20 Gy. The median of the mean dose to the total PTV was 19.5 Gy. Although the number of treated lesions (4-5 vs ≥6) did not influence survival, better survival was noted for a total PTV <10 cc versus ≥10 cc (7.1 vs 4.2 months, respectively; = .0001). A mean dose of ≥19 Gy to the entire PTV was also associated with increased survival (6.6 vs 5.0 months, respectively; = .0172). Patients receiving a dose of >12 Gy to ≥10 cc of normal brain had worse survival (5.1 vs 8.6 months, respectively; = .0028).
In single-fraction SRS for patients with multiple BM, smaller total tumor volume, higher total dose, and lower volume of normal brain receiving >12 Gy were associated with increased survival. These data suggest that using SRS for the treatment of multiple BM is efficacious and that outcomes may be affected more by total tumor volume than by the number of lesions.
由于全脑放射治疗（WBRT）存在神经认知方面的副作用，立体定向放射外科（SRS）的使用频率日益增加。SRS在多发性（>4个）脑转移瘤（BM）患者中的应用正在不断扩大。本研究总结了我们机构采用基于直线加速器的单次分割SRS治疗多发性BM的经验。
本机构审查委员会批准的这项回顾性单机构研究纳入了2013年1月1日至2015年9月30日期间接受单次分割SRS治疗且BM≥4个的所有患者。患者接受基于直线加速器的图像引导SRS治疗。
共有59例BM≥4个的患者接受了单次分割SRS治疗。中位随访时间为15.2个月，整个队列的中位总生存期为5.8个月。每位患者治疗的病灶中位数为5个（范围4 - 23个）。每位患者的中位计划靶体积（PTV）为4.8立方厘米（范围0.7 - 28.8立方厘米）。59例患者的380个BM的处方剂量范围为7至20 Gy。总PTV的平均剂量中位数为19.5 Gy。尽管治疗的病灶数量（4 - 5个与≥6个）不影响生存期，但总PTV<10立方厘米的患者生存期优于≥10立方厘米的患者（分别为7.1个月与4.2个月；P = 0.0001）。整个PTV的平均剂量≥19 Gy也与生存期延长相关（分别为6.6个月与5.0个月；P = 0.0172）。接受>12 Gy剂量照射且正常脑体积≥10立方厘米的患者生存期较差（分别为5.1个月与8.6个月；P = 0.0028）。
在多发性BM患者的单次分割SRS治疗中，较小的总肿瘤体积、较高的总剂量以及接受>12 Gy照射的正常脑体积较小与生存期延长相关。这些数据表明，使用SRS治疗多发性BM是有效的，并且结果可能更多地受总肿瘤体积而非病灶数量的影响。
