脑转移瘤的放射外科治疗的新模式：2阶段伽玛刀放射外科治疗策略探索及疗效分析

目的评估2阶段伽玛刀放射外科治疗体积较大或靠近高危神经结构且存在手术禁忌的转移瘤的疗效及安全性。方法回顾性分析2017年12月1日—2020年6月30日在上海伽玛医院接受分2阶段伽玛刀立体定向放射外科治疗的39例患者的53处大型或靠近危急神经结构的脑转移瘤。肿瘤治疗前的初始体积为（15.4±11.5）cm3 。为患者设计间隔较长［平均（13.1±9.3）d］的2个阶段的伽玛刀治疗方案。重点监测治疗后病灶体积缩小比例以分析本治疗方案对于肿瘤的局部控制效果，除此之外观察患者治疗后卡氏功能状态评分（KPS）改善情况、所有患者的整体生存、放射反应发生的情况等。结果100%患者顺利耐受2个阶段的治疗计划。到第2阶段治疗时，所有肿瘤体积缩小了平均24.8%±21.1%，第2阶段治疗完成后的3个月、6个月、9个月和12个月肿瘤体积分别平均缩小了68.3%±20.4%、74.6%±22.2%、70.4±23.7%和66.9±34.4%。12个月和24个月生存率分别为80%和60%。中位生存时间为24个月。11.3%的病灶出现复发，复发的中位时间为21.5（9~24）个月。15.1%的患者出现放射反应，中位时间为9个月（6～10个月）。结论分阶段放射外科治疗可作为大型或者靠近高危结构脑转移瘤的一种高效、安全的替代治疗方案。

Objective To evaluate the utility of two-staged gamma knife radiosurgery in patients with large, high-risk brain metastases. Method A total of 53 large or high-risk brain metastases in 39 patients treated with two-staged gamma knife radiosurgery at Shanghai Gamma Hospital from December 1, 2017 to June 30, 2020 were analyzed retrospectively. The initial tumor volume was（15.4±11.5）cm3. The two-staged gamma knife radiosurgery plan with a long interval(13.1±9.3 days) were designed for patients. Volumetric measurements at the first stage, second stage, and follow-up imaging studies were obtained to analyze the local control effect of this strategy. In addition, the improvement of Karnofsky performance scale(KPS), overall survival of the patients, and the occurrence of radiation toxicities were observed respectively. Results 100% of patients successfully tolerated the two-staged gamma knife radiosurgery. At the second stage of treatment, all tumor volumes decreased by an average of 24.8%±21.1%. After the second stage of treatment, the tumor volumes decreased by an average of 68.3%±20.4%, 74.6%±22.2%, 70.4±23.7%, and 66.9±34.4% at 3, 6, 9, and 12 months, respectively. The 12 month and 24 month survival rates were 80% and 60%, respectively. The median overall survival time was 24 months. 11.3% of the lesions experienced recurrence, with a median recurrence time of 21.5(9-24) months. 15.1% of patients experienced radiation reactions with a median time of 9 months(6-10 months). Conclusion Staged radiosurgery can be an efficient and safe alternative treatment for large or high risk brain metastases.