伽玛刀治疗22例原发视神经鞘脑膜瘤的疗效分析

Hyper-SGSI gamma knife in 22 patients with primary optic nerve sheath meningioma

目的探讨采用伽玛刀进行低分割、高剂量的分次立体定向放射治疗(FSRT)治疗原发性视神经鞘脑膜瘤的疗效。方法 2004年8月至2010年3月收治原发性视神经鞘脑膜瘤22例患者,均采用Hyper-SGSI型立体定向体部伽玛射线放射治疗系统进行FSRT治疗,1例进行常规分割,单次剂量2Gy;21例行低分割、高剂量的FSRT治疗,单次剂量3～5Gy靶区累积剂量为36～40Gy。治疗后6个月随访1次,中位随访时间25个月,观察患者的临床症状改善情况、视力保全率及肿瘤控制情况。结果截止于末次随访,全组患者的视力控制率为77.3%(17/22),其中视力改善4例,稳定13例,下降3例,失明2例。视力控制率随时间变化略有下降,1年视力控制率为95.0%(19/20),2年视力控制率为75.0%(9/12),但差异无统计学意义(P>0.05)。肿瘤控制率为100.0%,最大径缩小>50%的8例(36.4%),缩小25%～50%的11例(50.0%),缩小<10%～25%的3例(13.6%)。突眼症状改善率为100.0%,治疗前突眼度为(17.3±2.7)mm,治疗后突眼度为(14.9±1.5)mm(P<0.05)。有10例患者出现治疗相关反应,对症治疗可恢复。结论采用低分割、高剂量的FSRT治疗原发视神经鞘脑膜瘤的疗效确切,但视力改善不明显,对于确切分割模式及剂量尚需进一步探讨。

Objective To assess the efficacy of Hyper-SGSI gamma knife with different dose fractionations in patients with primary optic nerve sheath meningioma（ONSM）. Methods From Aug. 2004 to Mar. 2010, 22 patients with ONSM were treated with fractionated stereotactic radiotherapy（FSRT） by Hyper-SGSI gamma knife treatment system. 1 case was treated with conventional frac- tionation, the radiation dose was 50 Gy in 25 fractions; 21 patients were treated with hypofraction, the radiation dose were 36-40 Gy in 8-12 fractions. Clinical and radiographic follow-up were performed every 6 months after FSRT therapy, Efficacy of FSRT and improve- ment of symptoms were evaluated by clinic manifestation and change of tumor maximum diameter in different follow-up time. Results After a median follow-up of 25 months, the visual control rate in all patients was 77.3% （17/22）. Visual acuity was improved in 4 pa- tients,remained stable in 13 patients, and deteriorated in 3patients, blindness in 2 patients. The visual control rate would decline with time of follow-up, with one year follow-up was 95.0% （19/20） ,with two years follow-up was 75.0% （9/12）. The tumor control rate was 100. 0% （22 cases）. The maximum diameter of the tumor was reduced more than 50% in 8 patients （36.4%） ;25% - 50% in llpatients（50. 0% ） ;10% -25% in 3 patients（ 13.6% ）. The rate of improvement with proptosis was 100. 0% （17/17）. The degree of proptosis at pro and post treatment were （ 17.3 -＋ 2. 7 ）mm and （ 14. 9 -＋ 1.5 ） mm, respectively. There were statistical significance （ P 〈 0. 05）. Ten cases with reversible complications could be recovered after symptomatic treatment. Conclusion Fractionated ster- eotaetic radiotherapy can improves tumor control and proptosis for ONSM, while control rate for the visual observation is still needed for a long time. The best dose fractionation with FSRT for ONSM will be required for further study.