立体定向放射外科针对颅内非生殖性生殖细胞瘤常规放疗后残留病灶的疗效分析

目的探讨立体定向放射外科（SRS）治疗松果体区非生殖细胞瘤性生殖细胞肿瘤（NGGCTs）常规放疗后残留病灶的有效性和安全性。方法回顾性分析2008年1月—2018年12月广东三九脑科医院肿瘤中心收治的颅内生殖细胞肿瘤患者临床资料，按纳入标准筛选患者：（1）病理或临床诊断为NGGCTs；（2）病灶位于松果体区；（3）临床分期为局限期；（4）松果体病灶经过常规放疗50~54 Gy/25~30 f后可见肿瘤残留（病灶最大径直径>10 mm）。分析入组患者SRS治疗后肿瘤局部控制率、无进展生存时间、总生存时间及治疗相关毒性。结果符合标准并纳入分析患者共27例，均为男性患者，中位年龄16岁（8~31岁）；随访至2019年12月30日，2例失访，中位随访时间34个月（8~142个月）；SRS治疗后1个月客观反应率71.4%，疾病控制率为95.2%；3年无进展生存时间、3年总生存期分别为85.2%、88%；单因素分析显示年龄、同步化疗与预后无关（P=0.286、0.824）；放化疗前肿瘤部分切除术、AFP>500 ng/mL、辅助化疗周期数≤4是不利预后因素（P=0.037、0.01、0.006）；所有患者SRS治疗后未见急性放射反应，1例（3.7%）出现远期治疗相关脑部神经毒性。结论SRS治疗NGGCTs常规放疗后局部残留病灶安全、可行，耐受性好，可提高局部病灶控制，延长患者生存期，但由于病例数少需要进一步研究观察。

ObjectiveTo evaluate the safety and efficacy of stereotatic radiosurgery(SRS) in treating residual lesions of pineal non-germinomatous germ cell tumors(NGGCTs) after conventional radiotherapy. MethodsThe clinical data of patients with intracranial germ cell tumors admitted to Guangdong Sanjiu Brain Hospital from January 2008 to December 2018 who diagnosed with pineal NGGCTs pathologically or clinically were analyzed retrospectively. Among those, the patients received conventional radiotherapy with SRS were included. The residual lesions after radiotherapy were defined with a maximum diameter >10 mm. Prognosis related parameters such as local control rate, progress-free survival, overall survival and treatment-related toxicity were determined. Results Total of 27 patients were included in this study. Both of them were males with the median age of 16 years old. The median follow-up time was 34 months(range 8-142 months). The objective response rate and disease control rate were 71.4% and 95.2%, respectively. Three-year progression-free survival rate was 85.2% and 3-year total survival rate was 88.0%. The univariate analysis revealed that both age and concurrent chemotherapy were not correlated with the prognosis(P=0.286,0.824). Partial tumor resection before radiotherapy and chemotherapy, AFP>500 ng/mL, and less than 4 cycles of adjuvant chemotherapy were poor prognostic factors(P=0.037,0.010,0.006). Moreover, no acute radiation injury was observed after SRS. Only 1 out of 27 patients(3.7%) had brain neurotoxicity related to a prolonged course of radiochemotherapy. ConclusionsSRS for residual lesions of NGGCTs following conventional radiotherapy appears to be well tolerant and improved local control. However, the therapeutic efficacy of conventional radiotherapy combined with SRS warrants further investigations in a large-scale randomized controlled clinical trials.