立体定向放疗与全脑放疗局限性脑转移瘤的疗效预后分析

Prognostic Analysis of Whole-brain Radiotherapy and Stereotactic Radiotherapy for Treatment of Local Limited Brain Metastases

【目的】探讨立体定向放射治疗(SRT)与全脑放射治疗(WBRT)在局限性脑转移瘤治疗中的疗效和预后,为合理应用SRT和WBRT提供依据。【方法】选择2000年1月～2005年12月收治的转移灶≤4个且最大径≤4cm脑转移患者60例,按照原发肿瘤类型(肺癌和非肺癌)、脑转移灶数目(单发和2～4个)、有无颅外转移和化疗与否四项因素进行匹配设计分为WBRT加SRT、单纯SRT和单纯WBRT治疗组,三组的治疗剂量分别为WBRT30～36Gy+SRT18～20Gy、SRT28～32Gy和WBRT30～40Gy,分析全组以及据原发肿瘤类型、脑转移灶数目、有无颅外转移亚组不同治疗方法在局部控制率、局部新病灶发生率(χ2检验)和生存率(Kaplan-Meier法和Log-rank检验)的差异。【结果】全组局部控制率与局部新病灶发生率分别为80.0%(48/60)和20.0%(12/60)。全组患者中位生存时间13个月(3～36月),第1、2年生存率分别是38.1%和14.3%。WBRT加SRT、单纯SRT和单纯WBRT治疗组的局部控制率分别为95.0%、80.0%和60.0%(P<0.05),而局部新病灶发生率则分别为15.0%、35.0%和10.0%(P<0.05)。WBRT加SRT、单纯SRT和单纯WBRT治疗组的中位生存期分别为8、9和6个月,生存分析未显示不同治疗方法影响生存预后(P>0.05),分层分析亦未显示不同治疗方法在不同原发肿瘤亚组中影响生存预后(P>0.05),然而在单发脑转移患者和无颅外转移患者中,WBRT加SRT和单纯SRT治疗组的生存预后优于单纯WBRT治疗组,中位生存期分别为23、16和5个月(P<0.05),以及12、9和5个月(P<0.05)。【结论】SRT可明显改善局限性脑转移瘤患者的局部控制率,但未行WBRT治疗的患者局部新发脑转移率明显增加。在预后较好的单发脑转移瘤患者和无颅外转移患者中,联合应用SRT和WBRT能显著提高生存率。

[Objective] To investigate the effect of stereotactic radiotherapy （SRT） and whole brain radiotherapy （WBRT） for treatment of local limited brain metastasis （BM） in order to provide evidence for the rational options of SRT and WBRT. [Methods] From January 2000 to December 2005, 60 patients with less than 4 lesions and less than 4 cm tumor volume BMs, were eligible for this retrospective analysis. According to primary tumor category, numbers of BM, whether combining extracranial systemic metastases and chemotherapy, the patients were stratified as WBRT ＋ SRT, SRT alone, or WBRT alone by matched-pairing. A number of treatment results including local control of treated lesions,recurrence of new brain lesions and overall survival were compared between three treatment groups in all patients and subgroups of the patients with different primary tumor category, numbers of BM, whether combining extracranial systemic metastases and chemotherapy, respectively. The significance of local control of treated lesions, recurrence of new brain lesions and overall survival, resulted from x^2 test and Kaplan-Mierer combining with log-rank test, respectively. [Results] For the entire cohort, the local control rate and the recurrence rate of new brain lesions were 80.0% （48/60） and 23.3% （14/60）, and the median survival from the end of radiation for BM was 13 months, and the actuarial overall survival rate were 38.1% and 14.3% at 1, 2 years, respectively. The local control rates were 95.0%, 80.0%, and 60.0% for SRT＋WBRT, SRT, and WBRT alone groups respectively （P 〈 0.05）. However, the recurrence rates of new brain lesions were 15.0%, 35.0%, and 10.0% for SRT＋WBRT, SRT and WBRT alone groups respectively （P 〈 0.05）. The overall median survival were 8, 9, and 6 months for the SRT＋WBRT, SRT and WBRT groups respectively （P 〉 0.05）. And there was no survival differences by primary tumor category （P 〉 0.05）. But in the patients with solitary BM, the patients receiving SRT＋WBRT or SRT had better median survival of 23, 16 months compared with 5 months for those receiving WBRT alone （P 〈 0.05）. Similarly, the patients receiving SRT＋WBRT or SRT had better median survival of 12,9 months compared with 5 months for those receiving WBRT alone in the patients without extracranial systemic metastases （P 〈 0.05 ）. [ Conclusions] Local control of the treatment for BM is superior with SRT, however, the risk of developing new brain lesions is higher for patients not receiving WBRT. In the patients either with solitary BM or without extracranial systemic metastases, the treatment of SRT combining WBRT can provide superior survival prognosis.