Tsao M N, Lloyd N, Wong R, Chow E, Rakovitch E, Laperriere N
Toronto-Sunnybrook Regional Cancer Centre, Department of Radiation Oncology, 2075 Bayview Avenue, Toronto, Ontario, Canada M4N 3M5.
Cochrane Database Syst Rev. 2006 Jul 19(3):CD003869. doi: 10.1002/14651858.CD003869.pub2.
Brain radiotherapy is used to treat cancer patients who have brain metastases resulting from various primary malignancies.
To assess the effectiveness and adverse effects of whole brain radiotherapy (WBRT) in adult patients with multiple metastases to the brain.
CENTRAL (The Cochrane Library), MEDLINE, EMBASE, CANCERLIT, and CINAHL were searched.
Randomized controlled trials (RCTs) in which adult patients with multiple metastases to the brain from any primary cancer and treated with WBRT were included. Trials of prophylactic WBRT were excluded as well as trials that dealt with surgery or WBRT, or both, for the treatment of a single brain metastasis.
Two review authors independently abstracted information for each predetermined outcome: overall survival at six months, intracranial progression-free duration, local brain response, local brain control, quality of life, symptom control, neurological function, and the proportion of patients able to reduce the daily dexamethasone dose. Adverse effects were also collected.
Eight published reports (nine trials) showed no benefit of altered dose-fractionation schedules as compared to control fractionation (3000 cGy in 10 fractions) of WBRT on the probability of survival at six months. These studies also showed no difference in symptom control nor neurologic improvement among the different dose-fractionation schemes. The addition of radiosensitizers, in five RCTs, did not confer additional benefit to WBRT in either overall median survival times or brain tumor response rates. The addition of the radiosensitizer motexafin gadolinium did not improve quality of life nor time to neurologic progression overall. For the radiosensitizer misonidazole, there was no improvement in Karnofsky performance score outcomes. Three RCTs found no benefit in overall survival with the use of WBRT and a radiosurgery boost as compared to WBRT alone for selected patients with multiple brain metastases (up to four brain metastases). Overall, however, there was a statistically significant improvement in local brain control favoring the whole brain radiotherapy and radiosurgery boost arm. Only one trial of radiosurgery boost with WBRT reported an improved Karnofsky performance score outcome and improved ability to reduce dexamethasone dose. One RCT examined the use of WBRT and prednisone versus prednisone alone and produced inconclusive results.
AUTHORS' CONCLUSIONS: None of the RCTs with altered dose-fractionation schemes as compared to standard delivery (3000 cGy in ten fractions) found a benefit in terms of overall survival, neurologic function, or symptom control. The use of radiosensitizers or chemotherapy in conjunction with WBRT remains experimental. A radiosurgery boost with WBRT may improve local disease control in selected patients, although survival remains unchanged. The benefit of WBRT as compared to supportive care alone has not been studied in RCTs. It may be that supportive care alone, without WBRT, may be appropriate for some patients, particularly those with advanced disease and poor performance status.
脑部放射治疗用于治疗因各种原发性恶性肿瘤导致脑转移的癌症患者。
评估全脑放疗（WBRT）对成年多发脑转移患者的有效性和不良反应。
检索了CENTRAL（考克兰图书馆）、MEDLINE、EMBASE、CANCERLIT和CINAHL。
纳入了来自任何原发性癌症且接受WBRT治疗的成年多发脑转移患者的随机对照试验（RCT）。预防性WBRT试验以及针对单个脑转移瘤进行手术或WBRT或两者联合治疗的试验被排除。
两位综述作者独立提取每个预定结局的信息：六个月时的总生存率、颅内无进展生存期、局部脑反应、局部脑控制、生活质量、症状控制、神经功能以及能够减少每日地塞米松剂量的患者比例。还收集了不良反应。
八项已发表报告（九项试验）显示，与WBRT的对照分割方案（10次分割，3000 cGy）相比，改变剂量分割方案对六个月生存率无益处。这些研究还表明，不同剂量分割方案在症状控制和神经功能改善方面没有差异。在五项RCT中，添加放射增敏剂在总中位生存期或脑肿瘤反应率方面均未给WBRT带来额外益处。添加放射增敏剂莫特沙芬钆总体上并未改善生活质量或神经功能进展时间。对于放射增敏剂米索硝唑，卡诺夫斯基功能状态评分结果没有改善。三项RCT发现，对于部分多发脑转移（最多四个脑转移灶）患者，与单纯WBRT相比，使用WBRT联合放射外科强化治疗在总生存期方面没有益处。然而，总体而言，在局部脑控制方面有统计学显著改善，支持全脑放疗联合放射外科强化治疗组。只有一项WBRT联合放射外科强化治疗的试验报告了卡诺夫斯基功能状态评分结果改善以及减少地塞米松剂量的能力提高。一项RCT比较了WBRT联合泼尼松与单纯泼尼松的疗效，结果尚无定论。
与标准放疗方案（10次分割，3000 cGy）相比，改变剂量分割方案的RCT在总生存期、神经功能或症状控制方面均未发现益处。WBRT联合使用放射增敏剂或化疗仍处于试验阶段。WBRT联合放射外科强化治疗可能会改善部分患者的局部疾病控制，尽管生存期不变。RCT中尚未研究WBRT与单纯支持治疗相比的益处。可能对于某些患者，尤其是疾病晚期且身体状况较差的患者，单纯支持治疗而不进行WBRT可能是合适的。
