放疗激活剂增加脑肿瘤治疗疗效

癌症研究人员比较了乳腺癌脑转移至脑肿瘤患者接受全脑放射治疗合并补充氧气的时候，服用或者不服用efaproxiral（Efaproxyn，一种试验性放射激活剂）的疗效。

美国西北大学Feinberg医学院研究人员认为：efaproxiral能够提高脑转移性肿瘤全脑放射治疗的效果。

先前的研究结果提示：乳腺癌转移至脑部的肿瘤患者接受全脑放射治疗的时候，服用这种药物将患者生存率提高了一倍，而且明显提高生命质量。Efaproxiral是第一种合成的通过“易化”血红蛋白释放氧，使肿瘤组织中产生“致敏”氧剥夺区域的小分子药物，并且增加肿瘤中氧含量。

在癌症治疗中，肿瘤组织中氧的存在是放射治疗癌症的根本性因素。通过增加治疗时候肿瘤的氧含量，efaproxiral能够提高传统放射治疗的效果。与其他放射治疗激活剂或者化疗药物不同，这种药物不是穿过血脑屏障或者进入肿瘤来发挥产生作用的。

Radiation Sensitizer Used to Treat Brain Tumors
 
A cancer investigator is comparing the effects of whole-brain radiation therapy with supplemental oxygen with or without efaproxiral (Efaproxyn), an experimental radiation sensitizer, in individuals with brain metastases originating from metastatic breast cancer.

It is thought that efaproxiral may improve the effectiveness of whole brain radiation therapy in brain metastases from breast cancer, according to researchers at Northwestern University Feinberg School of Medicine (Chicago, IL, USA).

Results from a previous study suggested that the addition of this agent to whole brain radiation therapy doubled survival rates among patients with metastatic breast cancer and considerably improved their quality of life. Efaproxiral is the first synthetic small-molecule agent created to “sensitize” oxygen-deprived regions of tumors before radiation therapy by facilitating the release of oxygen from hemoglobin, and increasing the oxygen level in tumors.

The presence of oxygen in tumors is a fundamental element of the effectiveness of radiation therapy in cancer treatment. By increasing tumor oxygenation at the time of treatment, efaproxiral may boost the efficacy of conventional radiation therapy. Unlike other radiation sensitizers or chemotherapies, this agent does not have to cross the blood brain barrier or enter the tumor to be effective.