癌癥研究人員比較了乳腺癌腦轉移至腦腫瘤患者接受全腦放射治療合并補充氧氣的時候，服用或者不服用efaproxiral（Efaproxyn，一種試驗性放射激活劑）的療效。

美國西北大學Feinberg醫學院研究人員認為：efaproxiral能夠提高腦轉移性腫瘤全腦放射治療的效果。

先前的研究結果提示：乳腺癌轉移至腦部的腫瘤患者接受全腦放射治療的時候，服用這種藥物將患者生存率提高了一倍，而且明顯提高生命質量。Efaproxiral是第一種合成的通過“易化”血紅蛋白釋放氧，使腫瘤組織中產生“致敏”氧剝奪區域的小分子藥物，并且增加腫瘤中氧含量。

在癌癥治療中，腫瘤組織中氧的存在是放射治療癌癥的根本性因素。通過增加治療時候腫瘤的氧含量，efaproxiral能夠提高傳統放射治療的效果。與其他放射治療激活劑或者化療藥物不同，這種藥物不是穿過血腦屏障或者進入腫瘤來發揮產生作用的。

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.