open access: PLoS ONE: Whole Brain Radiation-Induced Impairments in Learning and Memory Are Time-Sensitive and Reversible by Systemic Hypoxia

"Close to 1.6 million new cases of cancer [1] and 64,530 primary brain tumors are expected to be diagnosed in the United States in 2011 [2]. The most common form of treatment for metastatic or primary tumors located in brain regions that are difficult to surgically remove continues to be whole brain radiation therapy (WBRT) [3]. Although this treatment regimen is effective in eliminating tumors, damage to normal brain tissue is inevitable. Several studies have shown that cognitive deficits occur in a relatively large percentage of brain tumor survivors, becoming evident months to years after treatment [3]–[6]......"