I. Introduction
With the growing scope of aging population, cancer has become a global public health problem. In the worldwide every year, 12.7 million public are diagnosed with cancer, and 7.6 million people died of cancer [4]. Meanwhile, the yearly rate of cancer continues to rise. By 2030, in each year there will be 26 million new cases and the death number will reach to 1.7 million people. A brain tumor is the growth of abnormal cells in the tissues of the brain. Brain tumors can be benign (noncancerous) or malignant (cancerous). In contrast to normal cells, cancer cells result from uncontrolled cell growth and can grow into adjacent tissue. Although benign tumors can grow large and harm healthy organs and tissue, which can potentially affect their working, they rarely invade other tissue. Major brain tumors start from the brain itself, while secondary brain tumors (i.e. metastatic tumors) originate from other parts in the body.