A brain MRI may have a new use in determining the effectiveness of certain brain cancer drugs. The drug in question is Avastin, a FDA approved drug for that is used to shrink brain tumors by cutting off blood supply to the tumor. Patients taking drug were given a brain MRI to examine their tumor. "By using MRI to measure the amount of water motion within the tumor, the researchers were able to predict with 70 percent accuracy which tumors would progress within six months and which would not" reports AJC News. Those patients with greater water motion have the highest rate of success in using Avastin. Knowing if a patient will respond to such drug allows doctors to personalize therapy to each patient. Tumors that are found to be progressing will be given harsher treatment, while those responding to Avastin would receive a weaker treatment. Patients can use this brain MRI to save themselves from the intense side effects related to unneeded harsher treatment.