<qa>  What is the average time period for blood tests?Blood tests will be obtained as per routine standard of care weekly during the initial six weeks of combined radiation and chemotherapy and on days 21 and 28 - 2 days of each cycle of monthly temozolomide.After the initial MRI or CAT scan, subsequent MRIs or CAT scans will be obtained per standard of care: four weeks after completion of radiation and then generally after every two cycles of chemotherapy unless medically indicated at other time points. 