HSV-tk and XRT and Chemotherapy for Newly Diagnosed GBM

This trial is testing a gene therapy approach combined with standard radiation therapy and chemotherapy (temozolomide) for people who have just been diagnosed with a highly aggressive brain cancer called glioblastoma (GBM) or anaplastic astrocytoma. The gene therapy uses a virus to plant a cancer-killing gene directly into the tumor. **You may be eligible if...** - You have been newly diagnosed with glioblastoma or anaplastic astrocytoma, confirmed by surgical biopsy - Your tumor is in a single location (not spread to multiple areas) and does not involve the brainstem - You have had surgery for this tumor and need further treatment - You have a life expectancy of at least 12 weeks **You may NOT be eligible if...** - You have cancer in multiple locations in the brain or in the brainstem - You are pregnant or unable to tolerate chemotherapy or radiation - You have had prior radiation to the brain - Your general health is very poor Talk to your doctor to see if this trial is right for you.