DTI-015 will be injected through a catheter (a hollow tube) into the center of the brain tumor. For patients undergoing a needle biopsy, computer ("stereotactic") guidance will be used to place the catheter. For patients undergoing an open brain operation, the catheter will be placed under the direct vision of the surgeon or with computer guidance. It is possible that the injection might not be done in the brain operation patients because there either is too much or too little tumor after the resection. The catheter will be removed after the injection.