Innovations in design and delivery of chemotherapy for brain tumors

Although surgery and radiotherapy long have been established as treatment modalities of patients with brain tumors, the role of chemotherapy in such patients is far from certain. Nevertheless, it has continued to play a significant part in the therapeutic armamentarium against these tumors in the last several decades and might have contributed to disease stabilization and cure of some patients with brain tumors. Concurrently, it has become obvious that a significant proportion of patients with brain tumors also suffer progressive disease during or following chemotherapy. The causes for such therapeutic failure have been explored and reported extensively. Invariably, the lack of response to chemotherapy has been caused by the presence of the blood-brain barrier and drug resistance. This article initially discusses factors that contribute to chemotherapy failure followed by a discussion of recent advances in design and delivery of chemotherapy that have attempted to overcome some of these obstacles and improve antitumor responses and survival in patients with brain tumors.