Functional magnetic resonance-guided brain tumor resection

The ultimate goal of brain tumor surgery is maximum tumor removal without the development of a new neurologic deficit. This is especially true in the treatment of intraparenchymal tumors such as gliomas and metastatic lesions. In the treatment of glioblastoma multiforme (GBM), for example, gross total resection (GTR) has been demonstrated in a number of studies to be one of the few attainable factors that is associated with prolonged survival (Buckner 2003; Jeremic et al. 1994; Lacroix et al. 2001; Vidiri et al. 2006; Ushio et al. 2005). GTR of low grade gliomas is also supported in the literature and has been demonstrated in several retrospective studies to be associated with a lower risk of tumor recurrence and prolonged patient survival (Claus et al. 2005; Laws et al. 1984; Nicolato et al. 1995; Philippon et al. 1993; Piepmeier et al. 1996). In one reported series where complete radiologic resection was attained in the treatment of low grade glial tumors, tumor recurrence was not reported (Berger et al. 1994). Additionally, GTR has been demonstrated to result in improved postoperative control of seizures (Chang et al. 2008), a major source of disability in these patients. It should be noted, however, that the appropriate treatment of low grade gliomas is not without controversy (Keles et al. 2001), and there are reported series that have failed to demonstrate a significant correlation between GTR and survival (Medbery et al. 1988; Piepmeier 1987). Reported series of high grade gliomas (HGG) that have failed to demonstrate a correlation between the extent of resection and prognosis have also been published (Kowalczuk et al. 1997; Lai et al. 1993).