The purpose of this study is to investigate whether stereotactic indigo carmine injection can safely increase the extent of tumor resection.

Low grade gliomas are brain tumors with usually poorly defined borders between tumor and normal brain. This characteristic of low grade gliomas makes the gross total resection of the tumor extremely difficult. Nevertheless, several studies have demonstrated that the risk of recurrence and progression into a more malignant tumor can be decreased with a more aggressive surgical resection. An aggressive attempt to achieve a gross total resection may result in the resection of normal brain and therefore neurological injury. For this reason, the more common error is to subtotally resect the tumor leaving significant volumes of tumor behind. Many techniques have been introduced to safely increase the extent of resection, since the extent of resection is associated with a higher survival rate. Each one of these techniques has several shortcomings. The current study will assess whether the intraoperative stereotactic injection of the indigo carmine at the tumor margins helps to safely increase of extent of tumor resection. In the first step of the study the safety and the correlation between resection of stained tissue/extend of tumor resection will be assessed. If the results are satisfactory, then the second step will ensue. In the second step we will assess the utility of indigo carmine as an additional adjunct to guide tumor resection.

Inclusion Criteria:

• Subjects with gliomas or other tumors that may have ill defined margins during the operative resection.

Exclusion Criteria:

• Subjects with a contraindication for brain MRI scan. Subjects who are pregnant, younger than 18 years old or have a contraindication for indigo carmine are excluded as well

Information collected from all study participants.