<qa>  What is the goal of the ILT?The goal is to evaluate the use of minimally invasive interstitial laser therapy ILT in the brain. Our group is in a unique position to offer image-guided ILT because of our expertise and resources here at Brigham Womens Hospital in the Departments of Neurosurgery and Radiology. The therapy will be monitored and controlled by the use of magnetic resonance imaging MRI. ILT is a minimally invasive procedure in which the targeted tissue is thermally destroyed in situ in a controlled fashion. The intra-operative MRI provides a way to see the treatment. It can be used to treat disease by guiding surgery by providing images of tissue changes during therapy. 