Brain mets/scar tissue

My doctors are not positive that I have a reoccurance but it looks that way. The scar tissue has increased in just 8 weeks since my last brain MRI. I am going to have a brain PET and another type of brain MRI. The RT oncologist recommended not to do gamma knife again because it will lead to more scar tissue. Instead he feels I should have another craniotomy to remove the scar tissue and possible brain tumor. Has anyone been down this road before or is familar?