If the anesthetic regimen can influence the serum level of inflammatory cytokines and if the levels of cytokines are related to the incidence of post operative complications, these complications may be a function of the anesthetic method. In an effort to find the best anesthetic regimen for patients undergoing craniotomy for intracranial tumors, the researchers will compare the effect of volatile anesthetic with that of total intravenous anesthesia (TIVA) on cytokine levels. The researchers will also compare the composite incidence of some common major post-operative complications after craniotomy for intracranial malignancy.