The Value of Simpson I–II Resection in Deep-Seated and Skull Base WHO Grade I Meningioma

Background: The prognostic value of the Simpson grading scale for deep-seated and skull base WHO grade I meningiomas has recently been questioned. The availability of adjuvant radiosurgery and the possible morbidity associated with aggressive resection of these lesions has resulted in some neurosurgeons adopting less aggressive surgical strategies. We aimed to compare tumor control rates following complete resection with treatment of involved dura (Simpson I–II) to that of less aggressive resection (Simpson III) or incomplete resection with or without adjuvant radiosurgery (Simpson IV +/−RS).