Modern neurosurgery emerged from the intersection of precise anatomy, innovative operations, and groundbreaking technologies. In the early twentieth century, Harvey Cushing’s (Fig. 21.1) meticulous approach and introduction of surgical hemostasis paved the way for cranial neurosurgery to advance beyond basic procedures like trephination and decompression. His pioneering work in brain tumor surgery and operative planning solidified neurosurgery as a distinct field and significantly improved the safety of intracranial operations [1].