Table 1.

GBM diagnosis methodology.

Preoperative imaging and assessment	Function
MR imaging/CT imaging	Provides detailed information about tumor size and location via noninvasive imaging techniques
Karnofsky performance status	Assessment tool for functional impairment, and can be used to assess the prognosis in individuals (0–100 scale, a score of 100 meaning normal with no evidence of disease)
Friedlein grading	Functional classification system considering tumor operability and prognosis based on location of the tumor being either close or within eloquent regions (Friedlein grading B, “FGB”) or at a safe distance from eloquent regions (Friedlein grading A, “FGA”)
Operative
needle biopsy	A neurosurgeon removes a small piece of the tumor tissue, which is sent to a pathologist for review and official diagnosis. Stereotactic biopsy involves the use of computer-assisted guidance to locate and resect the tumor mass
Postoperative analysis
Histopathology	Hematoxylin and eosin staining remains the gold standard for diagnosis and characterization of the tissue biopsy
World Health Organization (WHO) grading	CNS tumors are classified according to standards published by the WHO based on morphological features, growth pattern, and molecular profile of the neoplastic cells