Surgical Management of Glioblastoma

Abstract

Malignant gliomas are characterized by their propensity to invade surrounding brain parenchyma. The median survival of patients is less than 2 years with maximal surgical resection, chemotherapy, and radiotherapy. Although there have been controversial arguments about the role of surgical resection, there is increasing evidence that a safe and radical removal of malignant glioma is associated with a better survival outcome. Surgery is still essential to obtain brain tissue for pathological analysis, and reduce mass effect. Intraoperative magnetic resonance imaging, neuronavigation, ultrasonography, and fluorescence-guided surgery are the most used tools worldwide. 5-Aminolevulinic acid surgery, combined with Stupp protocol, produces a median survival of 15 months. The objectives of perioperative positioning are to enhance optimal exposure, prevent injury related to position, and maintain normal body alignment without excess flexion, extension, or rotation. Advances in surgical techniques have contributed to enhanced recovery after tumor resection, improved postoperative functional status, and decreased length of stay in the hospital. This chapter presents the current literature related to the surgical management of high-grade gliomas.

Real‐Time Imaging of Brain Tumor for Image‐Guided Surgery

“…There are three FDA-approved fluorescent imaging agents mainly used in glioma surgery: sodium fluorescein, 5-aminolevulinic acid (5-ALA) with protoporphyrin IX (PplX), and indocyanine green (ICG). [64] The optical properties and injection information of these three agents with pros and cons are displayed in Table 1 and Figure 7.…”

“…[65] This green fluorophore delivers to the tumor site via broken BBB and accumulates in the malignant tumor nonspecifically through vascular leaking defects, pooling defects, and abnormal vasculature or neovascularization. [64] Generally, modified microscopic equipment with a wavelength range of 560 nm is required to see the fluorescence, but no additional imaging device is required when used at high doses (5–10 mg kg −1 ) during image-guided surgery because of its green color. [66] Fluorescent and nonfluorescent areas correlated with tumor–normal brain distinction was confirmed histologically with the sensitivity of 82–94% and the specificity of 90–95%.…”

“…[64–66] In addition, high absorption and scattering of fluorescein result in the interrogation of only the surface layer, which reduces TBR and makes it difficult to use for cancer surgery. [65] Most importantly, the nonspecific accumulation in the tumor site and high background retention of fluorescein in normal brain areas are major disadvantages.…”

“…[65] Most importantly, the nonspecific accumulation in the tumor site and high background retention of fluorescein in normal brain areas are major disadvantages. [64] Schwake et al closed a clinical trial using sodium fluorescein in glioma resection due to the limited correspondence between fluorescein and tumor tissue (i.e., low specificity) and the generally high level of fluorescence signal throughout the brain (i.e., high background). [70] …”

“…[64] ICG accumulates in the lesion through EPR effect and is not tumor specific. Unspecific binding to proteins in vivo increases background fluorescence signal; even the autofluorescence is absent under NIR window.…”