Recent technological advances in pediatric brain tumor surgery

Abstract

X-rays and ventriculograms were the first imaging modalities used to localize intracranial lesions including brain tumors as far back as the 1880s. Subsequent advances in preoperative radiological localization included computed tomography (CT; 1971) and MRI (1977). Since then, other imaging modalities have been developed for clinical application although none as pivotal as CT and MRI. Intraoperative technological advances include the microscope, which has allowed precise surgery under magnification and improved lighting, and the endoscope, which has improved the treatment of hydrocephalus and allowed biopsy and complete resection of intraventricular, pituitary and pineal region tumors through a minimally invasive approach. Neuronavigation, intraoperative MRI, CT and ultrasound have increased the ability of the neurosurgeon to perform safe and maximal tumor resection. This may be facilitated by the use of fluorescing agents, which help define the tumor margin, and intraoperative neurophysiological monitoring, which helps identify and protect eloquent brain.

Keywords: Brain tumor; endoscope; microscope; paediatric; technological advances.

Figure 1.. Microscopic view of a high-grade glioma showing fluorescence.

(A) Standard operative light and (B) after 5-aminolevulinic acid injection.

Figure 2.. Intraoperative images of an hemangioblastoma.

Intraoperative images of a hemangioblastoma in the thoracic spinal cord of a 16-year-old patient before (A & B) and after (C & D) resection – standard operative light (A & C) and after indocyanine green injection (B & D). ICG: Indocyanine green.

Figure 3.. Endoscopic third ventriculostomy in a child with a tectal plate/aqueductal glioma.

(A) Right foramen of Monro. (B) Floor of the third ventricle and the bifurcation of basilar artery. (C) Tip of the balloon approaching the floor of the third ventricle. (D) Ventrioculostomy using balloon. (E) Pontine perforators visible through the floor of the third ventricle. (F) Thickened tectal plate with stenosed aqueduct (on the right of the image) and pineal recess (on the left).

Figure 4.. Large colloid cyst in a 15-year-old child.

(A) Sagittal T2 CUBE demonstrating the cyst in the third ventricle at the level of the foramina of Monro. (B) Endoscopic view through the left lateral ventricle of the colloid cyst in the third ventricle. (C) Bipolar coagulation of surface of colloid cyst. (D) Mucinous material. (E) Suction of content of cyst. (F & G) Resection of cyst wall using biopsy forceps. (H) Sagittal T2 ventriculostomy sequence demonstrating complete removal of the lesion.

Figure 5.. Adamantinomatous craniopharyngioma in a 2-year-old patient.

(A) Scan demonstrating extensive invasion through the floor of third ventricle. (B) Transnasal transsphenoidal endoscopic approach to the sella with the dura opened and craniopharyngioma visible. (C) Capsule of the craniopharyngioma. (D) Calcified solid component of the craniopharyngioma. (E) Left carotid artery, oculomotor and optic nerves. (F) View of the roof of the third ventricle and foramina of Monro from below. (G) Postoperative scan demonstrating complete resection.

Figure 6.. Ganglioglioma grade I.

Tumor in a 14-year-old patient abutting the corticospinal tracts (red) as demonstrated by diffusion tensor imaging superimposed on T1 postcontrast magnetic resonance.

Figure 7.. Glioblastoma in a 17-year-old patient.

Relationship between the tumor, the motor areas (finger apposition and foot rocking) and the corticospinal tract. Functional MRI (red: finger apposition; green: foot rocking) and diffusion tensor imaging (corticospinal tracts in blue). DTI: Diffusion tensor imaging; fMRI: Functional MRI.

Figure 8.. Fusion of T2 MRI volumetric sequence for neuronavigation with intraoperative ultrasound.

A: anterior; H: head; F: foot; P: posterior; L: Left; R: right.