Further Outpatient Care
In medically stable patients in whom no inpatient workup is required, follow-up can be done by a neurosurgeon in conjunction with a neurologist and neuro-oncologist. Some lesions might be followed in time without the need for an active acute intervention (e.g. tectal gliomas specially if found incidentally).
Patients who have received some form of treatment (surgery, chemo/radiation therapy) and are medically stable to continue treatment on an outpatient basis will need serial imaging periodically as well as additional forms of therapy like physical and occupational depending on their individual circumstances.
Patients with programable ventricular shunts should be advised that after every follow-up MRI they should have their shunt settings revised to avoid complications from under or overdrainage of CSF resulting from inadvertent shunt reprogramming.
Further Inpatient Care
The type of treatment as well as the clinical course of each patient will vary depending on the type of tumor and the neurologic status upon admission. Patients with localized lesions in surgically accessible areas and with no neurologic deficits might be scheduled electively. These patients will be admitted to the hospital on the same day of surgery and will typically be discharged three or four days after the procedure. Similarly, patients with unresectable tumors might be admitted for surgical biopsy which depending on location can be done using stereotactic techniques. These patients will also be discharged after a few days and depending on the final pathology report will be referred for any additional consults on the outpatient clinic.
Patients who present to the emergency department might require special treatment for the management of related complications like seizures (including status epilepticus) and intracranial hypertension. These conditions might require IV use of anti epileptic medications, intracranial pressure monitoring, external ventricular drain placement and even emergent surgical resection or decompression in cases of acute herniation. Although low-grade astrocytomas usually present with a more indolent course, some tumors might grow considerably before detection until patients present with acute deterioration or worsening symptoms. In cases like these patients might require transfer to an intensive care unit for specialized treatment and monitoring.
Inpatient & Outpatient Medications
As described above, an anticonvulsant (if seizures are present) and dexamethasone (if edema is significant) are continued on an inpatient or outpatient basis. In addition, antiulcer medication is given with the corticosteroid for GI prophylaxis.
Transfer
At some institutions, transferring the patient to another facility may be necessary if the proper consultations cannot be obtained. Particularly in patients with significant hydrocephalus, transfer to a facility with neurosurgical coverage is indicated. However, in patients with no hydrocephalus, surgery can be scheduled on an elective, but preferably urgent, basis.
Prognosis
As already discussed, prognosis greatly depends on the pathology of the tumor. Taking many published series together, median survival duration is approximately 7.5 years. However, patients with pilocytic astrocytomas who undergo gross total resection can expect a cure. For low-grade astrocytomas that continue their relentless slow growth, progressive neurologic deficit may occur over a period of years.
In a large, multi-institutional study of patients with low-grade gliomas, Chang et al found that the University of California, San Francisco (UCSF) preoperative scoring system accurately predicted overall survival (OS) and progression-free survival (PFS). The 537 patients in the study were assigned a prognostic score based upon the sum of points assigned to the presence of each of the 4 following factors: (1) location of tumor in presumed eloquent cortex, (2) Karnofsky Performance Scale (KPS) Score ≤80, (3) age >50 years, and (4) maximum diameter >4 cm. Stratification of patients based on scores generated groups (0-4) with statistically different OS and PFS estimates (p < 0.0001). The 5-year cumulative OS probabilities stratified by score group were as follows: score of 0, 0.98; score of 1, 0.90; score of 2, 0.81; score of 3, 0.53; and score of 4, 0.46. [17]
The molecular classification of low-grade diffuse gliomas [18] has shown that some mutations correlate with survival. The median survival of patients with TP53 mutation with or without IDH1/2 mutation was significantly shorter than that for patients with 1p/19q loss with or without IDH1/2 mutation. Multivariate analysis with adjustment for age and treatment confirmed these results and revealed that TP53 mutation is a significant prognostic marker for shorter survival and 1p/19q loss for longer survival, while IDH1/2 mutations are not prognostic.
For the pediatric population the prognosis is different. In cases of complete resection prognosis tends to be very good and close to complete cure with need for strict follow-up only. In cases of tumor remnant or inability to perform surgical resection (ie, deep-seated lesions), the mortality tends to occur either from tumor-related factors or treatment morbidity. In one summary [61] , researchers found that during a 30-year period the mortality rate was 12%, with a median time to death from diagnosis of 4.02 years (range, 0.21–24 years). Yet, their study mixed different kinds of tumors. In the case of tumor harbor BRAF mutation, we have an efficient tool that can either treat the lesion for complete resolution or reduce its size making it amenable to safer resection. Study is still ongoing in this regard.
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A 28-year-old male taxi driver presented to the emergency department after having a seizure. Noncontrast head CT scan was obtained showing the typical appearance of a low-grade astrocytoma. The lesion in the mesial left frontal lobe was hypodense on CT scan.
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Preoperative MRI of the brain of a 28-year-old male taxi driver who presented to the emergency department after having a seizure. On T1-weighted sequences, the tumor does not enhance and shows decreased signal intensity compared to normal brain. These findings are consistent with low-grade astrocytoma.
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For tumors, MRI has the advantage of showing the lesion in multiple planes. This image, a T1-weighted sagittal image of the brain of a 28-year-old male taxi driver who presented to the emergency department after having a seizure, shows the tumor along the mesial aspect of the frontal lobe. Note that mass effect is minimal, typical of a low-grade lesion.
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T2-weighted sequences of an MRI of the brain of a 28-year-old male taxi driver who presented to the emergency department after having a seizure show increased signal intensity compared with normal brain. The radiologic appearance is typical of low-grade astrocytoma.
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A 9-year-old boy presented with headaches and gradual onset of right hemiparesis. MRI of the brain was obtained. The T2-weighted sequence in this MRI shows a tumor in the left thalamus, which is a typical location for a juvenile pilocytic astrocytoma. Note the relatively well-circumscribed nature of the lesion.
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Coronal T1-weighted gadolinium-enhanced MRI of the brain shows the tumor of a 9-year-old boy who presented with headaches and gradual onset of a right hemiparesis. Note the heterogeneous enhancement of the tumor.
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Sagittal T1-weighted MRI of the brain shows juvenile pilocytic astrocytoma of a 9-year-old boy who presented with headaches and gradual onset of right hemiparesis. Stereotactic surgery has made resection of these low-grade tumors in this deep location feasible.
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A 3-year-old boy presented with speech regression. MRI of the brain revealed a tumor in the left mesial temporal lobe. This T1-weighted gadolinium-enhanced image shows an enhancing tumor involving the hippocampus, uncus, and amygdala. The surgical pathologic studies revealed a low-grade mixed tumor of astrocytes and atypical neurons, a ganglioglioma.
