Low-Grade Astrocytoma Treatment & Management

Updated: Oct 27, 2014
  • Author: George I Jallo, MD; Chief Editor: Tarakad S Ramachandran, MBBS, MBA, MPH, FAAN, FACP, FAHA, FRCP, FRCPC, FRS, LRCP, MRCP, MRCS  more...
  • Print
Treatment

Medical Care

From the history, physical, and radiologic appearance of a tumor on CT scan or MRI, a presumptive diagnosis of a low-grade glioma can be made. The primary care physician should coordinate care with a neurologist, neurosurgeon, and oncologist. The initial treatment steps depend on patient presentation. [9]

If the patient presents with seizures, first-line therapy is to start the patient on phenytoin (Dilantin), carbamazepine (Tegretol), or levetiracetam (Keppra).

If the patient presents with headache and has significant edema surrounding the tumor, dexamethasone (Decadron) therapy is appropriate in doses ranging from 2-4 mg every 6 hours. With dexamethasone, antiulcer medications (eg, antacid, H2 blocker) usually are prescribed. Corticosteroid therapy also may improve symptoms in patients who have low-grade astrocytomas of the spinal cord.

If hydrocephalus is observed on CT scan or MRI and the patient is symptomatic, surgical placement of a ventricular drainage device or an endoscopic third ventriculostomy (ETV) may be appropriate. Either an external ventricular drain or a ventriculoperitoneal shunt may be inserted. The exact procedure depends on any further plans for surgery.

Next:

Surgical Care

Aside from the initial measures noted in Medical Care, the cornerstone of therapy for most low-grade gliomas is surgery. [10, 11, 12]

Tumors in certain locations may be inoperable. However, most clinical series have shown that patients who undergo gross total resection have the longest survival durations. Even subtotal resection is of benefit if the tumor can be removed safely. Histologic diagnosis should be sought in every case (via biopsy or resection) if possible.

Surgery is also the primary mode of treatment for low-grade astrocytomas of the spinal cord. Depending on the appearance of the tumor at surgery, a gross total resection, subtotal resection, or only biopsy may be possible. However, resection may lead to symptomatic and objective improvement in these patients. Furthermore, in low-grade astrocytomas, long-term remission (>10 y) and even cure are frequent in both children and adults.

Intraoperative 5-ALA fluorescence can be used to help achieve a greater extent of resection. A study published by Sanai et al [13] showed that intraoperative confocal microscopy can help visualize cellular 5-ALA–induced tumor fluorescence within low-grade gliomas and at the brain-tumor interface. An ongoing study is investigating this further. The Barrow 5-ALA Intraoperative Confocal (BALANCE) Trial will measure the effect of 5-ALA on the amount of glioma tumor removal. The investigators' hypothesis is that 5-ALA fluorescence with the use of the special microscope during surgery will greatly lower the amount of tumor left behind.

The use of intraoperative MRI to guide the resection of gliomas in general has provided surgeons with a new tool to improve the extent of resection [14] . One problem with this technology is its high cost and limited availability. It also extends operating times which could be a downside for patients with high anesthetic risk.

Intraoperative neurophysiological monitoring has been used increasingly in the last few years. [15, 16] (See Intraoperative Neurophysiological Monitoring.) This is a preferred technique to remove lesions close to, or involving, eloquent (functionally important) regions of the brain. The goal of such monitoring is to identify changes in brain and spinal cord function prior to irreversible damage. Intraoperative monitoring also has been effective in localizing anatomical structures, which helps guide the surgeon during dissection.

One of the electrophysiological modalities is intraoperative cortical mapping, which can help to achieve a greater extent of resection. The mapping is often done with small electrodes that stimulate certain areas of the brain and evoke particular responses. This technique is often used in combination with awake craniotomy.

In awake craniotomy, the patient is awake during parts of the procedure. With the patient awake, it is possible to test regions of the brain before they are incised or removed, and patient’s function is tested continuously throughout the operation.

See Brain Cancer Treatment Protocols for summarized information.

Previous
Next:

Consultations

Patients in whom a low-grade astrocytoma is suspected should be evaluated primarily by a neurosurgeon. The neurosurgeon will guide the diagnostic evaluation and will ultimately decide upon the best course of treatment which in most cases will include some form of surgical procedure.

Patients who present with seizures must be evaluated by a neurologist, ideally one specializing in epilepsy to ensure the best control of symptoms through judicious use of anti-epileptic medications.

Although most patients with low-grade astrocytomas will initially requiere surgery as their only form of treatment, it is advisable to obtain an oncology consult. Depending on tumor hystology the risk of recurrence will vary and some patients will eventually benefit from combined forms of treatment including chemotherapy and/or radiation therapy.

Other consults should be considered only in individual circumstances (e.g. psychiatry in patients with concomitant psychoaffective disorders).

Previous
Next:

Diet

There are no special dietary restrictions for patients with brain tumors although patients with pre-existing medical conditions which warrant dietary modifications must continue to abide by their previous regimens to avoid potential complications (e.g. episodes of hypo/hyperglicemia in diabetic patients).

Previous
Next:

Activity

In general, no restrictions are placed on activity of patients with low-grade glioma. However, patients' activity may relate to their overall neurologic status. The presence of seizures may prevent the patient from driving. Neurologic deficits such as hemiparesis may improve after treatment. Physical therapy is often beneficial.

Previous