What is the correct statement regarding brain tumors?

Brain Tumors: Key Facts and Management

MRI is the gold standard for diagnosing brain tumors, not CT scan. Based on the most recent evidence, MRI is superior due to its high resolution and sensitivity in identifying brain metastases, particularly when multiple lesions are present 1.

Diagnostic Approach

• MRI is the preferred initial imaging study for suspected brain tumors, as it can identify multiple lesions when a prior CT identifies only a single tumor 1
• Gadolinium-enhanced MRI is specifically recommended as the gold standard for brain tumor diagnosis due to its superior sensitivity 1
• T2-weighted or fluid-attenuated inversion recovery MR images are best for visualizing perilesional vasogenic edema that commonly accompanies brain metastases 2

Clinical Presentation and Symptoms

• Common symptoms of brain tumors include headache (50%), seizures (20-50%), neurocognitive impairment (30-40%), and focal neurologic deficits (10-40%) 3
• Brain tumor symptoms are primarily determined by tumor location rather than size, as specific neurological deficits correspond to the affected brain regions 1
• Approximately 15-20% of patients with brain metastases present with seizures, which may accompany headache 2

Treatment Approaches

Medical Management

• Corticosteroids (particularly dexamethasone) are a cornerstone in managing brain tumors to control perilesional vasogenic edema 1
• The European Federation of Neurological Sciences recommends starting dosages of dexamethasone between 4-8 mg/day for managing brain tumor-related edema 2
• Ideally, steroid dose should be tapered as quickly as the clinical situation allows because of toxicity associated with long-term (>3 weeks) use 1

Surgical Management

• Surgical resection is the mainstay of therapy for primary brain tumors 4
• Indications for surgery include: diagnostic uncertainty, symptoms refractory to steroids, bulky metastases (>3-4 cm), and solitary brain metastases 1
• Postoperative MRI should be performed within 24-72 hours after surgery to document the extent of disease after surgical intervention 1

Radiation Therapy

• Radiation therapy options include standard fractionated external-beam RT, stereotactic radiosurgery, and whole-brain RT 1
• Whole-brain RT and stereotactic radiosurgery are used primarily for brain metastases, while standard fractionated RT is more common for primary brain tumors 1

Prognosis

• The natural history of untreated cerebral metastases is poor, with median survival reported as less than 2 months 2
• Five-year survival for primary malignant brain tumors is approximately 36% overall 3
• There is no evidence that prognosis differs significantly between males and females with brain tumors 1

Common Pitfalls and Considerations

• Prophylactic anticonvulsants are not recommended for patients with no history of seizures, according to both American Academy of Neurology and European Federation of Neurological Sciences 1
• For patients with incidentally discovered brain metastasis without significant mass effect or edema, withholding steroids and antiepilepsy medication may be appropriate 1
• The exact determination of tumor number on MRI is important as it guides treatment decisions - single metastasis occurs in approximately 25-33% of patients 1

Remember that brain tumors represent a heterogeneous group of neoplasms with varied outcomes and management strategies, requiring an interdisciplinary approach to optimize patient care 1.