In an adult patient presenting with a brain tumor, what is the recommended initial evaluation and management, including imaging, laboratory studies, steroid therapy, seizure prophylaxis, and treatment options based on tumor type?

Management of Adult Brain Tumors

Initial Imaging

Order a non-contrast CT head immediately as the first-line imaging study for any suspected brain tumor, as it can be performed rapidly and safely to assess for mass effect, hemorrhage, or hydrocephalus in emergent settings. 1

• Non-contrast CT provides rapid assessment and is particularly critical when immediate evaluation is needed 1
• CT can provide additional information regarding calcification or hemorrhage, and is useful for patients unable to undergo MRI 2
• In patients with a history of cancer, obtain contrast-enhanced imaging early (either CT with contrast or proceed directly to MRI with contrast) when metastatic disease is suspected 1

Definitive Imaging

MRI brain with and without gadolinium contrast is the standard imaging modality for definitive characterization and preoperative evaluation of brain tumors. 3, 1, 2

Essential MRI sequences include:

• T1-weighted images with and without contrast medium 3, 1, 2
• T2-weighted images and/or FLAIR imaging 3, 1, 2
• Three-dimensional scans using the same technique 3, 1

Advanced imaging options to better characterize the tumor:

• Diffusion-weighted imaging and perfusion studies can assist in distinguishing glioblastoma from other tumor types such as primary CNS lymphoma or metastases 1, 2
• Functional MRI, proton MR spectroscopy, and perfusion studies can be combined with standard sequences 3, 1, 2
• MRI images should be converted into digital format (e.g., CD) for possible subsequent dosimetric studies 3

Histological Confirmation

Histological confirmation of the diagnosis must be obtained, because neuroimaging alone is not sufficiently specific to distinguish between tumor types, infections, or inflammatory lesions. 3, 1

• Biopsy or surgical resection is standard practice 3, 1
• The sample should be representative of the lesion, particularly any area of contrast enhancement 1
• The 2000 WHO classification is the standard for diagnosis and histoprognostic grading of gliomas 3
• A search for deletions of 1p and 19q chromosomes should be undertaken, particularly in patients with oligodendroglial tumors 3

Exception: In elderly patients with deep-seated lesions presenting with very poor systemic or neurological condition, the clinician may consider that the risk from biopsy outweighs the risk from misdiagnosis and decide not to perform biopsy, though this should remain exceptional 3

Corticosteroid Therapy for Cerebral Edema

Patients with clinical or radiological evidence of brain edema should be treated with corticosteroids at the minimal effective dose, which should be regularly re-evaluated. 3

• Methylprednisolone and prednisolone should be prescribed as single daily doses in the morning 3
• Patients should be monitored for side effects 3
• If lymphoma is suspected, corticosteroid therapy must be avoided prior to obtaining histological confirmation, except for patients whose neurological status requires this therapy 3
• Prophylactic corticosteroid treatment should not be prescribed routinely for radiotherapy 3
• Peri-operative H2-receptor blockers or proton pump inhibitors can be used to prevent gastrointestinal complications in patients receiving high doses of corticosteroids 3

Seizure Management

For patients who have had seizures, anticonvulsant treatment should be prescribed routinely during the perioperative period and continued postoperatively. 3

• In patients who have not had seizures, peri-operative anticonvulsant treatment is an option, though its efficacy has not been demonstrated 3
• First-line treatment should be single-drug therapy 3
• Any inducing and/or potentiating effect on the toxic effects of chemotherapy should be taken into consideration when selecting anticonvulsants 3
• Non-enzyme-inducing anticonvulsants like levetiracetam are preferred to avoid impacting metabolism of other medications including antibiotics and steroids 4

Treatment Based on Tumor Type

Glioblastoma (Grade 4)

First-line therapy for glioblastoma is maximal safe surgical resection followed by concurrent radiation (60 Gy) and temozolomide chemotherapy. 5

• The combination of temozolomide with radiotherapy improved survival compared with radiotherapy alone (2-year survival: 27.2% vs 10.9%; 5-year survival: 9.8% vs 1.9%) 5
• The dose should not exceed a total of 60 Gy, delivered at 1.8 to 2 Gy per fraction, five times per week 3
• The gross tumor volume (GTV) corresponds to contrast-enhanced image or, after complete excision, to the edges of the operative cavity 3
• The clinical tumor volume (CTV) should include a safety margin of 20 mm outside the GTV limit in all three dimensions 3

Grade 2 Gliomas

For grade 2 gliomas, optimal resection involves total or subtotal removal of the tumor volume defined in T2 and/or FLAIR sequence on MRI. 3

If optimal resection is possible:

• In the presence of at least one poor prognostic factor (age >40 years, large or rapidly increasing tumor volume, involvement of deep structures, contrast enhancement on MRI), surgical resection should be undertaken 3
• In the absence of poor prognostic factors, surgical resection or surveillance with or without biopsy can be considered 3

If optimal resection is not possible:

• In the presence of at least one poor prognostic factor, partial resection, partial resection followed by radiotherapy, radiotherapy alone, or chemotherapy can be proposed 3
• When radiotherapy is proposed, the dose should be between 50 and 54 Gy 3

Anaplastic Oligodendroglial Tumors with 1p/19q Codeletion

Radiotherapy combined with procarbazine, lomustine (CCNU), and vincristine (PCV) significantly improves long-term survival compared to radiotherapy alone. 5

• Probable 20-year overall survival was 37.1% with PCV plus radiotherapy vs 13.6% with radiotherapy alone 5

Pilocytic Astrocytoma

Complete surgical resection should be offered to patients satisfying operability criteria, as it significantly improves survival and often cures these patients. 3

• Postoperative evaluation of surgical resection quality should be performed with MRI 3
• If MRI confirms complete resection, simple clinical follow-up is indicated 3

Post-Treatment Follow-Up

MRI is preferable to CT scanning for follow-up of disease progression. 3

• After surgical removal, MRI should be performed within 72 hours, with and without contrast medium, to assess any residual tumor 3
• Clinical and/or radiological deterioration in the 2 months after radiotherapy should be interpreted with caution and not automatically considered treatment failure, as radiation-induced edema is common 6
• The clinical and radiological evaluation of tumor evolution should take into account variations in the dose of corticosteroid 3

Common Pitfalls to Avoid

• Do not skip contrast administration when tumor, infection, or inflammatory pathology is suspected, as non-contrast studies have limited sensitivity 1
• Do not automatically attribute clinical deterioration within 2 months of radiotherapy to tumor progression—radiation-induced edema is the most common cause 6
• Do not give corticosteroids before biopsy if lymphoma is suspected, as this can obscure the diagnosis 3
• Do not prescribe prophylactic anticonvulsants routinely in patients who have never had seizures, as efficacy is unproven 3