Treatment of Benign Brain Tumors
For small (<30 mm) asymptomatic benign brain tumors, observation is the preferred initial approach, while symptomatic or large (≥30 mm) tumors should be treated with surgical resection if accessible, followed by radiation therapy only for incompletely resected lesions or higher-grade tumors. 1
Treatment Algorithm Based on Tumor Size and Symptoms
Small Tumors (<30 mm)
Asymptomatic:
- Observation is preferred as the initial management strategy 1
- Surgery should be considered only if there are potential neurologic consequences and the tumor is accessible 1
- Median growth rate for meningiomas (the most common benign brain tumor) is only 4 mm per year, supporting a conservative approach 1
Symptomatic:
- Surgery if accessible, followed by radiation therapy only if WHO grade 3 (malignant transformation) 1
- Radiation therapy alone may be considered if surgery is not feasible 1
Large Tumors (≥30 mm)
Asymptomatic:
- Surgery if accessible, followed by radiation therapy if WHO grade 3 1
- Consider radiation therapy if incomplete resection and WHO grade 1/2 1
- Observation remains an option for surgically inaccessible tumors 1
Symptomatic:
- Surgery if accessible is the primary approach 1
- Radiation therapy should follow if WHO grade 3, or consider if incomplete resection with WHO grade 1/2 1
- Radiation therapy alone if surgery is not feasible 1
Surgical Considerations
- Surgery remains the treatment of choice for most benign brain tumors, particularly meningiomas, pituitary adenomas, and acoustic neuromas 2
- Surgical options include stereotactic biopsy, open biopsy, subtotal resection, or complete gross total resection 1
- Postoperative MRI should be obtained within 24-72 hours after surgery to document the extent of residual disease 1, 3
- Recent advances in surgical techniques and intraoperative monitoring have significantly decreased surgical morbidity 2
- Surgery should be performed in high-volume specialized centers when possible 4
Radiation Therapy Options
Radiation therapy can be either external-beam or stereotactic radiosurgery (SRS) 1
Stereotactic Radiosurgery for Benign Meningiomas
- SRS is an effective evidence-based treatment option (recommendation level II) for WHO grade 1 meningiomas 1
- Prescription dose typically ranges between 12-15 Gy delivered in a single fraction 1
- 10-year local control rates range from 71% to 100% 1
- Toxicity rates are generally low 1
- SRS may be used as primary treatment for surgically inaccessible tumors or for recurrent lesions 5
Standard Radiation Therapy
- Standard fractionated external-beam RT is commonly used for primary brain tumors 3
- Radiation therapy is reserved for high-risk or refractory disease in benign tumors 6
Important Clinical Pitfalls
Avoid routine use of corticosteroids for asymptomatic tumors:
- Corticosteroids should only be used for symptomatic perilesional edema 3
- Use the lowest effective dose for the shortest duration 7
- Minimum dose is dexamethasone 4 mg every 6 hours, though doses may vary 7
- Long-term steroid use (>3 weeks) is associated with significant toxicity and should be avoided 3
Do not prescribe prophylactic anticonvulsants:
- Prophylactic anticonvulsants are not recommended for patients with no history of seizures 3
Consider long-term radiation complications:
- While radiation therapy is effective, delayed complications can occur in adults, including visual deterioration, pituitary dysfunction, and temporal lobe parenchymal changes 8
- These risks must be weighed against the benefits, particularly in younger patients with long life expectancy 8
Follow-Up and Monitoring
- Brain MRI every 2-3 months or at any instance of suspected neurological progression 7
- Neurological examination every 2-3 months using standardized procedures 7
- MRI with gadolinium contrast is the gold standard for monitoring 3