What is the treatment for schwannoma (nerve sheath tumor)?

Treatment of Schwannoma

The treatment of schwannoma should be determined by tumor size, location, symptoms, and patient factors, with observation (wait and scan) being the recommended first-line approach for small, asymptomatic tumors, while surgical resection is indicated for large tumors with brainstem compression. 1, 2

Treatment Algorithm Based on Tumor Size and Symptoms

Small Asymptomatic Tumors (Koos grades I-II)

• Observation (Wait and Scan) is the management of choice

  • Annual MRI follow-up for 5 years, then extended intervals
  • Evidence level III, recommendation level C 1
  • 87.7% of conservatively managed tumors show no growth 3
  • Mean growth rate is approximately 0.62-1 mm/year 3, 4

• Stereotactic Radiosurgery (SRS) is an alternative to observation

  • Can stop tumor growth and preserve long-term nerve function
  • Lower risk profile than surgery
  • Evidence level II, recommendation level B 1
  • Gamma Knife radiosurgery shows 64% stable hearing capability and favorable tumor control 5

• Surgery is NOT recommended for small asymptomatic tumors

  • Risk of functional deterioration up to 50%
  • Evidence class III, recommendation level C 1

Small Tumors with Complete Hearing Loss (Koos grades I-II)

• All treatment options can be justified
• Observation is usually first option (evidence class III, recommendation level C)
• SRS carries lower risk profile than surgery (evidence class II, recommendation level B) 1
• Surgery may be considered if cure is the primary goal

Medium-Sized Tumors (Koos grades III-IV, <3 cm)

• Treatment should be performed due to symptomatic burden
• Surgery or radiosurgery can be recommended at similar levels (recommendation level C)
• SRS has lower risk profile than surgery
• Subtotal resection to preserve function may be an option if subsequent SRS can be provided 1

Large Tumors with Brainstem Compression (Koos grade IV, >3 cm)

• Surgical resection is the only option
• Primary goal is decompression of brainstem and stretched cranial nerves
• Should be performed at high-volume centers
• Recommendation level: good practice point 1, 2

Follow-up Protocol

• For conservatively treated, radiated, or incompletely resected tumors:
  • Annual MRI and audiometry for 5 years
  • Doubled intervals thereafter if stable
• For completely resected tumors:
  • MRI controls postoperatively and at 2,5, and 10 years 1, 2

Important Considerations and Pitfalls

• Tumor growth detection: Volumetric measurements are more accurate than bidimensional measurements; significant growth is defined as ≥50% volume increase 6

• Quality of life impact: QoL cannot be predicted based on management strategy alone; poor QoL is more likely in patients with large, symptomatic tumors that were resected 1

• Multidisciplinary approach: Patients should be discussed in multidisciplinary tumor boards, especially for medium-sized tumors 1, 2

• Surgical expertise matters: If surgery is indicated, treatment at a high-volume center is recommended since surgical experience affects outcome 1

• Supportive care: Should focus on clinical symptoms and treatment complications, including management of facial nerve palsy and hearing loss 1

• Monitoring pitfalls: Even after 5 years of stability, 7.2% of tumors may exhibit growth, necessitating continued surveillance 1

• Non-vestibular schwannomas: For schwannomas in other locations (e.g., radial nerve), complete surgical removal with nerve preservation is the treatment of choice 7