Surveillance Protocol for Recurrent Meningioma
For patients with a history of meningioma, surveillance should be performed with MRI without and with IV contrast every 6-12 months for WHO grade 1 tumors, while WHO grade 2 and 3 tumors require more frequent follow-up. 1, 2
Surveillance Protocol Based on WHO Grade
WHO Grade 1 Meningiomas
- MRI brain without and with IV contrast every 6-12 months 1, 2
- Consider extending intervals after tumor has demonstrated stability 3
- Annual surveillance should continue for at least 10 years due to potential for late recurrences 1
WHO Grade 2 (Atypical) Meningiomas
- More frequent MRI surveillance is required compared to WHO grade 1 tumors 1
- MRI brain without and with IV contrast every 3-6 months initially 2, 4
- Consider perfusion MRI as a helpful adjunct to conventional MRI 1
WHO Grade 3 (Malignant) Meningiomas
- Most aggressive surveillance schedule is warranted due to 80% recurrence rate 4
- MRI brain without and with IV contrast every 3 months initially 1, 4
- Consider adding spine imaging if there are concerns for CSF dissemination 1
Advanced Imaging Considerations
When to Consider Additional Imaging
- For suspected recurrence with equivocal findings on conventional MRI 2, 5
- For differentiating between tumor recurrence and post-treatment changes 2, 5
- When tumor extension is unclear on conventional imaging 2, 5
Advanced Imaging Options
- MRI perfusion is useful for meningioma grading and can help detect recurrence 1
- Somatostatin receptor (SSTR) PET imaging provides superior detection sensitivity compared to contrast-enhanced MRI alone 2, 5
- DCE MRI characteristics correlate with DOTATATE avidity in higher-grade meningiomas 1
Special Considerations for High-Risk Patients
Risk Factors for Recurrence
- WHO grade 3 histology (80% recurrence rate) 4
- Brain and/or bone invasion (40% recurrence rate regardless of WHO grade) 4
- Ki-67 proliferation index ≥3% (20% recurrence rate regardless of WHO grade) 4
- Presence of cystic component strongly associated with tumor recurrence (OR 21.7) 6
Genetic Predisposition Syndromes
- Patients with genetic syndromes associated with meningiomas (NF2, SMARCE1, etc.) require specialized surveillance 1
- For SMARCE1-associated clear cell meningiomas: yearly MRI brain and spine until age 30, then every 2-3 years 1
- For LZTR1-associated meningiomas: MRI brain and spine every 2-3 years, beginning at age 15-19 1
Practical Implementation
Duration of Surveillance
- Continue surveillance for at least 10 years for all meningioma grades 1
- Late recurrences are not uncommon, particularly with higher-grade tumors 1, 4
- Consider lifelong surveillance for WHO grade 2 and 3 tumors 4
Imaging Protocol Specifications
- MRI should include pre- and post-contrast T1-weighted sequences 1
- Include T2 FLAIR sequences to evaluate for vasogenic edema 1
- SWI sequences are valuable for detecting intratumoral calcifications 1
Common Pitfalls and Caveats
- Post-treatment changes can mimic tumor recurrence on conventional MRI 2, 5
- Inflammatory lesions may present with increased uptake on SSTR PET, leading to false positives 5
- Rare cases of meningioma may show decreased or absent uptake on SSTR PET 5
- The postradiotherapy MRI should be considered the "new baseline" rather than the postsurgical MRI 1