Management of Residual Meningioma After Tumor Resection

Diagnostic Evaluation

MRI without and with IV contrast is the standard imaging modality for evaluating residual meningioma, with recommended follow-up intervals based on WHO tumor grade 3
For WHO grade 1 meningiomas, MRI surveillance should be performed every 6-12 months 3, 4
Somatostatin receptor (SSTR) PET imaging should be obtained if tumor extension is unclear or to differentiate recurrence from treatment-related changes 5, 6
SSTR PET/CT or PET/MRI provides more accurate delineation of residual tumor extent, particularly for WHO grade 2 and 3 tumors 3, 7

SRS is the preferred treatment option for WHO grade 1 residual meningioma, with 5-year progression-free survival (PFS) rates ranging from 86% to 99% 1, 2
SRS offers higher rates of tumor shrinkage compared to fractionated stereotactic radiotherapy (SRT) (53% vs 29%, p<0.04) 2
Post-SRS neurological preservation rates range from 80% to 100% 1
Tumor typically stabilizes after SRS, with 95% achieving steady state by 5 years and 90% by 10 years 1
Consider hypofractionated SRT for larger residual tumors or those with pre-existing edema to minimize complications 1, 8
SSTR PET imaging is particularly valuable for assessing response to radiotherapy in higher-grade meningiomas 5, 6
For treatment-refractory cases with positive SSTR expression, peptide receptor radionuclide therapy (PRRT) may be considered 5, 6

Routine radiological follow-up can be extended to longer intervals after the tumor has attained a steady state 1
Clinical follow-up should continue with routine neurological exams and ophthalmological assessment 1

For larger residual tumors or those near critical structures, hypofractionated SRT may have less likelihood of causing post-radiosurgical edema than single-fraction SRS 1, 8

SRS for residual meningioma shows 10-year PFS rates ranging from 69% to 97% 1
Tumor shrinkage is more common after SRS compared to SRT, though clinical improvement rates are similar 2