Monitoring

All patients with meningiomas, whether treated or not, should be followed at regular intervals by an experienced neurosurgeon or neuro-oncologist.[50] Guidance on monitoring frequency varies. The European Association of Neuro-Oncology (EANO) recommends annual brain magnetic resonance imaging (MRI) scans for suspected meningiomas or World Health Organization (WHO) grade 1 meningiomas for 5 years, with the interval doubling thereafter. For WHO grade 1 and 2 and unresected meningiomas, the National Comprehensive Cancer Network (NCCN) recommends an MRI at 3, 6, and 12 months, every 6 to 12 months for 5 years, and then every 1 to 3 years as clinically indicated.[43][74] For WHO grade 3 tumors, the NCCN recommends an MRI every 2 to 4 months for 3 years, then every 3 to 6 months.[43] For all grades of tumor, more frequent imaging may be needed for meningiomas that are treated for recurrence or with systemic therapy.[43] In pediatric patients under observation, the Children’s Cancer and Leukemia Group advises initial surveillance imaging within 3 months for meningiomas of any grade.[45]

Serial imaging plans should be tailored to each patient's case, as some incidental meningiomas have higher risk for growth. Emerging tools are available to help identify incidental meningiomas at higher risk, including the IMPACT calculator which takes into account patient age, performance status, radiologic features of the tumor, and provides a risk assessment for future growth.[73][74] IMPACT Calculator Opens in new window

The method of choice for monitoring growth of the tumor is T1-weighted MRI with and without gadolinium enhancement.[125] In the case of a tumor that has not been treated, dimensions of the tumor are measured for comparison. In surgically resected tumors, serial MRI studies are performed to rule out any recurrence. In tumors treated with stereotactic radiosurgery or fractionated stereotactic radiation therapy, serial MRI studies are performed (usually annually), to ensure there is no progression of the tumor. If the tumor does not recur or grow after 5 years, then MRI studies are performed every 2 years. For WHO grade 2 tumors, follow-up is recommended every 6 months for 5 years, then annually.[50] For WHO grade 3 tumors, follow-up should be every 3 to 6 months indefinitely.

There is no guideline on when to stop monitoring, but recurrence rates increase with time, so ongoing monitoring for a minimum of 8 years should be considered for WHO grade 1 tumors.[126] Continuing to monitor the patient for the rest of their life is reasonable given the increasing recurrence rates that occur with longer follow-up time. One study of parasagittal meningiomas with a 25-year follow-up period found that even for WHO grade 1 meningiomas that were completely resected, recurrence rates were as high 38%. This suggests the need for ongoing follow-up and longitudinal studies to better characterize the long-term prognosis.[114] WHO grade 2 and 3 meningiomas should continue with surveillance for the duration of a patient’s life.

Although health-related quality of life typically improves after surgery, studies suggest it declines in the long-term.[50][115] Guidelines recommend that follow-up include neuropsychologic assessment and assessment of quality of life to guide appropriate interventions.[43][50]

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