Extent of Peritumoral Edema and Meningioma Location Predicts Functional Outcomes and 1-Year Mortality after Resection in Older Patients

Background A disproportionally higher incidence of meningioma exists in older adults, affecting up to 0.1% of the older population versus 0.03% of younger adults. In older patients, surgical resection is associated with increased risk of complications and functional deficits. Thus, there is a need for preoperative prognostic markers that can determine which older patients may be at the highest risk when deciding whether or not to resect the tumor. For instance, prior studies of older meningioma patients have found that a skull base (SB) tumor location is associated with poorer postresection outcomes and greater risk of mortality compared with meningiomas of convexity, parasagittal, or falcine (CPF) areas. Further, peritumoral edema (PTE), which is seen in the majority of meningiomas, has also been implicated with poorer surgical outcomes and increased difficulty of resection, and could potentially represent an additional preoperative risk marker to help determine appropriate care plans for older patients.

Methods Medical records of 112 older patients (age ≥ 60 years) with an intracranial meningioma and evidence of PTE on MRI were reviewed from 2002 to 2016. Extent of PTE, measured as a ratio of edema to tumor volume (edema index, EI) using image-processing software, was correlated with postresection outcomes including surgical complications, 1-year mortality, tumor recurrence, and functional decline (as measured by Karnofsky performance status, KPS). Other preoperative factors, including meningioma location (SB or CPF), were entered as covariates in multivariate analyses of EI on outcomes.

Results Median EI was 1.65 (IQR = 1.34–2.56) with 30.4% of tumors located in the SB and 69.6% in CPF regions. SB tumors had a significantly smaller median volume than CPF tumors (14.9 vs. 30.8 cm³, p = 0.010). For functional outcomes, EI predicted a decrease in KPS at 6 months, 1 year, 2 years, and in most recent follow-up on multivariate analysis (ORs = 1.34–2.53, p < 0.05). Other preoperative factors such as presentation with a seizure or prior stroke trended toward additionally contributing to an increased likelihood of lower KPS at 2 years (OR = 3.06, p = 0.068) and last follow-up (OR = 5.55, p = 0.073), respectively. For one-year mortality, SB location was associated with a greater risk of death within 1 year relative to CPF tumors on multivariate analysis (OR = 10.64, p = 0.027), but EI was not (p = 0.68).

Conclusion Preoperative PTE may represent a significant marker for risk of poorer functional outcomes, in addition to SB tumor location, and can provide a quantitative measure that can assist patient care teams in determining the best treatment for older meningioma patients.