Trends in Meningioma Incidence, Treatment, and Imaging Surveillance

Importance: Meningioma incidence is rising globally, yet many tumors follow an indolent course. Despite low intervention rates, surveillance imaging is extensive, and it is unclear whether current practices meaningfully influence treatment decisions. Objective: To quantify nationwide Danish trends in meningioma incidence, treatment, and surveillance and identify potentially redundant follow-up imaging. Design, Setting, and Participants: This nationwide quality improvement study integrated data from the Danish National Patient Registry and Danish Pathology Registry. All adults diagnosed with meningioma based on radiologic or histopathologic findings in Denmark between January 1, 2010, and December 31, 2023, were included. Follow-up extended through December 31, 2024. Exposure: Meningioma diagnosis and neuroimaging. Main Outcomes and Measures: The primary outcomes were trends in meningioma incidence from 2010 through 2023, treatment conversion rates (surgery or radiotherapy), and surveillance imaging volume. Secondary outcomes included intervention timing and imaging use after final treatment. Results: A total of 8134 patients with meningioma were included (median age, 66 years [range, 18-102 years]; 6002 [73.7%] women). The age- and sex-standardized incidence rate increased from 6.4 (95% CI, 5.0-7.8) to 12.6 (95% CI, 10.8-14.5) per 100 000 person-years between 2010 and 2023, yet yearly treatment rates remained stable. A total of 5307 patients (65.2%) received no treatment, while 2665 (32.8%) underwent surgery and 439 (5.4%) received radiotherapy. Histopathologic examination confirmed World Health Organization grade 1 tumors in 2379 patients who underwent surgery (89.3%). Surveillance imaging was common, with 7143 patients (87.8%) receiving 1 or more follow-up magnetic resonance imaging (MRI) scan. Of 28 736 MRI scans, 23 992 (83.5%) were not followed by treatment. Imaging beyond 5 years after diagnosis rarely led to changes in treatment but accounted for a substantial proportion of total scans. Only 78 of 5547 patients (1.4%) underwent surgery after year 5. Conclusions and Relevance: In this quality improvement study, meningioma incidence increased substantially between 2010 and 2023, while treatment rates remained stable. Most imaging did not result in intervention, suggesting that a substantial proportion of follow-up imaging could be reduced within a risk-adapted framework.