Journal of Radiology
Open Access

Meningiomas are the most common primary brain tumors, accounting for approximately one-third of all brain tumors. Accurate diagnosis and characterization of meningiomas are crucial for effective treatment planning and patient management. In recent years, significant advancements in imaging technology have revolutionized the field, enabling improved visualization and better understanding of meningioma characteristics [1].

Traditionally, the primary imaging modality for meningiomas has been magnetic resonance imaging (MRI). MRI provides detailed anatomical information and is highly sensitive in detecting meningiomas. It can distinguish the tumor from surrounding brain tissue, assess its size and location, and identify any associated edema or mass effect on adjacent structures. Additionally, MRI helps differentiate meningiomas from other brain tumors based on their distinct imaging features, such as a dural tail sign, which is a characteristic extension of the tumor along the dura mater.

However, recent advancements in MRI techniques have further enhanced the evaluation of meningiomas. One such technique is perfusion-weighted imaging (PWI), which provides information about blood flow within the tumor. PWI helps determine the tumor’s vascularity, which is important for assessing tumor grade and planning treatment strategies. High-grade meningiomas typically exhibit increased blood flow compared to low-grade tumors, indicating a more aggressive behavior.

Another valuable addition to the imaging armamentarium is diffusion-weighted imaging (DWI), which measures the movement of water molecules within tissues. DWI helps assess the cellular density of meningiomas, aiding in tumor grading and predicting tumor behavior. Areas with restricted diffusion on DWI indicate high cellularity, suggesting a more aggressive tumor phenotype.

Beyond MRI, computed tomography (CT) plays a complementary role in meningioma imaging. CT scans provide excellent bony detail and are particularly useful in assessing skull base meningiomas, which often involve the cranial vault and adjacent structures [2,3]. CT angiography (CTA) can help visualize the vascular supply of meningiomas, aiding in surgical planning by identifying critical feeding vessels and potential collateral circulation.

In addition to these structural imaging techniques, advanced functional imaging modalities have emerged as promising tools for meningioma evaluation. Positron emission tomography (PET) with radiotracers such as 18F-fluorodeoxyglucose (FDG) or 68Ga- DOTATATE can provide valuable metabolic and receptor-based information. PET imaging helps distinguish between benign and malignant meningiomas, detect tumor recurrence, and identify distant metastases [4].

Furthermore, molecular imaging techniques like magnetic resonance spectroscopy (MRS) and amino acid positron emission tomography (AA-PET) have shown promise in meningioma characterization. MRS allows noninvasive assessment of metabolic profiles within the tumor, helping differentiate meningiomas from other intracranial lesions. AAPET, utilizing radiotracers such as 11C-methionine or 18F-fluoroethyl- L-tyrosine (FET), demonstrates increased amino acid uptake in meningiomas, aiding in tumor detection and differentiating between tumor recurrence and treatment-related changes.

The integration of these advanced imaging techniques into clinical practice has significantly impacted the diagnosis and management of meningiomas [5]. Accurate preoperative characterization of meningiomas using multimodal imaging allows neurosurgeons to plan optimal surgical approaches, ensuring maximal resection while preserving critical neurological function. Additionally, improved understanding of tumor biology through functional imaging can guide the selection of appropriate adjuvant therapies, including radiotherapy or medical treatments targeting specific molecular pathways.

Description

Despite these remarkable advancements, challenges remain in meningioma imaging. Certain subtypes of meningiomas, such as clear cell and chordoid meningiomas, may have overlapping imaging features with other tumors, necessitating histopathological confirmation for accurate diagnosis. Moreover, the availability and cost of advanced imaging techniques may limit their widespread use in resource-limited settings [6].

Prevalence: Meningiomas are the most common primary brain tumors, accounting for approximately 30% of all brain tumors [7]. They occur more frequently in women than in men, with a female-to-male ratio of about 2:1. Meningiomas are more commonly diagnosed in adults, particularly those aged 40 to 70 years.

Causes and risk factors: The exact cause of meningiomas is still unclear.

Female gender: Meningiomas are more prevalent in women, suggesting hormonal factors may play a role.

Radiation exposure: Previous radiation therapy to the head and neck increases the risk of developing meningiomas [8].

Genetic syndromes: Certain genetic conditions, such as neurofibromatosis type 2 (NF2) and familial meningioma syndrome, are associated with an increased risk of developing meningiomas.

Classification: Meningiomas can be classified based on their histological characteristics, which help determine their aggressiveness and prognosis [9].

Grade I (Benign): The majority of meningiomas (approximately 80%) fall into this category. These tumors tend to have slow growth rates and a favorable prognosis.

Grade II (Atypical): About 15% of meningiomas are classified as atypical. These tumors have a higher chance of recurrence and more aggressive behavior compared to grade I meningiomas.

Grade III (Malignant/Anaplastic): Malignant meningiomas are the least common (approximately 5%) but carry a higher risk of spreading to other parts of the brain and have a poorer prognosis.

Diagnosis: The diagnosis of meningioma typically involves a combination of imaging studies and histopathological examination. Imaging techniques, such as magnetic resonance imaging (MRI) and computed tomography (CT) scans, help visualize the tumor’s size, location, and characteristics. In some cases, a biopsy or surgical resection of the tumor may be necessary to obtain a tissue sample for pathological analysis [10].

Treatment: The management of meningiomas depends on several factors, including the tumor size, location, grade, and the patient’s overall health. Treatment options may include:

Surgery: Surgical resection is often the primary treatment for meningiomas.

Conclusion

Imaging plays a pivotal role in the diagnosis, characterization, and management of meningiomas. Recent technological advancements have expanded our capabilities in visualizing tumor characteristics, assessing vascularity, determining tumor grade, and predicting tumor behavior. Integration of advanced imaging modalities into routine clinical practice has transformed the field, enabling more precise treatment planning and better patient outcomes. As imaging techniques continue to evolve, we can expect further improvements in meningioma diagnosis and personalized treatment strategies in the future.

Acknowledgment

None

Conflict of Interest

None

1. Rogers L, Barani I, Chamberlain M, Kaley TJ, McDermott M, et al. (2015) Meningiomas: knowledge base, treatment outcomes, and uncertainties. A RANO review. J Neurosurg 122: 4-23.

Indexed at, Google Scholar, Crossref

2. Sahgal A, Weinberg V, Ma L, Chang E, Chao S, et al. (2013) Probabilities of radiation myelopathy specific to stereotactic body radiation therapy to guide safe practice. Int J Radiat Oncol Biol Phys 85: 341-347.

Indexed at, Google Scholar, Crossref

3. Goldsmith BJ, Wara WM, Wilson CB, Larson DA (1994) Postoperative irradiation for subtotally resected meningiomas. A retrospective analysis of 140 patients treated from 1967 to 1990. J Neurosurg 80: 195-201.

Indexed at, Google Scholar, Crossref

4. Rogers L, Zhang P, Vogelbaum MA, Perry A, Ashbyet LS, et al. (2018) Intermediate-risk meningioma: initial outcomes from NRG Oncology RTOG 0539. J Neurosurg 129: 35-47.

Indexed at, Google Scholar, Crossref

5. Combs SE, Adeberg S, Dittmar JO, Welzel T, Rieken S, et al. (2017) Skull base meningiomas: long-term results and patient self-reported outcome in 507 patients treated with fractionated stereotactic radiotherapy (FSRT) or intensity modulated radiotherapy (IMRT). BMC Cancer 17: 254.

Indexed at, Google Scholar, Crossref

6. Buerki RA, Horbinski CM, Kruser T, Horowitz PM, James CD, et al. (2018) An overview of meningiomas. Future Oncol 14: 2161-2177.

Indexed at, Google Scholar, Crossref

7. Walcott BP, Nahed BV, Brastianos PK, Loeffler JS (2013) Radiation Treatment for WHO Grade II and III Meningiomas. Front Oncol 3: 227.

Indexed at, Google Scholar, Crossref

8. Anvari K, Hosseini S, Rahighi S, Toussi MS, Roshani N, et al. (2016) Intracranial meningiomas: Prognostic factors and treatment outcome in patients undergoing postoperative radiation therapy. Adv Biomed Res 5: 83.

Indexed at, Google Scholar, Crossref

9. Pollock BE, Stafford SL, Utter A, Giannini C, Schreiner SA, et al. (2003) Stereotactic radiosurgery provides equivalent tumor control to Simpson Grade 1 resection for patients with small- to medium-size meningiomas. Int J Radiat Oncol Biol Phys 55: 1000-1005.

Indexed at, Google Scholar, Crossref

10. Combs SE, Schulz-Ertner D, Moschos D, Welzel T, Rieken S, et al. (2013) Skull base meningiomas: Long-term results and patient self-reported outcome in 507 patients treated with fractionated stereotactic radiotherapy (FSRT) or intensity modulated radiotherapy (IMRT). Radiother Oncol 106: 186-191.

Indexed at, Google Scholar, Crossref