Evaluation of Radiosurgery Target Volume Determination for Meningiomas Based on Computed Tomography (CT) And Magnetic Resonance Imaging (MRI)

Objective: Meningiomas arise from arachnoid cap cells and comprise the commonest benign tumor of the brain, accounting for more than one third of all intracranial neoplasms. Surgery and radiation therapy (RT) have been traditionally used in meningioma management. Radiosurgery is a sophisticated form of therapeutic irradiation with the capability of delivering high doses of radiation to well defined targets with typically steep dose gradients around the treatment volumes under robust stereotactic localization and image guidance. Target volume definition is an important part of menigioma radiosurgery. In this study, we assessed the use of multimodality imaging for target volume definition in radiosurgery of meningiomas. Methodology: We included 27 patients receiving meningioma radiosurgery at our department. All patients were treated with high precision radiosurgery after multidisciplinary assessment of patients regarding lesion size, location, association with critical neurovascular structures, symptomatology, and previous treatments. Target volume determination was done based on using only CT images and also by incorporation of MR fusion to perform a comparative assessment. Results: Comparative evaluation revealed improved target volume definition by incorporation of MRI into radiosurgery treatment planning for patients treated with radiosurgery for meningiomas. Conclusion: Improved target definition is a pertinent goal of optimal radiosurgical treatment planning. Our study supports the utility of MRI in meningioma radiosurgery treatment planning. Clearly, further research is warranted to refine target definition for radiosurgical management of meningiomas.