Aim:T1-weighted contrast-enhanced (T1+C) magnetic resonance imaging (MRI) sequences are usually used for planning meningioma treatment via Gamma-Knife radiosurgery (GKRS). However, practitioners should refrain from using contrast agents because of allergies or other systemic diseases. The fast imaging employing steady-state acquisition (FIESTA) sequence is a high-resolution T2-weighted MRI sequence with a high signal-to-noise ratio that provides good image contrast without using any contrast agent. However, in T1+C sequences, the tumor size appears more prominent due to the contrast agent effect, especially in meningiomas with sinus invasion. Thus, normal anatomical structures may be exposed to radiation. Therefore, we aimed to compare T1+C with FIESTA MRI sequences to protect healthy brain tissue during meningioma treatment with GKRS.Material and Methods:After reviewing the data of 54 patients with solitary meningioma who underwent GKRS between January 2020 and June 2022, demographic characteristics were noted, tumor volumes on T1+C and FIESTA MRI sequences were measured, and sequences were compared. The patients were then divided into two groups according to the presence of invasion to intracranial venous sinuses (groups 1 and 2, respectively). SPSS 11.5 software was used for data analysis, with the level of significance set at 0.05.Results:While no significant age and tumor size differences were observed between groups 1 and 2, sinus invasion was significantly higher among males. Tumor volumes measured in both groups were significantly smaller on FIESTA sequences than on T1+C sequences.Conclusion:The T1+C sequence has been the primary imaging method because of meningiomas\' high contrast enhancement feature. However, the T1+C sequence during GKRS planning is an effective imaging method in treating meningiomas; FIESTA sequences can more precisely delineate the tumor border. In this study, we consider that using the FIESTA/CISS sequence MRI for planning meningioma therapy with Gamma-Knife can reduce target volume and prevent irradiation of healthy brain tissue.