Lodoviga Giudice

Perioptic meningiomas pose a therapeutic challenge due to their proximity to critical visual structures. Single-fraction stereotactic radiosurgery is known to effectively control the growth of meningiomas, but this subgroup carries the risk of optic neuropathy, which is minimized with the introduction of dose hypofractionation. The Leksell Gamma Knife Icon has perfected fractionated stereotactic radiosurgery, maintaining submillimeter accuracy in each dose fraction without the need for an invasive frame. This study analyzes the feasibility, safety, and efficacy of multi-fraction Gamma Knife Icon radiosurgery for perioptic meningiomas, taking into account tumor control rates, visual preservation, and treatment-related toxicity. We conducted a retrospective analysis of 100 patients with a perioptic meningioma treated with fractionated Gamma Knife Icon radiosurgery between September 2017 and December 2022. A total of 80 Patients were female, and 20 were male; the mean age was 61.7 years (range 35–84). The most frequent anatomical locations included: cavernous sinus (35 pts), anterior clinoid (17 pts), sphenoid wing (14 pts) and olfactory groove (11 pts). The median tumor volume was 5.6 mL (range 0.12–31.7 mL). Most patients (89%) received 25 Gy in five fractions. Tumor control was achieved in 98% of cases, with a mean radiological follow-up of 41.2 months. Tumor volume did not predict radiological shrinkage (p = 0.639). Tumor shrinkage was observed more frequently in the no prior surgery group (p = 0.035). The mean clinical follow-up was 45.3 months. Among symptomatic patients (35 pts) at baseline, symptoms remained stable in 27 (77%) cases, improved in 5 (14%), and worsened in 3 (9%). No new symptoms were observed in asymptomatic patients. Overall clinical deterioration occurred in three (3%) patients—one because of tumor progression; although, without statistical evidence (p = 0.217), worsened patients had notable larger mean tumor volumes (12.6 mL vs. 6.8 mL). The dosimetric advantages of Gamma Knife technology are empowered by the biological benefits of fractionation and the convenience of non-invasive immobilization. Excellent tumor control rates and positive visual outcomes favor its routine application in properly selected patients.

Purpose: Grade II meningiomas are rarer than Grade I, and when operated on, bear a higher risk of local recurrence, with a 5-year progression free survival (PFS) ranging from 59 to 90%. Radiotherapy (RT) or radiosurgery, such as Gamma Knife radiosurgery (GKRS) can reduce the risk of relapse in patients with residual disease, even if their role, particularly after gross total resection (GTR), is still under debate. Main goal of this study was to compare the outcomes of different post-surgical management of grade II meningiomas, grouped by degree of surgical removal (Simpson Grade); next in order we wanted to define the role of GKRS for the treatment of residual disease or relapse. Methods: from November 2016 to November 2020 all patients harboring grade II meningiomas, were divided into three groups, based on post-surgical management: (1) wait and see, (2) conventional adjuvant radiotherapy and (3) stereotactic GKRS radiosurgery. Relapse rate and PFS were registered at the time of last follow up and results were classified as stable, recurrence next to or distant from the surgical cavity. In the second part of the study we collected data of all patients who underwent GKRS in our Centers from November 2017 to November 2020. Results: A total of 37 patients were recruited, including seven patients with multiple meningiomas. Out of 47 meningiomas, 33 (70.2%) were followed with a wait and see strategy, six (12.7%) were treated with adjuvant radiotherapy, and 8 patients (17.0%) with adjuvant GKRS. Follow up data were available for 43 (91.4%) meningiomas. Within the wait and see group, recurrence rates differed based on Simpson grades, lower recurrence rates being observed in three Simpson I cases (30%) compared to twelve relapses (60%) in patients with Simpson grade II/III. Finally, out of the 24 meningiomas undergoing GKRS (8 residual and 16 recurrence), 21 remained stable at follow up. Conclusions: Gross total resection (GTR) Simpson II and III have a significantly worse outcome as compared to Simpson I. The absence of adjuvant treatment leads to significant worsening of the disease progression curve. Adjuvant radiotherapy, especially GKRS, provides good local control of the disease and should be considered as an adjuvant treatment in all cases where Simpson I resection is not possible.