Comparison of Active Surveillance to Stereotactic Radiosurgery for the Management of Patients with an Incidental Frontobasal Meningioma-A Sub-Analysis of the IMPASSE Study.

Meningioma is a common incidental finding, and clinical course varies based on anatomical location. The aim of this sub-analysis of the IMPASSE study was to compare the outcomes of patients with an incidental frontobasal meningioma who underwent active surveillance to those who underwent upfront stereotactic radiosurgery (SRS). Data were retrospectively collected from 14 centres. The active surveillance (n = 28) and SRS (n = 84) cohorts were compared unmatched and matched for age, sex, and duration of follow-up (n = 25 each). The study endpoints included tumor progression, new symptom development, and need for further intervention. Tumor progression occurred in 52.0% and 0% of the matched active surveillance and SRS cohorts, respectively (p < 0.001). Five patients (6.0%) treated with SRS developed treatment related symptoms compared to none in the active monitoring cohort (p = 0.329). No patients in the matched cohorts developed symptoms attributable to treatment. Three patients managed with active surveillance (10.7%, unmatched; 12.0%, matched) underwent an intervention for tumor growth with no persistent side effects after treatment. No patients subject to SRS underwent further treatment. Active monitoring and SRS confer a similarly low risk of symptom development. Upfront treatment with SRS improves imaging-defined tumor control. Active surveillance and SRS are acceptable treatment options for incidental frontobasal meningioma.

An international multicenter matched cohort analysis of incidental meningioma progression during active surveillance or after stereotactic radiosurgery: the IMPASSE study.

BACKGROUND: The optimal management of patients with incidental meningiomas remains unclear. The aim of this study was to characterize the radiologic and neurological outcomes of expectant and stereotactic radiosurgery (SRS) management of asymptomatic meningioma patients. METHODS: Using data from 14 centers across 10 countries, the study compares SRS outcomes to active surveillance of asymptomatic meningiomas. Local tumor control of asymptomatic meningiomas and development of new neurological deficits attributable to the tumor were evaluated in the SRS and conservatively managed groups. RESULTS: In the unmatched cohorts, 727 meningioma patients underwent SRS and were followed for a mean of 57.2 months. In the conservatively managed cohort, 388 patients were followed for a mean of 43.5 months. Tumor control was 99.0% of SRS and 64.2% of conservatively managed patients (P < .001; OR 56.860 [95% CI 26.253-123.150]). New neurological deficits were 2.5% in the SRS and 2.8% of conservatively managed patients (P = .764; OR 0.890 [95% CI 0.416-1.904]). After 1:1 propensity matching for patient age, tumor volume, location, and imaging follow-up, tumor control in the SRS and conservatively managed cohorts was 99.4% and 62.1%, respectively (P < .001; OR 94.461 [95% CI 23.082-386.568]). In matched cohorts, new neurological deficits were noted in 2.3% of SRS-treated and 3.2% of conservatively managed patients (P = .475; OR 0.700 [95% CI 0.263-1.863]). CONCLUSIONS: SRS affords superior radiologic tumor control compared to active surveillance without increasing the risk of neurological deficits in asymptomatic meningioma patients. While SRS and active surveillance are reasonable options, SRS appears to alter the natural history of asymptomatic meningiomas including tumor progression in the majority of patients treated.

Gamma Knife Radiosurgery for Pituitary Tumors: A Systematic Review and Meta-Analysis.

To describe and evaluate outcomes of Gamma Knife radiosurgery (GK) for the treatment of pituitary tumors over the past twenty years, a systematic review and meta-analysis according to PRISMA statement was performed. Articles counting more than 30 patients were included. A weighted random effects models was used to calculate pooled outcome estimates. From 459 abstract reviews, 52 retrospective studies were included. Among them, 18 reported on non-functioning pituitary adenomas (NFPA), 13 on growth hormone (GH)-secreting adenomas, six on adrenocorticotropic hormone (ACTH)-secreting adenomas, four on prolactin hormone (PRL)-secreting adenomas, and 11 on craniopharyngiomas. Overall tumor control and five-year progression free survival (PFS) estimate after one GK procedure for NFPA was 93% (95% CI 89-97%) and 95% (95% CI 91-99%), respectively. In case of secreting pituitary adenomas, overall remission (cure without need for medication) estimates were 45% (95% CI 35-54%) for GH-secreting adenomas, 64% (95% CI 0.52-0.75%) for ACTH-secreting adenomas and 34% (95% CI: 19-48%) for PRL-secreting adenomas. The pooled analysis for overall tumor control and five-year PFS estimate after GK for craniopharyngioma was 74% (95% CI 67-81%) and 70% (95% CI: 64-76%), respectively. This meta-analysis confirms and quantifies safety and effectiveness of GK for pituitary tumors.

Clinical and Imaging Response to Trigeminal Schwannoma Radiosurgery: A Retrospective Analysis of a 28-Year Experience.

Objective The purpose of this study was to evaluate long-term clinical outcomes and tumor control after stereotactic radiosurgery (SRS) for trigeminal schwannoma (TS). Methods During a 28-year period (1989-2017), 50 patients underwent SRS for TS. The median patient age was 51 years (range: 15-87 years). A total of 17 patients had a previous tumor resection: 10 had a single procedure, 5 had two procedures, and 2 had three procedures. The median and mean times between tumor resection and SRS were 12 and 24 months (range: 1-90 months), respectively. Four patients had neurofibromatosis II (NF2). Based on location, tumors were classified as root type (7), ganglion type (22), or dumbbell type (21). The median radiosurgery target volume was 3.4 cm 3 (range: 0.10-18 cm 3 ), median target dose was 14 Gy (range: 12-20 Gy), and the median number of isocenters was 6 (range: 1-15). The median and mean times to last follow-up was 36.9 and 55.2 months (range: 4-205 months), respectively. Eighteen patients (36%) had longer than 5-year follow-up, and seven patients (14%) had longer than 10-year follow-up. Results The tumor control rate was 92% and the clinical improvement or stabilization rate was 94%. After SRS, the rates of progression free survival (PFS) at 1, 5, and 10 years were 98, 84, and 84%, respectively. Factors associated with improved PFS were female sex ( p = 0.014) and smaller tumor volume ( p = 0.022). In this series, we did not find that tumor type (root, ganglion, and dumbbell) had a statistically significant correlation to PFS. Forty-seven patients had neurological signs or symptoms at presentation. At last follow-up, neurological signs or symptoms improved in 22/47 (47%), remained unchanged in 24/50 (48%), and worsened due to tumor progression in 3/50 (6%). One patient (2%) developed temporary symptomatic adverse radiation effect (ARE) and three additional patients (6%) had transient imaging evidence of peritumoral reactive edema but no new symptoms. Conclusion As a single outpatient procedure, SRS was associated with long-term freedom from additional management in 84% of patients. Nearly half the treated patients experienced improvement in neurological symptoms or signs.