gms | German Medical Science

Objective: Skull base Meningiomas are the most frequent benign tumours treated with Gamma Knife Radiosurgery (GKRS). However, the assessment of its efficacy and safety in slow growing tumours is an ongoing process, requiring analysis of long-term results. This study involves the experience of several European Gamma Knife Centres. We report on the efficacy of GKRS for the treatment of skull base Meningiomas, clinical and radiological control and side effects

Methods: From 15 participating centers, we performed a retrospective observational analysis of a cohort of 3752 benign meningiomas treated with GKRS. All were treated with Gamma Knife radiosurgery at least 5 years before assessment for this study. Clinical and imaging data were retrieved from each center and uniformly entered into a database by 1 author (A.S.). A statistical analysis is presented.

Results: 3451 patients harbouring 3752 meningiomas treated in fifteen institutions recruited were evaluated. The median age was 56 years (range 6 - 89 years). The median tumour volume was 5.20 ccm (range 0.5 - 85 ccm) and tumour margin dose to the 50 % isodose line 13.5 Gy (range 3 - 45 Gy). The median radiological follow-up was 61 months, but detailed results were only available for 3259 meningiomas (86.8 %). The volume of treated tumours decreased in 1753 lesions (54 %) did not change in 1305 lesions (40 %) and increased in 200 lesions (6 %). The temporary morbidity rate after GKRS was 5.3 % and the permanent morbidity rate was 5.6 %. The actuarial control rate was 97.9 % at 5 years post GKRS.

Conclusion: GKRS is a safe and not invasive method of treatment of skull base meningiomas and the large number analysed confirms a high tumour control and low morbidity rate even after a long-term follow-up period.