gms | German Medical Science

Objective: Parasagittal meningiomas are benign tumors which are dreaded for their surgical hardly accessiblelocation with respect to infiltration of the superior sagittal sinus. Treatment options of most benignparasagittal meningiomas are radical microsurgery, debulking followed by radiosurgery orradiosurgery as first treatment option.We report on the efficacy of Gamma Knife radiosurgery (GKRS) for the treatment of parasagittalmeningiomas, comparing these major skull base subgroups with respect to infiltration of the sagittalsinus.

Methods: From 15 participating centers under the auspices of the european Gamma Knife Society, weperformed a retrospective observational analysis of a cohort of 237 benign meningiomas treatedwith 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 by1 author (A.S.). A comparative analysis is presented.

Results: 192 patients harboring 237 meningiomas treated in fifteen institutions recruited were evaluated. 157 were parasagittal meningiomas without sinus infiltration 80 showed no sinus infiltration. Themedian age was 58 years. The median tumour volume was 4.00 cc. The median tumour margindose to the 50 % isodose line was 14.2 Gy. The median cumulative imaging follow-up was 60 months. The detailed results from 210 meningiomas (88%) were available for analysis. The actuarialcontrol rate was 92% at 5 years post GKRS. The permanent morbidity rate was 8.1%. A main limitation is the retrospective nature of data retrieval.

Conclusion: Radiosurgery is a safe and not invasive method of treatment of parasagittal meningiomas and thelarge number analyzed shows a high imaging tumor control and low morbidity rate even in themedium to long-term. Different control rates are observed for those tumors showing sinus infiltration.