Analysis of treatment planning parameters in the Gamma Knife® technique for different prescription isodoses and volumes of meningiomas

The following Indexes: Homogeneity, Gradient, Conformity, Paddick Conformity and New Conformity of the dose distribution were compared. The parameters to assess a high dose to the organs at risk: V10/TV, V90%/TV and the Integral Dose were discussed. The higher the prescription isodose, the more uniform the dose distribution in the target, which is highly beneficial in the case of larger tumor sizes due to the lower risk of complications. For smaller tumors, higher dose heterogeneity is desirable. This can be obtained with a 40% prescription isodose. •GK is used for meningioma treatment with careful selection of planning parameters.•Tumor volume and isodose prescription fundamentally affect dosimetry parameters.•Effect of high dose to organs at risk is analyzed by V10/TV, V90%/TV, Integral Dose.•V90%/TV points to the most favorable prescription isodose 40% for small lesions.