Integration of the metabolic data of positron emission tomography in the dosimetry planning of radiosurgery with the gamma knife: early experience with brain tumors - Technical note

The purpose of this study was to assess the use of positron emission tomogr aphy (PET) as a stereotactic planning modality for gamma knife radiosurgery (GKS). The authors developed and validated a technique for fiducial marker imaging , importation, and handling of PET data for integration into GammaPlan plan ning software. The clinical feasibility in applying this approach to a sele cted group of patients presenting with recurrent glial tumors or metastases was evaluated. Positron emission tomography data can be integrated into GammaPlan, allowin g a high spatial accuracy, as validated using a phantom. Positron emission tomography data were successfully combined with magnetic resonance (MR) ima ges to define the target volume for the radiosurgical treatment of patients with recurrent glioma or metastasis. This approach may contribute to optim izing target selection for infiltrating or ill-defined brain lesions. Becau se PET is also useful for the pretreatment and follow-up evaluation, the us e of stereotactic PET in these patients can enable an accurate comparison o f PET-based metabolic data with MR-based anatomical data. This could give a better understanding of the metabolic changes following radiosurgery. The ability to use PET data in GKS represents a crucial step toward further developments in radiosurgery, as this approach provides additional informa tion that may open new perspectives for the optimization of the treatment o f brain tumors.