Efficacy of gamma knife surgery for control of peritumoral oedema associated with metastatic brain tumours

Objectives: To evaluate the efficacy of gamma knife surgery (GKS) for the control of peritumoral oedema associated with metastatic brain tumours. Methods: A retrospective study of 280 consecutive metastatic brain tumours—100 from lung cancers, 100 from breast cancers and 80 from renal-cell carcinomas, associated with peritumoral oedema. The peritumoral oedema index was measured as A*B*C, where A (cm) was the maximum diameter of peritumoral oedema on the axial image, B (cm) was the maximum diameter perpendicular to A, and C (cm) was the maximum diameter on the coronal image. Results: The oedema index of the renal cancer metastases was significantly larger than those of lung and breast cancer metastases (p