Radiotherapy for patients with brain metastases. History and future

To manage brain metastases is challenging in modern radiotherapy. Owing to the advances of lintier accelerator, acquisition of volumetric imaging before treatment, generation of the steep dose distribution using volumetric modulated arc therapy and sophisticated immobilization system are available in the clinical practice. Here, we calculate the margin to compensate uncertainty of the patient immobilization and mechanical accuracy, and demonstrate the technique for generating steep dose gradient in stereotactic irradiation. (author)