Radiosurgery of cerebral metastases

Context. Brain metastases can occur in 20 % of patients with cancer. Whole brain radiation is the standard therapy as well as microsurgical resection. Minimally invasive radiosurgery is an additional treatment option. The following review focuses on the options, advantages and limitations of radiosurgical treatment of brain metastases based on recently published guidelines and the literature. Objective. The aim of this review is a comprehensive survey of intracranial radiosurgery and the value as an established treatment option for patients with brain metastases. Material and methods. A targeted literature search was performed to review current guidelines as well as relevant publications concerning radiosurgical treatment of brain metastases. Results. Radiosurgery is defined as a specialized technique in radiation therapy by applying an ablative radiation dose with multiple beams from different directions in a single treatment session by means of a stereotactic guiding system. Local tumor control rates over 80 % can be achieved with a relatively low risk of side effects of less than 10 %; however, a strict case selection with regards to indication criteria is crucial. Metastases of the brain as targets for radiosurgery should be less than 2.5 cm in diameter and unsuitable for surgery because of the location or other surgical risk factors. The absolute number of metastases is less important than the summed volume. High quality imaging as well as systematic follow-up with high resolution magnetic resonance imaging (MRI) are essential not only for initial target definition but also for the early detection of local regional progression. If new intracranial metastases occur radiosurgery can be repeated even after whole brain radiation. In contrast whole brain radiation can still be applied after radiosurgery but can be postponed with respect to the impact on patient quality of life and long-term side effects. Conclusion. Specialized treatment systems for radiosurgery are becoming increasingly more available. The treatment process itself is streamlined and comfortable for the patient; however, the complex technology necessitates a specialized and well-trained team of physicians, physicists and technicians. The trend in oncology towards individualized and patient-focused therapy concepts is also reflected in a paradigm shift in radiation oncology: the standard application of whole brain radiation is withheld more and more in favor of a tailored treatment of brain metastases. As decision-making becomes more complex, a close interdisciplinary cooperation between radiation oncologists, neurosurgeons and oncologists is important. Respecting these prerequisites, radiosurgery adds another effective and safe treatment option to the neuro-oncological portfolio for multimodal therapy of brain metastases. © 2014 Springer-Verlag Berlin Heidelberg.