Stereotactic Radiosurgery of Multiple Brain Metastases: A Review of Treatment Techniques

SIMPLE SUMMARY: In the past year, there have been improvements in cancer treatment, especially for cancers that have spread throughout the body. However, treating tumors that spread to the brain, causing brain metastases, is still a challenge. The brain has extra protection that makes it hard for helpful medications to reach it. That's why local treatments like stereotactic radiosurgery, a precise way of using radiation to treat tumors, are important for addressing brain metastases. Nowadays, even multiple metastases can be treated simultaneously with stereotactic radiosurgery. Different techniques, such as the Gamma Knife that treats metastases one by one, and single-isocenter techniques that can treat many metastases at once using a traditional radiation device called a linear accelerator, are used for this purpose. This article compares the advantages and disadvantages of these treatments by examining other articles published on the topic. ABSTRACT: The advancement of systemic targeted treatments has led to improvements in the management of metastatic disease, particularly in terms of survival outcomes. However, brain metastases remain less responsive to systemic therapies, underscoring the significance of local interventions for comprehensive disease control. Over the past years, the threshold for treating brain metastases through stereotactic radiosurgery has risen. Yet, as the number of treated metastases increases, treatment complexity and duration also escalate. This trend has made multi-isocenter radiosurgery treatments, such as those with the Gamma Knife, challenging to plan and lengthy for patients. In contrast, single-isocenter approaches employing linear accelerators offer an efficient and expeditious treatment option. This review delves into the literature, comparing different linear-accelerator-based techniques with each other and in relation to dedicated systems, focusing on dosimetric considerations and feasibility.