Stereotactic Radiosurgery for Multiple Brain Metastases: Two Cases of Preserved Quality of Life

Brain metastases are the most common intracranial tumors in the adult population and have been historically treated with whole brain radiation therapy (WBRT). However, as medical advances improve life expectancy, stereotactic radiosurgery (SRS) has replaced WBRT as the standard of care for limited (one to three) brain metastases due to the relative sparing of neurocognitive function (NCF) and therefore quality of life (QoL). The use of SRS has been less documented in the case of multiple (four or more) brain metastases, with literature limited to non-randomized studies showing comparable survival and local control. In this series, we detail the case of two individuals who received SRS at our institution for multiple brain metastases and demonstrated remarkable response. The first patient is a 78-year-old woman who received Gamma Knife (GK) treatment to 17 lesions at our institution. This patient responded very well to treatment and maintains an excellent quality of life, with no deficits on serial neurological examination as she continues to travel and drive for ridesharing businesses. The second patient is an active 44-year-old woman who received SRS to 24 lesions at our institution. The patient has now been free of intracranial failures for two years and continues fulfilling her love for travel and long-distance biking. SRS is emerging as an acceptable alternative to WBRT in treating multiple brain metastases due to its preservation of NCF. Because omission of WBRT may lead to increased probability of distant brain metastasis failure, it is critical to follow these patients closely with frequent neuroimaging. In the event of a failure, it is also possible to use SRS salvage therapy with good response. Some patients who receive SRS alone demonstrate exceptional outcomes with excellent QoL, and it is possible that certain prognostication factors such as performance status, tumor histology, and tumor volume may play a role in identifying these patients. The decision to treat a patient with SRS alone for multiple brain metastases should be made carefully with consideration of systemic therapeutic options, overall prognosis, and the patient’s goals of care, with adherence to a careful follow-up plan by the physician and patient.