Evolution in the role of stereotactic radiosurgery in patients with multiple brain metastases: An international survey

Objective: Currently no firm consensus exists regarding utilization of stereotactic radiosurgery (SRS) alone versus whole brain radiation (WBRT) ± SRS in patients with multiple brain metastases. The International Gamma Knife Research Foundation conducted a survey to review international practice patterns. Methods: Through 2 international radiosurgery societies, clinicians who are involved in the radiosurgical management of patients with brain metastases were invited to complete a questionnaire. Respondents selected therapeutic options based on brief case vignettes and could select (1) SRS alone, (2) SRS with adjuvant WBRT, (3) WBRT alone, or (4) omission of upfront local radiation. Results: A total of 71 respondents replied to the survey, including 41 radiation oncologists (57%), 24 neurosurgeons (34%), and 6 (8%) other clinicians. For a patient with 7 brain metastases (NSCLC), all under 1 cm, and stable extracranial disease, 77% would perform SRS alone and 17% would recommend WBRT alone. For a patient with 7 or more brain metastases, the majority selected SRS alone, irrespective of tumor histology (p > 0.5). However, neurosurgeons would more often utilize SRS alone or SRS combined with WBRT compared to radiation oncologists (p = 0.002). Key clinical factors in selection were KPS (82% of respondents), total tumor volume (81%), number (80%), and less-so histology (42%). Conclusion: Regardless of number of metastases, patients with small total volume of brain disease, high KPS, or who are receiving novel therapies are often recommended to undergo SRS. Neurosurgeons more often recommend SRS, emphasizing the importance of additional studies to clarify the role of SRS in these patients.