Metastatic brain tumors

Abstract

Stereotactic radiosurgery has developed an increasingly important role in the management of brain metastases. However, its use has also sparked controversy about the appropriate treatment for patients with brain metastases. Studies have shown benefits of SRS as sole treatment, as adjuvant therapy after surgery, as an adjunct to WBRT, and as salvage treatment after WBRT. Retrospective studies suggest that patients treated with SRS or surgery have comparable outcomes. RTOG 9508 provides level 1 evidence of a survival benefit of SRS and WBRT compared with WBRT alone for patients with a single lesion. For patients with more than one lesion, the use of SRS and WBRT should be considered based on performance status, extent and activity of extracranial disease, and steroid use. More recently, the omission of WBRT has been advocated by concerns of the potential risks of cognitive decline with WBRT and apparent lack of survival benefit of additional WBRT. Surgical resection followed by SRS boost exhibits good local control for single brain metastasis. The potential cognitive side effects of WBRT must be balanced against the risk for increased distant brain metastases and the cost of more frequent follow-up scans when treating brain metastases with SRS alone. A recent phase III trial has shown benefit in cognition for patients undergoing WBRT who take memantine. As the prognosis improves for cancer patients, the challenge of increasing progression free survival while limiting cognitive decline and other side effects will continue to make the management of brain metastases controversial.​