title: Neurocognitive assessment following whole brain radiation therapy and radiosurgery for patients with cerebral metastases.
abstract: The treatment of metastatic brain lesions remains a central challenge in oncology. Because most chemotherapeutic agents do not effectively cross the blood-brain barrier, it is widely accepted that radiation remains the primary modality of treatment. The mode by which radiation should be delivered has, however, become a source of intense controversy in recent years. The controversy involves whether patients with a limited number of brain metastases should undergo whole brain radiation therapy (WBRT) or stereotactic radiosurgery (SRS) delivered only to the radiographically visible tumours. Survival is comparable for patients treated with either modality. Instead, the controversy involves the neurocognitive function (NCF) of radiating cerebrum that appeared radiographically normal relative to effects of the growth from micro-metastatic foci. A fundamental question in this debate involves quantifying the effect of WBRT in patients with cerebral metastasis. To disentangle the effects of WBRT on neurocognition from the effects inherent to the underlying disease, we analysed the results from randomised controlled studies of prophylactic cranial irradiation in oncology patients as well as studies where patients with limited cerebral metastasis were randomised to SRS versus SRS+WBRT. In aggregate, these results suggest deleterious effects of WBRT in select neurocognitive domains. However, there are insufficient data to resolve the controversy of upfront WBRT versus SRS in the management of patients with limited cerebral metastases.
authors.affiliation: Center for Theoretical and Applied Neuro-Oncology, University of California, , La Jolla, California, USA.
authors.forename: Susan G R
authors.initials: SG
authors.lastname: McDuff
authors.forename: Zachary J
authors.initials: ZJ
authors.lastname: Taich
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Lawson
authors.forename: Parag
authors.initials: P
authors.lastname: Sanghvi
authors.forename: Eric T
authors.initials: ET
authors.lastname: Wong
authors.forename: Fred G
authors.initials: FG
authors.lastname: Barker
authors.forename: Fred H
authors.initials: FH
authors.lastname: Hochberg
authors.forename: Jay S
authors.initials: JS
authors.lastname: Loeffler
authors.forename: Peter C
authors.initials: PC
authors.lastname: Warnke
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Murphy
authors.forename: Arno J
authors.initials: AJ
authors.lastname: Mundt
authors.forename: Bob S
authors.initials: BS
authors.lastname: Carter
authors.forename: Carrie R
authors.initials: CR
authors.lastname: McDonald
authors.forename: Clark C
authors.initials: CC
authors.lastname: Chen
mesh_terms: D001932:Brain Neoplasms / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery*; D003071:Cognition / Q000528:radiation effects*; D003131:Combined Modality Therapy; D016371:Cranial Irradiation / Q000009:adverse effects* / Q000379:methods / Q000401:mortality; D006801:Humans; D009483:Neuropsychological Tests; D016634:Radiosurgery / Q000009:adverse effects* / Q000379:methods / Q000401:mortality
keywords: COGNITIVE NEUROPSYCHOLOGY; MEMORY; NEUROONCOLOGY; NEUROSURGERY; RADIOTHERAPY