Purpose: Among patients with brain metastases, hippocampal avoidance whole brain radiation (HA-WBRT) preserves neurocognitive function relative to conventional WBRT but the feasibility of hippocampal sparing in patients with metastases in/near the hippocampus is unknown. We identified the incidence of hippocampal/perihippocampal metastases and evaluated the feasibility of HA-WBRT in such patients.
Materials/methods: Dosimetric data from 34 patients randomized to HA-WBRT (30 Gy/10 fractions) in a phase III trial (NCT03075072) comparing HA-WBRT to stereotactic radiation in patients with 5 to 20 brain metastases were analyzed. Patients with metastases in/near the hippocampi received HA-WBRT with prioritization of tumor coverage over hippocampal avoidance. Target coverage and hippocampal sparing metrics were compared between patients with targets in/near the hippocampus versus not.
Results: In total, 9 of 34 (26%) patients had targets in the hippocampus and an additional 5 of 34 (15%) patients had targets in the hippocampal avoidance zone (HAZ, hippocampus plus 5 mm expansion) but outside the hippocampus. Patients with targets within the hippocampus and those with targets in the HAZ but outside the hippocampus were spared 34% and 73% of the ipsilateral mean biologically equivalent prescription dose, respectively. Of the latter cohort, 88% and 25% met conventional hippocampal sparing metrics of Dmin ≤ 9 Gy and Dmax ≤ 16 Gy, respectively. Among 11 patients with unilateral hippocampal/perihippocampal involvement, the uninvolved/contralateral hippocampus was limited to Dmin ≤ 9 Gy and Dmax ≤ 17 Gy in all cases.
Conclusions: In this study, a substantial percentage of patients with 5 to 20 brain metastases harbored metastases in/near the hippocampus. In such cases, minimizing hippocampal dose while providing tumor coverage was feasible and may translate to neurocognitive protection.
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http://dx.doi.org/10.1016/j.meddos.2020.06.004 | DOI Listing |
Int J Radiat Oncol Biol Phys
February 2025
Vagelos College of Physicians and Surgeons, Columbia University, New York, New York.
Ecotoxicol Environ Saf
January 2025
Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, Shenyang, Liaoning, China; Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, China. Electronic address:
Deltamethrin (DM), a broad-spectrum insecticide, is widely used in the world. It can exert direct action on the central nervous system to produce neurotoxicity. Exposure to DM can lead to iron metabolism disorder, oxidative stress and learning and memory dysfunction.
View Article and Find Full Text PDFNature
January 2025
Department of Brain and Cognitive Sciences and McGovern Institute, MIT, Cambridge, MA, USA.
Hippocampal circuits in the brain enable two distinct cognitive functions: the construction of spatial maps for navigation, and the storage of sequential episodic memories. Although there have been advances in modelling spatial representations in the hippocampus, we lack good models of its role in episodic memory. Here we present a neocortical-entorhinal-hippocampal network model that implements a high-capacity general associative memory, spatial memory and episodic memory.
View Article and Find Full Text PDFPLoS Biol
January 2025
Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, United States of America.
Worrying about perceived threats is a hallmark of multiple psychological disorders including anxiety. This concern about future events is particularly important when an individual is faced with an approach-avoidance conflict. Potential goals to approach are known to be represented in the dorsal hippocampus during theta cycles.
View Article and Find Full Text PDFAlzheimers Dement
January 2025
Department of Neuroscience, University of California, Berkeley, California, USA.
Introduction: Successful cognitive aging is related to both maintaining brain structure and avoiding Alzheimer's disease (AD) pathology, but how these factors interplay is unclear.
Methods: A total of 109 cognitively normal older adults (70+ years old) underwent amyloid beta (Aβ) and tau positron emission tomography (PET) imaging, structural magnetic resonance imaging (MRI), and cognitive testing. Cognitive aging was quantified using the cognitive age gap (CAG), subtracting chronological age from predicted cognitive age.
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