A Radiation-Induced Hippocampal Vascular Injury Surrogate Marker Predicts Late Neurocognitive Dysfunction

Journal Article · Sun Nov 15 04:00:00 EST 2015 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2015.08.014· OSTI ID:22645017

Farjam, Reza ^[1]; Pramanik, Priyanka; Aryal, Madhava P. ^[2]; Srinivasan, Ashok ^[3]; Chapman, Christopher H. ^[2]; Tsien, Christina I. ^[4]; Lawrence, Theodore S. ^[2]; Cao, Yue ^[2]

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1. Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)
2. Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)
3. Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States)
4. Department of Radiation Oncology, Washington University in St. Louis, St. Louis, Missouri (United States)

Purpose: We aimed to develop a hippocampal vascular injury surrogate marker for early prediction of late neurocognitive dysfunction in patients receiving brain radiation therapy (RT). Methods and Materials: Twenty-seven patients (17 males and 10 females, 31-80 years of age) were enrolled in an institutional review board-approved prospective longitudinal study. Patients received diagnoses of low-grade glioma or benign tumor and were treated by (3D) conformal or intensity-modulated RT with a median dose of 54 Gy (50.4-59.4 Gy in 1.8-Gy fractions). Six dynamic-contrast enhanced MRI scans were performed from pre-RT to 18-month post-RT, and quantified for vascular parameters related to blood-brain barrier permeability, K{sup trans}, and the fraction of blood plasma volume, V{sub p}. The temporal changes in the means of hippocampal transfer constant K{sup trans} and V{sub p} after starting RT were modeled by integrating the dose effects with age, sex, hippocampal laterality, and presence of tumor or edema near a hippocampus. Finally, the early vascular dose response in hippocampi was correlated with neurocognitive dysfunction at 6 and 18 months post-RT. Results: The mean K{sup trans} Increased significantly from pre-RT to 1-month post-RT (P<.0004), which significantly depended on sex (P<.0007) and age (P<.00004), with the dose response more pronounced in older females. Also, the vascular dose response in the left hippocampus of females correlated significantly with changes in memory function at 6 (r=−0.95, P<.0006) and 18-months (r=−0.88, P<.02) post-RT. Conclusions: The early hippocampal vascular dose response could be a predictor of late neurocognitive dysfunction. A personalized hippocampus sparing strategy may be considered in the future.

• OSTI ID: 22645017
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 4 Vol. 93; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BLOOD PLASMA
BLOOD-BRAIN BARRIER
FEMALES
FORECASTING
GLIOMAS
GY RANGE 10-100
HIPPOCAMPUS
INJURIES
NMR IMAGING
PATIENTS
RADIATION DOSES
RADIOTHERAPY