title: Hippocampal proton MR spectroscopy as a novel approach in the assessment of radiation injury and the correlation to neurocognitive function impairment: initial experiences.
abstract: BACKGROUND
  The hippocampus is considered as the main radiosensitive brain structure responsible for postradiotherapy cognitive decline. We prospectively assessed correlation of memory change to hippocampal N-acetylaspartate (h-tNAA) concentration, a neuronal density and viability marker, by (1)H-MR spectroscopy focused on the hippocampus.
  
  
  METHODS
  Patients with brain metastases underwent whole brain radiotherapy (WBRT) to a dose of 30 Gy in ten fractions daily. Pre-radiotherapy (1)H-MR spectroscopy focused on the h-tNAA concentration and memory testing was performed. Memory was evaluated by Auditory Verbal Learning Test (AVLT) and Brief Visuospatial Memory Test-Revised (BVMT-R). Total recall, recognition and delayed recall were reported. The both investigation procedures were repeated 4 months after WBRT and the h-tNAA and memory changes were correlated.
  
  
  RESULTS
  Of the 20 patients, ten passed whole protocol. The h-tNAA concentration significantly decreased from pre-WBRT 8.9, 8.86 and 8.88 [mM] in the right, left and both hippocampi to 7.16, 7.65 and 7.4 after WBRT, respectively. In the memory tests a significant decrease was observed in AVLT total-recall, BVMT-R total-recall and BVMT-R delayed-recall. Weak to moderate correlations were observed between left h-tNAA and AVLT recognition and all BVMT-R subtests and between the right h-tNAA and AVLT total-recall.
  
  
  CONCLUSIONS
  A significant decrease in h-tNAA after WBRT was proven by (1)H-MR spectroscopy as a feasible method for the in vivo investigation of radiation injury. Continuing patient recruitment focusing on other cognitive tests and metabolites is needed.
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic. ppospisil@mou.cz.|Department of Radiation Oncology, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic. ppospisil@mou.cz.
authors.forename: Petr
authors.initials: P
authors.lastname: Pospisil
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic. tomas.kazda@mou.cz.|Department of Radiation Oncology, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic. tomas.kazda@mou.cz.|International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91, Brno, Czech Republic. tomas.kazda@mou.cz.
authors.forename: Tomas
authors.initials: T
authors.lastname: Kazda
authors.affiliation: International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91, Brno, Czech Republic. martin.bulik@fnusa.cz.|Department of Diagnostic Imaging, Faculty of Medicine, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic. martin.bulik@fnusa.cz.|Department of Diagnostic Imaging, St. Anne's University Hospital Brno, Pekarska 53, 656 91, Brno, Czech Republic. martin.bulik@fnusa.cz.
authors.forename: Martin
authors.initials: M
authors.lastname: Bulik
authors.affiliation: International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91, Brno, Czech Republic. marie.dobiaskova@fnusa.cz.|Department of Clinical Psychology, St. Anne's University Hospital Brno, Pekarska 53, Brno, Czech Republic. marie.dobiaskova@fnusa.cz.
authors.forename: Marie
authors.initials: M
authors.lastname: Dobiaskova
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic. burkon@mou.cz.|Department of Radiation Oncology, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic. burkon@mou.cz.
authors.forename: Petr
authors.initials: P
authors.lastname: Burkon
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic. hynkova@mou.cz.|Department of Radiation Oncology, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic. hynkova@mou.cz.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Hynkova
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic. slampa@mou.cz.|Department of Radiation Oncology, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic. slampa@mou.cz.
authors.forename: Pavel
authors.initials: P
authors.lastname: Slampa
authors.affiliation: Department of Neurosurgery - St. Anne's University Hospital Brno, Faculty of Medicine, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic. radim.jancalek@fnusa.cz.|Department of Neurosurgery, St. Anne's University Hospital Brno, Pekarska 53, 656 91, Brno, Czech Republic. radim.jancalek@fnusa.cz.
authors.forename: Radim
authors.initials: R
authors.lastname: Jancalek
mesh_terms: D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D001932:Brain Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000556:secondary; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology; D016371:Cranial Irradiation / Q000009:adverse effects*; D005260:Female; D006624:Hippocampus / Q000528:radiation effects*; D006801:Humans; D053208:Kaplan-Meier Estimate; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008568:Memory; D008875:Middle Aged; D009483:Neuropsychological Tests; D011522:Protons; D011832:Radiation Injuries / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; D011522:Protons; D001224:Aspartic Acid; C000179:N-acetylaspartate