title: Raman spectroscopy demonstrates Amifostine induced preservation of bone mineralization patterns in the irradiated murine mandible.
abstract: OBJECTIVE
  Adjuvant radiotherapy in the management of head and neck cancer remains severely debilitating. Fortunately, newly developed agents aimed at decreasing radiation-induced damage have shown great promise. Amifostine (AMF) is a compound, which confers radio-protection to the exposed normal tissues, such as bone. Our intent is to utilize Raman spectroscopy to demonstrate how AMF preserves the mineral composition of the murine mandible following human equivalent radiation.
  
  
  METHODS
  Sprague Dawley rats were randomized into 3 experimental groups: control (n=5), XRT (n=5), and AMF-XRT (n=5). Both XRT and AMF groups underwent bioequivalent radiation of 70Gy in 5 fractions to the left hemimandible. AMF-XRT received Amifostine prior to radiation. Fifty-six days post-radiation, the hemimandibles were harvested, and Raman spectra were taken in the region of interest spanning 2mm behind the last molar. Bone mineral and matrix-specific Raman bands were analyzed using one-way ANOVA, with statistical significance at p<0.05.
  
  
  RESULTS
  The full-width at half-maximum of the primary phosphate band (FWHM) and the ratio of carbonate/phosphate intensities demonstrated significant differences between AMF-XRT versus XRT (p<0.01) and XRT versus control (p<0.01). There was no difference between AMF-XRT and control (p>0.05) in both Raman metrics. Computer-aided spectral subtraction further confirmed these results where AMF-XRT was spectrally similar to the control. Interestingly, the collagen cross-link ratio did not differ between XRT and AMF-XRT (p<0.01) but was significantly different from the control (p<0.01).
  
  
  CONCLUSIONS
  Our novel findings demonstrate that AMF prophylaxis maintains and protects bone mineral quality in the setting of radiation. Raman spectroscopy is an emerging and exceptionally attractive clinical translational technology to investigate and monitor both the destructive effects of radiation and the therapeutic remediation of AMF on the structural, physical and chemical qualities of bone.
authors.affiliation: University of Michigan Hospital and Health Systems, Pediatric Plastic Surgery Section, 1540 E. Hospital Drive, MI 48109, USA.
authors.forename: Catherine N
authors.initials: CN
authors.lastname: Tchanque-Fossuo
authors.affiliation: University of Michigan Hospital and Health Systems, Department of Chemistry, 930 N. University, Ann Arbor, MI 48109, USA.
authors.forename: Bo
authors.initials: B
authors.lastname: Gong
authors.affiliation: University of Michigan Hospital and Health Systems, Pediatric Plastic Surgery Section, 1540 E. Hospital Drive, MI 48109, USA.
authors.forename: Behdod
authors.initials: B
authors.lastname: Poushanchi
authors.affiliation: University of Michigan Hospital and Health Systems, Pediatric Plastic Surgery Section, 1540 E. Hospital Drive, MI 48109, USA.
authors.forename: Alexis
authors.initials: A
authors.lastname: Donneys
authors.affiliation: University of Michigan Hospital and Health Systems, Pediatric Plastic Surgery Section, 1540 E. Hospital Drive, MI 48109, USA.
authors.forename: Deniz
authors.initials: D
authors.lastname: Sarhaddi
authors.affiliation: University of Michigan Hospital and Health Systems, Department of Otolaryngology-Head and Neck Surgery, University of Michigan Medical School, 1500 E. Medical Center Drive, Ann Arbor, MI 48109, USA.
authors.forename: K Kelly
authors.initials: KK
authors.lastname: Gallagher
authors.affiliation: University of Michigan Hospital and Health Systems, Pediatric Plastic Surgery Section, 1540 E. Hospital Drive, MI 48109, USA.
authors.forename: Sagar S
authors.initials: SS
authors.lastname: Deshpande
authors.affiliation: University of Michigan, Department of Orthopaedic Surgery, A. Alfred Taubman Biomedical Science Research Building, 109 Zina Pitcher Pl, Ann Arbor, MI, 48109, USA.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Goldstein
authors.affiliation: University of Michigan Hospital and Health Systems, Department of Chemistry, 930 N. University, Ann Arbor, MI 48109, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Morris
authors.affiliation: University of Michigan Hospital and Health Systems, Pediatric Plastic Surgery Section, 1540 E. Hospital Drive, MI 48109, USA.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Buchman
mesh_terms: D004999:Amifostine / Q000494:pharmacology*; D000818:Animals; D002113:Calcification, Physiologic / Q000187:drug effects*; D002254:Carbonates / Q000378:metabolism; D006801:Humans; D008297:Male; D008334:Mandible / Q000187:drug effects* / Q000528:radiation effects*; D051379:Mice; D010710:Phosphates / Q000378:metabolism; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013059:Spectrum Analysis, Raman; D014965:X-Rays
chemical_list: D002254:Carbonates; D010710:Phosphates; D011837:Radiation-Protective Agents; D004999:Amifostine