title: In vivo 1H magnetic resonance spectroscopy of lactate in patients with stage IV head and neck squamous cell carcinoma.
abstract: OBJECTIVE
  To investigate in vivo(1)H magnetic resonance spectroscopy imaging of lactate for assessing tumor hypoxia in head and neck cancers and to determine its utility in predicting the response and outcomes.
  
  
  METHODS
  Volume-localized lactate-edited (1)H magnetic resonance spectroscopy at 1.5 T was performed in vivo on involved neck nodes and control subcutaneous tissues in 36 patients with Stage IV head and neck cancer. The signal intensities (SIs) of lactate, choline, and creatine and the choline/creatine ratio were measured. The tumor partial pressure of oxygen (pO(2)) was obtained in the same lymph node before MRS. Patients were treated with either two cycles of induction chemotherapy (tirapazamine, cisplatin, 5-fluorouracil) followed by simultaneous chemoradiotherapy or the same regimen without tirapazamine. The lactate SI and the choline/creatine ratio correlated with the tumor pO(2), nodal response, and locoregional control.
  
  
  RESULTS
  The lactate SI was greater for the involved nodes (median, 0.25) than for the subcutaneous tissue (median, 0.04; p = 0.07). No significant correlation was found between the lactate SI and tumor pO(2) (mean, 0.46 +/- 0.10 for hypoxic nodes [pO(2) < or =10 mm Hg, n = 15] vs. 0.36 +/- 0.07 for nonhypoxic nodes [pO(2) >10 mm Hg, n = 21], p = 0.44). A significant correlation was found between the choline/creatine ratios and tumor pO(2) (mean, 2.74 +/- 0.34 for hypoxic nodes vs. 1.78 +/- 0.31 for nonhypoxic nodes, p = 0.02). No correlation was found between the lactate SI and the complete nodal response (p = 0.52) or locoregional control rates.
  
  
  CONCLUSIONS
  The lactate SI did not correlate with tumor pO(2), treatment response, or locoregional control. Additional research is needed to refine this technique.
authors.affiliation: Department of Radiation Oncology, Stanford University Medical Center, Stanford, CA 94305-5847, USA. qle@stanford.edu
authors.forename: Quynh-Thu
authors.initials: QT
authors.lastname: Le
authors.forename: Albert
authors.initials: A
authors.lastname: Koong
authors.forename: Yee Yie
authors.initials: YY
authors.lastname: Lieskovsky
authors.forename: Balasubramanian
authors.initials: B
authors.lastname: Narasimhan
authors.forename: Edward
authors.initials: E
authors.lastname: Graves
authors.forename: Harlan
authors.initials: H
authors.lastname: Pinto
authors.forename: J Martin
authors.initials: JM
authors.lastname: Brown
authors.forename: Daniel
authors.initials: D
authors.lastname: Spielman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy*; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy*; D006801:Humans; D019344:Lactic Acid / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D011522:Protons; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D011522:Protons; D019344:Lactic Acid