• Quynh-Thu Le, Albert Koong, Yee Yie Lieskovsky, Balasubramanian Narasimhan, Edward Graves, Harlan Pinto, J Martin Brown, and Daniel Spielman.
• Department of Radiation Oncology, Stanford University Medical Center, Stanford, CA 94305-5847, USA. qle@stanford.edu
• Int. J. Radiat. Oncol. Biol. Phys. 2008 Jul 15; 71 (4): 1151-7.

PurposeTo 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 And MaterialsVolume-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.ResultsThe 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.ConclusionsThe lactate SI did not correlate with tumor pO(2), treatment response, or locoregional control. Additional research is needed to refine this technique.

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