NMR spectroscopy evaluation of plasma "oncolipids" in head and neck cancer

Malignant tumors and chronic infections in the masticator space: preliminary assessment with in vivo single-voxel 1H-MR spectroscopy

BACKGROUND AND PURPOSE

Differential diagnosis between malignant tumors and chronic infections in the masticator space remains challenging. The purpose of the study was to categorize various changes of both lesions by using single-voxel 1H-MR spectroscopy.

MATERIALS AND METHODS

Twenty-four masticator space lesions, 7 chronic infections, and 17 malignant tumors were assessed with 1H-MR spectroscopy before treatment procedures. The MR spectroscopic findings were compared with surgical and histopathologic results. Localization technique for 1H-MR spectroscopy was made by a point-resolved spectroscopy sequence at an echo time of 144 ms. Choline (Cho) signals (identified at 3.2 ppm) and Cho signal intensity-to-noise ratio (Cho/noise) were considered as evaluating criteria.

RESULTS

All the lesions were found with 3 1H-MR spectroscopic types: type 1, lesions without Cho signals (3 chronic infections); type 2, lesions with Cho signals and Cho/noise ratio <3 (4 chronic infections and 4 malignant tumors); and type 3, lesions with Cho signals and Cho/noise ratio >3 (13 malignant tumors). The mean +/- SD of the Cho/noise ratio between chronic infections and malignant tumors was 2.31 +/- 0.19 and 5.76 +/- 3.29 (P < .01), respectively.

CONCLUSION

In vivo single-voxel 1H-MR spectroscopy may be helpful in the assessment of masticator space lesions. Differences of Cho signals and Cho/noise ratios between malignant tumors and chronic infections provide valuable information in the differentiation of these 2 lesions.

Circulating markers in squamous cell carcinoma of the head and neck: a review

Biological markers of disease enhance the ability to diagnose, treat and evaluate results of therapy and are especially intriguing for their potential use in the management of malignant tumours. The serum levels of various biochemical substances have been shown to be abnormal for many cancers and are utilised in the management of affected patients. Several markers have been thoroughly investigated for potential clinical utility in head and neck carcinoma. Although no single marker has been found to be adequately sensitive and specific, combinations of markers may improve the utility for some aspects of patient management. This review highlights the literature to date in the realm of circulating markers for head and neck carcinoma. A discussion of the potential usefulness and limitations of such markers follows.

Proton magnetic resonance spectroscopy of fractionated plasma lipoproteins and reconstituted plasma from healthy subjects and patients with cancer

Proton nuclear magnetic resonance spectra at 500 MHz of plasma and the very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL) fractions isolated by KBr gradient ultracentrifugation were analysed in 16 cancer patients, six pregnant and nine non-pregnant healthy subjects. In spectra with narrow plasma composite aliphatic peaks (methylene at 1.2-1.4 p.p.m. and methyl at 0.8-0.9 p.p.m., respectively), a relative increase in either VLDL, LDL, or both, or a decrease in HDL signals was observed. The mechanism for line-width narrowing seemed different in cancer patients (less signals from HDL relative to VLDL) compared with pregnant women (more signals from LDL). By reconstitution of plasma samples from both healthy subjects and patients with malignant disease, decreased concentration of VLDL or HDL resulted in broadening or narrowing of the composite peaks, respectively. The effects of VLDL and HDL on the plasma line width were moderated by the signals from LDL. Within lipoprotein fractions, the methylene and methyl resonances were shifted to a higher field with increased observation temperature, the change in shift being greatest for HDL. The line width of composite peaks in plasma varied with the observation temperature, depending on the relative concentrations of individual lipoproteins. The correlation coefficient (r) for the relation between total plasma triglyceride level and the average of the line-width of the composite methylene and methyl peaks was -0.78 (p less than 0.001). For spectra of individual lipoproteins, statistical significant relationships were found between line-widths and triglyceride content of the LDL fraction (methyl line-width, r = -0.63) (p less than 0.001) and between methylene line-width and cholesterol of HDL (r = 0.54) (p = 0.003). In summary, the shape and width of the composite aliphatic peaks of plasma were affected by the relative concentration, chemical shift and transition temperature of both VLDL, LDL, and HDL, and by the total triglyceride level. Comparing pregnancy and malignant disease, the lipoprotein resonances contributed differently in giving narrow composite signals.