Intratumour heterogeneity in microvessel oxyhaemoglobin saturations.

The aim of the present study was to examine intratumour heterogeneity in microvessel oxyhaemoglobin (HbO2) saturations in human melanoma xenografts. The HbO2 saturations, measured with a cryospectrophotometric micromethod, were found to vary substantially within single tumours. All tumours showed a decrease in overall HbO2 saturation from the periphery towards the centre, although the profiles could vary substantially between individual tumours. Local differences could be large, and many tumours had HbO2 saturations spanning from 0 to 100% in peripheral regions. In central tumour regions, low saturations were prevailing although subregions of intermediate and high saturations could also be found.