Correlation of pretreatment polarographically measured oxygen pressures with quantified contrast-enhanced power doppler ultrasonography in spontaneous canine tumors and their impact on outcome after radiation therapy.

PURPOSE

To evaluate the use of noninvasive quantified contrast-enhanced power Doppler ultrasonography as a surrogate in the estimation of tumor hypoxia measured by invasive pO(2) histography in canine tumors.

MATERIAL AND METHODS

Data of pretreatment tumor oxygenation status, tumor vascularity and blood volume, and tumor response after radiation therapy was collected in 48 spontaneous malignant oral tumors (Table 1). Tumor oxygenation status was correlated to vascularity and blood volume, and influences on outcome after treatment were analyzed.

RESULTS

Although vascularity and blood volume correlated moderately with median pO(2) (r = 0.51 and 0.61; p = 0.001 and < 0.0001) and percentage of pO(2) readings < or = 2.5, 5, and 10 mmHg (r = -0.37 to -0.42; p < 0.01-0.03) for all tumors, they did not correlate within the different histology groups (p = 0.06-0.9). For all tumors, pretreatment oxygenation status, vascularity and blood volume were not found to be of prognostic value (Tables 2 and 3).

CONCLUSION

These analyses show that quantified contrast-enhanced power Doppler ultrasonography does not represent a noninvasive indirect method to assess tumor hypoxia measured by invasive pO(2) histography. Both technologies were nonprognostic indicators in spontaneous malignant canine oral tumors.