CT measurement of perfusion and permeability within lymphoma masses and its ability to assess grade, activity, and chemotherapeutic response.

PURPOSE

Structural CT criteria such as nodal size and appearance have a poor correlation with the grade and activity of a lymphoma mass. This study investigates the potential for functional CT perfusion and permeability measurements to assess lymphoma grade and activity.

METHOD

Thirty-nine patients with proven lymphoma underwent 47 dynamic contrast-enhanced CT studies. Lymphoma grade was classified as low or intermediate/high. In seven patients who underwent repeated studies, measurements were correlated against change in disease activity in the intervening period.

RESULTS

Median perfusion values were higher in active disease (0.55 vs. 0.37 ml/min/ml) and intermediate/high-grade lymphoma (0.56 vs. 0.46 ml/min/ml). Perfusion below 0.2 ml/min/ml implied inactive disease (p < 0.03), whereas > 0.5 ml/min/ml suggested intermediate/high-grade lymphoma (p = 0.11). Median values of permeability were little different between patient groups. Only perfusion fell when disease became inactive.

CONCLUSION

Only CT perfusion measurements of nodes have potential for assessing lymphoma grade, activity, and treatment response.