Dynamic Contrast-enhanced MR Imaging of Uterine Cervical Cancer: Pharmacokinetic Analysis with Histopathologic Correlation and Its Importance in Predicting the Outcome of Radiation Therapy

PURPOSE: To investigate the histopathologic bases of different enhancement patterns on dynamic contrast material-enhanced magnetic resonance (MR) images of cervical cancer and to assess their importance in predicting the outcome of patients after radiation therapy. MATERIALS AND METHODS: Dynamic enhanced MR imaging and pharmacokinetic analyses were performed in 26 patients with cervical cancer who subsequently underwent hysterectomy and in 36 patients with cervical cancer who received radiation therapy. Histopathologic findings and clinical outcomes were correlated with results of dynamic MR imaging and pharmacokinetic analysis. RESULTS: On dynamic MR images of the surgical patients, areas with intense homogeneous enhancement showed increased permeability (k = 27.4 x 10(-3)) compared with areas with poor enhancement (k = 19.0 x 10(-3)). Well-enhanced areas were predominantly composed of cancer cell fascicles, whereas poorly enhanced areas were composed of fibrous tissue with scattered cancer cells. Radiation therapy was more effective in tumors with higher tissue permeability (k = 31.3 x 10(-3)) on dynamic MR images than in those with lower tissue permeability (k = 18.3 x 10(-3)). CONCLUSION: Areas of increased contrast enhancement are mainly composed of abundant cancer cell fascicles, whereas poorly perfused areas are composed of fibrous tissue with scattered cancer cells. Radiation therapy is more effective in well-enhanced tumors, resulting in improved local control.