Temporal DCE Profile of Brain Metastasis with A Comparison of Pseudoprogression Cases

Purpose: To demonstrate Dynamic Contrast-Enhanced (DCE) perfusion changes in brain metastasis patients after chemoradiation therapy within the treatment responders (true-response group and pseudoprogression group) and between the true-response and pseudoprogression groups. Materials and Methods: 38 true-response patients with 38 brain metastases (13 melanoma, 11 lung, 7 breast, 7 others) with 3 consecutive DCE-MRI examinations (pretreatment, first follow-up and second follow-up) and 7 pseudoprogression patients with 10 melanoma metastases with 2 consecutive DCE-MRI examinations (pretreatment, first follow-up) were evaluated. DCE-MRI parameters and permeability graphs increase (rapid, slow, medium) and course pattern (washout, plateau, persistent) were analyzed and compared between the timing of the examinations and between the true-response and pseudoprogression groups, using paired t-tests and Mann-Whitney U-tests as appropriate. Automatic assessment of washout curves by Olea Brain Software was reviewed. Results: Pretreatment mean wash-in (15.3+/-24.7 vs 6.50+/-14.2, P<0.02), Vp (0.13+/-0.17 vs 0.06+/-0.06, P<0.01), Ktrans (0.37+/-0.48 vs 0.16+/-0.18, P<0.01), peak enhancement (123+/-98 vs 76+/-60.5, P<0.01), AUC (14x104+/-18x104 vs 5x104+/-10x104, P<0.001) values were significantly higher than that of post-treatment. Other DCE metrics and permeability graph factors between pre-and post-treatment MRI were not significantly different. There was no statistically significant difference in any imaging factors in pre-or first post-treatment DCE-MRI examinations between the true-response and pseudoprogression groups. Conclusion: Wash-in, Vp, Ktrans, peak enhancement, AUC values in DCE perfusion were significantly decreased after chemoradiation therapy in the responders. No statistically significant difference was shown between the true-response and pseudoprogression groups on either pre-or post-treatment, indicating the homogeneous permeability profiles in the responders.