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 (14×104±18×104 vs 5×104±10×104, 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. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement no external funding was received ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: An IRB-exempt approval was obtained for this retrospective study under the HUM00193148 number from the University of Michigan. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors * DCE Perfusion : Dynamic contrast enhanced perfusion Vp : Plasma volume Ve : Extracellular space volume Ktrans : Transfer volume constant from plasma to tissue Kep : Transfer rate constant SER : Signal enhancement ratio AUC : Area under the curve