MRI-based maps differentiating tumor from nontumor tissues for improved clinical management of brain tumor patients.

Abstract

e13002 Background: We have recently demonstrated delayed contrast extravasation MRI for calculating maps providing clear, high resolution depiction of tumor/non-tumor tissues. >100 brain tumor patients have been recruited in 3 clinical studies. In all cases increased tumor volumes (TVs) on our maps were followed by progression while stable/decreased TVs did not require treatment changes. Following histological validation the maps are being used for clinical decisions. Methods: Our maps were applied for improved patient management in 23 patients post treatment in which consensus regarding tumor progression vs. treatment effects (TEs) has not been reached. In all cases increased enhancement was shown on T1-MRI and rCBV was low/inconclusive. Results: In 5 GBM patients 1-3 months post surgery our maps showed significant TVs, therefore 2 were started on Avastin and 3 were re-operated. One of the latter showed increased enhancement on T1-MRI after the second operation. The maps showed no TV consistent with later clinical improvement. Two GBM patients 3-4.5 months post chemoRT showed increased TEs and stable TVs consistent with pseudoprogression. Adjuvant TMZ was continued followed by decreased lesion volumes. 2 patients (GBM/AA) showed increased TVs 5 months/years post chemoRT and were referred to Avastin/surgery. One patient was scanned 2 wks post chemoRT with clinical deterioration and rescanned 3 wks later when stabilized showing significantly increased TVs with no change on standard MRI. The patient was re-operated. Brain mets patients were recruited 1-21 months post SRS. Four showed significant TVs and were referred to treatment (surgery, WBRT, Xeloda). Two were followed for 3-6 months and upon increase in TV were referred to surgery. In 6 patients 73-100% of the enhancing lesion consisted of TEs thus are currently stable under FU. In 3 the lesion has resolved within 2-4 months. Active tumor was confirmed histologically in all above resected lesions. Conclusions: Following validation of our easily interpreted color code maps patients are now referred from 4 major Israeli hospitals with a question of progression vs TEs. Our data suggests that the maps may be used for improved patient management when standard MRI is inconclusive.