Portal de Periódicos da CAPES

Delayed contrast extravasation MRI: a new paradigm in neuro-oncology

2014; Oxford University Press; Volume: 17; Issue: 3 Linguagem: Inglês

10.1093/neuonc/nou230

1523-5866

Leor Zach, David Guez, David Last, Dianne Daniels, Yuval Grober, Ouzi Nissim, Chen Hoffmann, Dvora Nass, Alisa Talianski, Roberto Spiegelmann, Galia Tsarfaty, Sharona Salomon, Moshe Hadani, Andrew A. Kanner, Deborah T. Blumenthal, Felix Bukstein, Michal Yalon, Jacob Zauberman, Jonathan Roth, Yigal Shoshan, Evgeniya Fridman, Marc Wygoda, Dror Limon, Tzahala Tzuk, Zvi R. Cohen, Yael Mardor,

Lanthanide and Transition Metal Complexes

Conventional magnetic resonance imaging (MRI) is unable to differentiate tumor/nontumor enhancing tissues. We have applied delayed-contrast MRI for calculating high resolution treatment response assessment maps (TRAMs) clearly differentiating tumor/nontumor tissues in brain tumor patients. One hundred and fifty patients with primary/metastatic tumors were recruited and scanned by delayed-contrast MRI and perfusion MRI. Of those, 47 patients underwent resection during their participation in the study. Region of interest/threshold analysis was performed on the TRAMs and on relative cerebral blood volume maps, and correlation with histology was studied. Relative cerebral blood volume was also assessed by the study neuroradiologist. Histological validation confirmed that regions of contrast agent clearance in the TRAMs >1 h post contrast injection represent active tumor, while regions of contrast accumulation represent nontumor tissues with 100% sensitivity and 92% positive predictive value to active tumor. Significant correlation was found between tumor burden in the TRAMs and histology in a subgroup of lesions resected en bloc (r2 = 0.90, P < .0001). Relative cerebral blood volume yielded sensitivity/positive predictive values of 51%/96% and there was no correlation with tumor burden. The feasibility of applying the TRAMs for differentiating progression from treatment effects, depicting tumor within hemorrhages, and detecting residual tumor postsurgery is demonstrated. The TRAMs present a novel model-independent approach providing efficient separation between tumor/nontumor tissues by adding a short MRI scan >1 h post contrast injection. The methodology uses robust acquisition sequences, providing high resolution and easy to interpret maps with minimal sensitivity to susceptibility artifacts. The presented results provide histological validation of the TRAMs and demonstrate their potential contribution to the management of brain tumor patients.