Intratumor mapping of intracellular water lifetime: metabolic images of breast cancer?

摘要: Shutter-speed pharmacokinetic analysis of dynamic-contrast-enhanced (DCE)-MRI data allows evaluation equilibrium inter-compartmental water interchange kinetics. The process measured here - transcytolemmal exchange is characterized by the mean intracellular molecule lifetime (τi). τi biomarker a true intensive property not accessible any formulation tracer paradigm, which inherently assumes it effectively zero when applied to DCE-MRI. We present population-averaged in vivo human breast whole tumor changes induced therapy, along with those other parameters. In responding patients, DCE parameters change significantly after only one neoadjuvant chemotherapy cycle: while K(trans) (measuring mostly contrast agent (CA) extravasation) and kep (CA intravasation rate constant) decrease, increases. However, high-resolution, (1 mm)(2), parametric maps exhibit significant intratumor heterogeneity, lost averaging. A typical 400 ms value means trans-membrane cycling flux 10(13) H2O molecules s(-1)/cell for 12 µm diameter cell. Analyses variations (and therapy-induced changes) combination concomitant ve (extracellular volume fraction) indicate that former are dominated alterations cell membrane permeability coefficient, PW, size. These can be interpreted light literature results showing PW (active) component reciprocally reflects driving P-type ATPase ion pump turnover. For mammalian cells, this Na(+), K(+)-ATPase pump. promise potential discriminate metabolic microenvironmental states regions within tumors vivo, their therapy.