Tissue concentration of systemically administered antineoplastic agents in @entity1 XXXX .

@entity1 @entity1313 @entity5 @entity3003 @entity2664 @entity2879 @entity11 @entity3 @entity2903
The blood-brain-barrier (BBB) limits the penetration of many systemic antineoplastic therapies. Consequently, many agents may be used in clinical studies and clinical practice though they may not achieve therapeutic levels within the @entity5 . We sought to compile the currently available @entity1 data on antineoplastic drug concentrations in brain and @entity5 tissue according to BBB status. A review of the literature was conducted for @entity1 studies providing concentrations of antineoplastic agents in blood and metastatic @entity1313 or high-grade @entity11 . Studies were considered optimal if they reported simultaneous tissue and blood concentration, multiple sampling times and locations, MRI localization, BBB status at sampling site, @entity5 histology, and individual subject data. Twenty-Four studies of 19 compounds were included. These examined 18 agents in contrast-enhancing regions of high-grade @entity11 , with optimal data for 2. For metastatic @entity1313 , adequate data was found for 9 agents. Considerable heterogeneity was found in the measurement value, @entity5 type, measurement timing, and sampling location within and among studies, limiting the applicability of the results. Tissue to blood ratios ranged from 0.054 for @entity3003 to 34 for @entity2664 in high-grade @entity11 , and were lowest for @entity2903 (0.118) and @entity2879 (0.116), and highest for @entity2664 (32.02) in @entity3 . The available data examining the concentration of antineoplastic agents in brain and @entity5 tissue is sparse and limited by considerable heterogeneity. More studies with careful quantification of antineoplastic agents in brain and @entity5 tissue is required for the rational development of therapeutic regimens.
