BACKGROUND: The purpose of this article was to evaluate the utility of a pharmacokinetically modeled measure of regional contrast access, based on dynamic contrast-enhanced magnetic resonance imaging (MRI) studies after preoperative chemotherapy, as a predictor of @entity421 . METHODS: The kinetic parameters of a two-compartment pharmacokinetic model of MRI contrast agent accumulation were analyzed in relation to disease free survival in 31 @entity1 who received protocol-based therapy for nonmetastatic @entity421 . The modeled exchange rate of contrast between the plasma and the @entity5 extravascular extracellular fluid space served as a measure of regional contrast access. The prognostic impact of both the clinically accepted standard of histologic evaluation of @entity5 @entity39 and the regional contrast access were analyzed with @entity5 size as an influential factor. RESULTS: Although the histologic grade of response was not a statistically significant prognostic factor in these @entity1 (P = 0.884), regional contrast access after preoperative chemotherapy was significantly predictive of disease free survival (P = 0.035) in the Cox proportional hazards model. Lower regional access before surgery and smaller @entity5 size were associated with a better treatment outcome. Log-rank analyses of Kaplan-Meier curves indicated that the impact of regional access was most pronounced in @entity1 with larger @entity5 (P = 0.052). Higher regional access at presentation also was associated significantly with greater decreases during therapy. CONCLUSIONS: Dynamic MRI estimates of regional contrast access after preoperative chemotherapy, when combined with @entity5 size, holds promise for the early identification of @entity1 at risk of recurrence. The availability of such response predictors could facilitate the development of risk-adapted treatment approaches.

Dynamic magnetic resonance imaging of regional contrast access as an additional prognostic factor in XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity421 :: ('MESH:D012516', 'Disease') :: ['osteosarcoma of the extremities', 'disease free survival in osteosarcoma'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'tumors'] @entity39 :: ('MESH:D009336', 'Disease') :: ['necrosis']
@entity421 :: (MESH:D012516,Disease) :: ['pediatric osteosarcoma']
