Preliminary results on the influence of chemoradiation on apparent diffusion coefficients of primary XXXX measured by magnetic resonance imaging.

@entity1 @entity5 @entity189 @entity16178
PURPOSE: To study changes of the apparent diffusion coefficient (ADC) measured by magnetic resonance imaging (MRI) in @entity1 with primary @entity189 during a course of combined chemoradiation. @entity1 AND METHODS: Diffusion-weighted echo-planar imaging at 1.5 T was performed in @entity1 (n = 8) with primary @entity189 ( @entity16178 ) undergoing preoperative chemoradiation. Mean @entity5 ADC values and ADC histograms were determined and compared weekly during the course of therapy. Surgical resection of the @entity5 enabled a correlation of ADC values with the pathologic classification. RESULTS: In four @entity1 @entity5 T-downstaging (ypT0-2) was observed, and in four @entity1 no downstaging (ypT3) was seen. In all @entity1 , ADC values were higher before onset of chemoradiation therapy compared to the end of chemoradiation. Separating the @entity1 into two groups, a significant increase in ADC value during week 1 of therapy, followed by a steady decrease, was found for the therapy-responder group. In the nonresponder group, no initial increase of ADC values was observed. After the 1st week of therapy, ADC values were significantly lower in the nonresponder group during the remaining duration of therapy. CONCLUSION: With these preliminary results it could be shown that MR diffusion imaging is able to detect individual changes of @entity5 ADC values during the course of combined chemoradiation reflecting biological changes within the @entity5 tissue. Further studies will be necessary to prove the possible value of totally noninvasive ADC imaging on predicting therapy outcome.
