UNASSIGNED: To investigate the predictive capacity of the apparent diffusion coefficient (ADC) as a biomarker of radiation response in brain @entity3 . Seventy brain @entity3 from 42 @entity1 treated with either stereotactic radiosurgery or whole brain radiotherapy were imaged at baseline, 1  week, and 1  month post-treatment using diffusion-weighted MRI. Mean and median relative ADC for @entity3 was calculated by normalizing ADC measurements to baseline ADC. At 1  year post-treatment, or last available follow-up MRI, volume criteria determined final @entity5 response status. Uni- and multivariate analysis was used to account for factors associated with @entity5 response at 1  week and 1  month. A generalized estimating equations model @entity5 per subject. Optimal thresholds that distinguished responders from non-responders, as well as sensitivity and specificity were determined by receiver operator characteristic analysis and Youden's index. Lower relative ADC values distinguished responders from non-responders at 1  week and 1  month (P  <  0.05). Optimal cut-off values for response were 1.060 at 1  week with a sensitivity and specificity of 75.0 and 56.3  %, respectively. At 1  month, the cut-off was 0.971 with a sensitivity and specificity of 70.0 and 68.8  %, respectively. A multivariate general estimating equations analysis identified no prior radiation [odds ratio (OR) 0.211 and 0.137, P  =  0.033 and 0.0177], and a lower median relative ADC at 1  week and 1  month (OR 0.619 and 0.694, P  =  0.0036 and 0.005), as predictors of @entity5 response. Lower relative ADC values at 1  week and 1  month following radiation distinguished responders from non-responders and may be a promising biomarker of early radiation response.

The predictive capacity of apparent diffusion coefficient (ADC) in response assessment of brain XXXX following radiation.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumour', 'took into consideration multiple tumours'] @entity3 :: ('MESH:D009362', 'Disease') :: ['metastases']
@entity3 :: (MESH:D009362,Disease) :: ['metastases']
