Tumor perfusion rate determined noninvasively by dynamic computed tomography predicts outcome in XXXX after radiotherapy.

@entity5 @entity135 @entity1 @entity213
PURPOSE: To investigate the value of CT-determined @entity5 perfusion as a predictive factor of local and regional failure and cause-specific survival in @entity135 treated by radiotherapy. MATERIALS AND METHODS: In 105 @entity1 , the perfusion of a primary @entity213 was estimated using dynamic CT. A contrast agent bolus was rapidly injected i.v., while during the first pass a dynamic data acquisition was performed at the level of the largest axial @entity5 surface. The perfusion in the selected @entity5 region of interest was calculated by dividing the slope of the @entity5 -time density curve by the maximal value in arterial density. Primary and nodal @entity5 volume was calculated from the CT images. All @entity1 were treated by radiotherapy with curative intent; in 15 @entity1 , adjuvant concomitant chemotherapy was administered. Mean follow-up time was 2.2 years. Actuarial (life-table) statistical analysis was done; multivariate analysis was performed using the Cox proportional hazards model. RESULTS: When the @entity1 were stratified according to the median perfusion value (83.5 mL/min/100 g), those with the lower perfusion rate had a significantly higher local failure rate (p < 0.05). In the multivariate analysis, perfusion rate (p = 0.01) and T category (p = 0.03) were found to be the independent predictors of local failure. Perfusion rate had predictive value regarding neither regional control nor cause-specific survival. CONCLUSIONS: CT-determined @entity5 perfusion rate was found to be an independent predictor of local outcome in irradiated @entity135 . The results of this study confirm the hypothesis that less-perfused @entity5 respond poorly to radiotherapy.
