Metastatic Renal Cell Carcinoma Treated with Sunitinib: Early Evaluation of Treatment Response Using Dynamic Contrast-Enhanced Ultrasonography

Purpose: To determine the utility of dynamic contrast-enhanced ultrasonography (DCE-US) as a prognostic tool for metastatic renal cell carcinoma patients receiving sunitinib and to identify DCE-US parameters that correlate with early treatment response. Experimental Design: Thirty-eight patients received 50 mg/d sunitinib on schedule 4/2 (4 weeks on followed by 2 weeks off treatment). After two cycles, response evaluation criteria in solid tumors were used to classify patients as responders or nonresponders. DCE-US evaluations were done before treatment and at day 15; variations between days 0 and 15 were calculated for seven DCE-US functional parameters and were compared for responders and nonresponders. The correlation between DCE-US parameters and disease-free survival (DFS) and overall survival (OS) was assessed. Results: The ratio between DCE-US examinations at baseline and day 15 significantly correlated with response in five of the seven DCE-US parameters. Two DCE-US parameters (time to peak intensity and slope of the wash-in) were significantly associated with DFS; time to peak intensity was also significantly associated with OS. Conclusions: DCE-US is a useful tool for predicting the early efficacy of sunitinib in metastatic renal cell carcinoma patients. Robust correlations were observed between functional parameters and classic assessments, including DFS and OS. Clin Cancer Res; 16(4); 1216-25. (C) 2010 AACR.