The DCE-US methodology has been successfully provided to several centers across France together with strict rules for quality assessment. Only 3% of examinations carried out at these centers were considered not interpretable.

4618 Background: A prospective study of dynamic contrast-enhanced ultrasound (DCE-US) with quantification for the evaluation of antiangiogenic treatments was launched (19 centers), supported by the French National Cancer Institute. The objectives were the diffusion of the standardized method, a cost evaluation and the identification of perfusion parameters predicting tumor response. Methods: All patients had DCE-US at baseline, D7, D14, D30, D60 and every two months. Each examination included a bolus injection of sonovue (Bracco) and 3 minutes of raw linear data with an Aplio (Toshiba). Raw data were analyzed with a mathematical model (patent PCT/IB2006/003742) to evaluate 7 parameters characterizing the tumor perfusion curve. Response to treatment was evaluated every 2 months with RECIST criteria. In order to have sufficient follow-up data, the statistical analysis has to be performed more than 6 months after the inclusion of the last analyzed patient. Inclusions were closed in March 2010. Results: A total of 539 patients have been included (mainly RCC (157) and HCC (107)); more than 2 000 DCE-US and 1700 CT-scan were performed. A follow-up more than 12 months showed that 3 parameters have a strong significant difference (p<0.0003) according to the response at 6 months. The decrease of more than 40% of AUC at one month is correlated to the TTP (p< 001) and OS (p< 0.04). Conclusions: Final results confirm the usefulness of this tool to monitor anti-angiogenic treatments. The criteria: the decrease of more than 40% of AUC at one month is predictive of response.