OBJECTIVES: The aim was to assess the cost of dynamic contrast -enhanced ultrasound (DCE -US) with quantification of tumor perfusion parameters from raw linear data on a large sample of patients and tumors. METHODS: Eighteen French hospitals participated in the study. All consecutive exams performed to assess targeted treatment efficacy were registered. The cost of each DCE -US was computed based on resource use data collected during the study: the duration of each exam, the type of staff and equipment and the amount of US contrast agent. To value resources we used unit costs at the Gustave-Roussy Institute. A sensitivity analysis was conducted. RESULTS: A total of 1452 DCE -US were recorded in 367 patients with mainly hepatocellular carcinoma (22%), or metastasis from kidney cancer (33%), colon cancer (12%) or melanoma (10%). Sorafenib, sunitinib and bevacizumab were the three most frequent treatments. The median number of DCE -US per patient was 5. Quantification of perfusion parameters was possible in 881 DCE -US (62%). The mean duration of a DCE -US was 28 minutes. The radiologist’s intervention lasted 24 minutes on average. Quantification of the tumor perfusion parameters lasted 17 minutes. The mean cost of a DCE -US was estimated at €173. In the sensitivity analysis, the cost ranged from €152 € to €197. The cost of the baseline DCE -US was 10% higher than subsequent exams. A second bolus injection was required in 1/5 baseline exams to choose a relevant target at treatment initiation. CONCLUSIONS: The cost of DCE -US is higher than conventional US mostly because of contrast agent use which accounts for half the cost of the procedure. Despite a 20% rate of re -injections and longer exams at baseline, the cost variability of DCE-US is rather low. This new technique strongly challenges CT perfusion in the monitoring of targeted treatments: it is cheaper and reduces the risk of radiation -related cancers.