The aim of this clinical trial is to investigate whether the therapeutic response of chemotherapy can be improved by focused ultrasound and microbubbles. Patients with liver metastases from breast cancer and colorectal cancer will be included. Computer Tomography (CT) will be performed as a baseline scan before treatment start. Two metastases in each patients liver will be preselected and randomized to either "target lesion" to be treated or "control lesion" to serve as internal control. The patients will receive conventional treatment with chemotherapy according to national guidelines. After intravenous chemotherapy infusion the patients will receive the experimental treatment. The target lesion will get focused ultrasound (FUS). Simultaneously repeated bolus-doses of microbubbles will be administered intravenously. The investigators will measure the difference in response between FUS- treated and -untreated lesions on the post-treatment CT scan.

Inclusion Criteria:

• Histologically verified breast carcinoma or colorectal carcinoma
• 2 or multiple liver metastases
• considered eligible by a consulting oncologist for first line treatment with chemotherapy in the group of taxanes (patients with breast cancer) or the combination regimen FOLFIRI (patients with colorectal carcinoma)
• Signed informed consent and expected cooperation of the patients for the treatment and follow up must be obtained and documented according to ICH GCP, and national/local regulations

Exclusion Criteria:

• Known contraindications for ultrasound contrast-enhancement agent Sonovue® (Bracco)
• Hematological bleeding status before experimental treatment: Hb < 8g/dL, trc < 80 x109/l, APTT˃ 45s, INR ˃ 1,5
• Considered eligible for surgical removal of liver metastases
• Pregnancy

Yes.Individual participant data that underlie the results reported in this article, after deidentification(text, tables, figures, and appendices). Protocol can be shared beginning 3 months and ending 5 years following article publication. Interested researchers who provide a reasonable, sound proposal are encouraged to direct this to the first author.