Treatment of hepatic metastases of colorectal cancer by robotic stereotactic radiation (Cyberknife ®).

Cyberknife(®) is a dedicated stereotactic radiotherapy device. This new technology permits precise delivery of high dose gradient radiation therapy while sparing the surrounding organs at risk. Hepatic metastases of colorectal cancer (HMCRC) are an example of a lesion where treatment with Cyberknife(®) is indicated because they are located in a radio-sensitive organ and curative treatment is based on focal eradication (resection, radiofrequency ablation,...). The local control rate at one year is reported to be 70 to 100% depending on the study. Tolerance is excellent with less than a 5% rate of acute grade 3 or 4 side effects (nausea, vomiting, gastro-duodenal ulcer). The specific hepatotoxicity of radiotherapy, so-called radiation-induced liver disease (RILD), was found in only one study. Candidates for stereotactic radiotherapy are patients in whom disease is controlled except for intrahepatic disease with 1-3 hepatic metastases ≤ 6 cm in size who have contraindications for surgery, a WHO stage ≤ 2, a volume of healthy liver ≥ 700 cm(3) and normal liver function. It is actually a very simple treatment that results in very good local control with few contraindications. Its place in the management strategy of liver metastases needs further clarification.