Liver metastases and hepatocellula carcinoma

Robot-guided radiosurgery with the Cyberknife offers a treatment alternative for primary liver tumors and especially for metastases in the liver.

Tumors on respiratory organs such as the liver can be treated without patient immobilization or anesthesia. The Cyberknife’s tracking technology can follow the breathing-induced movement of the liver and still precisely hit the tumor with an accuracy of about one millimeter. The surrounding liver tissue is spared. Therapy-related functional disturbances of the liver are rare and regenerative hepatic capacity is hardly affected. However, the liver focus must be marked in advance with a small gold pen. This is done CT-guided from the outside with a needle under local anesthesia. If the indication criteria for radiosurgical treatment are met

In the case of tumors of the liver, a distinction must be made between primary liver tumors and metastases, i.e., metastases of a cancer outside the liver.

Primary hepatocellular carcinomas are rare. They arise from a degeneration of the liver cells themselves. The so-called HCC (hepatocellular carcinoma) or liver (cell) cancer is a malignant tumor that can develop as a result of chronic liver inflammation or liver cirrhosis, among other things.

Hepatocellular carcinoma (HCC) is the most common malignant liver tumor in adults, accounting for approximately 90 percent of all cases. Other primary tumors of the liver are cholangio-cellular carcinoma and angiosarcoma. In Germany, approximately 6,000 people are diagnosed with HCC each year.

Hepatocellular carcinomas are often discovered late, as they cause hardly any symptoms at first. Signs may include nausea, vomiting or loss of appetite, but also a pressure pain in the right upper abdomen, the accumulation of fluid in the abdominal cavity (ascites) or severe weight loss. Later, jaundice may also occur as an indication of liver disease.

Ultrasound examination is a simple but sensitive method for evaluating the liver. If abnormalities are detected, a magnetic resonance imaging (MRI) scan is connected to specify the diagnosis and assess the location and extent of the tumor.

Established treatment methods for HCC include surgical removal of the tumor (partial liver resection), radiofrequency, laser or microwave therapy (local ablative procedures), and destruction of the tumor by a chemotherapeutic agent (chemoembolization). In addition to conventional external radiation, internal radiation of the tumor may also be possible.

Only 15 percent of primary liver tumors are amenable to curative surgery. Palliative interventional radiological procedures such as radiofrequency ablation (RFA) and brachytherapy (SIRT) are used, as well as percutaneous ethanol injections (TACE) or chemotherapy.

For liver metastases, surgery is the method of choice; however, in many cases this is not feasible. Conventional radiotherapy is subject to certain limitations due to the radiosensitivity of healthy liver tissue and the respiratory variability of the liver. Using breath tracking, cyberknife radiosurgery can be a good treatment alternative even for metastases.

By means of radiosurgery, very precise irradiation of the tumor with a usually single, high dose is possible. The tumor is destroyed in a focused manner by the high radiation dose. Healthy surrounding tissue is spared as much as possible. The effectiveness of radiosurgical liver treatment has been demonstrated in several scientific publications. In HCC, response rates of 60 to 90 percent have been achieved. For metastases, the local control rate after twelve months is reported to be 75 to 90 percent. Because of the minimized radiation exposure to surrounding tissues, therapy-related disturbances in liver function are rare. Acutely, short-term nausea may occur; late complications are rare and mild at best.

For patients, the radiosurgical method is comfortable because it is painless and can be performed on an outpatient basis.