Liver metastases and hepatocellular carcinoma

Robot-controlled cyberknife radiosurgery offers a treatment alternative for primary liver tumors and especially for metastases in the liver.

Tumors in respiratory organs such as the liver can be treated without fixation of the patient or anesthesia. The tracking technology of the Cyberknife system can follow the movement of the liver caused by breathing and still hit the tumor with an accuracy of about one millimeter. The surrounding liver tissue is spared. Therapy-related functional disorders of the liver are rare and the regenerative hepatic capacity is hardly affected. However, the focus of the liver must be marked in advance with a small gold fiducial. This is done externally with a CT-guided needle under local anesthesia.

Definition

In the case of liver tumors, a distinction must be made between primary liver tumors and metastases, i.e. spread of 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, among other things, as a result of chronic liver inflammation or liver cirrhosis.

Frequency

At around 90%, hepatocellular carcinoma (HCC) is the most common malignant liver tumor in adults. Other primary liver tumors are cholangiocellular carcinoma and angiosarcoma. In Germany, around 6,000 people develop HCC every year.

Symptoms

Hepatocellular carcinomas are often discovered late because they hardly cause any symptoms initially. Signs can be nausea, vomiting or loss of appetite, but also tenderness in the upper right abdomen, accumulation of fluid in the abdominal cavity (ascites) or severe weight loss. Later, an icterus, the so-called jaundice, can occur as an indication of liver disease.

Diagnosis

The ultrasound examination is a simple but sensitive method for assessing the liver. If there are any abnormalities, magnetic resonance imaging (MRI) is added to specify the diagnosis and to assess the location and extent of the tumor.”

Therapy

Established treatment methods for HCC are the surgical removal of the tumor (partial removal of the liver), radiofrequency, laser or microwave therapy (local ablative procedures), and the destruction of the tumor with a chemotherapeutic agent (chemoembolization). In addition to conventional radiation from the outside, internal radiation of the tumor is also possible.

Only 15 percent of primary liver tumors are amenable to curative surgery. Interventional radiological procedures such as radiofrequency ablation (RFA) and brachytherapy (SIRT) are used palliatively, as well as trans-arterial chemoembolization (TACE) or systemic chemotherapy.

In the case of liver metastases, surgery is the method of choice, but in many cases it is not feasible. Conventional radiation therapy is subject to certain limitations due to the radiosensitivity of healthy liver tissue and the liver’s ability to move when breathing. Using breath tracking, Cyberknife radiosurgery can be a good treatment alternative for metastases.

Radiosurgery

Using radiosurgery, a very precise irradiation of the tumor is possible with a mostly single, high dose. The tumor is destroyed in a focused manner by the high dose of iradiation. Healthy surrounding tissue is protected as much as possible. The effectiveness of aradiosurgical liver treatment has been proven in several scientific publications. Response rates of 60 to 90% have been achieved for HCC. In the case of metastases, the local control rate after twelve months is 75 to 90%. Due to the minimized radiation exposure of the surrounding tissue, treatment-related liver function disorders are rare. Short-term nausea can occur acutely, late complications are rare and at most minor.

Radiosurgery is comfortable for patients because it is painfree and can be performed on an outpatient basis.