The Potential Role of Ga-68-PSMA in Staging, Restaging and Monitoring Response in Primary Liver Cancer: Comparison With F-18-FDG

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the second leading cause of cancer-related deaths in the world. Hepatitis C virus (HCV) is the most common underlying cause of cirrhosis and HCC in the western world.

The staging of the disease is done by combining blood tests and imaging tests. Ultrasound scanning, computed tomograph (CT) and magnetic resonance imaging (MRI) scans are methods based on identifying or significant change in the liver.

Those changes are sometimes difficult to identify, especially when there are changes in liver structure resulting from disease, such as cirrhosis of the liver.

In many cases it is also difficult to detect secondary scattering in anatomical tests, such as identifying a disease in normal size lymph nodes or early skeletal dissociation.

Functional imaging is not based on structural changes, but on the ability to detect changes in the function and properties of the tissue, such as a change in the cell's metabolic consumption or the presence of proteins that characterize the tumor tissue.PET scans can show tumor cell activity (the cancer cells are more aggressive, get more sugar and therefore see more absorption in PET), detect small tumors and metastases outside the liver (because they do a whole body test). To complete this test, a CT scan is also performed on the same device (PET-CT scanner).

There is a new material called prostate-specific mRNA that is marked with gallium isotope (Ga-68-PSMA). It is the substance that is absorbed into the cells of the blood vessels of the tumor. The Ga-68-PSMA is now widely used in the diagnosis of prostate cancer. The new researches also found the possibility of using Ga-68-PSMA in primary liver cancer in patients because of the over-expression of the antigen in the blood vessels.

Therefore, the tests with Ga-68-PSMA and F-18-FDG will complement each other and will give a complete picture of the extent of the disease.

Each patient has individual characteristics of the tumor, and according to the results it will be possible to adapt the test to the patient with the appropriate material for the disease and this will be effective for the decision to treat and follow up.

At the end of the study it will be possible to offer the study participant the appropriate functional imaging test.