Liver cancer is the sixth most common cancer worldwide and the third leading cause of cancer death. Liver cancer typically develops in the hepatocytes, the primary cell type of the liver. It can be a result of various factors, with the most common cause being chronic liver diseases such as cirrhosis, often caused by long-term alcohol abuse or viral infections like hepatitis B and C. Other risk factors include exposure to aflatoxins, a type of toxin produced by molds in certain foods, and certain hereditary conditions.
The symptoms of liver cancer can be subtle in the early stages but may include jaundice (yellowing of the skin and eyes), abdominal pain or swelling, unexplained weight loss, fatigue, loss of appetite, and nausea. Early detection and diagnosis are essential for improving patient outcomes, and imaging plays a vital role in this process. In recent years, there have been significant advances in liver cancer imaging, with new technologies and techniques emerging that offer improved accuracy and sensitivity.
Here, we discuss some of the most important innovations in liver cancer imaging:
Contrast-enhanced ultrasound (CEUS)
CEUS uses microbubble contrast agents to improve the visibility of liver lesions. Studies have shown that CEUS is more sensitive than conventional ultrasound in detecting and characterizing liver tumors.
Magnetic resonance imaging (MRI)
MRI offers excellent soft tissue contrast and can be used to create detailed images of the liver. MRI with gadolinium contrast is the gold standard imaging modality for liver cancer diagnosis and staging.
Computed tomography (CT)
CT is a fast and widely available imaging modality that can be used to detect liver tumors. CT with contrast is often used as the first-line imaging test for suspected liver cancer.
18F -FDG (Flurodeoxy glucose) Positron emission tomography -CT (PET CT)
Using 18F-FDG PET-CT combination, in addition to diagnostic CECT, the detection rate of hepatocellular cancer (HCC) increases. 18F-FDG PET scans have an expanded capacity to identify higher gradeHCCs. Using 18F-FDG PET-CT combination has a rolein detecting vascular invasion, regional metastatic lymph nodes and extrahepatic metastatic lesions when compared to separate 18F-FDG PET or CECT scans. Glucose metabolism activity of SUV is a critical predictor of prognosis.
In addition to these standard imaging modalities, several newer technologies are also being used to improve liver cancer imaging. These include:
Ga68 FAPI (Fibroblast activated protein inhibitor) PET CT
The ability of novel PET agent 68Ga-FAPI-04 PET/CT to correctly identify primary liver tumors and metastatic lesions has been found to be equivalent to that of CE-CT and liver MRI
Diffusion-weighted MRI (DW-MRI)
DW-MRI can measure the diffusion of water molecules in tissues. DW-MRI is useful for distinguishing between malignant and benign liver lesions, as well as for assessing tumor response to treatment.
Magnetic resonance spectroscopy (MRS)
MRS can measure the metabolic profile of tissues. MRS can be used to identify specific biomarkers that are associated with liver cancer.
Optical imaging
Optical imaging techniques, such as fluorescence imaging and Raman spectroscopy, are being developed to image liver tumors at the molecular level. These techniques have the potential to improve the sensitivity and specificity of liver cancer detection.
Another important innovation in liver cancer imaging is the development of artificial intelligence (AI)-powered algorithms. AI can be used to analyze medical images and identify subtle patterns that may be missed by the human eye. AI-powered algorithms have been shown to improve the accuracy of liver cancer diagnosis and staging.
Overall, the field of liver cancer imaging is rapidly evolving. New technologies and techniques are emerging that offer improved accuracy and sensitivity for the detection, diagnosis, and staging of liver cancer. These innovations are leading to better patient outcomes and improved survival rates.
As research continues, we can expect to see even more innovations in liver cancer imaging in the years to come. These innovations will play a vital role in improving the early detection and diagnosis of liver cancer, leading to better patient outcomes and improved survival rates.
(The Author is Consultant –Nuclear Medicine, HCG Cancer Centre, Nagpur)
