Page 10 - ARNM-3-1

Advances in Radiotherapy
& Nuclear Medicine Diagnostics gude of biliary tract cancer

malignancy of the liver and biliary tract. Despite advances factors and are often diagnosed at an advanced stage of
4
in diagnosis and treatment, the incidence of new cases and the disease. 15,16 Symptoms of biliary tract cancer include
mortality from this disease continues to rise steadily. cholestatic jaundice, pruritus, abdominal discomfort
5,6
Depending on the tumor’s location, CCA is classified into and pain, liver enlargement, unexplained weight loss,
intrahepatic cholangiocarcinoma (iCCA) and extrahepatic nausea and vomiting, fever, a palpable tumor in the right
cholangiocarcinoma (eCCA), which is further divided hypogastric area, and Courvoisier’s sign – a painless,
into perihilar cholangiocarcinoma (pCCA) and distal enlarged, palpable through the abdomen gallbladder,
forms. Histologically, conventional perihilar and distal typically indicative of tumors located peripherally from
7,8
bile duct carcinomas are typically mucin-producing the junction of the cystic duct and the common hepatic
adenocarcinomas or papillary tumors, while intrahepatic duct. 17,18 The onset of jaundice and pruritus often signifies
bile duct carcinomas exhibit greater heterogeneity and significant tumor progression. In most patients at this
can be subclassified based on the extent or size of the bile stage, the tumor is inoperable, and the median survival
duct involved. The incidence of CCA is relatively low in time is typically <12 months from diagnosis. 19-22 The
9
Western countries. However, it is notably higher in regions progression of CCA is further aggravated by its dense
such as China and Thailand. CCA also exhibits geographic stromal environment, which contains numerous cancer-
11
concentration, with clusters found in northern India, associated fibroblasts that support tumor growth.
Japan, and several South American countries. On the Surgical resection or liver transplantation remains the only
other hand, the incidence of iCCA has been steadily rising, treatment offering long-term, disease-free survival. 23,24
particularly in Western nations. Epidemiological data from Although the 1-year survival rate for CCA patients has
developed countries, such as the United Kingdom and the improved over time, the 5-year survival rate has not
25
Unites States of America, demonstrate a steady increase in shown any significant change, remaining below 5%. To
the incidence of iCCA over the past three decades. Global reduce cancer-related mortality, it is essential to identify
incidence rates of CCA vary significantly across regions. preventable risk factors and implement surveillance
21
The highest rates are observed in Asia, with northeastern strategies in high-risk populations. The diagnosis of
Thailand reporting the greatest age-standardized incidence. CCA typically involves a combination of liver function
In Western countries, the incidence is lower, although Italy tests, tumor marker tests, imaging techniques such as
has the highest rate in the West. Mortality patterns for ultrasound, computed tomography (CT), magnetic
iCCA and eCCA show distinct regional trends. Over the resonance imaging (MRI) combined with magnetic
past decade, iCCA mortality has notably increased in most resonance cholangiopancreatography (MRCP), endoscopic
European countries, particularly in Western Europe, with retrograde cholangiopancreatography (ERCP), and biopsy
26,27
the highest rates observed in Ireland, the United Kingdom, for histological confirmation. Imaging studies play
Portugal, and Spain. a crucial role in assessing the extent of the lesion and
determining resectability, with multi-detector CT (MDCT)
The Baltic countries, particularly Latvia and Lithuania, used for overall staging and ERCP for local evaluation.
28
have experienced the most dramatic increases in iCCA Despite technological advances, diagnosing CCA remains
mortality. Since 2008, nearly all European countries challenging, and up to 20% of biliary strictures may yield
have seen an upward trend in iCCA mortality, except for indeterminate results despite extensive evaluation. 29,30
Austria. In North America, iCCA mortality has also risen Therefore, optimal management requires the integration of
in both the United States and Canada, with similar trends clinical information, imaging, cytological and histological
in Oceania (Australia and New Zealand) and the Middle studies, and rapid multidisciplinary assessment. 15,31
East (Israel and Turkey). East Asia continues to report Histopathological biopsy remains the gold standard
higher iCCA mortality rates, although the sharp increases for diagnosis, including MRCP, endoscopic ultrasound
seen in other regions have not been observed. 10 (EUS), ERCP, and cholangioscopy, which have improved
Risk factors for the development of CCA include diagnostic accuracy. 16
primary sclerosing cholangitis, biliary cysts, liver This paper aims to examine the role of various imaging
malformations, choledocholithiasis (especially secondary methods – ultrasonography (USG), CT, MRI, direct
to chronic cholangitis), smoking, diabetes mellitus, older cholangiography (ERC), EUS, and positron emission
age, certain hereditary diseases (such as Lynch syndrome tomography (PET) – in the diagnosis, staging, treatment
and cystic fibrosis), and infestations of the parasitic flukes response prediction, and therapy of biliary tract cancer. The
Clonorchis sinensis, Opisthorchis viverrini, and Opisthorchis range of diagnostic tools is extensive, with each method
felineus. 11-14 However, the majority of patients with biliary offering distinct advantages and disadvantages (Figure 1).
tract cancer do not have any known or suspected risk The choice of diagnostic approach is often determined by

Volume 3 Issue 1 (2025) 2 doi: 10.36922/arnm.4557