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

the assessment of the tumor’s metabolic activity, detection to confirm a diagnosis of a porcelain gallbladder. Meanwhile,
of metastases throughout the body, including those too cholecystography is a radiological examination of the
small to be detected by CT or MRI, and combining this gallbladder. Cholecystography, once considered the standard
functional information with anatomical imaging for a test for suspected cholelithiasis, is now rarely used due to its
more comprehensive view. low diagnostic value. At present, for gallbladder diseases,

Modern diagnostic imaging integrates multiple USG of the bile ducts (hepatobiliary USG) is the preferred
advanced techniques to provide a comprehensive imaging method. If cholecystography is still deemed
understanding of pathological changes. Combined necessary, the procedure involves administering a contrast
imaging systems, such as PET/CT and PET/MRI, allow agent to the patient – either orally (typically in the form of
for simultaneous anatomical (CT, MRI) and metabolic dragees, known as oral cholecystography) or intravenously
(PET) assessment of tumors. This approach is particularly (intravenous cholecystography). The contrast agent enters
valuable for accurately localizing lesions, evaluating the bloodstream and is secreted through the liver into the bile.
their aggressiveness, and determining tumor spread. For Subsequently, a series of X-rays are taken of the gallbladder,
instance, PET/CT not only reveals the size of a brain cystic duct, and common bile ducts (biliary ducts), although
tumor but also identifies the most metabolically active the latter is usually not well-visualized. The bile, along
areas, directly influencing therapy planning – surpassing with the contrast agent, outlines the gallbladder, allowing
102
the capabilities of CT imaging alone. It is worth the assessment of its location, shape, and size, and helping
noting that before PET/CT examination, the histological to detect possible obstructions, such as stones. In cases of
features of tissues and inflammatory conditions should be cholecystitis, the characteristic feature is the absence of
assessed, taking into account specific clinical features and visualization of the gallbladder. As for ERC, the term refers to
complications related to the treatment. 103 various methods used to examine the bile ducts and pancreas,
including retrograde, percutaneous, intraoperative, and post-
In addition, other complementary methods should operative techniques. ERC is often performed in conjunction
be considered, such as initial diagnostic approaches, like with cholecystography, a radiographic examination of the
laboratory tests and morphological imaging techniques gallbladder. Table 2 summarizes the imaging methods used
that assess the metabolic changes in tissues. 104 in biliary tract cancer.
PET is also one of the diagnostic methods that enable
the assessment of disease stage (including lymph nodes 2.6. Advanced imaging techniques
and distant metastases) and the identification of relapse Digital cholangioscopy is a valuable technique that
in patients with biliary tract cancer. It primarily aids enables direct endoscopic visualization of the biliary
in treatment planning, particularly in cases of distant tree, facilitating optical diagnosis, targeted biopsy, and
metastases, which are frequently assessed. The role of therapeutic interventions. Its applications encompass both
PET in diagnosing the primary tumor, however, remains diagnostic and therapeutic roles.
a subject of debate. Although its diagnostic range is broad, Diagnostic indications include: (i) evaluating
ongoing studies are still analyzing the effectiveness of PET indeterminate biliary strictures; (ii) clarifying unclear filling
compared to other methods. 105
defects; (iii) staging CCA; (iv) assessing ampullary tumors
PET, utilizing various tracers, is an advanced functional for extension into the common bile duct; (v) investigating
imaging technique that is increasingly recognized for its unexplained bile duct dilation; (vi) exploring cystic lesions
value and cost-effectiveness in the pre-operative staging of the biliary tree; (vii) diagnosing unexplained hemobilia;
of numerous cancers. By capitalizing on the metabolic and (viii) managing post-transplant biliary complications.
characteristics of tumors, PET can detect occult metastatic
disease that might be missed or appear ambiguous on Therapeutic indications include: (i) lithotripsy for
standard cross-sectional imaging. This capability can difficult stones; (ii) retrieving migrated stents; (iii)
significantly alter disease staging and influence treatment removing foreign bodies; (iv) assisting in guidewire
decisions. Traditional radiological examinations, such as placement; (v) transpapillary gallbladder drainage; and
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(vi) endoscopic tumor ablation therapy.
abdominal X-ray, oral cholecystography, and intravenous
or infusion ERC, are now rarely used due to advances in One of the most well-established and widely studied
technology and the development of innovative diagnostic applications of digital cholangioscopy is the diagnosis of
methods. An overview X-ray of the abdominal cavity is indeterminate biliary strictures and the performance of
typically performed where there is suspicion of air in the intraductal lithotripsy for challenging bile duct stones. The
bile ducts, for example, following surgeries that involve adverse events associated with digital cholangioscopy are
anastomosis between the bile ducts and the digestive tract, or similar to those of ERCP, with no significant increase in

Volume 3 Issue 1 (2025) 8 doi: 10.36922/arnm.4557