TN01 HILAR CHOLANGIOCARCINOMA: RADIOLOGICAL DIAGNOSIS, STAGING AND PRE‐OPERATIVE INTERVENTION

Hilar intrahepatic cholangiocarcinoma (I‐CAC) accounts for 25% of CAC. Complete surgical resection offers the best possibility of cure but this demands accurate pre‐operative assessment and staging as well as appropriate ancilllary procedures such as selective portal vein embolisation and targeted biliary drainage. CT (MD‐CT) and MRI are the primary imaging modalities used for the assessment of hilar I‐CAC but despite advances in imaging technology, overall accuracy for assessing resectability of hilar I‐CAC is approximately 60–75% for modalities. Hilar I‐CAC may present as thickening of the biliary wall with infltrative margins or (less commonly) a polypoid intra‐ductal or exophyic mass. The mass typically demonstrates delayed enhancement after contrast as a result of the sclerosis and fibrosis of surrounding tissues frequently seen in CAC. The extent of intraductal tumour spread is more accurately demonstrated with MRI/MRCP but the high spatial resolution of MD‐CT allows possibly more accurate definition of vascular invasion and small lymph metastases. These structures may also be evaluated with pre‐operative laparoscopy. CAC is FDG avid and CT‐PET has a role in detecting nodal and peritoneal metastases. Selective pre‐operative percutaneous transhepatic biliary drainage (PTBD) of the obstructed hepatic segments in the future hepatic remnant has been shown to improve post‐operative outcomes. Pre‐operative selective portal vein embolisation has been used to promote hypertrophy in patients with marginal remnant volumes. The degree of compensatory hypertrophy is an important predictor of outcome and is dependant on technical procedural success and underlying liver disease.