- Pp. 95-103 (9)Hanne Prytz
Cholangiocarcinoma (CC) is the second most common primary hepatic malignancy. Primary sclerosing cholangitis (PSC) predisposes for CC with a yearly incidence of 1.5%. Symptoms of CC are late and therefore the prognosis is poor. Ultrasonography (US), computer tomography (CT), magnetic resonance imaging (MRI), and cholangiographic techniques with cytology are the best imaging modalities, but these techniques are less useful for detection of tumour recurrence after surgery and metastases. Positron emission tomography (PET) using [<sup>18</sup>F]fluoro-2-deoxy-D-glucose (<sup>18</sup>F-FDG PET) has a diagnostic sensitivity for diagnosis of the primary tumour in CC complicating PSC ranging from 0-1.0 and a specificity of 0.67-1.0 in small studies of advanced PSC. The sensitivity and specificity of <sup>18</sup>F-FDG PET for diagnosis of CC in patients with suspected bile duct cancer were 0.61-0.94 and 0.80- 1.0, respectively. With <sup>18</sup>F-FDG PET/CT, sensitivity and specificity were 0.68-1.0 and 0.63-1.0, respectively, in this group of patients. Mass lesions and intrahepatic CC were more readily diagnosed than tumours with an infiltrating growth pattern and extrahepatic CC. Direct comparison of <sup>18</sup>F-FDG PET, <sup>18</sup>F-FDG PET/CT on 1 hand and CT on the other for diagnosis of the primary tumour showed no significant differences in sensitivity or specificity between the modalities. This also holds true for detection of regional lymph node metastases. However, <sup>18</sup>F-FDG PET and <sup>18</sup>F-FDG PET/CT performed better than CT for diagnosis of both recurrence of CC and distant metastases. The usefulness of <sup>18</sup>FFDG PET/CT for screening and surveillance of PSC-patients for CC remains to be established.