FDG PET in the diagnosis of hilar cholangiocarcinoma

Abstract

Resectional surgery offers a curative intent and a survival benefit for patients with hilar cholangiocarcinoma, but is associated with high morbidity. Since morphological imaging cannot solve differential diagnosis preoperatively, in order to exclude patients inappropriate to this aggressive surgery, we evaluated the impact of functional imaging using fluorodeoxyglucose positron emission tomography (FDG PET) in the detection of cholangiocarcinoma and its usefulness in the differentiation from benign Klatskin tumour-mimicking lesions. Fifteen consecutive patients aged 47-78 years underwent standardized whole-body FDG PET with attenuation correction before potentially curative surgery using a conventional full-ring PET scanner with an axial field-of-view of 16.2 cm. FDG PET was evaluated visually and semiquantitatively using tumour-to-background ratios (T/B) ratios. All lesions were evaluated histopathologically. FDG PET presumed to be indicative for carcinoma was positive in 12 of 15 patients, true positive in 10 (T/B ratio, 3.2+/-1.9) and false positive in two of them (T/B ratios, 2.1 and 2.8) with Klatskin tumour-mimicking lesions. While all true positive PET results were seen in the tubular type of cholangiocarcinoma with a high amount of tumour cells and only low production of mucus, a false negative FDG PET in three patients was observed in mucinous adenocarcinoma. Additionally, FDG PET detected locoregional lymph nodes in two patients and distant metastases in a further three patients. Due to false positive results FDG PET does not allow the differentiation of benign from malignant lesions, and FDG PET should be avoided in patients with mucinous cholangiocarcinoma. However, FDG PET may have significant influence on the treatment strategy in as much as 20% of the patients, since it may detect distant metastases.

Advances in diagnosis, treatment and palliation of cholangiocarcinoma: 1990-2009

“…In a small series by Chikamoto et al [154] , PET had a sensitivity of 80% for detecting local recurrence after resection in patients with HCC. One of the limitations of PET is that patients with biliary inflammatory conditions such as PSC or cholangitis may have false positive results [152,155] while patients with mucinous CC may have falsely negative scans due to poor uptake of FDG [155] .…”

Diagnosis and initial management of cholangiocarcinoma with obstructive jaundice

“…PET with [18F]-fluorodeoxyglucose can be used to rule out metastatic disease, although the findings should be interpreted cautiously because of false positive results in inflammatory lesions; moreover a normal PET scan does not exclude cancer [30] .…”

Comprehensive management of cholangiocarcinoma: Part I. Diagnosis

“…53 It is subjected; however, to false positive and negative results and low detection rates of small tumors. [54][55][56] The sensitivity of CT, MRI-MRCP and PET-CT, as demonstrated in the study of 123 potentially resectable ICC patients, was 95%, 100%, and 95% respectively. The high sensitivity of these modalities was also demonstrated in the diagnosis of ECC (89% for CT, 95% for MRI-MRCP, and 81% for PET-CT).…”