Diagnosis and staging of hepatobiliary malignancies: Potential incremental value of (18)F-FDG-PET/MRI compared to MRI of the liver

Abstract

Objective The purpose of the study was to investigate the potential added value of 18F-FDG-PET/MRI (functional information derived from PET) over standard diagnostic liver MRI (excellent soft tissue characterization) in diagnosing and staging suspected primary hepatobiliary malignancies including extrahepatic cholangiocarcinoma (ECC), intrahepatic cholangiocellular carcinoma (ICC) and gallbladder cancer (GBCA). Methods Twenty consecutive patients with suspected hepatobiliary malignancy were included in this retrospective study. All patients underwent combined whole-body (WB) 18F-FDG-PET/MRI including contrast-enhanced MRI of the liver, contrast-enhanced WB-MRI and WB 18F-FDG-PET. Two experienced readers staged hepatobiliary disease using TNM criteria: first based on MRI alone and then based on combined 18F-FDG-PET/MRI. Subsequently, the impact of FDG-PET/MRI on clinical management compared to MRI alone was recorded. Histopathologic proof served as the reference standard. Results Hepatobiliary neoplasms were present in 16/20 patients (ECC n = 3, ICC n = 8, GBCA n = 5), two patients revealed benign disease, two were excluded. TNM staging with 18F-FDG-PET/MRI was identical to MRI alone in 11/18 (61.1 %) patients and correctly changed the stage in 4/18 (22.2 %), resulting in a change in management for 2/4 patients (11.1 %). 18F-FDG-PET/MRI was false-positive in 3/18 cases (16.7 %). Both MRI and 18F-FDG-PET/MRI were falsely positive in 1 case without malignancy. Conclusions A small incremental benefit of 18F-FDG-PET/MRI over standard MRI of the liver was observed. However, in some cases 18F-FDG-PET/MRI may lead to false-positive findings. Overall there is seemingly limited role of 18F-FDG-PET/MRI in patients with suspected hepatobiliary malignancy.

New trends in diagnosis and management of gallbladder carcinoma

“…US plain, contrast-enhanced US, high-frequency US, high-resolution US, and endoscopic US in combination with three-phase contrast-enhanced multidetector CT[ 53 ] and contrast-enhanced MRI constitute the basic steps for diagnosis and preoperative staging[ 7 , 12 , 27 , 28 ].…”

“…18 F-FDG PET-CT[ 54 , 55 ] or 18 F-FDG PET-MRI[ 28 ] must be performed before every intended major curative resection to exclude any occult metastatic lesion, which is not visible by the other imaging techniques, particularly in port-site metastases after laparoscopic cholecystectomy[ 29 ] and in ambiguous cases or at follow-up[ 12 , 31 , 56 ].…”

“…Preoperative staging is of great importance in the decision-making plan of therapeutic management. Preoperative staging is based on MRI contrast-enhanced findings, the leading technique for liver metastasis imaging[ 28 ], enhanced three-phase CT angiography or magnetic resonance angiography for major vessel assessment. It is also necessary to use 18 F-FDG positron emission tomography (PET)-CT[ 29 , 30 ] or 18 F-FDG PET-MRI[ 28 ] to more accurately detect metastases and any other occult deposits with active metabolic uptake.…”

“…Preoperative staging is based on MRI contrast-enhanced findings, the leading technique for liver metastasis imaging[ 28 ], enhanced three-phase CT angiography or magnetic resonance angiography for major vessel assessment. It is also necessary to use 18 F-FDG positron emission tomography (PET)-CT[ 29 , 30 ] or 18 F-FDG PET-MRI[ 28 ] to more accurately detect metastases and any other occult deposits with active metabolic uptake. PET is complementary to traditional imaging for primary lesions and imperative for doubtful metastases with high specificity, including follow-up[ 31 ].…”