Utility of dual phase liver CT for metastatic melanoma staging and surveillance

Abstract

Rationale and objectives: To evaluate the clinical utility of dual phase computed tomography (CT) for assessment of hepatic metastases in patients with metastatic melanoma.

Materials and methods: A retrospective case-control study of dual phase CT examinations consisting of late hepatic arterial and portal venous phases performed on patients with melanoma was undertaken. In 2010, 420 dual phase CT examinations were performed on 188 patients. Of these, 46 CT examinations on 24 patients with hepatic metastases were combined with 52 control studies for evaluation. Two blinded reviewers independently evaluated single portal venous phase alone and dual phase imaging on separate occasions. The presence of hepatic lesions, the conspicuity of the lesions, and the likelihood that the detected lesions were metastases was recorded. Agreement between readers, sensitivity and specificity was calculated.

Results: In no case was hepatic metastatic disease only apparent on arterial phase imaging. Arterially enhancing hepatic lesions only visible on the arterial phase or much more conspicuous on the arterial phase were present in 10 studies (10%), all of which were benign. Liver metastases were rated as being more accurately assessed on the portal venous phase in up to 100%. In a per scan analysis dual phase and venous phase imaging had similar sensitivities of 96% (95%, CI: 86-100) and 98% (95%, CI: 89-100), respectively.

Conclusion: Single portal venous phase imaging is adequate for staging and surveillance in patients with metastatic melanoma.

Keywords: Arterial enhancement; Dual phase CT; Hypervascular liver lesion; Liver metastases; Melanoma; Multiphasic CT.