Distinguishing small hepatic hemangiomas from vascular liver metastases in gastrinoma: use of a somatostatin-receptor scintigraphic agent.

Purpose: To compare somatostatin-receptor scintigraphy and conventional imaging modalities in the differentiation of small hepatic hemangiomas from small liver metastases in Zollinger-Ellison syndrome.

Materials And Methods: Twenty-nine patients had hypervascular liver lesions smaller than 2 cm that could have been either metastases or hemangiomas. Fourteen patients had metastases, 14 had hemangiomas, and one had both. Scintigraphy was compared with computed tomography (CT), magnetic resonance (MR) imaging, and angiography for the correct identification of the lesions.

Results: The hemangiomas and liver metastases both had a mean size of 1.3 cm. In the patients with hepatic hemangiomas, scintigraphy showed no lesions. CT, angiography, or MR imaging showed a lesion in 40%-93%. With metastases present, any liver lesion was detected in 93% with scintigraphy versus 20%-60% with another modality. Scintigraphy depicted liver metastases in 93% of patients, which was higher than the sensitivities of other modalities. The accuracy (96%) and positive (100%) and negative (93%) predictive values of scintigraphy for detecting liver metastases were superior to those of other modalities. There were 45 liver metastases and 31 hemangiomas; a per lesion analysis gave results similar to the per patient analysis results.

Conclusion: In Zollinger-Ellison syndrome, somatostatin-receptor scintigraphy provides an excellent diagnostic tool to differentiate small hepatic hemangiomas from small liver metastases.