Hepatic Ultrasonography for Surveillance in Patients With Uveal Melanoma

Abstract

Importance: There is a lack of information regarding the role of systemic surveillance in patients with primary uveal melanoma.

Objective: To evaluate the utility of serial hepatic ultrasonography (USG) for detection of asymptomatic liver metastases in patients undergoing surveillance after primary treatment of uveal melanoma.

Design, setting, and participants: Retrospective cohort study reviewing data from patients with primary uveal melanoma treated between October 2003 and October 2012 at a multispecialty tertiary care center. Patients were managed using a standardized protocol. Initial staging was done with contrast-enhanced computed tomography of the chest, abdomen, and pelvis. This was followed by periodic surveillance with hepatic USG and liver function tests scheduled every 6 months for the first 5 years and annually thereafter. Abnormal surveillance hepatic USG findings were categorized as (1) cyst or hemangioma, (2) indeterminate lesion, (3) suspicious for metastasis, or (4) consistent with metastasis. If indicated, hepatic USG abnormalities were confirmed by additional imaging modalities (confirmatory scans) such as computed tomography or magnetic resonance imaging. Liver biopsy was performed only if the confirmatory scan was positive.

Main outcomes and measures: Sensitivity, specificity, and positive predictive value of hepatic USG for detecting asymptomatic liver metastases.

Results: In 263 patients (121 men, 142 women; mean [SD] age at diagnosis, 61.1 [13.9] years), a total of 1390 hepatic USGs were performed, with a mean of 5.3 per patient (range, 1-17 per patient). Overall, 86 hepatic USGs of 71 patients (27%) were reported as abnormal. Of the 13 lesions identified as a cyst/hemangioma and 17 as indeterminate, 1 was found to be metastatic in each group (8% and 6%, respectively). Of 36 patients with findings suspicious for metastasis, 23 (64%) had metastasis confirmed. All 5 patients (100%) with findings consistent with metastasis had biopsy-proven metastasis. The sensitivity, specificity, and positive predictive value of hepatic USG for findings that were indeterminate or suspicious for metastasis were 96% (95% CI, 80%-99%), 88% (95% CI, 83%-91%), and 45% (95% CI, 33%-59%), respectively. Specificity of the confirmatory scan was greater than that of hepatic USG (93% [95% CI, 89%-96%] vs 88% [95% CI, 83%-91%], respectively; P < .001). Only 4 of 30 patients (13%) with metastasis had abnormal findings on simultaneous liver function tests.

Conclusions and relevance: A stepwise surveillance protocol based on serial hepatic USGs followed by confirmatory scans offers high likelihood of detecting asymptomatic metastases in patients with primary uveal melanoma.