Contemporary diagnostic imaging modalities for the staging and surveillance of melanoma patients: a meta-analysis

Abstract

Background: Meta-analyses were performed to examine the utility of ultrasonography, computed tomography (CT), positron emission tomography (PET), and a combination of both (PET-CT) for the staging and surveillance of melanoma patients.

Method: Patient-level data from 74 studies containing 10,528 patients (between January 1, 1990, and June, 30, 2009) were used to derive characteristics of the diagnostic tests used. Meta-analyses were conducted by use of Bayesian bivariate binomial models to estimate sensitivity and specificity. Diagnostic odds ratios [ie, true-positive results/false-negative results)/(false-positive results/true-negative results)] and their 95% credible intervals (CrIs) and positive predictive values were used as indicators of test performance.

Results: Among the four imaging methods examined for the staging of regional lymph nodes, ultrasonography had the highest sensitivity (60%, 95% CrI = 33% to 83%), specificity (97%, 95% CrI = 88% to 99%), and diagnostic odds ratio (42, 95% CrI = 8.08 to 249.8). For staging of distant metastases, PET-CT had the highest sensitivity (80%, 95% CrI = 53% to 93%), specificity (87%, 95% CrI = 54% to 97%), and diagnostic odds ratio (25, 95% CrI = 3.58 to 198.7). Similar trends were observed for melanoma surveillance of lymph node involvement, with ultrasonography having the highest sensitivity (96%, 95% CrI = 85% to 99%), specificity (99%, 95% CrI = 95% to 100%), and diagnostic odds ratio (1675, 95% CrI = 226.6 to 15,920). For distant metastases, PET-CT had the highest sensitivity (86%, 95% CrI = 76% to 93%), specificity (91%, 95% CrI = 79% to 97%), and diagnostic odds ratio (67, 95% CrI = 20.42 to 229.7). Positive predictive values were likewise highest for ultrasonography in lymph node staging and for PET-CT in detecting distant metastases.

Conclusion: Among the compared modalities, ultrasonography was superior for detecting lymph node metastases, and PET-CT was superior for the detection of distant metastases in both the staging and surveillance of melanoma patients.

Figure 1

Histogram of the Distribution of Quality Assessment of Diagnostic Accuracy Studies (QUADAS) scores for diagnostic studies (n = 74).

Figure 2

Forest plots of the test characteristics of four diagnostic modalities. A) Forest plots for sensitivity and specificity for ultrasonography (US), computed tomography (CT), positron emission tomography (PET), and PET-CT for the clinical scenarios indicated. B) Forest plots for diagnostic odds ratio for ultrasonography (US), computed tomography (CT), positron emission tomography (PET), and PET-CT for the clinical scenarios indicated. The squares represent the median and the whiskers represent the 95% credible interval.

Figure 3

Funnel plot for diagnostic odds ratio (dOR) with standard error. A) Ultrasonography (US). B) Computed tomography (CT). C) Positron emission tomography (PET). D) PET-CT. Data from each modality are plotted against their standard error (SE). Solid line = summary estimate of the dOR; dashed line = 95% confidence limits around the dOR.