Increased Uniformity in Diagnostic Accuracy of Pigmented Lesions Using Electrical Impedance Spectroscopy Information.

Background: Novel non-invasive technologies augment information available to a clinician to enhance diagnosis. Electrical impedance spectroscopy (EIS) is a highly sensitive technology used before biopsy to differentiate equivocal lesions through differences in electrical resistance of benign versus malignant cells. A recent study of an EIS device approved by the United States Food and Drug Administration supported this device's impact on clinical management among dermatology residents. The device provides an EIS score, which increases with greater likelihood of malignancy.

Objective: We investigated whether the addition of an EIS score improved uniformity and diagnostic accuracy of pigmented lesions.

Methods: A post-hoc analysis of previously collected data from a survey of 164 dermatology residents was performed. Residents were asked to determine whether they would biopsy a lesion based on clinical morphology alone versus clinical morphology with an EIS score. A total of 45 lesions were assessed (including 17 malignant and 28 benign lesions). Subjects were grouped by percent correct pre-EIS score biopsy decisions and divided into quartiles.

Results: With clinical assessment alone, the mean correct decisions to biopsy was 59.9%. With the addition of EIS score, the mean increased to 71.0%. All quartiles significantly increased their correct biopsy decisions with EIS (<0.001), but the lowest scoring quartiles improved more than the highest scoring quartiles.

Conclusion: The data from the EIS device were designed to be integrated into the biopsy decision as an additional piece of information in the diagnostic pathway. The study findings are consistent with this objective. In addition to clinical judgment, the use of the EIS score most increased the lowest-scoring residents, but all were improved after integrating the EIS score. EIS information improved homogeneity of ability and diagnostic accuracy.