Skin fiducial markers enable accurate computerized navigation resection of simulated soft tissue tumors: A static...

This static cadaveric model pilot study evaluated the agreement between planned and resected margins of simulated soft tissue tumors (SSTT) using skin fiducial markers for computerized navigation registration.

Markers were applied before magnetic resonance imaging scans of lower extremities implanted with SSTT. A navigation pointer was used for registration and to guide SSTT resection with approximately 10 mm planned margins. Digital calipers were used to measure resection margins. Kolmogorov-Smirnov tests were used to confirm measurement normality. A one-sample t test was used to determine measurement group differences (P ≤ 0.05). Bland-Altman analysis and histogram plots compared planned and resected margins.

Ninety-eight resection margins were measured. The planned margin mean was 10.0 mm (95% confidence interval [CI] = 9.8-10.2 mm) and the resected margin mean was 11.5 mm (95% CI = 11.0-12.1 mm). One-sample t test results identified a 0.75 mm, 95% CI = 0.5-0.99 mm difference (P < 0.001). Good measurement agreement was observed with 94.9% (93/98) of resections occurring within two standard deviations of the mean measurement difference.

Skin fiducial marker use for computerized navigation system registration displayed promising results. With further research, these markers may become an effective, noninvasive method for aiding in soft tissue tumor resection.