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The ability to detect malignant tissue in surgical margins during breast cancer surgery would reduce the risk of local recurrence and the need for subsequent surgeries to remove residual cancer. A surgical study conducted by Utah Valley University with the Huntsman Cancer Institute showed that high-frequency ultrasound (20–80 MHz), and the parameters peak density (number of spectral peaks and valleys from 20 to 80 MHz) and attenuation, are sensitive to breast tissue pathology. Pathology results from this surgical study showed that many margin specimens contained micro-tumors measuring 1 mm in diameter or smaller. The present study’s objective was to determine the sensitivity of high-frequency ultrasound to these micro-tumors using phantoms. Phantoms were created from distilled water, agarose powder, 10X TBE stock solution, and 390–925μm diameter polyethylene microspheres to simulate breast tumors. Microspheres were embedded in phantoms singularly and in clusters of 3–12 microspheres. Pitch-catch measurements were acquired using large (6.35 mm diameter) and small (1.5 mm diameter) 50-MHz transducers, a high-frequency ultrasound system, and glycerol as the coupling agent. Both large and small transducers were sensitive to single microspheres and microsphere clusters across all microsphere diameters. The phantom results confirm the sensitivity of high-frequency ultrasound to breast cancer micro-tumors and validate the surgical study.

The Breast Cancer Research Laboratory at Utah Valley University has been developing high-frequency (HF) ultrasound (20–80 MHz) to differentiate between malignant and benign tissues. Results from our breast cancer clinical trials thus far are promising, with high sensitivities and specificities. The objective of this study was to determine whether HF ultrasound can provide pathology sensitive measurements for diagnosing skin cancer and distinguishing between tissue structures. Formalin-preserved porcine tissues were first used to test the feasibility of the approach. The results show that both spectral peak density and wave velocity were sensitive to structure, and that normal skin tissue was significantly discernible from other tissues. An 80-patient clinical study is currently being conducted at the Huntsman Cancer Institute with the collection of ultrasonic measurements from at least 320 skin biopsies. Multiple pulse-echo and through-transmission measurements are acquired from each biopsy specimen. The ultrasound data are correlated to conventional pathology to determine sensitivity and specificity. If successful, HF ultrasound may provide an earlier diagnosis of skin cancer and a rapid, intraoperative method for differentiating between melanoma and benign pathologies. By improving on current methods, HF ultrasound may provide dermatologists with faster and more accurate results, and thus better patient treatment and outcomes.

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