Sensitivity study of high-frequency ultrasound to skin cancer using micro-tumor mimicking phantoms

Abstract

Skin cancer is the most common cancer in the United States. An estimated one in five Americans will be diagnosed with skin cancer in their lifetime with approximately 145,000 new cases each year. Mohs surgery (Mohs micrographic surgery) is a surgical technique used to treat skin cancer. During Mohs surgery, thin layers of skin tissue are excised from the cancer site and examined until only cancer-free tissue remains. The examination of excised layers is tedious and time-consuming (4-5 hours). A rapid assessment tool for detecting cancerous tissue in excised margins would prove beneficial for both dermatologists and their patients. High-frequency (HF) ultrasound (20-80 MHz) has been explored as a rapid assessment tool for such cases. The purpose of this study was to test the sensitivity of HF ultrasound to micro-tumors present in skin cancer margins using histology mimicking phantoms. Phantoms were created from distilled water, agarose powder, 10X TBE stock solution, and polyethylene microspheres to simulate micro-tumors. Pitch-catch and pulse-echo measurements were acquired using a high-frequency ultrasound system with glycerol as the coupling agent. The phantom results show consistent increases in attenuation when testing positions containing micro-tumors, confirming the sensitivity of HF ultrasound to skin cancer pathologies.