Novel laser-sonic scanner shows potential for tumor detection
A laser-sonic scanner developed by researchers at California Institute of Technology detected tumors in a small cohort of patients in as little as 15 seconds by shining pulses of light into the breast, according to a study published in Nature Communications.
“This scanner is the only single-breath-hold technology that gives us high-contrast, high-resolution 3-D images of the entire breast without using ionizing radiation or contrast agent that can potentially cause harm,” Lihong Wang, PhD, Bren professor of medical engineering and electrical engineering at the Caltech Optical Imaging Laboratory at California Institute of Technology, said in a press release. “Our goal is to build a dream machine for breast screening, diagnosis, monitoring and prognosis without any harm to the patient.”
HemOnc Today spoke with Wang about how this device was conceptualized, preliminary efficacy and safety results, and the potential benefits it may offer for breast cancer screening and disease detection.
Question: How was this device conceptualized?
Answer: We started with microwave-sonic imaging. The problem with pure microwave imaging is the long wavelength, which limits the spatial resolution. We decided to combine microwave and acoustic wave synergistically. The combination provided us microwave contrast, which is quite high for soft tissue, at ultrasonic resolution. By detecting the microwave-induced ultrasound signal, we formed sharp images. After a few years, we were able to get great images by optimizing the detection geometry and image reconstruction math. The excitement triggered us to swap the microwave source with a laser while the rest of the optimized system was kept essentially the same. By combining laser light with sound, we can see what the naked eye can see, except much deeper into tissue.
Q: How does it work?
A: We ask the patient to hold their breath and within 15 seconds, and we acquire a data set for the entire breast. This technical breakthrough took many years to achieve, but we are very happy with the advancement that has been made to date.
Q: How has it been tested?
A: We first tested our imaging system in the lab using tissue-mimicking nonbiological materials and ex-vivo tissue. We then took the system to the clinic and worked with radiologists to image seven patients with breast cancer, and we had a high success rate. We are detecting tiny blood vessels without injecting any contrast agents and without causing any harm to our patients. Because we can see blood vessels so well, we can see tumors well, and we can quantify blood vessel density and tissue stiffness to differentiate tumors from the normal background tissue.
Q: Can you describe the preliminary efficacy and safety results?
A: The laser exposure is well within the safety limit, and the ultrasonic exposure is orders of magnitude weaker than that of standard clinical ultrasound imaging. No painful breast compression is needed..
Q: What research is underway or planned to further confirm its effectiveness?
A: Investors are interested in our technology, have licensed our intellectual property, and have started companies to commercialize it. The first cohort of patients was quite small for clinical testing purposes, so it is considered a pilot study. The next step is to test our technology in a larger group of patients. With a larger patient population, we will be able to clinically establish the technology. It will then go through regulatory approval, either in the United States or overseas. The investors want to start with approval in China.
Q: When might this be ready for mainstream use?
A: Once we go through this process, hopefully the technology will become available for clinical use. It is always hard to predict, but I am optimistic that this technology will start approaching mainstream use within several years.
Q: What are the potential implications on breast cancer screening and disease detection ?
A: This technology has many strengths. It is expected to have high specificity, high sensitivity and high throughput. Our hope is that our technology can be used for all sorts of applications, such as screening, detection and monitoring of therapy. There is a whole range of potential implications. – by Jennifer Southall
Wang L, et al. Nat Commun. 2018;doi:10.1038/s41467-018-04576-z.
For more information:
Lihong Wang PhD, can be reached at California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125; email: firstname.lastname@example.org.
Disclosure: Wang reports financial interests in the companies that have licensed the intellectual property for this scanner.