Human Cherenkov Imaging
Dartmouth’s Optics in Medicine Laboratory completed the world’s first human trial of the Cherenkov effect as a means of seeing radiation therapy in action.
The lab devised a technique for using the Cherenkov effect—the emission of light by a charged particle passing through a medium at a speed greater than the speed of light in that medium—to collect detailed images of the effects of radiation on tumors.
Led by Thayer Professor Brian Pogue and Geisel School of Medicine medical physicist David Gladstone and radiologist Lesley Jarvis, M.D., the initial trial was conducted at Dartmouth-Hitchcock’s Norris Cotton Cancer Center on a woman undergoing radiation for breast cancer. The research group then conducted a pilot study on 12 breast cancer patients.
“Our lab has researched a number of applications of the Cherenkov effect in radiation therapy including spectroscopy, tomography, and dosimetry in a water tank,” says Thayer Ph.D. candidate Adam Glaser. “We have found that imaging the surface dose in breast radiotherapy is one of the most impactful applications of this technique.”
“While our main research focus is improving this new technique, our team is also looking at how Cherenkov imaging can be used to study delivery accuracy in cancer treatment regimens, as well as looking at molecular signals which can be probed from the blue light within the targeted cancer tissue,” says Dartmouth physics graduate student Rongxiao Zhang.
According to Geisel medical student Whitney Hitchcock, the radiation used to treat cancer tumors can produce “hot spots” on a patient’s skin. While most of the 12 women in the trial experienced only temporary skin irritation from their planned radiation, the data-rich Cherenkoscopic images allow the researchers to study correlations between hot spots and the development of skin problems such as swelling, redness, and scaling.
The Optics in Medicine Lab group is currently using a single camera for Cherenkoscopic images, but in future the researchers hope to develop a multiple camera system to improve imaging and eventually apply the technique to other types of cancer.
Professor Kofi Odame is developing a wearable device that will monitor asthma symptoms—an aid for the nearly 19 million Americans with asthma who, according to the Centers for Disease Control and Prevention, do not manage their symptoms adequately and may end up in hospitals or ERs.
The device consists of any modern smart phone, a thin strip of adhesive silicone that sticks to a patient’s chest, and a piezoelectric transducer (PZT) embedded in the silicone that picks up sounds in the chest and transmits them to a smart phone equipped with software that detects if the sounds are asthmatic coughs or wheezes. “People’s smart phones will display the frequency of their coughing and wheezing—which will indicate to them whether they should leave an area, step up their medication, or even see a doctor,” Odame says.
Several students are contributing to the project. Justice Amoh ’13 Th’13 is leading the design team and developing machine-learning algorithms for detecting wheezes and coughs. Engineering major Teresa Ou ’15 built the circuit board that filters and amplifies signals from the PZT sensor and is installing a Bluetooth system for wireless communication with a smart phone. Malika Khurana ’15, from Dartmouth’s Neukom Digital Arts Leadership and Innovation Lab, heads product design and prototyping. Computer science (CS) graduate students Vibhu Yadav (advisor: CS Professor Daniel Rockmore) and Athina Panotopoulou (advisor: CS Professor Lori Loeb) are contributing to the smart phone app development and algorithm design, respectively.
“You need an algorithm that tells you whether someone’s coughing or whether he’s talking, laughing, sneezing, or just moving around,” says Amoh.
The goal is to make the system capable of detecting subtle changes in airway constriction that people may not notice on their own. “The device will help make people more aware of their symptoms and what’s triggering them. Then people can play a more active role in managing their disease,” says Odame.
—Alex Arconecomments powered by Disqus