Engineers at Stanford University in the US have created a small self-contained device with a stretchy/flexible sensor that can be attached to the skin to measure the changing size of tumors below.
The noninvasive, battery-powered device called FAST for “Flexible Autonomous Sensor Measuring Tumors”, it represents a completely new, fast, inexpensive, wireless and accurate way to test the efficacy of anticancer drugs. On a larger scale, it could lead to promising new directions in cancer treatment.
The sensor is sensitive to one hundredth of a millimeter (10 micrometers) and can wirelessly transmit results to a smartphone app in real time at the touch of a button.
FAST can detect changes in tumor volume on a time scale of one minute
Each year, researchers test thousands of potential anticancer drugs in mice with subcutaneous tumors. Few reach patients, and the process of searching for new therapies is slow because the technologies to measure tumor regression of drug treatment take weeks to read a response.
The biological variation inherent in tumors, the shortcomings of existing measurement methods, and the relatively small size of the samples make drug screening difficult and time-consuming.
“In some cases, tumors under observation need to be measured by hand,” says Alex Abramson, first author of the study.
The use of metal calipers in the form of clips to measure soft tissue is not ideal, and radiological methods cannot provide the type of continuous data needed for real-time evaluation.
FAST can detect changes in tumor volume on a time scale of one minutewhile caliper and bioluminescence measurements typically require observation periods of weeks to read changes in tumor size.
The researchers say the new device offers at least three significant advances. First of all, it provides continuous monitoring, since the sensor is physically connected to the mouse and remains in place throughout the experimental period. In second place, flexible sensor wraps around tumor and thus is able to measure changes in shape that are difficult to discern with other methods. Third, FAST it is self-contained and non-invasive. It is attached to the skin, like a Band-Aid, is battery-powered and connects wirelessly. The mouse is free to move without getting in the way of the device or cables, and scientists do not need to actively manipulate the mice after sensor placement.
Additionally, FAST packs are reusable, costing only a few $60 and can be attached to the mouse in a matter of minutes.