Cancer is a dynamic disease, yet doctors have only static snapshots of its progress available to them as they formulate treatment strategies. A new TicTac-sized sensor that doctors can implant in their patients is poised to change that.
The sensor, developed by researchers at MIT's Koch Institute for Integrative Cancer Research, enables doctors to detect critical changes in tumor size earlier than they are able to using current tools, according to a report in the journal Lab on a Chip.
"We wanted to make a device that would give us a chemical signal about what's happening in the tumor," senior study author Michael Cima of MIT said in a statement. "Rather than waiting months to see if the tumor is shrinking, you could get an early read to see if you're moving in the right direction."
Cancerous tissues become more acidic as they are bombarded with the agents used in chemotherapy. Current monitoring tools such as MRI won't detect these changes, but the new devices are specifically designed to pick up on them.
"Many times, you can see the response chemically before you see a tumor actually shrink," Cima said in a statement. "In fact, some therapies will trigger an immune system reaction, and the inflammation will make the tumor appear to be growing, even while the therapy is effective.
In addition to acidity, the sensor detects oxygen levels. This measurement is allows doctors to calibrate how much radiation a patient needs. If a tumor has less oxygen, that means a doctor needs to blast it with more radiation to keep it in check. Conversely, if the doctor sees that a tumor has more oxygen, he or she can protect the patient from undergoing more radiation than is necessary.
So far, the researchers have only tested the device in rodents for a few weeks at a time. They will need to perform more tests to ensure that it will be safe to implant in humans for extended periods of time. However, the sensors are made out of the same materials that pacemakers and other implantable electronics are made from, so this is unlikely to be a problem.
