In the fight against cancer, doctors currently lack reliable means to determine how a particular therapy is affecting their patients in real time, but this may be about to change. Researchers at MIT’s Koch Institute for Integrative Cancer Research (MA, USA) have developed a biochemical sensor that can be implanted in cancerous tissue during an initial biopsy, an invention that could help close this information gap.
The size of a tumor is currently determined using an MRI or other scanning method, while information on the cancer’s reaction to treatment is determined by the pathologist’s examination of biopsy tissue. However, these methods only provide data about the cancer at the moment they were conducted, and as biopsies are invasive, clinicians aim to minimize their use.
Once implanted, the sensor wirelessly sends data about key biomarkers to an external device. The device allows doctors to analyze the patient’s progress and adjust therapy accordingly. Increased precision in cancer treatment is critical, as it can increase the efficacy of the therapy and reduce the patient’s exposure to side effects.
“We wanted to make a device that would give us a chemical signal about what’s happening in the tumor,” explained Michael Cima, who oversaw development of the sensor. “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.”
The sensor is capable of providing on-demand data on two biomarkers linked to tumor response to treatment: pH and dissolved oxygen. The pH provides a real-time image of the tumor’s condition, as when cancerous tissue is being fought by chemotherapy agents, it becomes more acidic. Determining oxygen levels at the tumor site is also useful for doctors, as in low-oxygen conditions, more radiation is needed to treat the tumor. This data therefore allows them to adjust the dose.
“There are thousands of people alive today, because they have implantable electronics, like pacemakers and defibrillators,” Cima concluded. “We’re making these sensors out of materials that are in these kinds of long-term implants, and given that they’re so small, I don’t think there will be a problem.”
Sources: Real-time data for cancer therapy; Vassiliou CC, Liu VH, Cima MJ. Miniaturized, biopsy-implantable chemical sensor with wireless, magnetic resonance readout. Lab. Chip 15(17), 3465—3472 (2015).