By Janet Fang
Posting in Cancer
Breath is drawn over sensors that change color depending on the volatile compound. The new tech detects the cancer with 83% accuracy, even distinguishing between different subtypes.
The test is 83% accurate, matching what’s possible with low-dose CT scans. And it can also distinguish between several different subtypes of lung cancer – something that usually requires an invasive biopsy. Technology Review reports.
Existing tests for this leading cause of cancer death worldwide result in too many false positives, forcing patients to have unnecessary biopsies or be exposed to radiation from imaging procedures. And none are currently approved by Medicare.
Chemical results of a tumor's metabolism are dissolved in blood and can end up in the breath – dogs can identify breath samples from lung cancer patients with 98% accuracy. A method called gas chromatography mass spectrometry can do the same, but it requires skill and lab space.
The breath analysis instrument (pictured) could be the noninvasive, reliable, and portable solution.
- Patients breathe through a tube for 5 minutes.
- Pumps draw the breath through a series of filters to dry it out and remove bacteria.
- Then it’s drawn over an array of sensors consisting of colored reactants that are each sensitive different volatile compounds.
- Different spots in the array (24 in the initial version, 130 in the current one) change color to varying degrees.
- A photo is taken of the array of colored reactants before and after.
- The system subtracts one image from the other, generating a colored pattern for that sample.
The company is running additional lung and colon cancer clinical trials of equipment that’s 1,000 times more sensitive than the recently completed trial. The test is expected to cost $75.
From MIT Technology Review.
Feb 15, 2012