Technology featuring a surgical tool known as the “intelligent knife” (iKnife) is able to analyze smoke released from tissue during electrosurgical dissection to determine quickly whether the tissue is cancerous.
Electrosurgical knives use an electric current to heat tissue rapidly and minimize blood loss. The tissue is vaporized, creating an aerosol, or “smoke,” which is normally sucked into extraction systems, according to a statement from the Imperial College of London in London, United Kingdom. The smoke, however, contains useful biological information regarding the characteristics of the tissue emitting the smoke. The iKnife can sample that aerosol.
As the Imperial College’s Zoltán Takáts, who invented the iKnife, and his fellow investigators explained in Science Translational Medicine (2013;5:194ra93), the iKnife couples electrosurgery with an emerging technique known as rapid evaporative ionization mass spectrometry (REIMS). REIMS enables almost real-time characterization of human tissue in vivo by analysis of the aerosol released during electrosurgical dissection. Diagnosis takes up to 3 seconds, far less than the 20 or 30 minutes required for an in-surgery histology diagnosis.
In order to validate the iKnife technique, Takáts and colleagues applied it to the laboratory analysis of fresh tissue samples from 302 patients. The analysis yielded characteristics of 1,624 cancerous (including brain, lung, breast, stomach, colon, and liver tumors) and 1,309 noncancerous tissues, to create a reference library of tissue-specific mass spectrometry signatures. The iKnife was then used in the operating room, where it was used in conjunction with existing electrosurgical equipment to collect data during 81 resections.
Tissue identification by means of intraoperative REIMS matched the postoperative histologic diagnosis in all 81 of the cases studied. The iKnife technology also was able to distinguish between histologic tumor types as well as between primary and metastatic tumors.