DeviceTherapeutic i-Knife for breast cancer surgery

A NIHR Imperial BRC-funded surgical innovation can identify marginal cancer tissue without disrupting surgical workflow. It does so by capitalising on spectroscopic analysis of surgical smoke from electrosurgery to determine tissue properties.

Recently licensed to Waters Corporation, the iKnife heats tissue as it cuts to make a clean incision. Smoke from the tissue is ionised using Rapid Evaporative Ionisation Mass Spectrometry (REIMS) technology and analysed using a mass spectrometer, providing information about the chemical composition of the cells.

The iKnife can accurately differentiate cancer and normal breast tissues in real time. Our research addresses high rates of positive radial resection margins following breast-conserving surgery (BCS). Approximately 20-30% of patients undergo reoperation. We have developed a histologically validated REIMS database of ex vivo breast tissues (n=561 normal, n=139 tumour) demonstrating high overall accuracy (95.6%) that rivals other margin assessment techniques and provides near real-time results (1-2s).

Further funding has enabled iKnife testing in vivo (n=27 breast procedures). Preliminary classification models demonstrated 100% sensitivity in correctly identifying tumour spectra (specificity 76.2%). Future work will further intraoperative validation towards a multicentre randomized controlled trial (RCT) comparing REIMS-guided versus conventional BCS.

The successful translation of the iKnife has the potential to reduce the human costs (11,000 women per annum undergo reoperative intervention) and economic impact (£22m triennial) of reoperative breast surgery. Furthermore, there will be added value in limiting trauma, improving cosmesis and quality of life.