The right measure is usually one of the greatest challenges of oncological surgeons; the tumor should be removed, taking as little as possible of the surrounding healthy tissue with it. This demanding procedure is now to be simplified by a pen-shaped measuring instrument, with which the differentiation between healthy tissue and malignancy should be possible intraoperatively within a few seconds.
Until now, to be certain that R0 was resected, it has often been necessary to wait a few days, or at least a prolonged surgical time when performing a frozen section, which is inferior to the diagnostic certainty of fixed and paraffin-embedded specimens. This situation is stressful for the patient and possibly leads to avoidable second interventions, if the precise demarcation and the desired safety distance were already quickly and easily apparent intraoperatively. A research group led by Dr. Livia Eberlin at the University of Texas at Austin has now developed a pen-shaped probe that is connected to a mass spectrometer and should decisively simplify the difficult distinction between healthy and degenerated tissue, especially in the peripheral zones, even intraoperatively. The “pen” is held on the tissue for a few seconds. During this time, the probe releases a small amount of water in which molecules of the tissue portion to be examined dissolve. The water is then sucked up again and fed to the mass spectrometer. This then gives the operators the result (malignant or healthy) of the analysis ten seconds later.
By analyzing more than 253 human tissue samples, some of which contained healthy cells and others cancer cells from breast, lung, thyroid and ovarian cancers, specific molecular profiles of each cancer type were established. With this tool, the sensitivity in the further tests was 96.4%, the specificity 96.2%, in some cases even different subtypes of malignancies could be distinguished. Even in the all-important marginal zones, where healthy and degenerated tissue mix, the so-called MasSpec Pen delivered accurate results.
The tests performed in vivo confirmed the promising results of the ex vivo tests. In addition to the precise differentiation between malignancy and surrounding tissue, operations on cancerous mice showed no tissue-damaging effect on the tissue left behind.
If testing in real operating rooms yields similar results, and if these can be confirmed in other types of cancer, the MasSpec Pen would be a valuable tool for accurate, time-efficient and at the same time gentle tumor surgery.
Literature:
- Zhang J, et al: Nondestructive tissue analysis for ex vivo and in vivo cancer diagnosis using a handheld mass spectrometry system. Sci Transl Med 2017 Sep 6; 9(406). pii: eaan3968.
InFo ONCOLOGY & HEMATOLOGY 2017; 5(5): 4.
