Electro-Scalpel "Sniffs Out" Tumors

TechReviewAl writes "Researchers in Germany have developed a surgical tool that uses chemical analysis to identify cancerous tissue as a surgeon cuts. The instrument uses a modified mass spectrometer — a device that uses ionized molecules to perform very accurate chemical analysis — to pinpoint tumors so that surgeons can make sure they remove everything. Mass spectrometry has been used to study biopsied biological samples before, but never used in-situ. The key was to harness ionized gas already produced by the electro-scalpel."

Re:That is freakin' brilliant.

[MichaelSmith]

Yeah. Having seen what chemotherapy did to my father in law a couple of months ago I will be asking for surgery if I need cancer treatment in the future, no matter how invasive it is.

Maybe they can build it into an arthroscope to get into those hard to reach locations.

Also I wonder if they could use it for localised radiotherapy. The GC tells you where to embed the tiny radioactive sources.

Re:That is freakin' brilliant.

[MichaelSmith]

What is the the smoke used for?

It is fed into a Gas Chromatograph which gives the surgeon feedback about the sort of tissue he is cutting through. Seven years ago I watched an obstetrician operate on my wife with a cutting tool like this. She prefers that I not describe the experience in graphic detail in her presence.

Pocket GC == Tricorder

Yes, but...

[vegiVamp]

The way I read it, it tells you what tissue you're cutting *when you're cutting it*, not beforehand. It doesn't "sniff out" cancer as much as that it tells you wether or not the thing you're currently damaging is cancer or not.

Re:Yes, but...

[smellsofbikes]

It *might* be possible to combine this with an ablative short-pulse laser, so you hit the area with a quick laser pulse, which will remove something less than one cell-depth of tissue, and then analyze the resultant burst of materials. Problem with that is lasers are sufficiently destructive it might be hard to find much useful stuff in the debris, compared to the non-micro-destructive materials released via electro-cautery. But mass spec is pretty amazing in its sensitivity. Since nobody else has yet talked about this, what a mass spectrometer does is it relies on molecules that have been fragmented. It uses an electric field to accelerate the fragments that are charged, and shoots them past a magnet. The deflection is a function of the mass. By varying the electric field strength, you can select for what mass you want to have hit the detector, and with computer processing of the results, you can do a surprisingly good job of figuring out what's in the mix based on knowing how things generally break up and the comparative weights of common organic chunks: if you see something of atomic weight 44 you presume you just found a propyl group ((CH3)2CH-) and so forth. So I think it's entirely possible they could make this into something that only does microscopic damage at any one point.

Of course, then I think it'd be nice to hook it up to an x/y scanner and have a computer do the work, so it'd just scan back and forth, and drill in wherever there's a problem until there's no longer a problem: a real-time version of current Mohs Surgery [wikipedia.org] that they use for removing skin cancer while minimizing adjacent tissue damage/removal.

Re:Can anyone tell me the difference

[reverseengineer]

I'm not sure what exactly they use as a marker in this case, but I know that one distinguishing feature for cancer cells is increased oxidative stress that attacks membrane lipids. Due to this, cancer cells have much larger concentrations of small-chain alkanes than you would expect in a healthy cell. Using alkanes as your biomarker has the further advantage of their structural simplicity; you can just dial in on the mass of something like pentane or hexane molecular ions without having to do detective work on a bunch of fragments.

Since the shorter alkanes are highly volatile, there have already been experiments to show that lung cancers can be detected by GC-MS of collected breath, and even some experiments that dogs have a sense of smell acute enough to pick up on these markers.