Slashdot Mirror
Ultrasound Technique Provides a New Radiation Free Way To Visualize Tumors
FirephoxRising writes "Traditionally ultrasound has seen limited use in cancer treatment due to clarity and resolution issues. But researchers at the UNC School of Medicine have overcome this limitation by combining ultrasound with a contrast agent composed of tiny bubbles that pair with an antibody that many cancer cells produce at higher levels than do normal cells. 'The SFRP2-moleculary targeted contrast agent showed specific visualization of the tumor vasculature,' said Klauber-DeMore. 'In contrast, there was no visualization of normal blood vessels. This suggests that the contrast agent may help distinguish malignant from benign masses found on imaging.'"
Unfortunately the ultrasonics cause a Karman vortex street, which has been known to induce panic, particularly in snow hikers.
Also FatPhil on SoylentNews, id 863
So, if this contrast agent attaches to cancer cells more than normal ones, could it be used to deliver targeted death to the cancer cells?
This guy is mad
That happens sometimes when your horse loses interest in you....
You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
With tumors surely more traditional X-rays could only help matters (radiotherapy-lite)
Lol....nice try. External beam radiation therapy (XRT) ....varies depending on the type and stage of cancer being treated. For curative cases, the typical dose for a solid epithelial tumor ranges from 60 to 80 Gy, while lymphomas are treated with 20 to 40 Gy. Whereas a CT scan (the cardiac one being the highest dosing) tops out at 40-100 mGy or 2-3 orders of magnitude less.
In reference to the article, it is an interesting concept. Will need some work to improve its general applicability. By this the SFRP2 is only specific for colorectal and myelomas, so the technique is very limited. Also, please note that ultrasound is horrible to use around bowel, especially colon...the gas in the colon very effectively blocks the sound waves and you get very poor/incomplete images. Besides, colonoscopy is the gold standard for screening and has the advantage of being therapeutic or allowing tissue biopsies which can seal the diagnosis. Granted most need at least some sedation, but at 10 year intervals for most, this is a pretty acceptable tradeoff.
The only other question I have is the applicability....again, even if they can increase the scope of the detection, a full scan of the body for mets would be very unsatisfactory using ultrasound....now if we start talking about sarcomas, renal cell, breast cancer, yeah, I could see this working out. Lung, brain, ENT cancers, not so much.
Microbubbles have been used both experimentally and commercially as a contrast-enhancing agent in ultrasound imaging for at least twenty years.
Coupling affinity probes (like antibodies) to microbubbles in order to increase their specificity has been done for more than a decade. Extensive work has been done in tissue and animal models. (The study in the Slashdot story is just another mouse study.)
Unlike the study promoted here, there are a number of published reports - as well as clinical trials - involving use of these probe-coupled microbubbles in real human beings to study real people with real diseases. (See for example this 2012 review.) It's nice that UNC is studying this stuff and it's good to see the number of targets for this technique being increased...but breathless press releases aside, this particular study isn't really cutting-edge.
~Idarubicin
Yes, we've come a long way in cancer treatment, and some ways in cancer detection. Problem is that there are some cancers that start very small, and move faster than the annual physical. The bean counters are standing in the way of the ultrasounds that can in fact see small tumors sooner than CT. The rationale is that (2) it costs a lot to screen false positives and (2) it makes people worry more. I have news for you - after losing two immediate family members way too soon to cancers that were only discovered once the symptoms got dangerous, something needs to change. Too often we're not finding cancer when it starts but rather when it displaces and entire organ or produces blood. I'll take 6 months of worrying and a middling increase in cost to find out it it was nothing over ten or 50 years of death.
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
Is that "surely" in the sense of "I know absolutely nothing about the subject"?
In case you hadn't noticed, radiation can also cause cancer! That alone should have clued you in to the fact that it's a little more complicated than your first-grade understanding of medicine.
Still, you keep brushing your teeth with radium toothpaste if you think it'll help you live longer.
systemd is Roko's Basilisk.
Oh definitely! This still leaves the ultrasound creating bubbles, cooking tissue, emitters being inserted in nasty places... and the resolution is nothing compared to a PET scan for detection.
There is a strong dose dependence and delivering the dose to the right place involved. The imaging X-rays will tend to irradiate all the wrong tissues and with just enough radiation to make the cancer worse. It would be bad if radiation from imaging turned a benign tumor malignant.
The technique in TFA is also a very specific imaging. Unlike a typical contrast dye, this will specifically highlight the cancer.
As TFA points out, ultrasound is much cheaper and more portable as well. The former benefits everyone and the latter is good for rural patients.
Only for ass cancer.
Oh definitely! This still leaves the ultrasound creating bubbles, cooking tissue, emitters being inserted in nasty places... and the resolution is nothing compared to a PET scan for detection.
Okay, it's pretty obvious that you don't know how the technology works either.
The sensitivity of PET scanning may be better under some circumstances and for some organs and tissues; it's early days for affinity-tagged microbubble contrast in ultrasound, whereas PET is an older, more mature technology. PET is also quite good for scanning large volumes. On the other hand, its spatial resolution is crap compared to virtually any other imaging modality (save for its poor cousin SPECT)--including run-of-the-mill ultrasound. PET scanning requires exposure to a goodly bit of ionizing radiation; ultrasound is one of the few imaging modalities that does not.
Under anything like normal conditions (with or without microbubble contrast), ultrasound imaging does not create bubbles or cause significant heating of tissue. The microbubbles discussed here are exogenous and introduced intravenously (for most types of studies); once in the body they tend to break down within a few tens of minutes. The microbubbles are typically tens of microns in size and are carried harmlessly through the circulatory system. Gas from burst bubbles escapes readily through the lungs.
You use PET scanning to look for distant metastases throughout the body, and a positive PET signal indicates the need for further investigation rather than representing a firm diagnosis by itself. Ultrasound with affinity-tagged microbubbles is used to interrogate a (suspected) primary tumour and the immediately surrounding tissue; it's a different clinical problem entirely.
As a side bonus, ultrasound is probably hands-down the cheapest imaging modality available to clinicians--which means that instruments are plentiful and fast access is readily available even to patients who don't happen to live near a major hospital's radiology department.
~Idarubicin
There are several ultrasound machine makers that create very good images, and not necessarily the most expensive machines either. One key advantage also is that even with less resolution you get real time images. Ultrasound is very safe, and even then is still regulated with very strict power controls. There is no "cooked tissue".
I suspect the real story here is likely finding a good target (SFRP2), more so than the microbubbles. Finding a specific enough target always seems to be the limiting factor in immunotherapy, nanoparticle-based drug delivery, GNP-based radiothermal therapy, etc.
Now if they could find a good target for more cancers (I definitely agree on breast as a good target--elastography ultrasound is already a big topic of interest there), it could have a nice impact on treatment options. Since you can't really image too frequently by MRI, CT, etc. due to exposure limits, you can't do high-frequency watchful waiting, which biases clinicians and patients towards intervention when they detect something.
In breast cancer, this is a pretty hot topic: all these frequent / early mammograms are detecting lots of DCIS, and the standard thing to do is lumpectomy. But there's growing evidence that these are likely being overtreated, and many if left alone would likely not progress to invasive carcinoma for a long time. But since there's no great way to know on a patient-by-patient basis, and since you can't really keep a close eye on them by frequent imaging, it's tough to do otherwise.
But if you could image the breast cancer really well by ultrasound, you could do such a watchful waiting: image frequently, and so long as there's no change, keep monitoring. (Not sure if this would have have the resolution to detect an in situ cancer like DCIS, though. Will have to read the article.) It would be nice to see such watchful waiting options open up for other cancers where treatment choices are perhaps otherwise unclear.
I've also seen early work attempting to use interference patterns in ultrasound (putting a few piezoelectric membranes at the right spacing, etc.) to induce apoptosis at specific spots. It would be interesting to see if this work could help enhance that ...
OpenSource.MathCancer.org: open source comp bio
Without a hyphen, the story is much more interesting. It could say:
Ultrasound Technique Provides a New Radiation
Free Way To Visualize Tumors
Very interesting.
I am so sick and tired of reading about diagnostic tools for cancer being treated as an advancement.
For half a century patients have been able to get pretty pictures of their tumors and they end up dying anyway.
The one thing many of these new "advancements" seem to have is adding on to the bill, but not really treating to the patient.
Who cares about 3D pictures of tumors, after 50+ years of cancer diagnostic pics address the problem already.
Got Geometrodynamics? Awe, too hard to figure out? Too bad.
Since you can't really image too frequently by MRI, CT, etc. due to exposure limits,
There are exposure limits to MRI? Why? I can see it being too costly to do frequently, but I don't see how it could affect the patient.
ultra sound ablative surgery: ex. http://www.ncbi.nlm.nih.gov/pu... .
Essentially you zap with low power to see where you are aiming, then high power to vibrate/boil the tissue you wish to destroy. The beauty of it is compared to most radiotherapy (proton might be better but is relatively rare and expensive) the distribution of normal to target dose is much better.