Why can't you use magnetic or radiation to detect PC ?

chrisz · Regular Joined: 09 Apr 2007 Posts: 44

Do you know of any other cancers that you can't use MRI's, CT's, etc.
to detect like it evidently is with Prostate Cancer ?

Even after you have your Prostate removed, they use Radiological as well as other standard methods to scan your body in various places to check to metastases. But it seems to not be used to detect a tumor in the Prostate.
Why ???

Chris

brainman

Hi Chris. An MRI or CT can detect Prostate Cancer although occasionally neither work. I am not sure why those scans are less successful for Prostate cancer than other cancers. Prostate cancer is also difficult to biopsy... maybe for the same reason?

MRI and CT are useless with any type of leukemia.
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Replicant · Moderator Joined: 01 Nov 2006 Posts: 271

Hey Chris, that's an excellent question.

Here's my non professional's take on it.

In its early stages, prostate cancer is microscopic. The tumor is multi-focal. It's usually not just one big lump. When the whole prostate is taken out and removed, the average number is seven focal points of cancer. There's not much for a scan to pick up on. An exception might be color doppler ultrasound, which is supposed to show areas more likely to harbor cancer and therefore good for biopsy targets. It doesn't diagnose prostate cancer, though.

When cancer is early and localized, there's nothing for the CT to detect the cells have to be examined under a microscope to see if they're normal or not. Normal cells are well-differentiated--they're distinct little circles and ovals with clear cell boundaries. Cancerous cells are poorly differentiated. The Phoenix5 website has a pictorial of this. This difference in cell appearance is where Gleason scores come from.

Later on, MRIs and CT's can pick up on the spread of prostate cancer outside the prostate, but by then it's probably not curable any more, and PSA is likely 20 or higher.

In a nutshell, I think the answer as to why scans don't detect tumors while confined to the prostate is that the scans can't tell the difference in cell structure like a pathologist with a microscope can.

I'd pick up Walsh's "Guide to Surviving Prostate Cancer" and maybe Scardino's latest book for more clarification of this.

Best wishes.
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Replicant

Dx Feb 2006, PSA 9 @age 43
RRP Apr 2006 - Gleason 3+4, T3a, N0M0, pos margins
PSA 5/06 <0.1, 8/06 0.2, 12/06 0.6, 1/07 0.7.
Salvage radiation (IMRT) total dose 70.2 Gy, Jan-Mar 2007@ age 44
PSA 6/07 0.1, 9/07 <0.1, 12/07 <0.1, 4/08 <0.1, 11/08 <0.1
http://pcabefore50.blogspot.com

chrisz · Regular Joined: 09 Apr 2007 Posts: 44

Replicant,

I think you have the answer. I'm gonna ask the Udoc next month, if I can remember.

That Gleason score is a measure of how much a Prostate Cancer cell is differentiated from a normal Prostate cell. Sure hard to pick that up on Ct scan, maybe, unless, it's a high Gleason cancer and is growing much more rapidly than most PC does. A friend of mind had that type of cancer, avoided the doctor until it was too late. The cancer spread so rapidly that he died within 10 months of diagnosis .

Thanks,

Chris

Replicant · Moderator Joined: 01 Nov 2006 Posts: 271

I have the Walsh book in hand now. On p. 172, Walsh quotes Johns Hopkins pathologist Jonathan Epstein: "'Breast or lung cancer makes a solid nodule, just like a fist, that you can usually detect by palpation or imaging'...but prostate cancer tends to infiltrate normal tissue, meandering around normal cells...it spreads out like a hand whose fingers flow into nearby tissue 'like a river flooding a valley'. This means that there can be a significant amount of cancer--even if it's not in the form of an obvious lump that's easy to feel or see on ultrasound."
_________________
Replicant

Dx Feb 2006, PSA 9 @age 43
RRP Apr 2006 - Gleason 3+4, T3a, N0M0, pos margins
PSA 5/06 <0.1, 8/06 0.2, 12/06 0.6, 1/07 0.7.
Salvage radiation (IMRT) total dose 70.2 Gy, Jan-Mar 2007@ age 44
PSA 6/07 0.1, 9/07 <0.1, 12/07 <0.1, 4/08 <0.1, 11/08 <0.1
http://pcabefore50.blogspot.com

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