Originally Posted by sbear1102
Just started reading this post. kcon, is it expected to see small nodes on a CT scan? Or is this an abnormal finding. Is the key word "enlarged nodes" to indicate possible lymph node metastasis?
Hi kra53m and sbear1102,
kcon has already covered the facts, but here's another look from a different viewpoint with some background and other imaging options.
The bottom line: the CT scan is extremely unlikely to be positive except in cases with clear high-risk PSA and Gleason characteristics, and even then positive scan results are unusual.
I know it's hard to relax when you are awaiting results or interpretation, but you are almost certainly so entitled.
The downside: CT scanning really should not be done on men with low-risk case characteristics, but it is still pretty much routine from what I'm seeing.
Hopefully that will change as recently published expert judgement and guidelines, described below, reach more urologists.
Regarding nodes, yes, enlargement is what the doctors are looking for, and unfortunately it takes quite a bit of growth of the cancer before the CT scan can pick up something unusual that could well be cancer.
This is from shaky memory, but I believe it takes a tumor about the size of a pea to show up on a CT scan for a lymph node. Basically, if the CT scan is negative, as is virtually always the case for men with low-risk case characteristics (and even with higher case characteristics), it is not telling you there is no cancer, rather it is saying there definitely is not [U]a lot[U] of cancer in the nodes. CT scanning may be more sensitive for other sites, such as the liver, but it is quite unusual for prostate cancer to go to those other sites early its existence when most of us are diagnosed. Prostate cancer really prefers the lymph nodes and bones as early targets.
Here's a key excerpt of what the outstanding book "A Primer on Prostate Cancer - the Empowered Patient's Guide," Dr. Stephen B. Strum and Donna Pogliano, said about CT scanning for prostate cancer in 2002 (believe unchanged in the 2005 revision), in the discussion of CT scanning on pages 62 and 63: "Unfortunately, a CT scan of the pelvis and of the abdomen is routinely ordered in virtually all newly diagnosed men with PC. However, it is our contention, based on published literature, that this is a serious waste of healthcare dollars while exposing the patient to unnecessary radiation and inconvenience.... For at least 90% of men undergoing baseline staging procedures, a CT scan of the pelvis is not indicated [meaning not needed]. In 99.9% of all newly diagnosed patients with PC, a CT of the abdomen is definitely not needed...."
This past April, the American Urological Association came out with its expert "Prostate-Specific Antigen Best Practice Statement," which covered various staging techniques, including CT scanning, as they related to PSA. Here's the key sentence about the role of CT scanning on page 35: "3. Computed tomography [meaning CT] or magnetic resonance imaging scans may be considered for the staging of men with high-risk clinically localized prostate cancer when the PSA is greater than 20.0 ng/mL or when locally advanced or when the Gleason score is greater than or equal to 8.... Although the histologic incidence [meaning occurence] of positive pelvic lymph nodes is substantial when PSA levels exceed 25.0 ng/mL, the sensitivity of CT scanning for detecting positive nodes is only about 30% to 35%, even at these levels (Flanigan 1996)." In other words, even when there is cancer in a node for a higher risk case, the CT scan is going to pick it up only 30% to 35% of the time. The AUA did indicate that endo-rectal MRIs showed promise, but they were not yet willing to give their full seal of acceptance.
So you ask what a CT scan looks like, and I hope I'm not being too cynical in writing that, for a man with low-risk case characteristics
, it looks like extra money in the pockets of those associated with those scans, as well as some unnecessary inconvenience, cost and anxiety for us.
There are some scans that are really good at picking up lymph node and other soft tissue metastasis,
but they are either expensive or really inconvenient, with a low payoff for low-risk cases.
That low payoff is not because they cannot find small cancer, as is the disadvantage for CT scanning, but simply because the likelihood of spread for low-risk men is so low. Still, if you really want to nail down the key details of the case and can finance the cost through insurance or your own money, the two scans are (1) fusion ProstaScint and (2) Combidex MRI. Personally, if
I had the extra money and time and was newly diagnosed, I would go to the Netherlands and get a Combidex scan just for added assurance.
Fusion ProstaScint is highly effective in scanning the whole body, but it is fairly expensive (around $5,000 several years ago as I recall; my regular - not fusion - ProstaScint was around $3,400 in early 2000). It can still miss really small cancers, but it will pick up almost all. It was a moment for celebration when my ProstaScint result was essentially negative for my high risk case - really unexpected; while there are a few false positives and false negatives for ProstaScint, my case for more than nine years now has behaved in a way that confirms my ProstaScint result.
The Primer discusses both regular ProstaScint and the much more effective Fusion ProstaScint on pages 54 through 57, and includes an excellent graphic illustration as well as photos of both regular and fusion ProstaScint results. (The color graphics and photos are one reason the Primer is such a valuable resource to us; I can't think of any other prostate cancer book for patients with that quality of visual information. That is a great aid to our understanding.) The improvement in the fusion version is striking, though that particular image for a Fusion ProstaScint has been cleaned up a bit. ("Fusion" means that you are imaged with both ProstaScint and CT imaging, also sometimes PET imaging which is normally not useful for low-risk prostate cancer.) Insurance is probably still quite willing to cover Fusion ProstaScint for higher risk cases, but not for low-risk cases.
The Combidex imaging, formerly known by the unhandy acronym USPIO (Ultra Small Superparamagnetic Iron Oxide) for its special contrast agent, is unfortunately at this point available only in the Netherlands. It is highly effective at detecting any
cancer in lymph nodes throughout the body. (This is the kind of reliable result we think we are getting from a CT scan (but are not) in the early days after getting our rude introductions to this disease.) The Prostate Cancer Research Institute has published several outstanding articles on Combidex technology and its key doctor in a fairly recent edition of its free newsletter "PCRI Insights".
If you have the 2005 edition of the Primer (the second edition), you can read some information about Combidex.
Hope this helps,