If after my long association with prostate cancer, I could achieve one objective—strike one blow for all the thousands of men facing the uncertainty of lymphatic involvement—it would be to see the presently FDA scorned and excommunicated compound “Combidex,” restored to favor, in production and universally available for the Combidex MRI.
This contrast fluid consists of minute Fe nanoparticles (iron particles) that
are injected into a vein in the arm. After 24 hours, metastases in lymph nodes
(LN) that show less “uptake” of the iron oxide nanoparticles, are visible as a
white structure in a dark background, whereas normal nodes display as black and
are thus not distinguishable. The white metastatic lymph nodes light up like light
bulbs in the darkness, and can hardly be missed by the radiologist.
I do my due diligence: regular PSAs. But
lately, I have been anxious; concerned that my immune system is no longer doing
its job as well as it did in the past. True, I have no compelling evidence that
my cancer is “on the move,” changing color by Mark’s Blue Scale, edging from
“Sky” to “Teal” to “Azure”, with each deepening “Shade” bringing
heightened “Risk.” And yet sometimes in
the night I wonder: Is that a swelling I
feel in certain lymph nodes?
What makes this a period of greater insecurity
is the absence of my old ally “Combidex”.
It wouldn’t be that difficult to set my mind at ease about whether or not
there is lymphatic involvement if, as I did five years ago, I could again take
myself off to the clinic of Dr. Jelle Barentsz, Professor of Radiology at
Radboud University in Nijmegen, The Netherlands, and undergo a Combidex MRI.
There are other tests available. But from what
I’ve seen of the stats, either they don’t do the job the way Combidex did, or
more research is required. Still, here are four you might want to check out. I
confess that I am out of my depth here, reporting as a non-medical voice
without pretension of authority or a guarantee of accuracy:
1. 11C Choline PET CT while
effective to a point, is not good in detecting nodes <5 mm. In this regard, Combidex
was clearly superior.
2. Feraheme (ferumoxytol) is not as
effective going to normal nodes as Combidex, and thus has a significantly
higher number of false positives! Anyone who uses this agent for nodal imaging
should be aware of this, So again, this substance is not a good substitute for
Combidex.
3. The new Prostascint Imaging (Indium-111: Labeled Capromab Pendetide) which shows
promise (it is more specific PSMA) but is still in its early phases of testing.
Indications are that Prostascint may be useful to evaluate
post-prostatectomy patients with rising PSA who have an otherwise negative or
equivocal workup for metastases. Another potential role for Prostascint
(controversial) is in the staging of newly diagnosed prostate cancer.
What is worth doing? My mind is preoccupied
with thoughts of risk (doing nothing) versus trauma (the ghastly side effects).
I have long thoughts about the “velocity of change.” I meditate about risk versus trauma. And I pine for
Combidex.
Perhaps my Better Angels have been on the job.
Because just as I finished this blog, I received a note from Dr. Barentsz in
the Netherlands, informing me that maybe—just maybe—Combidex is about to stage
a come back. And asking for my help. Did he ever come to the right man! I will
lay out the strategy in my final “Life After Combidex” blog.
Hot dog! Combidex redux!
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