The co-authors of Invasion of the Prostate Snatchers, blog alternate posts weekly. We invite you to post your comments.

Tuesday, November 27, 2012

Life After Combidex - Part 2


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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