Timing for 2nd PET/CT Scan after chemo - Advanced Prostate...

Advanced Prostate Cancer
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Timing for 2nd PET/CT Scan after chemo


If you went through 6 cycles of Docetaxel ... how long after your last infusion did you have your PET/CT Scan?

This will be my husband's 2nd PET/CT Scan, and we're trying to determine the best time frame after his last chemo to have the scan.

Thanking you in advance for your information/advice/suggestions.

24 Replies

You can see what his PSA and bone ALP do first - if they continue to improve, you can put off the scan.

What is ALP?? (sorry for my ignorance)

bone alkaline phosphatase

My blood test reports have just come in. My PSA has risen to 7.314 from 6.58. My "bone alkaline phosphatase" or Alkaline Phosphatase with Bone Fraction Ostase came in at 12.5, where the normal range is 5.5-24.6

Therefore, on the face of it, my PSA is not going down (not going up much either) and my bone alkaline phosphatase test is normal.

My next chemo session is scheduled for 4th February. How many days after that should I take a PSMA test to determine whether mets have increased in size and qty ?? An early reply would be much appreciated. Thank you.

Stable is good - at least better than rising. If that was your 6th cycle, you should discuss next steps with your oncologist. I have no idea what your treatment history was in the past, what your scan history was, or why you want a PSMA PET scan at all, so I can't comment.

I want a PSMA PET-CT scan to figure out whether the mets have decreased or increased both in size and qty. My MO has already given me the go ahead to get this test done.

The ONLY question, imho, is when exactly to do the test. Should I wait 7/14/21/42/56/70 days after my 6th session of chemo on the 4th of Feb ? The idea being not to do it too soon after chemo.

My feeling is that I should wait for 42 days (ie 6 weeks), no more no less. If the mets have increased in size/qty, stop docetaxel and commence Xtandi/Zytiga.

Thank you for your reply, much obliged.

And if they have NOT increased in size and quantity, what would you do?

I would continue with docetaxel (chemo) for upto another 6 cycles (provided I can tolerate it) before doing another PSMA PET-CT scan.

Does it not make sense to you ??

You might consider taking a break from chemo for a while to allow for some recovery, and doing Xofigo, Zytiga or Xtandi anyway.

Thank you for this idea.

Can I get back to docetaxel later if I need to ?

Should I start on Xofigo/Zytiga/Xtandi immediately ?

Many many thanks for your help.

Yes. There's no reason why docetaxel should not work again later, but if not, that's what cabazitaxel (Jevtana) is for. Xofigo is 6 injections, 4 weeks apart. So you can move onto Zytiga or Xtandi in about 5 months. Consider also doing Provenge during the Xofigo - I suspect it works particularly well with radiation. It's an option to discuss with your MO.

I thought Xofigo was used when the cancer had spread to the bones but not to other parts of the body ?

I have mets (last PSMA PET-CT scan on 12th October, 18) in my skull, neck, collar bone, ribs, back, lung, thighs, etc, etc.

So, wouldn't that rule out Xofigo for me ?

All the body parts you mentioned are bones. It is only ruled out for visceral mets (lung, liver, etc.)

I also have mets in the lung.

This new information (for me, at least) on Zofigo makes it imperative that I take another PSMA PET-CT scan before I start on Zofigo. What if the mets have spread to visceral areas ?

I shall definitely query my MO on Monday, 4th February as to how long I have to wait after completing my 6th cycle of chemo (on 4th Feb) before I can take a PSMA PET-CT scan.

Thank you once again for taking the time and trouble to reply to me.

If you have had lung mets, insurance probably will not pay for Xofigo

I do not have "insurance" anyway and pay for everything myself. And, when I say "everything", I mean absolutely everything.

Btw, I am an Indian citizen who lives in Bombay (Mumbai).

As far as I can tell, the only reason for the exclusion for visceral mets for Xofigo is because that's the way Bayer tested it. They knew it was only effective against bone mets, so they excluded men with lymph-node only or with any visceral mets (because they are usually deadlier than bone mets).

But Lu-177-PSMA-617 is available in India - why are you not pursuing that? It is good for bone mets, visceral mets and lymph node mets. I know there was a pilot test of Ac-225-PSMA-617 in South Africa.

Thank you, Tall_Allen.

The reason I am not pursuing Lu-177-PSMA-617 is because my MO's have not even mentioned this to me thus far. I will bring this up with them tomorrow.

Thanks again, much obliged.

I have not been able to find any hospital in Mumbai (through the Internet) that offers Lu177-PSMA-617 treatment. There is Fortis in Gurgaon though.

Could you help, please. Thank you very much.

I'm not familiar with who in India offers it. Perhaps call the All India Institute of Medical Sciences in New Delhi

I'll find out, thanks Tall_Allen.


I have two more cycles before I have the same question and answer. I will not be in any hurry that is for certain. I will probably want to wait until my PSA shows three consecutive increases before getting a second scan, but keep in mind I have lymph node metastatic so I would expect to see little on a scan with a low PSA.

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