MRI & G68-PSMA

On August 7, a whole body MRI found a lesion at T6 and the report said”possible metastatic”. My MO ordered another MRI for the spine only on August 29 and the report said:
“Since August 7, 2018, unchanged subcm T6 lesion that possibly represents an atypical hemangioma versus metastasis. CT may be helpful to evaluate bony matrix, oradditional follow up MRI.”

I am scheduled to do a G68-PSMA in 10 days from now and also applied for the 18f-DCFPYL at NIH at end of year.
My question is: is it worth it to do the psma scan now or may be better wait to end of year where psa probably will be higher and the possibilities of finding something will also be higher? Considering my PSADT is 5.5 months now.

Thank you

As Bobby Mac wrote, chances are very low, that you will locate the met with a PSMA PET/CT now. Also, if you determine it is a met, what will you do with this knowledge? Probably just wait till the PSA value gets so high that you will want to start with ADT.
So you may just wait until the PSA value gets above 2.0 - then the PSMA PET/CT will work very well. Same with the 18f-DCFPYL PET/CT.

Why not do a bone scan? As long as that is negative, you could choose observation.

George

There is no confirmed metastasis so I would hold off on chemo -

If the cancer is only in the nodes there is a chance of cure!
With your PSA level the PSMA scan has about a 50% chance of picking up hot spots.

You need to decide if it is worth while to get the psma scan.

Bobby Mac

I have a rather unusual case.

I was diagnosed in a biopsy in March 2011 with Gleason 3 + 3 cancer that was treated with brachytherapy in June 2011. My PSA of 3.4 just before the biopsy went down to 0.1 by June 2012. Then my PSA started rising from December 2013, first slowly and then more rapidly to reach 1.5 by July 2016.

A second biopsy found a large extra capsular cancerous mass in September 2016. No cancer inside the prostate was found. So, I had cyberknife plus ADT to treat the extra capsular cancer. From April 2017 to January 2018, my PSA remained undetectable. Then a rapid rise: Apri 6: 0.2, July 13: 0.9, August 28: 1.3. PSADT is 1.73 months.

According to my URO and also my opinion that ADT is in my future. But the question is when. The very short PSADT is troubling. I am scheduled for an Axumin PET/CT scan on October 12. I am also planning to see a medical oncologist soon after that scan for second opinion. If the scan finds something suspicious, then treatment option will take some concrete shape. if it turns out to be negative, then what? Should I wait for PSA to rise further? Or in view of the short PSADT, start ADT soon.

As yet I do not really get why a short PSADT requires an early start of ADT. Yes, it indicates that you are a high-risk patient and you should measure the PSA value more often than usual. But in the end, you just reach the PSA value, which you use as a trigger to start ADT, earlier. As I see it, this should be 10 ng/ml as I already explained.

I did radiate my mets after a PSMA PET/MRI with SBRT to delay progression. This is not as easy as it may sound. The PSMA PET report describes the locations of the mets but the RO may not find these when he is looking at his planning CT. He does not have a PSMA PET/CT.
I think it only makes sense to use SBRT radiation. An IMRT radiation stretching over 45 days with the risk of side effects, just to delay the progression by about a year, is too much effort I think.
Then, if you have bone mets you have to find an RO who is ready to radiate these with SBRT using a dose of 3x10 Gy or similar. The common radiation with IMRT is palliative to treat bone pain and will not destroy the mets.
Finally the mets may recur at locations difficult to radiate.

As an alternative you can choose an extended LND. But the surgeon uses a standard template for selecting the lymphnodes to remove and may miss the met you saw on the PSMA PET. This is not unusual.

In spite of all this, I will try to radiate recurring mets again with SBRT.

George

Going for brachy:

You just cannot trust the Gleason score that is determined with a biopsy. Just a few days ago I read this patient profile: Gleason 3+3 after biopsy and Gleason 4+4 after surgery. At a conference I heard that up to 50% of all Gleason scores are upgraded after surgery. All you can do now is send the biopsy results to Epstein and see if they come up with a different opinion. This is still possible since they have to keep the samples for years to allow for a second opinion. If e.g. a 4+4 cancer lesion within the prostate has not been hit during biopsy, Epstein cannot find it as well though.

The only reason for the rise of the PSA value I can think of are metastases. If these cannot be located you have to start with ADT. My opinion, based on the Crook study, is that you can wait for 10 ng/ml. But your doctor probably has a different opinion. You get the side effects, not your doctor.

George

AK123,

you wrote: "Is it safe to wait until January to sort these things out before starting ADT?" For me this means you plan to do the 18f-DCFPYL PET/CT and then start ADT. That is why I said the 18f-DCFPYL PET/CT is not required if you start with ADT anyway.

If you have mets you can start with ADT as the guidelines and Tall Allen recommend. Or, if you have done a 18f-DCFPYL PET/CT or Ga-68 PSMA PET/CT and see the location of the mets, try to remove these mets and, since removing the mets will usually lower your PSA value, live for some time without ADT since you consider your PSA value too low to start with ADT.

You can remove the mets with SBRT radiation, IMRT radiation or extended LND. I discussed these alternatives in detail.

You can also remove the mets and combine that with ADT so new mets will not appear quickly.

ADT will not minimize the disease burden, it just stops the tumor to progress for some time. It makes mets shrink too. It may destroy micromets, but you cannot prove that because you cannot see nor count micromets. But on the average ADT will work for two to three years and then you will become resistant.

Whether you choose ADT or destroying mets is up to you. Your current PSA value does not require to start ADT now, I disagree with your doctor on that. You can wait for a PSA value of 2 ng/ml which will provide good results with a 18f-DCFPYL PET/CT or Ga-68 PSMA PET/CT.

The 18f-DCFPYL PET/CT or Ga-68 PSMA PET/CT imaging are very new and so there are no long-term studies available whether to treat the visible mets or go for ADT only. You have to do what you think is beneficial for you i.e. apply common sense.

George