Five months post-op and PSA is 0.142

Hi Jimmeydee. I hope you are steadily recovering from the RT side effects. Bowel issues do tend to linger. I am assuming your SRT has not included six months of HT. Otherwise your PSA would be more or less undetectable at this stage. As far as the RT is concerned it is still very early days. The radiation doesn't kill the cancer cell outright. It  damages the DNA to such an extent it can't repair and can't divide and eventually dies. The next test should start to show some results.

Thanks, Chris - fingers crossed 

Jimmy, do you know what tracer was used with your PSMA scan. My first scan was the 18f 100?, which picked up one lymph node tumor, 10 months later Gallium 68 tracer picked up the second lymph node tumor and showed some avidity in the first tumor. The G68  scan also said, no avidity shown in the prostate bed, but as we know, seeing nothing does not mean nothing is there. I did have 6 months of bicalutamide with my second SABR treatment.

My scans were at a much higher PSA  level than yours. I had the educated guess SRT, which appears to have been the right thing to do. 

It did take my PSA a lot longer than yours to rise following treatments. Near the beginning of my profile lists all my PSA results and major treatments.

Thanks Chris 

Edited by member 04 Feb 2024 at 19:09  | Reason: Bic

Lyn ,I have often given people the same advice about the 18 months result being the important one. In the situation Jimmy and I are in, is that still a valid observation. 

My PSA dropped for a while after SRT to the bed but started to rise presumably because the first lymph node had not been treated and was still growing. Again with the after treatment to the first node the PSA stalled, then shot up presumably because of the second node. 

Jamie said the next step was scan again at 1 or if the doubling time was 3 Months or less. 

Thanks Chris 

Thanks, Chris. Maybe I should have be clearer that I had SRT to the prostate bed as well as the pelvic nodes which I guess is why I currently feel in limbo with my persistent (and again rising) PSA…

It is precisely because of cell cycle / kinetics. RT kills some cancer cells immediately but not all - its purpose is to damage the DNA so that the cancer cells can't replicate. That takes 18 months to have full effect because prostate cancer cells are rather slow at dividing & multiplying.

This is what PCUK says on the website: "After radiotherapy or brachytherapy, your PSA should drop to its lowest level (nadir) after 18 months to two years. Your PSA level won’t fall to zero as your healthy prostate cells will continue to produce some PSA.

Your PSA level may actually rise after radiotherapy treatment, and then fall again. This is called ‘PSA bounce’. It could happen up to three years after treatment. It is normal, and doesn’t mean that the cancer has come back."

https://prostatecanceruk.org/prostate-information-and-support/treatments/follow-up-after-treatment#:~:text=A%20rise%20in%20your%20PSA,have%20some%20prostate%20cancer%20cells.&text=After%20radiotherapy%20or%20brachytherapy%2C%20your,18%20months%20to%20two%20years.

"Conclusions
The present results suggest that the PSA nadir level within 18 months after radiotherapy may serve as an early parameter for long-term biochemical control according to ASTRO definitions following radical dose escalation by HDR-BT for prostate cancer. Excellent outcomes were associated with nPSA18 < 0.5 ng/mL"

https://www.sciencedirect.com/science/article/abs/pii/S1538472118304355

Edited by member 05 Feb 2024 at 13:40  | Reason: to activate hyperlinks

Thanks, Lyn

Science direct link does not take to full publication so will chase it otherwise as not clear whether the groups studied included post-prostatectomy patients who did not have only localised disease. 

Interesting to note, however, that 50% of patients reached their PSA nadir by 7 months (the median) so much earlier than 18months. 

I guess cell turnover and cell dynamics must also be affected by the aggressiveness of the cells meaning faster turnover with more aggressive disease? 

As I understand things, if opting for primary de novo radiotherapy (so intact prostate) then, yes, it can take considerable time to reach post R/T nadir. Even so, according to the truncated version of the linked article, 50% of men hit their nadir 11 months ahead of the magical 18 month mark. Or have I got that all wrong?!! Need to read the full article, I guess…