PSA results following SBRT treatment

Hi Rudge4cc4c0 I had SABR (which I understand is the same) last year. All my treatments and stats are in my profile, Just click on my name or Avatar.  Any questions please come back to us.

Hello  Rudge

As far as I am aware- I’ve been wrong before - but with ALL types of Radiotherapy you reach the nadir or lowest reading after 18 months. Indeed in the first couple of months you can get PSA bounce where the PSA rises.

Best wishes - Brian.

Thanks for the reply.

Yes I understand that the nadir level is reached some 18 to 24 months after the treatment has finished.

However, from what I understand the most dramatic drop in the PSA is usually in the first 6 to 8 weeks when one would normally see a drop of some 40% to 50%  from the pre treatment reading, which is not what has happened in my case, which raises concern.

Hence seeing if there there are some here who have had SBRT and can provide their own experience for comparison?

Accepted that individually we will all response to the various treatments in different ways, but when the medium is around a 40% to 50% fall and yours is only around 12% it tends to raise ones concern.

Hi Rudge

Wow, that's the longest I've seen anyone on AS for and still with a lowish PSA after that time.

Just as a matter of interest do you know what the tumour size was at the beginning and then after 10 years.

In answer to your question unless SBRT differs a fair bit to other Radiotherapy types I would say the fall was a bit disappointing.

You would  expect a larger drop although as it is low anyway didn't have much to drop to.

I think just wait and see what further PSA says, I should add that when I had my first PSA after Radiotherapy it was 6 months so it does seem yours is a bit early .

Best wishes 

Steve 

For the first 4yrs the MRI scans only gave dimensional size of the lesion and not volume. When it was first given as a volume as well it was 0.55cc, but looking back based on the previous dimensions it would have been around the same 0.5cc volume initially.

It was 0.84cc prior to treatment with a total of 8% G4 grade prior to treatment from the bi-ops dome.

No. not cc but mm, actual length of tumour 

Just to give an example  my tumour started at 3mm and over 4 years on AS went up to 13mm

Steve 

Lesions/tumors are 3 dimensional, so just looking at one dimension would be misleading because whilst one dimension my increase the others may reduce such that the overall volume remains much the same?

It's the overall size/volume which I believe is relevant not just one dimension?

I know what you are saying but have always considered size in mm means a good deal, not perfect but does give a good idea.my earlier post about my own tumour going from 3mm to 13mm in 4 years.

Mm can also give a reasonable idea about proximity/nearness to capsule edge

Perhaps an expert may come on at some point

Best wishes 

Steve 

I'm assuming that you have had repeat bi-ops as the apparent size has increased which is the most relevant and important criteria?  

This all nearly 10 years , no I refused a second biopsy but did go ahead with Radiotherapy.

Steve