Any stories of hope?

I had two years of HT, six months prior to the RT, and 18 months after. I won't pretend I know exactly how it helps, I can give you a plausible theory. The first thing to know is that every cell in a human whether male or female starts off pretty much the same. They then have to differentiate in to different organs etc. Cells will only develop into prostate cells if there is testosterone present.

Whilst on HT, testosterone is suppressed, and the prostate cells think "I'm not sure I should be here", so they are reluctant to divide and indeed some will die. Competing with this is the cancer mutation saying carry on dividing whatever.

Your immune system does fight cancer, and I presume with the cancer cells now reluctant to divide there is more of a chance of them falling victim to the immune system.

Some cancer cells will be so aggressive that they divide even without testosterone and eventually from a small start these become the dominant strain and HT is no longer effective.

So whilst HT is not enough to wipe out cancer it can slow it down, so that when RT is used the cells aren't able to reproduce faster than they are being killed.

So if there are micro mets outside of the RT target zone, I don't think they will be eliminated, though the immune system may knock out a lot of the cells during that time.

So the main treatment may knock out half a million prostate cancer cells, but there may be a thousand left in micro mets. It can take a year for a cancerous prostate cell to divide. So after a year you now have two thousand cancer cells in the body, and another year 4000 cells, then 8000. but it probably needs a million cancer cells before you have problems and because prostate cancer is so slow going that is going to take about ten years.

Now we all hope all of our cancerous cells have been zapped or cut out, but if one was left behind in a year it will be two, in ten years it will be a thousand, and in 20 years a million. So the more effective the treatment the longer you have got, and if it did get all the cancer cells you really are cured. As long as I've got enough time free from serious cancer to find a more fun way of dying it doesn't matter.

Anyone fancy a bungy jump.

Edited by member 11 Jan 2022 at 01:22  | Reason: Not specified

The lifetime dose applies to a particular piece of body tissue. If you have prostate treatment, they give the max lifetime dose to prostate tissue, with the intention of killing the cancer, but not destroying the prostate - you would have horrendous, possibly fatal problems if your prostate was rendered necrotic (i.e. sufficient cells died that the body can no longer supply blood to it or fight infection in it). However, other tissues around will have a significantly reduced dose, and further away, no dose at all. Those can be treated later if necessary. For tissues close to the prostate, they will have had some dose and that means they can have some more, but limited, in some cases possibly not enough for further treatment.

As for what the max dose is, I don't know how that's measured. The measurement of radiation absorbed by tissue is the Gray (Gy), and this is used for treatment dosing. However, the max lifetime dose of Gy is not one specific number - it depends on the period over which it's administered. For example, when administered at a low rate over a long time such as LDR brachytherapy over about 200 days with Iodine 125, the dose is typically 170Gy. At the other end of the spectrum, treatment with HDR brachy over 2 fractions a couple of weeks apart, 30Gy is roughly equivalent, and in between we have EBRT over 37 sessions at 74Gy, or EBRT over 20 sessions at 60Gy, all being roughly the same max lifetime dose. (Actually, this is not quite true - external beam is more limited in dosing due to avoiding damage to the tissues it passes through, whereas brachytherapy can deliver a higher targeted dose to the prostate because the radiation doesn't need to pass through other tissues and the prostate can handle, and even benefits from, a higher dose than many other tissues.)

When planning second and subsequent radiotherapy treatments, a key factor is, can a sufficient dose be delivered to the target area without any tissues (the target, or other tissues the beam needs to pass through to get to the target, known as Organs At Risk) exceeding their max lifetime dose.

There is also the thought that some time later well after full recovery from radiotherapy, it might be possible to add a little more in an area which had max lifetime dose, but this isn't much used as yet in treatments. One well recognised oncologist said in a lecture I attended that we need to get braver in trying this.

Not always- PSA should fall significantly but it doesn't really matter whether it falls to 1, 0.1 or 0.01.

You won't have much idea of whether the RT was successful for another 18 months as the RT carries on doing its work for at least that long. If his PSA is still around 2.0 in 5 years time, the onco will say it was probably a success.

Edited by member 07 Feb 2022 at 18:40  | Reason: Not specified

Yes I had HDR brachy (not the more common seeds). I just did whatever the doctors thought best. Two years of hormone therapy was not much fun, but all in all the treatment isn't too bad. Side effects like incontinence and erectile dysfunction are unlikely with RT. 

Survival rates are what you are probably most interested in. Well the chance of prostate cancer killing him in the next five years are very small. The chances of him being around in 15 years are probably about 50/50. 

These odds are based on the limited information we have so far. The only way you get better information is by living longer and knowing how long you've been cancer free. Hence my statement about telling you what the future holds when I get there.

Best wishes,

Chris

Hermit

The G is a predictor of risk but not a cert.