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 00:22
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Yeah, pretty much same diagnosis and same treatment. Sure I'm only four years down the line, all good at the moment. Who knows what the future holds, I'll tell you when I get there.
Click on my avatar to see profile.
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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.
User
Tony was diagnosed at age 61 with G9 T3b hia score was 4 + 5, and told his cancer was really aggresive and he would die of it, he is now 77 and will be 78 in november, Tony had HT and RT same as your dad to start with and after a few years of HT he went on it only if his PSA went up above a certain level, the HT stopped working in 2017 and he has been on a few treatments since then, including chemo in 2018 and more RT. Even after the chemo Tony has lived a completely normal life with no problems up until 2019 when he started to get a bit weaker but he was diagnosed with kidney disease about 10 years ago and a lot of his problems are to do with this, he is now on Dialysis 3 times a week. Sice his diagnosis of cancer he has been on many holidays all round the world and up until 2018 he was playing golf twice a week and the gym 3 times a week.
I hope this gives you hope
regards Barbara xx
Edited by member 18 Jan 2022 at 12:08
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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 17:40
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"Life can only be understood backwards; but it must be lived forwards." Soren Kierkegaard
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Hi,
One of the measures of hope is that he's having radiotherapy. Some people just have hormones which is more palliative. The doctor's must believe there is hope.
Another measure is what you mean by hope. Some people think it's going to be quick when for most it takes a long time and there are several treatment options with new ones appearing every year.
All the best, Peter
User
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.
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Hi similar diagnosis Nov 2020 37 lots off radiotherapy half way through 2 years off hormone therapy PSA down from 24.9 now 0.01 and feeling fine 6 monthly PSA checks see how we go so far so good gaz
User
He's presumably having curative treatment? In that case he gets treated and he gets on with his life. Localised prostate cancer is an eminently treatable condition. I'm not sure what it is you're hoping for? I had RT three years ago. Life is good.
Best wishes,
Chris
User
Well said Chris it's true have your treatment and plod on glad to hear you are doing well gaz
User
When I went in to see the consultant after choosing my treatment path, I was asked to sign the paperwork. Looking through it, under 'Reason for treatment' he had written one word - 'Curative'. When I asked him about this, he just said, 'Yes, we are going to cure you'. That just filled me up with hope. And so far, so good - two years on, PSA less than 0.04.
Hermit
User
Well I'm glad you are 8 years post breast cancer (well not the getting it bit). If you have dealt with cancer you know the future is uncertain, but you can still get on with life.
I agree with Chris that I have never heard of brachy after RT.
It may be possible, the lifetime dose is about protecting organs at risk. Brachy has a very short range, a few millimetres, and if you have cancer in prostate which is not a very important organ in an older man, it may be you can give it a lot of short-range radiation. I have no evidence for the above, but it sounds plausible to me.
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No - the Gleason score is the total of the two Gleason grades - they look at the cells under a microscope and give them a score from 1 - 5 with 1 being normal and 5 being the most distorted / deformed. They decide which is the most prevalent pattern (let's assume that in your dad's case, the majority of cells are a 4) and then the second most prevalent pattern (in your dad's case a 5). Add the two Gleason grades together to get the score - G9. The higher the G score, the more aggressive a cancer might be but it isn't a given - a man can have G10 but a small tumour and achieve full remission, or he can have a G6 (the lowest score you can have for prostate cancer) but it has spread (rare but possible). He can have a G9 (5 + 4) and no mets or a G9 (4+5) and incurable or a G7 but a rare type of prostate cancer that does not respond to any treatment.
The G is a predictor of risk but not a cert.
"Life can only be understood backwards; but it must be lived forwards." Soren Kierkegaard
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Dear Barbara
Thank you so much for your lovely message. This really means a lot. It is so lovely to hear that you have been able to go on holidays together and continue to enjoy your lives despite this diagnosis. That is very inspiring and I am slowly changing the way I have been thinking about everything and your message has certainly helped me a lot. I really wish you all the best. Tony sounds like an incredible man!
K xx
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Yeah, pretty much same diagnosis and same treatment. Sure I'm only four years down the line, all good at the moment. Who knows what the future holds, I'll tell you when I get there.
Click on my avatar to see profile.
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Thank you for your reply.....it helps to know there is hope! Did you do Brachytherapy? He chose not to do it.
User
Hi,
One of the measures of hope is that he's having radiotherapy. Some people just have hormones which is more palliative. The doctor's must believe there is hope.
Another measure is what you mean by hope. Some people think it's going to be quick when for most it takes a long time and there are several treatment options with new ones appearing every year.
All the best, Peter
User
It's difficult if you can't talk to him about it. Maybe you could suggest he has a look at this forum?
I was in a similar position ... Gleason 9 with some stray mets in the vicinity of the prostate. Treated by preliminary hormone therapy, followed by radiotherapy and now I'm following up with 2 or 3 years of hormone therapy. Post RT and for the duration of my HT up until now I've had a psa reading of .01 which could not be better.
The treatment is not easy but there's no reason not to have hope, though I suppose it's a choice in a way. Most of us here don't know what the next few years might bring but after the initial shock it's quite possible to re-set a life both in the interest of the person suffering PCa and for everyone around them.
Jules
User
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.
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Hi similar diagnosis Nov 2020 37 lots off radiotherapy half way through 2 years off hormone therapy PSA down from 24.9 now 0.01 and feeling fine 6 monthly PSA checks see how we go so far so good gaz
User
He's presumably having curative treatment? In that case he gets treated and he gets on with his life. Localised prostate cancer is an eminently treatable condition. I'm not sure what it is you're hoping for? I had RT three years ago. Life is good.
Best wishes,
Chris
User
Well said Chris it's true have your treatment and plod on glad to hear you are doing well gaz
User
When I went in to see the consultant after choosing my treatment path, I was asked to sign the paperwork. Looking through it, under 'Reason for treatment' he had written one word - 'Curative'. When I asked him about this, he just said, 'Yes, we are going to cure you'. That just filled me up with hope. And so far, so good - two years on, PSA less than 0.04.
Hermit
User
Thank you once again for your reply Dave. He has chosen not to have seed implants - I am in a difficult position because I don´t think he is really aware of how helpful these could potentially be. I don´t know if I should talk to him about this (like you, I like to research treatments etc...I myself have had a very aggressive breast Cancer at the age of 32 and I am 8 years out and all seems to be well but I will never say I am cured because I never know what will happen..but I researched a lot to make sure I was choosing the best options with regard to treatment). I am worried that I may scare him... he is just getting on with his life and enjoying it. However, I also feel that maybe he should know about my concern regarding this treatment? - He has had his radiation but was told he could have the seed implants later if he changed his mind or the RT/HT was not enough.
50/50 chance is what I figured too....well using old technology/statistics etc....so probably higher now....I hope :)
User
Thank you everyone for your quick, useful and kind responses. They are all very encouraging and helpful :)
User
Are you sure about that? RT generally gives you your “lifetime dose”, and it’s not possible to have any further radiation to the prostate region. I’ve never heard of anyone having brachytherapy after RT!
Best wishes,
Chris
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I might be wrong about that. I thought that is what he told me but thank you so much for pointing that out to me. I wanted to speak about this to him but I definitely won´t if it is indeed no longer an option after the initial treatment. Thank you Chris!
User
Well I'm glad you are 8 years post breast cancer (well not the getting it bit). If you have dealt with cancer you know the future is uncertain, but you can still get on with life.
I agree with Chris that I have never heard of brachy after RT.
It may be possible, the lifetime dose is about protecting organs at risk. Brachy has a very short range, a few millimetres, and if you have cancer in prostate which is not a very important organ in an older man, it may be you can give it a lot of short-range radiation. I have no evidence for the above, but it sounds plausible to me.
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Thank you very much Dave. I am going to look into this more. I also have a question regarding hormone therapy. I had hormone therapy after breast cancer to deal with possible micro-mets left after chemotherapy. For prostate cancer, is hormone therapy given to starve micro-mets in a similar way with the hope of inhibiting their growth?
Thank you once again and best wishes to you.
User
Chris and Gaz - the funny thing is...this is exactly what my father is doing! Just carrying on with life as normal and enjoying it. I need to learn from him!!!
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Thank you also Peter, Jules and Hermit for your encouraging words :)
User
In a similar situation to your father, though with a lower psa, brachytherapy was not offered or recommended as an option to me. It might be that he's not missing out on a useful form of treatment and the RT on its own is considered to be perfectly adequate.
The mets ... You haven't said if they're local or elsewhere in his body. Some forms of RT now will target local mets in the same round of treatment that deals with prostate BUT this apparently varies depending on where the treatment is delivered.
Also on mets ... my understanding is that the HT will starve the micro-mets but it will not get rid of them. This is an important point and somebody else here might care to comment, given the importance of mets for your father, in the future.
Jules
User
Originally Posted by: Online Community Member
The mets ... You haven't said if they're local or elsewhere in his body. Some forms of RT now will target local mets in the same round of treatment that deals with prostate BUT this apparently varies depending on where the treatment is delivered.
Also on mets ... my understanding is that the HT will starve the micro-mets but it will not get rid of them. This is an important point and somebody else here might care to comment, given the importance of mets for your father, in the future.
Jules
I think you have misread it microcolei - I don't think K has said that her dad has mets?
"Life can only be understood backwards; but it must be lived forwards." Soren Kierkegaard
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A very quick reply
My husband had similar initial diagnosis. He lived with prostate cancer for over nine years and during that time he had several different types of treatments. We did lots of things during that time and enjoyed life as much as we could. Sadly his final treatment of chemotherapy did not work but there is always hope and new treatments coming all the time. Live every day and don't put things off - it is not the things you do that you regret but the things that you don't do.
Never give up hope.
User
Originally Posted by: Online Community MemberThank you very much Dave. I am going to look into this more. I also have a question regarding hormone therapy. I had hormone therapy after breast cancer to deal with possible micro-mets left after chemotherapy. For prostate cancer, is hormone therapy given to starve micro-mets in a similar way with the hope of inhibiting their growth?
Thank you once again and best wishes to you.
Breast cancer & prostate cancer are related but the treatments are not directly comparable. In breast cancer cases, the person can have lumpectomy, mastectomy, radiotherapy and, depending on the staging and type, chemo. Most who have needed chemo will also be advised to have HT in case there are micromets. In prostate cancer, most men on RT or brachytherapy will have HT as well, not to mop up micromets but to starve the prostate cancer while the RT does its job. Prostate cancer cells divide very slowly in comparison to other cancers - the RT doesn't cause much damage to the PCa cells at the time and does most of its work over the next 18 months. The HT starves the cancer for that 18 months.
It is fairly normal for men on a curative pathway to be offered surgery, brachy or external RT. Your dad may or may not have been offered surgery but between brachy & EBRT, it seems he chose EBRT and he no doubt had reasons for doing so. Men with extensive PCa might be offered combined brachy / EBRT but the brachy always comes first - it doesn't sound like your dad falls into that group. It is good that he is getting on with his life - that is how people survive cancer, as you have found out yourself. Little point questioning the choices that he made - it would be like someone questioning whether you were right to choose the route that you took.
"Life can only be understood backwards; but it must be lived forwards." Soren Kierkegaard
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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 00:22
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Hello Dave...I have to admit I am really struggling with my father´s diagnosis. I want to be optimistic but I am finding it hard to be at this moment in time. I am not able to talk to anyone about this so this support group is amazing. I wanted to ask you where the statistics you gave me come from. Are there any papers you could recommend me looking at? I know that every individual is different. This is just how I deal with these things. I did the same when I was diagnosed. Knowing as much as possible helped me.
Thank you so much and wishing you all the best. K
User
Hi Katherine,
At the top of this thread is a link to a future learn course on cancer
https://community.prostatecanceruk.org/posts/t9929-Online-Cancer-Courses
My prediction on life expectancy are based on this
https://prostate.predict.nhs.uk/
If you look at the survival curves and find how many years till you have a 50% chance of survival then this is what a statistician would call median life expectancy.
The 1 year to divide (or doubling time) is based on 400 days. Mentioned in this thread.
https://community.prostatecanceruk.org/posts/t27371-PSA-level-query
Not too sure where the figure came from, but it does fit in with the expected growth of prostate cancer.
The rule for doubling is: 2,4,8,16,32,64,128,256,512,1024 this is exponential growth conveniently these figures are common in computers so i am very familiar with the numbers. Basically 1000 times the original figure every 10 years.
To say that 1 million cells is the threshold for prostate cancer to become troublesome is not precise it is based on the observation that prostate cancer kills after about 10 to 15 years. And I'm assuming a man starts with one cancer cell, if he starts with 10 then the fatal dose of prostate cancer cells would be 10 million. The exact figures on a cellular level are not important ,it is important that the timescales are realistic.
My opinions on when and if a cancer needs treatment are based on this video.
https://www.google.com/search?q=med+life+crisis+screening&client=ms-android-sonymobile-rvo3&prmd=nisxv&source=lnms&tbm=vid&sa=X&ved=2ahUKEwi2ouXI0ar1AhXRTMAKHZvHAcYQ_AUoBHoECAIQBA&biw=412&bih=832&dpr=2.63#fpstate=ive&vld=cid:7e83d768,vid:yNzQ_sLGIuA,st:0
Hope all the above helps, I tend to geek out on information when I need to get to grips with things.
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Yes, my error, I'd been wondering about a more complete diagnosis of Katherine's father's condition but I shouldn't have assumed mets would be present.
Jules
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Hello. Yes....there was no evidence of mets in the MRI at the time.
K
User
Thank you so much Dave. I am not a mathematician by any means but I think I understand it. My flatmates are maths teachers so they can give me a little lesson if I need more help with understanding it! Anyway, this really means a lot. Having the facts helps me.
I was 32 when I was diagnosed with my really aggressive breast cancer....yet I don't worry about that at all...I finished my Zoladex and hormone therapy last year (I am now 38) and honestly hardly think about it all....even though it could come back anytime. But when it comes to my father....I am in pieces. I will learn to live with it. It will just take time.
Thank you once again for your comforting response.
K
Edited by member 11 Jan 2022 at 22:37
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I totally agree with you LynEyre... When I heard that it was a high grade cancer (gleason9) I assumed this meant that it was growing at a really fast rate.... So my breast cancer was (Her2+) and I think I have been trying to make too many comparisons between two completely different types of cancers. I am just not that well informed about prostate cancer.
K
Edited by member 11 Jan 2022 at 22:38
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Hello Gillyflower.... am so sorry about your loss. Thank you for using your experience to help support me. This gives me hope.
K
Edited by member 11 Jan 2022 at 22:39
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That's great!
As you say, it's harder to deal with the reality of someone close to you having cancer than it is to deal with your own cancer. I hope the strength you gained from dealing with your own cancer helps in some way to deal with your father's.
Jules
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No - the Gleason score is the total of the two Gleason grades - they look at the cells under a microscope and give them a score from 1 - 5 with 1 being normal and 5 being the most distorted / deformed. They decide which is the most prevalent pattern (let's assume that in your dad's case, the majority of cells are a 4) and then the second most prevalent pattern (in your dad's case a 5). Add the two Gleason grades together to get the score - G9. The higher the G score, the more aggressive a cancer might be but it isn't a given - a man can have G10 but a small tumour and achieve full remission, or he can have a G6 (the lowest score you can have for prostate cancer) but it has spread (rare but possible). He can have a G9 (5 + 4) and no mets or a G9 (4+5) and incurable or a G7 but a rare type of prostate cancer that does not respond to any treatment.
The G is a predictor of risk but not a cert.
"Life can only be understood backwards; but it must be lived forwards." Soren Kierkegaard
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Originally Posted by: Online Community MemberNo - the Gleason score is the total of the two Gleason grades - they look at the cells under a microscope and give them a score from 1 - 5 with 1 being normal and 5 being the most distorted / deformed. They decide which is the most prevalent pattern (let's assume that in your dad's case, the majority of cells are a 4) and then the second most prevalent pattern (in your dad's case a 5). Add the two Gleason grades together to get the score - G9. The higher the G score, the more aggressive a cancer might be but it isn't a given - a man can have G10 but a small tumour and achieve full remission, or he can have a G6 (the lowest score you can have for prostate cancer) but it has spread (rare but possible). He can have a G9 (5 + 4) and no mets or a G9 (4+5) and incurable or a G7 but a rare type of prostate cancer that does not respond to any treatment.
The G is a predictor of risk but not a cert.
Thank you for clearing this up - this makes sense now - it is all rather confusing at first.
User
Good evening. I have another question....perhaps someone might know the answer....
If you have radiotherapy to tye prostate for your initial treatment and then have a recurrence in the pelvic lymph nodes, can these nodes then receive radiation? (given that the initial radiation was only to the prostate?). I think this is sometimes done in the USA but I am not sure about the UK....
Thank you for your help...once again
K
User
If they thought there was any possibility of spread to the lymph nodes, they'd irradiate the whole pelvic region, not just the prostate. That's the treatment I had, because my PSA was anomalously high for the cancer the biopsy found, and there was a concern about undetectable "micromets" in the lymph nodes.
Best wishes,
Chris
Edited by member 14 Jan 2022 at 22:41
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The order of the two doesn't matter (Mount Vernon does the EBRT first, and the HDR brachy immediately afterwards, or sometimes just before the EBRT finishes). What is significant is that if you're having both, they're both half-doses (roughly speaking), so you still don't exceed the max lifetime dose in the prostate. In practice, it does allow a higher dose (boost) to the prostate without the extra collateral damage that would be done if this was attempted with external beam alone.
You can have them both with LDR brachy, but that's rarer and I'm not sure the protocol in that case.
The combined EBRT and brachytherapy is called Brachytherapy Boost (or HDR Boost). It tends to be beneficial for high risk local or locally advanced prostate cancer where there's a recognised risk of micro-mets in pelvic lymph nodes, but not if any lymph node mets are actually identified in scans.
User
Andy, can you give us a figure for the max lifetime dose and are you saying that it's still ok to use RT in other areas if the max dose has been reached in the prostate?
Jules
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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.
User
Thanks Andy, most informative.
Jules
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This is amazingly helpful Andy! Thank you very much
Originally Posted by: Online Community MemberThe 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.
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Tony was diagnosed at age 61 with G9 T3b hia score was 4 + 5, and told his cancer was really aggresive and he would die of it, he is now 77 and will be 78 in november, Tony had HT and RT same as your dad to start with and after a few years of HT he went on it only if his PSA went up above a certain level, the HT stopped working in 2017 and he has been on a few treatments since then, including chemo in 2018 and more RT. Even after the chemo Tony has lived a completely normal life with no problems up until 2019 when he started to get a bit weaker but he was diagnosed with kidney disease about 10 years ago and a lot of his problems are to do with this, he is now on Dialysis 3 times a week. Sice his diagnosis of cancer he has been on many holidays all round the world and up until 2018 he was playing golf twice a week and the gym 3 times a week.
I hope this gives you hope
regards Barbara xx
Edited by member 18 Jan 2022 at 12:08
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Dear Barbara
Thank you so much for your lovely message. This really means a lot. It is so lovely to hear that you have been able to go on holidays together and continue to enjoy your lives despite this diagnosis. That is very inspiring and I am slowly changing the way I have been thinking about everything and your message has certainly helped me a lot. I really wish you all the best. Tony sounds like an incredible man!
K xx
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Hello. My father has had his first psa test since finishing radiotherapy in december and he is on hormone therapy....his psa is undetectable. My question is, do psa levels always drop to undetectable levels post RT and whilst on hormone therapy? I am also aware that we won't really know how effective the treatment has been until he comes off the hormone treatment. Thank you once again for your help and support! K
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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 17:40
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"Life can only be understood backwards; but it must be lived forwards." Soren Kierkegaard
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Thank you Lyn. I guess the psa will rise after the HT stops because he still has a prostate.