Anyone had proton therapy after prostatectomy?

Posted by alexperic @alexperic, May 16, 2025

Has anyone had proton therapy after prostatectomy .

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Profile picture for heavyphil @heavyphil

Hey Brian, As usual I am looking thru the narrow lens of my own experience with IMRT 5 yrs after surgery.
From what I understand ( and I could certainly be wrong) proton radiation is usually given as ‘adjuvant salvage’ radiation immediately after surgery when there are known metastases directly outside the prostate bed or in the pelvic nodes.
These areas can, of course, be targeted and proton therapy is very effective at treating them and causing minimal peripheral damage. However, in cases such as mine, with rising PSA 5 yrs post-op and NO visible activity on PSMA I do not believe proton therapy would be as effective; there are targets (bed and nodes) but the radiation beams produced by proton radiation vary in intensity from the center (strongest) to the periphery (weakest) and you may overtreat one part of the target and undertreat the other.
IMRT offers more consistency thru its arc - which ironically is both its strongest and weakest points: it will fry everything evenly, but do more damage to other organs on the way in - and out!
It would be interesting to know if the men you met were in the adjuvant salvage or late salvage stage. Thanks for the post!
Phil

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hey guys,

is there any mention of 'salvage' side effects? 'late' salvage OR 'adjuvant' salvage? Is continence and erectile function pretty much gone at that point???? can they get precise enough with salvage to avoid some of the nerves etc? with proton or photon?
if proton is used now for late salvage and can be precise enough, that might be a great reason to choose it................

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I had proton therapy on the prostate bed after prostatectomy due to the finding of local recurrence. This was followed by a approximately tenfold decrease in PSA to 0.4, but later the PSA started to increase again. Over the next 3 years, the PSA continued to rise, but repeated PET/CT PSMA examinations found nothing. Now my PSA is 5.6 and I will probably have another PET/CT PSMA. And then we will see, or maybe not again...

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Profile picture for ivan222 @ivan222

I had proton therapy on the prostate bed after prostatectomy due to the finding of local recurrence. This was followed by a approximately tenfold decrease in PSA to 0.4, but later the PSA started to increase again. Over the next 3 years, the PSA continued to rise, but repeated PET/CT PSMA examinations found nothing. Now my PSA is 5.6 and I will probably have another PET/CT PSMA. And then we will see, or maybe not again...

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The pet scan can’t see metastasis smaller than 2.5 mm And the UCSF radiologist says even 5 mm is tough to see. That may be your problem. Some doctor say just wait until you can see it and then zap it. That works for some people.

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Profile picture for matthewdore @matthewdore

hey guys,

is there any mention of 'salvage' side effects? 'late' salvage OR 'adjuvant' salvage? Is continence and erectile function pretty much gone at that point???? can they get precise enough with salvage to avoid some of the nerves etc? with proton or photon?
if proton is used now for late salvage and can be precise enough, that might be a great reason to choose it................

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Could come down to sparing nerves or killing the cancer. I choose killing the cancer.

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Profile picture for jeff Marchi @jeffmarc

The pet scan can’t see metastasis smaller than 2.5 mm And the UCSF radiologist says even 5 mm is tough to see. That may be your problem. Some doctor say just wait until you can see it and then zap it. That works for some people.

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That may be the case, but in order to produce a PSA of 5.97, there would have to be probably a lot of small metastases, which I obviously would not want. The second possibility is that the recurrence in the prostate bed has returned, or rather, that the previous PT did not completely destroyed it. Incidentally, each of the three previous PET/CT PSMA scans showed several small lymph nodes in the pelvic area as possible micrometastases. However, their condition did not change over the years (size still max. 5 mm, SUV max. 3), while the PSA continued to rise. So it didn't make sense that these tiny nodes were the "culprits."

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Profile picture for ivan222 @ivan222

That may be the case, but in order to produce a PSA of 5.97, there would have to be probably a lot of small metastases, which I obviously would not want. The second possibility is that the recurrence in the prostate bed has returned, or rather, that the previous PT did not completely destroyed it. Incidentally, each of the three previous PET/CT PSMA scans showed several small lymph nodes in the pelvic area as possible micrometastases. However, their condition did not change over the years (size still max. 5 mm, SUV max. 3), while the PSA continued to rise. So it didn't make sense that these tiny nodes were the "culprits."

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I know it’s a difficult situation. The thing is, the PSA is being Produced by metastasis somewhere. If they can’t be seen, then they’re too small, or too new. It is somewhat unlikely that they are in your prostate bed that that’s where the PSA is coming from.

Some of the doctors like to wait until the metastasis show up and then zap them even though the PSA is rising. They feel that that takes care of the problem And you’ve already had salvage radiation so there really aren’t A lot of other options. Yeah, those SUV Max 3 guys are not exactly the culprits, they’ve grown up!!!

Hopefully, your next PSMA PET scan will find something.

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Profile picture for ivan222 @ivan222

That may be the case, but in order to produce a PSA of 5.97, there would have to be probably a lot of small metastases, which I obviously would not want. The second possibility is that the recurrence in the prostate bed has returned, or rather, that the previous PT did not completely destroyed it. Incidentally, each of the three previous PET/CT PSMA scans showed several small lymph nodes in the pelvic area as possible micrometastases. However, their condition did not change over the years (size still max. 5 mm, SUV max. 3), while the PSA continued to rise. So it didn't make sense that these tiny nodes were the "culprits."

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This is why all SRT now targets the nodes. You can ‘see’ some nodes have cancer, but others probably have it too.
Cumulatively, they could add to the PSA bring what it is. Why not zap the nodes and see what happens?
Phil

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Profile picture for jeff Marchi @jeffmarc

I know it’s a difficult situation. The thing is, the PSA is being Produced by metastasis somewhere. If they can’t be seen, then they’re too small, or too new. It is somewhat unlikely that they are in your prostate bed that that’s where the PSA is coming from.

Some of the doctors like to wait until the metastasis show up and then zap them even though the PSA is rising. They feel that that takes care of the problem And you’ve already had salvage radiation so there really aren’t A lot of other options. Yeah, those SUV Max 3 guys are not exactly the culprits, they’ve grown up!!!

Hopefully, your next PSMA PET scan will find something.

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Thank you for sharing your opinion. I will let you know when my case reaches some resolution.

Just one more interesting fact: According to Google AI, the sensitivity of PET/CT PSMA for PSA ≥2.0 ng/mL should be 95-97%. And I have 5.97 and nothing... Perhaps this could be caused by a large number of small targets. However, this is probably not entirely common—otherwise, the sensitivity would likely be lower, as these cases would reduce it.
Fortunately, the process hasn't been too fast so far. I had RAPE in April 2017...

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Profile picture for heavyphil @heavyphil

This is why all SRT now targets the nodes. You can ‘see’ some nodes have cancer, but others probably have it too.
Cumulatively, they could add to the PSA bring what it is. Why not zap the nodes and see what happens?
Phil

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I have had PT on some suspicious nodes in the past, but it had no effect on PSA. Therefore, I do not think it would make sense to “attack” slightly suspicious nodes now, which have not changed over the years. Rather, I still hope that renewed local recurrence will be proven. Repeated use of PT on the same site is, as I have read, possible, although it is not without risk… Anyway, thanks for your opinion. I will report here how it develops.
Ivan

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Profile picture for ivan222 @ivan222

Thank you for sharing your opinion. I will let you know when my case reaches some resolution.

Just one more interesting fact: According to Google AI, the sensitivity of PET/CT PSMA for PSA ≥2.0 ng/mL should be 95-97%. And I have 5.97 and nothing... Perhaps this could be caused by a large number of small targets. However, this is probably not entirely common—otherwise, the sensitivity would likely be lower, as these cases would reduce it.
Fortunately, the process hasn't been too fast so far. I had RAPE in April 2017...

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@ivan222 I’m curious if you’ve had any updates on this since your post in this chat in Sept. In another chat I was asking about my husband’s PCa: after RP in Aug. 2025, first PSA test was only down to 1.5, rose to 1.9 2 weeks later and 2.0 by Jan. 2026. Asking for anther PSA on Tuesday so we can find out doubling time. We’re now looking at radiation (photons IMRT) 38 treatments Plus 6 months of ADT. So i came here looking for differences between photon and proton radiation. In the last month, husband has also has post RP PSMA PET, Prostate MRI, and yesterday a PET/MRI combination and none of them are showing anything. We feel we’re going in blind and “hoping” its in the prostate bed or surrounding LN, even though nothing is showing. I appreciate some of the responses here saying photons are used when post surgery to go through areas but am super concerned with more damage (UI not bad, left nerves not spared so Cialis and Viagara work part way but not enough -though not our main concern). Have your scans ever shown where the PSA is coming from?

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