Proton vs Photon

@jeffmarc From the data you are referencing it looks to me like there is very little to no difference from photon therapy or another therapy. Those differences would be difficult to tease out why the outcomes were slightly different. I like the studies because of the size, but don’t buy you can really tell much else.

I had SBRT Proton because it made more sense to me that photons could result in later cancers due to its trajectory through the body. Your data suggests otherwise. I also chose it because it seemed like less chance of urinary & other side effects. 5 months later it seems borne out, but I think it is too soon to draw conclusions on that.

I chose SBRT Proton because I couldn’t tell much difference between IMRT & SBRT in terms of outcomes. I understand the financial incentives for IMRT and chose SBRT. Certainly not having to go for 40+ sessions was a big plus. I’m 74 and planning on ending my ADT ‘early’ at 15+ months (9 before and 6 after) because none of the studies convince me that it will affect my longterm outcome. That remains to be seen.

I have followed and participated in this forum and feel I’ve gotten better first hand experiences, even if not entirely evidence driven than I’ve gotten from my doctors.

@robertov
Proton radiation is used for children who have brain tumors and other things that need to be treated so that they don’t have secondary cancers later in life. It is definitely supposed to have fewer side effects.

Just yesterday, I was reading about one person who had it and it was very successful and they had no side effects but somebody else they know had it and had prostatitis and other problems that you get with photon radiation.

If you’ve been undetectable for A long time before you stop taking ADT it may work out for you. Get PSA tests every three months to see if anything’s changing. It’s not uncommon for the PSA to rise a little and then go back down after stopping ADT.

I’ve heard from radiologist that say there is really no significant difference between photon and proton overall results. Somebody your age should really not have to worry about the differences.

https://pmc.ncbi.nlm.nih.gov/articles/PMC10681151/
...may answer my typo question above. Stereotactic beam proton therapy (SBPT) is a variant acronym for SBRT. The idea is to reduce the treatment sessions by increasing each dose over fewer sessions a la 'hypofractionation'

https://pmc.ncbi.nlm.nih.gov/articles/PMC10681151/
...may answer my typo question above. Stereotactic beam proton therapy (SBPT) is a variant acronym for SBRT. The idea is to reduce the treatment sessions by increasing each dose over fewer sessions a la 'hypofractionation'

I was recently diagnosed September 2025 . Drs and research studies all said the same thing - survival rates are statistically the same with all modes: photon, proton, or surgery. The big difference is in the side effects and quality of life. For me, my priority consideration for choosing a treatment was long-term quality of life, particularly given the difficult struggles my dad had with debilitating urinary strictures from his prostate radiation - didn't show up until 20 years after his treatment. (I know times are different and much more advanced, but that surplus radiation dose to normal cells is on all our minds)

I did a lot of deep research, as many of you have, and was 100% settled on Proton Therapy. It made intuitive sense to me, if you cut out the exit dose, you are cutting out half the risk to normal tissue. The predictable distance that protons travel surely makes it more precise. I followed up with visits to three different proton centers: Mayo Phoenix and Wash U St. Louis have all modes of RT; and I also visited a private Proton Center. Neither Wash U nor Mayo recommended Proton Beam for me. I leaned in to each and told them I was specifically looking for Protons, why didn't they want to sell them to me? I'm not a doctor and this is my own interpretation of what I heard:

Proton Beams are very precise in the maximum distance they travel before releasing all their energy. However, not all protons travel the maximum and may not reach that target, leaving unanswered questions about the evenness of the treatment exposure and the actual dose received in any one specific spot. Second, when a Proton release its energy, it releases it in a little cloud, the behavior and width of which is still unknown. Proton therapy has been around since the 60s I believe, but the actual physics of protons in the body is still a bit of a mystery. By comparison, the physics and behavior of light waves (Photons, X-rays, EBRT) has been studied for centuries and its behavior is well known. The edges of the radiation beam are very precise and there is no scatter from release because they pass completely through your body. The radiation energy is relatively low risk from any single one of the EBRT beams, but they are quite potent where the multiple beams all intersect at a pinpoint, and this point of intersection is painted in 3D throughout the Prostate similar to how Proton Therapy is described. Again, I am not a doctor or physicist, just a guy doing his own research.

Studies show that side effects, curability, and longevity are similar for all modes of treatment and I may place the above discussion into the category of me over-thinking and over-analyzing. However, in my case where my lesion is very close to my bladder sphincter, I ended up choosing the precise edge of a photon beam over the the precise distance a photon can travel. With the relatively recent introduction of adaptive therapy techniques, I felt that achieving my goal of reducing risk to my long-term quality of life would be better with photons and adaptive therapy. I start my IMRT treatments in a couple of weeks.

Everyone is different, every situation is different, everybody's goals and priorities are different. I hope I'm not preachy, just trying to share my personal experience. We are lucky to live in a time that can offer a wide variety of treatments with high success rates, but it is unfortunate that us non-doctors are left to make our own treatment decision. There is no wrong decision, only what's right for you. I hope you find this useful.

I was recently diagnosed September 2025 . Drs and research studies all said the same thing - survival rates are statistically the same with all modes: photon, proton, or surgery. The big difference is in the side effects and quality of life. For me, my priority consideration for choosing a treatment was long-term quality of life, particularly given the difficult struggles my dad had with debilitating urinary strictures from his prostate radiation - didn't show up until 20 years after his treatment. (I know times are different and much more advanced, but that surplus radiation dose to normal cells is on all our minds)

I did a lot of deep research, as many of you have, and was 100% settled on Proton Therapy. It made intuitive sense to me, if you cut out the exit dose, you are cutting out half the risk to normal tissue. The predictable distance that protons travel surely makes it more precise. I followed up with visits to three different proton centers: Mayo Phoenix and Wash U St. Louis have all modes of RT; and I also visited a private Proton Center. Neither Wash U nor Mayo recommended Proton Beam for me. I leaned in to each and told them I was specifically looking for Protons, why didn't they want to sell them to me? I'm not a doctor and this is my own interpretation of what I heard:

Proton Beams are very precise in the maximum distance they travel before releasing all their energy. However, not all protons travel the maximum and may not reach that target, leaving unanswered questions about the evenness of the treatment exposure and the actual dose received in any one specific spot. Second, when a Proton release its energy, it releases it in a little cloud, the behavior and width of which is still unknown. Proton therapy has been around since the 60s I believe, but the actual physics of protons in the body is still a bit of a mystery. By comparison, the physics and behavior of light waves (Photons, X-rays, EBRT) has been studied for centuries and its behavior is well known. The edges of the radiation beam are very precise and there is no scatter from release because they pass completely through your body. The radiation energy is relatively low risk from any single one of the EBRT beams, but they are quite potent where the multiple beams all intersect at a pinpoint, and this point of intersection is painted in 3D throughout the Prostate similar to how Proton Therapy is described. Again, I am not a doctor or physicist, just a guy doing his own research.

Studies show that side effects, curability, and longevity are similar for all modes of treatment and I may place the above discussion into the category of me over-thinking and over-analyzing. However, in my case where my lesion is very close to my bladder sphincter, I ended up choosing the precise edge of a photon beam over the the precise distance a photon can travel. With the relatively recent introduction of adaptive therapy techniques, I felt that achieving my goal of reducing risk to my long-term quality of life would be better with photons and adaptive therapy. I start my IMRT treatments in a couple of weeks.

Everyone is different, every situation is different, everybody's goals and priorities are different. I hope I'm not preachy, just trying to share my personal experience. We are lucky to live in a time that can offer a wide variety of treatments with high success rates, but it is unfortunate that us non-doctors are left to make our own treatment decision. There is no wrong decision, only what's right for you. I hope you find this useful.