External RT to prostate when already mCRPC?

[WatchTheSunsets]

Hello,

I'm writing because of my father. Information in bio.

A month ago he had a Ga68 PSMA PET/CT. Conclusion:

A voluminous inhomogeneously filling prostate arching into the lumen of the bladder, diffusely bilaterally with significantly increased accumulation of Ga PSMA.

Dorsally the prostate arches against the rectum, with possible infiltration of the wall.

Mets in: 1 pelvic lymph node, 5 vertebrae, hip, rib.

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After the PSMA PET/CT the doctor said that in case of problems from local growth of the prostate like pains in the pelvis, blood when urinating, difficulty urinating,... that a possibility of local irradiation of the prostate area can also be considered.

My dad has no problems from local growth, no symptoms.

This month the doctor offered external RT. It would be 20 fractions to prostate and seminal vesicles. I don't know the dosage.

RO said that because PSMA scan can't rule out the infiltration of the rectum wall, a part of the rectum has to be irradiated with the same dosage as prostate. Meaning that standard organ-at-risk limits could not be met. I think the same may partially apply to the bladder.

My dad failed on Zoladex and Xtandi. Had no RP, RT or docetaxel. Zytiga was stopped due to side effects.

Questions:

Does anyone have experience with this RT approach?

Is this a "debulking"?

Can those 20 fractions remove the tumor or is it only a try to slow the growth?

Is it safe for the organs at risk?

Isn't is better to go with docetaxel?

Can docetaxel shrink the tumor?

Thank you!

[GP24]

In this trial, the ARTO trial, stereotactic radiation showed a significant benefit for castration resistent patients: ascopubs.org/doi/10.1200/JC...

[Tall_Allen]

Two major randomized clinical trials have now proven that there is no benefit in irradiating the prostate after more than 3 metastases have been discovered on a bone scan/CT. You state what has been discovered on a PET/CT but not a bone scan.

prostatecancer.news/2018/09...

Consider docetaxel+Xtandi as in this clinical trial:

prostatecancer.news/2022/10...

[WatchTheSunsets in reply to Tall_Allen]

Thank you for the answer.

Previous bone scans or standard CT scans showed in total 5 mets: 3 in pelvis, 1 in spine, 1 in rib.

Latest bone scan from showed only the met in rib (due to effect of Xtandi).

[Tall_Allen in reply to WatchTheSunsets]

Only the first bone scan counts.

[raoulmaher]

I have had 32 fractions to prostate and seminal vesicles - all this acheives is to reduce the cancer load in the prostate and the communication path that is the spead to distant places - there can be damage to the rectum there is spacer to help with this - what is your dads PSA - is there a reason politely he does not communicatate on here - we are friendly !!! - lots of wives , girlfriends - partners etc seem to be representing their male sufferer - kindest Raoul

[WatchTheSunsets in reply to raoulmaher]

Hello, thank you for your message.

Current PSA is 54.7. Latest PSA history is in bio.

Father doesn't communicate here because we found this forum only recently and because we live in EU and he's not good at English.

Spacer can't be used because father's prostate is too near to the rectum - as per the PSMA PET/CT doctors don't know if the rectum wall isn't already infiltrated with prostate cancer.

[janebob99]

Many men use a rectal spacer (SpaceOAR or Barrigel) to reduce the radiation dose to the rectal wall. This bio-degradable, gel-like spacer increases the distance between the prostate and the rectal wall by about 1/2 inch.

Many studies support its effectiveness.

Bob in New Mexico

[Cenerus in reply to janebob99]

I don’t think a spacer will help here because the description from her and the her doctor is that the cancer has possibly infiltrated the rectum already. The radiation would need to include the rectum wall. I’m just guessing, but it looks like the RT is attempting to stop the spread into the rectum and bladder, which has also been invaded. It’s a tough situation. The cure will likely cause radiation protists, but the rectum is already compromised. Docitaxel might help and I’m not sure why it’s not being employed before the RT to the rectum and bladder. Maybe the doctors wants to ensure that the spread to those two organs is halted by using radiation.

[janebob99 in reply to Cenerus]

thank you! I missed that.

[EdBar]

I was metastatic at dx, mets throughout my skeleton and several nodes. An excellent radiology oncologist suggested debulking my prostate with IMRT. He said it could help ADT be more effective in the long run. It made sense to me, to reduce the tumor burden. So I went ahead with it, 45 rounds, treating the prostate and several nodes being careful not to damage any part of my intestines or other organs.

That was about 10 years ago, I was later told by Snuffy Myers that it was one of the best things I could have done. Another oncologist told me it was a smart move for the same reasons that you stated in your post. In hindsight I’d do it again in a heartbeat. I’m still here 10+ years after a Stage 4 Gleason 9 dx. You can read my profile to see what other treatments I’ve had on my journey.

Ed

[Leader4077]

At least TRY the chemo, Docetaxel or another…….that is why they have it…….it can slow the spread.

[Kcski]

Hi,

My dad, who is 77, had Docetaxel about four years ago. It was his first line of treatment. He had six rounds that he tolerated well. The last couple of rounds were unpleasant, but he got through it. Anyway the cancer kill was AMAZING! It shrunk his bladder Mets big time! The benefits lasted close to two years. He then went on to a pill testosterone blocker. He is on that now. I would totally recommend Docetaxel!

Best of luck and love,

Karyn