Scanning options as PSA rises, retroperitoneal lymph node involvement

[Seattle1956]

Hi all - Stage 4, addressed with triplet therapy (Docetaxel, resumed Lupron, added darolutamide) starting in August 2022. PSA increasing since summer 2023, measured at 8 in January 2025. Bone & CT scans twice, first one picked up a single retroperitoneal lymph node > cm., second picked up three. My treatment center plans to continue to use bone + CT scans unless and until I change treatment to Pluvicto. But a recent talk by Eugene Kwon, at Mayo, seemed to say that this is a mistake, that a PSMA PET scan is appropriate. Further, he suggested - if I understood correctly - that the retroperitoneal lymph nodes can be individually treated if they are the only site of the cancer. (1) Any opinions on diagnostic use of bone/CT scan versus PSMA PET? (2) Any opinions on whether retroperitoneal nodes can be successfully treated (I'm not sure how) if the cancer is detected only there? Many thanks!

[Tall_Allen]

Eugene Kwon is less qualified to have an opinion than I am.

He is neither a medical oncologist nor a radiation oncologist - just a urologist who sell whacky ideas on youtube to patients.

[Seattle1956 in reply to Tall_Allen]

Thanks, T_A, important datum. What do you think about the scanning question, and have you ever heard of retroperitoneal lymph nodes being addressed individually rather than systemically?

[Tall_Allen in reply to Seattle1956]

Individual pelvic lymph node treatment is whacky. Cancer cells may drift in the lymph drainage area in the pelvis for a while, but once outside of the pelvic drainage area, they are in systemic circulation. Even within the pelvic drainage area, there are many cancer cells that cannot be seen on even our most sensitive imaging. Our most sensitive imaging cannot see anything smaller than 5 mm. So we have to treat what we can't see. That's why the entire pelvic drainage area has to be irradiated even if only one met is detected there.

But your retroperitoneal lymph node is outside the pelvic drainage area and must have gotten there through systemic circulation. Therefore systemic treatment is necessary. If you want to irradiate the lymph node too, if safe, why not? But safety in that area can be problematic. And there is no data yet proving that there is any net benefit. It will probably reduce PSA, and it can possibly delay progression.

This is what happened to patients at Mayo when individual metastases were targeted:

prostatecancer.news/2020/12...

[Seattle1956 in reply to Tall_Allen]

Many thanks again, Tall_Allen, this is of course very helpful.

[103532]

Hi! Please read my husband’s bio. When he bad a BCR after RP (Gleason 9, Stage 3b), a PSMA Pet found 3 or four sub centimeter retroperitoneal lymph nodes which were PSMA avid. The onc at Yale felt he was in the early metastatic process and began doublet therapy with Lupron and Abi 1000 with pred. He did have Casodex for a few weeks initially to prevent flare. After two months, we had the nodes targeted with radiation which also included the pelvic nodal chain and slightly above the retroperitoneal nodal chain. They also hit him with full IMRT to the pelvis and prostate bed. He has had no issues from the radiation except for bloating and gas with some foods such as some raw veggies, cucumbers, etc. The plan is for him to remain on the Abi until he has completed his two years and remain on Lupron until he completes three years. He was germline negative. The hope is that this will delay progression. Hope being then important word. We consulted with Sloan Kettering who agreed with the treatment plan. I pray each night that we can control this for many years. I am happy to share if you have any questions on his treatments.🙏

Stephanie

[Seattle1956 in reply to 103532]

Thank you, Stephanie. Very interesting, the radiation slightly above the retroperitoneal nodal chain.

[NanoMRI]

On the other hand, with five pelvic nodes identified by Ferrotran MRI imaging at 0.093, bones and other organs NED based on additional imaging, I went for salvage pelvic extended pelvic lymph node surgery using frozen section pathology method. Six nodes confirmed cancerous including para-aortic. Nadir <0.010. That was seven years ago.

I personally know several men who are very grateful patients of Dr Kwon. Several members have shared their positive experiences - then to be criticized.

I have a different perspective of whacky.