Advanced prostate cancer (LN+), need your input...

[Radonc90]

I'd appreciate any opinions on this case...

Pt is a 70 yo man, in good health, diagnosed with advanced prostate ca in Oct 2019.

I saw him in Oct 2019:
- Gleason 8, PSA 54.
- CT abd-pelvis showed: multiple pelvic nodes (common iliac LNs about 2 cm, L internal iliac nodes
about 3 cm, R internal iliac node about 2 cm etc.)
- In the abd: probable IMA nodes, also 2.5 cm para-aortic LN near the left renal artery.

- Since Oct 2019, medonc has been treating the pt with chemo (Taxol etc.) and hormonal Rx.

In July 2021, I just saw pt, almost 20 months later:
- PSA is now 4.0.
- Repeat CT abd-pelvis showed good response: common iliac LNs about 1 cm, L internal iliac nodes
about 1.5 cm, R internal iliac node about 1 cm etc.
- In the abd: IMA nodes no longer seen. The previous para-aortic LN near the left renal artery
is no longer seen.

Urologist suggested pelvic RT as "consolidation Rx".

I am hesitating bc I am not sure pelvic RT would improve OS such an advanced case as diagnosed in Oct 2019.

Any thoughts?

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[DoctwoB]

I'd appreciate any opinions on this case...

Pt is a 70 yo man, in good health, diagnosed with advanced prostate ca in Oct 2019.

I saw him in Oct 2019:
- Gleason 8, PSA 54.
- CT abd-pelvis showed: multiple pelvic nodes (common iliac LNs about 2 cm, L internal iliac nodes
about 3 cm, R internal iliac node about 2 cm etc.)
- In the abd: probable IMA nodes, also 2.5 cm para-aortic LN near the left renal artery.

- Since Oct 2019, medonc has been treating the pt with chemo (Taxol etc.) and hormonal Rx.

In July 2021, I just saw pt, almost 20 months later:
- PSA is now 4.0.
- Repeat CT abd-pelvis showed good response: common iliac LNs about 1 cm, L internal iliac nodes
about 1.5 cm, R internal iliac node about 1 cm etc.
- In the abd: IMA nodes no longer seen. The previous para-aortic LN near the left renal artery
is no longer seen.

Urologist suggested pelvic RT as "consolidation Rx".

I am hesitating bc I am not sure pelvic RT would improve OS such an advanced case as diagnosed in Oct 2019.

Any thoughts?

Is he on novel hormonal agent? If not that is step 1.

You considering prostate + nodal xrt? or just pelvic nodes? I would not do the latter. He is low-volume metastatic per STAMPEDE, so could definitely consider xrt to the prostate. not unreasonable to treat pelvic nodes if treating prostate given that is his only other visible site of metastatic disease. I would also probably get a PSMA-PET first if available to see if we're missing a bunch of bony lesions.

 

[Radonc90]

Thanks, just to clarify...

- If I ever treat this pt, I'd treat prostate + pelvic nodes.

 

[RickyScott]

Thanks, just to clarify...

- If I ever treat this pt, I'd treat prostate + pelvic nodes.

I have treated the pelvis and retroperitoneal nodes in this situation.

 

[Ray D. Ayshun]

Thanks, just to clarify...

- If I ever treat this pt, I'd treat prostate + pelvic nodes.

You can do prostate alone per stampede or go for it and do it all, boosting nodes as high as is safe. I like to go for it, but involve the patient as well.

Edit: in addition to being a cancer, it's also becoming a chronic disease, so if fields start looking crazy I might stop at the prostate as it sounds like you'd also be treating abdominal nodes. This i think is a case where disease burden may be too great.

 

[StIGMA]

initial bone scan? Assuming no bone metastases would strongly consider consolidating all initial disease in good PS patient.

could treat more traditional fields and SBRT potential oligoprogressive LN or mets in future too

 

[TheWallnerus]

I'd appreciate any opinions on this case...

Pt is a 70 yo man, in good health, diagnosed with advanced prostate ca in Oct 2019.

I saw him in Oct 2019:
- Gleason 8, PSA 54.
- CT abd-pelvis showed: multiple pelvic nodes (common iliac LNs about 2 cm, L internal iliac nodes
about 3 cm, R internal iliac node about 2 cm etc.)
- In the abd: probable IMA nodes, also 2.5 cm para-aortic LN near the left renal artery.

- Since Oct 2019, medonc has been treating the pt with chemo (Taxol etc.) and hormonal Rx.

In July 2021, I just saw pt, almost 20 months later:
- PSA is now 4.0.
- Repeat CT abd-pelvis showed good response: common iliac LNs about 1 cm, L internal iliac nodes
about 1.5 cm, R internal iliac node about 1 cm etc.
- In the abd: IMA nodes no longer seen. The previous para-aortic LN near the left renal artery
is no longer seen.

Urologist suggested pelvic RT as "consolidation Rx".

I am hesitating bc I am not sure pelvic RT would improve OS such an advanced case as diagnosed in Oct 2019.

Any thoughts?

Pelvic RT? Sounds as if the field would need to resemble old style seminoma. I'm somewhat surprised urologist referred the patient; he's letting his inner rad onc come out. The med onc didn't have a hand in referral I bet. I would place money on RT not affecting survival in Gl 8, PSA 54, cN1M1a prostate cancer. A negative bone scan would not convincingly rule out bony disease with all those risk factors IMHO. So if you had a positive bone scan, would you treat all those nodal regions, or pelvis, or just prostate only? Data must be so sparse for "nodal consolidation" in metastatic prostate I am not aware of the data, although I vaguely recall something recently I'm sure someone will cite. At least with prostate only you've got a reasonable leg to stand on.

 

[deleted314957]

Any good rad literature relating prognosis to tumor volume in unilateral disease confined to the prostate and has clean margins?

 

[Radonc90]

Forgot to mention bone scan at Dx time (Oct 2019) was normal.

 

[Ray D. Ayshun]

If there was a 2.5 cm node by the kidneys, treating comprehensively only offers toxicity. Treat the prostate, know we have a zillion systemic bullets, and treat progression when they fail...when he's 80.

 

[evilbooyaa]

I would target everything up to the level that gross disease is still seen. If chemo/hormonal therapy took IMA/renal lymph nodes to nothing, I'd treat up to the aortic bifurcation with 55/20 including to prostate. It's a bit between 'full comprehensive' and 'prostate alone', but with nodal only mets (even if non-regional) I would give this patient benefit of the doubt.

Could try boosting the gross nodes to 60/20 and prostate to 60/20 if feasible and can meet dose constraints - will depend on location along the chain. Elective nodal volumes gets 44/20.

 

[HardenedBeam]

I've treated Prostate, Pelvis, and PA nodes after a good response to chemotherapy. I think it makes sense to go for it in that setting.

I had IMPT so the toxicity wasn't as much of a concern but I'd still go for it if I only had xrays.

 

[evilbooyaa]

I've treated Prostate, Pelvis, and PA nodes after a good response to chemotherapy. I think it makes sense to go for it in that setting.

I had IMPT so the toxicity wasn't as much of a concern but I'd still go for it if I only had xrays.

Data that shows clinical toxicity from IMPT is better than from IMRT when treating pelvic lymph nodes - GO!

 

[HardenedBeam]

Data that shows clinical toxicity from IMPT is better than from IMRT when treating pelvic lymph nodes - GO!

I know you don't believe in DVHs but treating the pelvis and PA nodes with IMPT gives you about 1/20th the mean bowel dose but yea the toxicity is the same!

 

[SneakyBooger]

STAMPEDE treated prostate only.

Personally, I would also treat LN's if can be done "safely".

I would treat with 180/fraction - see SWOG S1802.

 

[mavrik13]

I'd treat prostate + pelvis to aortic bifurcation. 55/20 to prostate (I see no reason to go to 60) and would treat pelvis to 44, with boost to residual nodes (would look at the scan, likely 50). I personally believe in consolidative RT in these sort of situation, but admit there isn't data to back it up (versus just treating the prostate)

 

[IonsAreOurFuture]

I agree with HardenedBeam's post. I would treat with curative intent. Consider the PA node by the kidney as an oligomet. You can treat it separately with SBRT, but it's probably safer to just treat prostate, pelvis and para-aortics in one single course.

I've done this with IMRT and I've done this with IMPT. My latest IMRT patient with PA nodes had nausea and diarrhea for a month afterward and I worried he was developing an ulcer, or maybe I was from worrying. The IMPT patient treated at the same time had no nausea or diarrhea, he actually complained of constipation from the low-gas diet he was on.

In either case, I usually try to give 60 - 66 Gy to the grossly enlarged nodes with SIB technique.

 

[RickyScott]

I agree with HardenedBeam's post. I would treat with curative intent. Consider the PA node by the kidney as an oligomet. You can treat it separately with SBRT, but it's probably safer to just treat prostate, pelvis and para-aortics in one single course.

I've done this with IMRT and I've done this with IMPT. My latest IMRT patient with PA nodes had nausea and diarrhea for a month afterward and I worried he was developing an ulcer, or maybe I was from worrying. The IMPT patient treated at the same time had no nausea or diarrhea, he actually complained of constipation from the low-gas diet he was on.

In either case, I usually try to give 60 - 66 Gy to the grossly enlarged nodes with SIB technique.

Have given imrt numerous time to pelvic and para-aortic (up to renal hilum) without issue. (Long term anal and cervical surviors with concurrent chemo) Would love to see your imrt plan. In my experience average bowel dose can be around 20 gy or less and pts don’t have any issues. Lowering this dose to 5 gy wouldn’t benefit them acutely and you would have all the range uncertainties, bed problems with protons

 

[IonsAreOurFuture]

Have given imrt numerous time to pelvic and para-aortic (up to renal hilum) without issue. (Long term anal and cervical surviors with concurrent chemo) Would love to see your imrt plan. In my experience average bowel dose can be around 20 gy or less and pts don’t have any issues. Lowering this dose to 5 gy wouldn’t benefit them acutely and you would have all the range uncertainties, bed problems with protons

I think it's great that you are treating anal and cervical cancer patients for curative intent who have para-aortic nodes. I think the current GI and GU staging systems are inadequate at separating out node-only patients who have a better prognosis from those with hematogenous spread. Sometimes I need to treat above the renal vessels, but even when I don't go there, I'm really glad to have protons.

I find that using protons helps me to treat these para-aortic patients with greater confidence, not less. It's easier to meet the QUANTEC dose constraints for bowel, especially for individual bowel loops (V15 <120 cc), which is a more precise structure than Bowel Bag which is largely fatty and includes colon (V45<195 cc). See: DEFINE_ME

I agree with you that one needs to be concerned about the distal end range-out, but so far (knock on wood), it hasn't been an issue in clinic. I think that a theoretical bowel overdose is a smaller issue than a known bowel overdose. It's interesting to me that so many worry about range uncertainty for protons but not for X-rays, in which the range uncertainty is basically infinite, as the rays don't stop, they just attenuate with distance and shielding.

Anyway, as requested, patient 1's IMRT plan. Gross nodes get 60 Gy in 30 fx, uninvolved nodes get 51 Gy in 30 fx. Mean Bowel Bag dose = 1622 cGy. Mean dose to kidneys: 1316 cGy. He had diarrhea, nausea, and vomiting twice daily despite Zofran, for his first month post XRT:

Patient 2's proton plan. It reminds me of CSI for medulloblastoma. Same prescription dose, same planning system, treatment completed within a week of patient 1. Mean Bowel Bag dose = 412 cGy vs 1622. Of note, he has unfavorable anatomy in that he does not have a lot of fat between his nodes and his bowel loops, unlike patient 1. Mean dose to Kidneys = 370 cGy vs 1316. He did not have any N/V or diarrhea. Had mild constipation, despite this being a much hotter plan as well as extending into the pelvis down around S3, iliacs and presacral nodes, instead of stopping at L4 like the other guy.

 

[RickyScott]

young prostate pt who had paraaortics treated 5 years ago and off hormones for 2 years. I put 50% on to show limited amount of bowel that gets 50%. Protons certainly are better at lower doses levels, but this has no clinical impact. initial treatment was chemo, then hormones x 18 months, and pt wanted to stop hormones. Gave the xrt and 6 more months of hormones.

 

[SubserviantToABR]

young prostate pt who had paraaortics treated 5 years ago and off hormones for 2 years. I put 50% on to show limited amount of bowel that gets 50%. Protons certainly are better at lower doses, but this has no clinical impact. initial treatment was chemo, then hormones x 18 months, and pt wanted to stop hormones.

View attachment 342643

All of these proton people show us pretty pictures, but they never show the clinical relevance of their treatment. If it does not matter to the patient, why do we need to do protons? The burden of proof is on the proton people who have had the technology for over 50 years, without a randomized phase III trial demonstrating its utility. It costs 2-3X as much, but is it 2-3X better?

It is pretty disingenuous for these proton people to think the overwhelming majority of radiation oncologists are stupid enough to fall for tired, old tricks. Give us the data!

Also, remember, Nancy Lee said that she will continue to use it, even if the data shows that it is not beneficial. Let u$ remember why.

 

[evilbooyaa]

I think it's great that you are treating anal and cervical cancer patients for curative intent who have para-aortic nodes. I think the current GI and GU staging systems are inadequate at separating out node-only patients who have a better prognosis from those with hematogenous spread. Sometimes I need to treat above the renal vessels, but even when I don't go there, I'm really glad to have protons.

I find that using protons helps me to treat these para-aortic patients with greater confidence, not less. It's easier to meet the QUANTEC dose constraints for bowel, especially for individual bowel loops (V15 <120 cc), which is a more precise structure than Bowel Bag which is largely fatty and includes colon (V45<195 cc). See: DEFINE_ME

I agree with you that one needs to be concerned about the distal end range-out, but so far (knock on wood), it hasn't been an issue in clinic. I think that a theoretical bowel overdose is a smaller issue than a known bowel overdose. It's interesting to me that so many worry about range uncertainty for protons but not for X-rays, in which the range uncertainty is basically infinite, as the rays don't stop, they just attenuate with distance and shielding.

Anyway, as requested, patient 1's IMRT plan. Gross nodes get 60 Gy in 30 fx, uninvolved nodes get 51 Gy in 30 fx. Mean Bowel Bag dose = 1622 cGy. Mean dose to kidneys: 1316 cGy. He had diarrhea, nausea, and vomiting twice daily despite Zofran, for his first month post XRT:

View attachment 342641

If you did VMAT and didn't have the 20-30Gy coursing through multiple angles of the bowel you'd have improved the patient's risk of diarrhea/nausea. Static IMRT has higher medium doses than VMAT.

Your kidney mean dose is higher because your bringing beams through the kidney with your static IMRT plan.

Please provide evidence that mean bowel bag dose is a valuable constraint as a marker for clinical toxicity.
V15 < 120cc for bowel loops, same question. The papers they cite within the QUANTEC paper suggest thresholds as high as 350-390cc when contouring bowel loops for things in the V15-V18 range.

 

[RickyScott]

If you did VMAT and didn't have the 20-30Gy coursing through multiple angles of the bowel you'd have improved the patient's risk of diarrhea/nausea. Static IMRT has higher medium doses than VMAT.

Your kidney mean dose is higher because your bringing beams through the kidney with your static IMRT plan.

Please provide evidence that mean bowel bag dose is a valuable constraint as a marker for clinical toxicity.
V15 < 120cc for bowel loops, same question. The papers they cite within the QUANTEC paper suggest thresholds as high as 350-390cc when contouring bowel loops for things in the V15-V18 range.

Well planned pelvis and para-aortic extended field is better tolerated than old 4 field box pelvic alone field, with less bowel dose.