SBRT prostate after prior EBRT?

[thesauce]

Has anyone done SBRT after prior EBRT or brachy? I found 2 relatively recent studies and it seems to be equally-effective and better tolerated than some other modalities out there. Thoughts?

A Systematic Review and Meta-analysis of Local Salvage Therapies After Radiotherapy for Prostate Cancer (MASTER) - PubMed

In a large study-level meta-analysis, we looked at treatment outcomes and toxicity for men treated with a number of salvage treatments for radiorecurrent prostate cancer. We conclude that relapse-free survival at 5 years is equivalent among salvage modalities, but reirradiation may lead to lower...

pubmed.ncbi.nlm.nih.gov

Reirradiation for isolated local recurrence of prostate cancer: Mono-institutional series of 64 patients treated with salvage stereotactic body radiotherapy (SBRT) - PubMed

Salvage SBRT reirradiation for the locally recurrent PCa offer a satisfactory tumor control and excellent toxicity profile, if BED ≥130 Gy is administered.

pubmed.ncbi.nlm.nih.gov

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[Gfunk6]

I do it all the time. I use Dr. Fuller's protocol published in PRO.

High-dose-rate stereotactic body radiation therapy for postradiation therapy locally recurrent prostatic carcinoma: Preliminary prostate-specific antigen response, disease-free survival, and toxicity assessment - PubMed

Two-year disease-free survival is encouraging, and the prostate-specific antigen response kinetic appears comparable with that seen in de novo patients treated with SBRT, albeit still a preliminary finding. Grade ≥2 genitourinary toxicity was occasionally seen with no obvious predictive factor...

pubmed.ncbi.nlm.nih.gov

 

[ramsesthenice]

Has anyone done SBRT after prior EBRT or brachy? I found 2 relatively recent studies and it seems to be equally-effective and better tolerated than some other modalities out there. Thoughts?

A Systematic Review and Meta-analysis of Local Salvage Therapies After Radiotherapy for Prostate Cancer (MASTER) - PubMed

In a large study-level meta-analysis, we looked at treatment outcomes and toxicity for men treated with a number of salvage treatments for radiorecurrent prostate cancer. We conclude that relapse-free survival at 5 years is equivalent among salvage modalities, but reirradiation may lead to lower...

pubmed.ncbi.nlm.nih.gov

Reirradiation for isolated local recurrence of prostate cancer: Mono-institutional series of 64 patients treated with salvage stereotactic body radiotherapy (SBRT) - PubMed

Salvage SBRT reirradiation for the locally recurrent PCa offer a satisfactory tumor control and excellent toxicity profile, if BED ≥130 Gy is administered.

pubmed.ncbi.nlm.nih.gov

Unless they have had prior LDR brachy, I typically prefer HDR for in-gland salvage. There is a pretty good literature for it. I have yet to see a major complication or even severe LUTs. The literature on salvage SBRT is mixed but I know folks (apparently GFunk is one of them) who do it and it seems to go ok as well.

 

[tomhobbes]

Yes, our practice does. I personally have not done it for in-gland recurrences less than 4 years after previous EBRT. I do try to get a perirectal spacer in before re-RT, but optimal spacer placement is not as high as in the RT-naive setting given fibrosis/scarring in that space. It does take a fair amount more dissection and gentle manipulation to create the pocket. We've used 35-36.25/5fx.

 

[OTN]

I've done it after HDR which was done more than 10 years ago. It was scary to do, but the patient has done well.

 

[BobbyHeenan]

I haven't done this.

Excuse my ignorance.

Do you all do just focal radiation based upon biopsy location/MRI (and now PSMA or axumin)? LIke gross disease plus (small) margin?

Of note, on quick glance at the Fuller paper they only included patients with G1 toxicity at XRT round 1 only. So clearly you need to be selective.

 

[Gfunk6]

I treat whole gland but dose escalate to gross disease

 

[BobbyHeenan]

I treat whole gland but dose escalate to gross disease

I think that's what I would probably do too in my theoretical world.

But a congruent saturation biopsy, MRI, and now with PSMA pet would be really tempting to just treat a hot area.

 

[thecarbonionangle]

HDR or SBRT 6x6 with spaceOAR.

 

[ramsesthenice]

I think that's what I would probably do too in my theoretical world.

But a congruent saturation biopsy, MRI, and now with PSMA pet would be really tempting to just treat a hot area.

I see where you are coming from but the counter argument is you only get one shot at this. I’ve re-treated the whole gland with HDR 30/3 (albeit in folks with good baseline urinary function) a few times without any notable toxicity. In the definitive setting, hemi-gland BT failed miserably even with pretty thorough work up. Until I see good data otherwise, I feel like if you are going to do it, do it right.

 

[GI_RadOnc]

36.25 / 5 fractions; checking every day that no hot spot in urethra (max dose 38.8) as well as the prostate/rectal boundary is appropriate. Some patients have had fluciclovine PET, only a few with PSMA-PET due to availability where we are. We may have done between 5 and 10 cases thus far. Since we have MR guidance, we have been using that. Not enough for a series yet.

 

[ramsesthenice]

On a slightly different but related note, I have also used 45/30 BID as an aggressive palliation dose for folks with symptomatic in gland recurrences after full dose in guys who also have Mets and been extremely happy with it. First guy I did it in was close to needing a suprapubic cath. Told him I might make things better or worse and ended up getting him 2.5 years of complete resolution of his LUTS. Oddly enough, it helped with his castrate resistance too. I eventually ended up treating his PA nodes with a modest dose and he’s still doing great on ADT (though PSA is starting to rise slowly again even on ADT…but still, happy to buy a couple more years). No toxicity issues. I’ve also used this dose a couple times for secondary rectal cancers after bladder or prostate RT in medically inoperable folks a few times. Not enough for a series but something that has served me well.

 

[Neuronix]

36.25 / 5 fractions; checking every day that no hot spot in urethra (max dose 38.8) as well as the prostate/rectal boundary is appropriate. Some patients have had fluciclovine PET, only a few with PSMA-PET due to availability where we are. We may have done between 5 and 10 cases thus far. Since we have MR guidance, we have been using that. Not enough for a series yet.

Putting spacer in?

 

[GI_RadOnc]

Putting spacer in?

I have not put in SPACE-OAR in my couple of patients; not sure about my colleagues'.

 

[medgator]

Putting spacer in?

Not sure if prior radiation affects denonvilliers fascia? Edit: just checked it seems to be a relative contraindication

 

[Gfunk6]

Not sure if prior radiation affects denonvilliers fascia? Edit: just checked it seems to be a relative contraindication

I just put in a SpaceOAR on a patient with locally recurrent prostate cancer s/p IMRT (78 Gy) delivered about 7 years ago. Axumin PET confirmed local recurrence without regional or metastatic disease.

Both the prostate and denonvilliers fascia were notably fibrotic based on the tactile feel with the needles. However, the fascia in particular appeared normal (like fat) on TRUS.

 

[Neuronix]

Doot. Yes, super fibrotic in recurrent setting hard to inject. I asked the question not realizing I was in a recurrent thread. Lol

 

[cancer_doc]

Putting spacer in?

Yes, definitely try to place SpaceOAR. I have performed a few and I will usually encounter some fibrosis of the Denonvilliers Fascia. Most will open up with hydrodissection to allow adequate placement of the gel, but some are totally stuck. It those situations, I may decide to go partial prostate vs whole gland, depending on disease location/size and pt's baseline GI/urinary status. Salvage brachy, HIFU, Cryo can be considered if you have the expertise locally...