Oligometastatic SBRT: any benefit if you can’t treat all of the lesions?

[thesauce]

I know there is quite a bit of controversy here, so I wanted to open the discussion.

Say you have a patient that is 77, ECOG 0, with a history of high risk prostate cancer that has had radiation to the prostate twice (std frac EBRT in 2012 and salvage brachy in 2018).

He recently experienced BCR and PSMA demonstrated recurrence in an internal iliac node (not treated before) AND a focal area on the right side of the prostate gland. Re-biopsy of the gland confirmed recurrence.

Patient has refused cryo and hifu and ADT. He wants RT again. I’m assuming no one would treat the prostate again? Would there be any utility to treating only the pelvic LN with SBRT?

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[deleted1116990]

I know there is quite a bit of controversy here, so I wanted to open the discussion.

Say you have a patient that is 77, ECOG 0, with a history of high risk prostate cancer that has had radiation to the prostate twice (std frac EBRT in 2012 and salvage brachy in 2018).

He recently experienced BCR and PSMA demonstrated recurrence in an internal iliac node (not treated before) AND a focal area on the right side of the prostate gland. Re-biopsy of the gland confirmed recurrence.

Patient has refused cryo and hifu and ADT. He wants RT again. I’m assuming no one would treat the prostate again? Would there be any utility to treating only the pelvic LN with SBRT?

Where in the prostate and how big? Wonder if you could drop a couple more seeds on the focal lesion then SBRT the node.

He will then need ADT/come-to-jesus talk when this comes back in a few years.

 

[Ray D. Ayshun]

Any deets on original gleason score, new gleason score, present PSA and PSA doubling time? perhaps nothing is an option. perhaps could convince yourself the pelvic nodal disease represent the more aggressive biology in the evolutionary process, while the apparently radioresistant disease in the prostate can be ignored, and you just SBRT the node and observe. Sounds like a no rules situation, and obv, first do no harm is the starting point here.

 

[imhopeful432]

I know there is quite a bit of controversy here, so I wanted to open the discussion.

Say you have a patient that is 77, ECOG 0, with a history of high risk prostate cancer that has had radiation to the prostate twice (std frac EBRT in 2012 and salvage brachy in 2018).

He recently experienced BCR and PSMA demonstrated recurrence in an internal iliac node (not treated before) AND a focal area on the right side of the prostate gland. Re-biopsy of the gland confirmed recurrence.

Patient has refused cryo and hifu and ADT. He wants RT again. I’m assuming no one would treat the prostate again? Would there be any utility to treating only the pelvic LN with SBRT?

Would do....all of the options you suggested first. But if it is a slow PSA rise, not unreasonable to consider focal brachy + SBRT (with the goal of delaying progression/ADT) as long as the patient understands high likelihood (near certainty) of recurrence elsewhere at some point

 

[BobbyHeenan]

I think you hinted at something that would push me to want to treat....

If this dude HATED life on ADT, then more rationale to treat. If he's never had ADT at all I'd maybe see how he does on 3 months ADT.

Almost everyone doesn't like ADT. But we all have that sub set of men who say they'd rather be damn near dead than on it. If he's like that then I think there is solid rationale (sorta ORIOLE-ish) to treat. I'd be real real nervous about that prostate though. I personally wouldn't do that brachy but someone better than me could I bet.

 

[DoctwoB]

I've had salvage brachy patients. Most are pretty miserable due to LUTS. one is a urethral cripple and is heading towards a urinary diversion. I've never had a salvage brachy patient who got prior XRT and brachy. I would not recommend it.

Best options are to either ignore the prostate and treat elsewhere or consider an alternative form of salvage therapy. Send him to somewhere doing irreversible electroporation or maybe HIFU if he wants local therapy. Wouldn't recommend cryo post salvage brachy, would be worried about fistulae.

Edit, saw he doesn't want HIFU. Would consider the IRE route: Feasibility and safety of focal irreversible electroporation as salvage treatment for localized radio-recurrent prostate cancer - PubMed

 

[evilbooyaa]

I've had salvage brachy patients. Most are pretty miserable due to LUTS. one is a urethral cripple and is heading towards a urinary diversion. I've never had a salvage brachy patient who got prior XRT and brachy. I would not recommend it.

Best options are to either ignore the prostate and treat elsewhere or consider an alternative form of salvage therapy. Send him to somewhere doing irreversible electroporation or maybe HIFU if he wants local therapy. Wouldn't recommend cryo post salvage brachy, would be worried about fistulae.

Edit, saw he doesn't want HIFU. Would consider the IRE route: Feasibility and safety of focal irreversible electroporation as salvage treatment for localized radio-recurrent prostate cancer - PubMed

You see the numerator. Salvage brachy after EBRT more toxic than brachy upfront, no doubt about it.

But, do you see the denominator?

Regardless, re-RT a 3rd time, I would not be enthusiastic for.

I have had a similar situation (but with locally recurrent rectal cancer s/p RT + Surgery, who also had an oligolung met) - I sent him off for systemic therapy. I do not see a purpose of treating oligomets unless you can zap em all. Unless you're trying to stimulate the elusive abscopal effect...

 

[DoctwoB]

You see the numerator. Salvage brachy after EBRT more toxic than brachy upfront, no doubt about it.

But, do you see the denominator?

Regardless, re-RT a 3rd time, I would not be enthusiastic for.

I have had a similar situation (but with locally recurrent rectal cancer s/p RT + Surgery, who also had an oligolung met) - I sent him off for systemic therapy. I do not see a purpose of treating oligomets unless you can zap em all. Unless you're trying to stimulate the elusive abscopal effect...

In this case I do see the denominator (admittedly small N of both numerator and denominator) as I'm involved in all brachys pre/post op, as opposed to some of my other beefs about all the ER calls of post-XRT issues where the numerator is frustratingly high but the denominator is unknown.

 

[TheWallnerus]

I've had salvage brachy patients. Most are pretty miserable due to LUTS. one is a urethral cripple and is heading towards a urinary diversion. I've never had a salvage brachy patient who got prior XRT and brachy. I would not recommend it

Regardless, re-RT a 3rd time, I would not be enthusiastic for.

Thrice locally definitively irradiated

Never seen it, never heard of it…

Twice irradiated patients tend to have quite high grade urotoxicity especially at 5 to 10 years. This is a fair trade off for the outside chance for a cure.

I have never thought about it or had to think about it, but I would never re-reirradiate.

 

[thesauce]

Where in the prostate and how big? Wonder if you could drop a couple more seeds on the focal lesion then SBRT the node.

He will then need ADT/come-to-jesus talk when this comes back in a few years.

Only a single foci and <1cm.

I could conceivably do HDR or LDR here, but honestly I don’t know if that’s any safer than modern SBRT.

 

[thesauce]

Any deets on original gleason score, new gleason score, present PSA and PSA doubling time? perhaps nothing is an option. perhaps could convince yourself the pelvic nodal disease represent the more aggressive biology in the evolutionary process, while the apparently radioresistant disease in the prostate can be ignored, and you just SBRT the node and observe. Sounds like a no rules situation, and obv, first do no harm is the starting point here.

Gleason 8 with PSA 14 at original. Went to nadir of 0.35 after EBRT and came up to 2.5 at the time of LDR. Went back to undetectable and stayed until it came up to 1 about 2 years ago (BS and CT negative at that time), then 1.5 last year, and now 3.1.

New Gleason is 4+3 but not sure how to interpret that in the context of prior RT.

 

[Ray D. Ayshun]

Gleason 8 with PSA 14 at original. Went to nadir of 0.35 after EBRT and came up to 2.5 at the time of LDR. Went back to undetectable and stayed until it came up to 1 about 2 years ago (BS and CT negative at that time), then 1.5 last year, and now 3.1.

New Gleason is 4+3 but not sure how to interpret that in the context of prior RT.

Maybe the bad stuff's in the node. At least that's what I'd tell myself to justify treating it alone. Otherwise, I'd have trouble sleeping the first night after I decided to reretreat the prostate. And many after. Hard to justify. Good news is, if you do nothing, he can always do adt next year. Or the next. Then there's the zillion other bullets. He'll opt in for adt at some point. Just wait him out.

 

[Palex80]

I think you can make the argument that giving SBRT to that node will result in minimal to no toxicity and is thus justified, even if you cant treat the prostate.

 

[TheWallnerus]

I think you can make the argument that giving SBRT to that node will result in minimal to no toxicity and is thus justified, even if you cant treat the prostate.

If I were an American rad onc working for an insurance company and you called me to get approval for this, I would deny

 

[Ray D. Ayshun]

If I were an American rad onc working for an insurance company and you called me to get approval for this, I would deny

 

[evilbooyaa]

In this case I do see the denominator (admittedly small N of both numerator and denominator) as I'm involved in all brachys pre/post op, as opposed to some of my other beefs about all the ER calls of post-XRT issues where the numerator is frustratingly high but the denominator is unknown.

Fair enough. Like I said, it's not a common scenario and even one round of re-irradiation is dicey.

 

[thesauce]

How about a slight twist: patient got upfront 45 Gy EBRT + HDR brachy boost 10 years ago and now has recurrence in the left portion of the gland (was only treated once - although combo therapy)

…If biopsy is only positive on the left, do you SBRT (if so, whole gland or focal)? Brachy again? Other?

 

[FindMeOnTheLinks]

How about a slight twist: patient got upfront 45 Gy EBRT + HDR brachy boost 10 years ago and now has recurrence in the left portion of the gland (was only treated once - although combo therapy)

…If biopsy is only positive on the left, do you SBRT (if so, whole gland or focal)? Brachy again? Other?

Don’t think even in this scenario there is any strong data to suggest one approach better than another in terms of biochemical control and certainly not more firm end points like MFS... Even in the most well-selected cases biochemical control is somewhere around ~50% regardless of modality. Though, there’s a nice meta-analysis showing that grade 3 urinary tox much higher for cryo than for brachy/sbrt IIRC. Will have to dig it up….Don’t know of any data showing toxicity advantage for treating partial gland vs whole gland regardless of Xrt modality. In my training I’ve seen both done. In the end, probably just boils down how you were trained and what you were comfortable with

 

[cmw021]

I believe this is the meta-analysis you are referring to.

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

 

[evilbooyaa]

Don’t think even in this scenario there is any strong data to suggest one approach better than another in terms of biochemical control and certainly not more firm end points like MFS... Even in the most well-selected cases biochemical control is somewhere around ~50% regardless of modality. Though, there’s a nice meta-analysis showing that grade 3 urinary tox much higher for cryo than for brachy/sbrt IIRC. Will have to dig it up….Don’t know of any data showing toxicity advantage for treating partial gland vs whole gland regardless of Xrt modality. In my training I’ve seen both done. In the end, probably just boils down how you were trained and what you were comfortable with

GU tox is lower with RT compared to RP (and HIFU, which had the most GU tox). No significant difference to Cryo from MASTER meta-anslysis.

Cryo looks like the best thing Urology can do in this situation.

How about a slight twist: patient got upfront 45 Gy EBRT + HDR brachy boost 10 years ago and now has recurrence in the left portion of the gland (was only treated once - although combo therapy)

…If biopsy is only positive on the left, do you SBRT (if so, whole gland or focal)? Brachy again? Other?

Focal SBRT or LDR would be not unreasonable, although focal HDR likely the least toxic.