Case: Oligoprogressive pCa with local recurrence

[communitydoc13]

Early 70s and debilitatated due to morbid obesity with DM, chronic orthopedic issues and immobilization. Biochemical failure almost 4 years out from XRT alone for unfavorable intermediate risk disease (XRT alone provided due to above medical confounders and patient choice). PSA kinetics concerning (PSA ~13 with doubling time of 3+ mos).

PSMA PET shows isolated sacral met and posterior prostate recurrence (away from urethra but abutting rectum).

Will counsel regarding importance of ADT with consideration of abi or similar presently. Plan for SBRT to sacral met and looking for local options regarding posterior prostate recurrence.

Any thoughts regarding local options for retreatment of prostate? Nothing, Cryo, HIFU? It's a peripheral and posterior lesion.

Any thoughts on SpaceOar placement in this setting to faciliate SBRT? (I would not offer SBRT without spaceoar as abutment of rectum).

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[OTN]

I usually refer for cryo for local recurrence. I have done repeat SBRT to the prostate after initial RT, but it was more than 10 years after the initial treatment. There's data for repeat SBRT, but I wouldn't be excited to do it in the setting of either concomitant mets or at only 4 years after initial RT.

 

[Gfunk6]

Repeat SBRT to prostate - use fiducials + SpaceOAR to spare rectum and facilitate dose escalation.

 

[communitydoc13]

Repeat SBRT to prostate - use fiducials + SpaceOAR to spare rectum and facilitate dose escalation.

You have good experience with SpaceOAR placement years post prior XRT?

 

[MidwestRadOnc]

Nothing. I'd be concerned the bone met (if correlated on CT imaging) is the source of the rapidly rising PSA and ablate it then monitor. You could be seeing false positive signal in the prostate or indolent treated disease. I wouldn't risk excessive toxicity without good evidence this is a major threat to this now metastatic patient with multiple competing factors for a short life expectancy. Repeat PSMA scan 3 months post SBRT to bone met and see what PSA is doing and changes in uptake in prostate?

 

[Gfunk6]

You have good experience with SpaceOAR placement years post prior XRT?

Yes, extremely good. If possible, I try to treat the whole prostate to 34 Gy in 5 fractions and then dose escalate to gross disease. However, in certain cases I would just treat the gross disease; in your case it makes sense to do so since the disease is already outside the prostate.

 

[tomhobbes]

For me, would ideally like to see biopsy-proven in-gland recurrence before considering re-irradiation. Of course decision to pursue aggressive treatment here driven by his overall PS. If re-treat is on the table can consider SBRT or brachy. Spacer prior to reRT can be placed but sometimes challenging due to fibrosis and likely require some time dissecting before placement.

I personally like to have at least 4-5 years in between courses of external beam RT. My partners have done shorter. Another option is to start ADT to buy him more lag time between the external beam courses. We have some times skipped the spacer for glands that have shrunk down under 15-20 cc as spacer placement for these small glands, with shorter "runway" for the spacer needle tip, is challenging (at least in my hands) and dosimetric benefit is not as great as for a larger gland with greater posterior prostate-rectum abutment.

 

[communitydoc13]

biopsy-proven in-gland recurrence before considering re-irradiation

You could be seeing false positive signal in the prostate or indolent treated disease.

I would consider this particular imaging finding to be pathognomonic for localized in-gland recurrence (often not the case). Well circumscribed and super-hot with clear abutment of capsule posteriorly.

Minimizing procedures is ideal for this guy and horrible infection post-bx years ago, so probably not going to emphasize bx (in this particular case only).

 

[DoctwoB]

My 2 cents:

First: I would not offer salvage therapy without biopsy. Sure he's probably locally recurrent based on PSMA, but i have yet to see compelling data there isn't a reasonable rate of false positive. Salvage therapy often has significant toxicity, not signing up for that without tissue.

Second: Are we sure salvage therapy is appropriate in this individual? An immobile morbidly obese patient is highly unlikely to die of prostate cancer. Even if he were, he is already metastatic. The likelihood of cure with salvage local therapy + SBRT to oligometastatic site is quite low. In reality it is likely at best a delay in progression.

I would personally start ADT + Abi and if low expected toxicity SBRT the solitary bone met. Then trial a holiday off the therapy in a few years and see what the PSA does.

 

[evilbooyaa]

First reaction reading just the OP:

First off, biopsy the prostate. PSMA PET/CT ALONE is not sufficient, IMO, to warrant the potential toxicities of repeat local therapy to the prostate. Probably worth getting an MRI prior to it. Confirm there is local disease before any form of local re-treatment. Get saturation biopsies so you can determine if focal treatment to just PSMA avid nodule is appropriate vs whole gland treatment, regardless of whether it is SBRT or Cryo in this position. MASTER meta-analysis tells us that all salvage options are equally efficacious, but the LEAST toxic are SBRT, brachytherapy (I personally would favor HDR), and Cryotherapy. RP and HIFU are more toxic. This is completely separate from the question of whether retreatment of the prostate is warranted in the setting of metastatic (even if oligometastatic) disease

What is SUV of the sacral bone met? Does that need a biopsy to confirm mets before treating as such? I presume the plan is no ADT?

Abutting rectum is tough in terms of repeating SBRT. I am not personally enthusiastic for attempting SpaceOAR in setting of irradiated prostate. Consider Barrigel, which you can inject just a little bit in (as opposed to having to go full court press w/ SpaceOAR or SpaceOAR VUE) and see if you're getting separation. And if it goes into the rectal wall, Barrigel is reversible as opposed to spaceOAR.

Reading through the other posts:

I usually refer for cryo for local recurrence. I have done repeat SBRT to the prostate after initial RT, but it was more than 10 years after the initial treatment. There's data for repeat SBRT, but I wouldn't be excited to do it in the setting of either concomitant mets or at only 4 years after initial RT.

I don't necessarily let 4 years limit my rec for re-SBRT, especially if the initial RT was not SBRT. Re-doing SBRT in the setting of upfront SBRT is a bit more 'worrisome' for me given paucity of data to that approach. That being said, the concomitant mets is definitely an important consideration and some would say a hard contra-indication to any form of prostate re-treatment.

My 2 cents:

First: I would not offer salvage therapy without biopsy. Sure he's probably locally recurrent based on PSMA, but i have yet to see compelling data there isn't a reasonable rate of false positive. Salvage therapy often has significant toxicity, not signing up for that without tissue.

Second: Are we sure salvage therapy is appropriate in this individual? An immobile morbidly obese patient is highly unlikely to die of prostate cancer. Even if he were, he is already metastatic. The likelihood of cure with salvage local therapy + SBRT to oligometastatic site is quite low. In reality it is likely at best a delay in progression.

I would personally start ADT + Abi and if low expected toxicity SBRT the solitary bone met. Then trial a holiday off the therapy in a few years and see what the PSA does.

I think observation vs ADT +/- Abi is also a VERY reasonable approach for this unhealthy patient who on paper, may not have a 5-10 year life expectancy.

 

[TheWallnerus]

Early 70s and debilitatated due to morbid obesity with DM, chronic orthopedic issues and immobilization. Biochemical failure almost 4 years out from XRT alone for unfavorable intermediate risk disease (XRT alone provided due to above medical confounders and patient choice). PSA kinetics concerning (PSA ~13 with doubling time of 3+ mos).

PSMA PET shows isolated sacral met and posterior prostate recurrence (away from urethra but abutting rectum).

Will counsel regarding importance of ADT with consideration of abi or similar presently. Plan for SBRT to sacral met and looking for local options regarding posterior prostate recurrence.

Any thoughts regarding local options for retreatment of prostate? Nothing, Cryo, HIFU? It's a peripheral and posterior lesion.

Any thoughts on SpaceOar placement in this setting to faciliate SBRT? (I would not offer SBRT without spaceoar as abutment of rectum).

How do morbidly obese men with DM fare with SpaceOAR? Known to have more complications, or no one knows?

 

[Palex80]

How do morbidly obese men with DM fare with SpaceOAR? Known to have more complications, or no one knows?

Rectal complications are lower, once the patient survives placement of SpaceOAR.

 

[ramsesthenice]

I am confident that I do more re-irradiation than most. And I would not treat the prostate for this guy yet. My logic:

His life expectancy sounds not the greatest and he already has metastatic progression. Chance of cure is very low as is risk of death from disease in the prostate.

His disease in the gland is posterior and less likely to cause symptomatic progression than an anterior lesion. Rectal invasion direct from the prostate is pretty uncommon.

The benefit of local control in the gland before proving you can get systemic control (not specific to this case) is unclear at best.

My thoughts: try systemic therapy +/- sacral SBRT. If he tolerates systemic therapy well, leave well enough alone until there is a more compelling reason to treat.

I also don’t think biopsies are necessary. If you absolutely must, please use a transperineal approach. Risk of rectal complications at this point with a trans rectal approach is fairly significant.

 

[DoctwoB]

I am confident that I do more re-irradiation than most. And I would not treat the prostate for this guy yet. My logic:

His life expectancy sounds not the greatest and he already has metastatic progression. Chance of cure is very low as is risk of death from disease in the prostate.

His disease in the gland is posterior and less likely to cause symptomatic progression than an anterior lesion. Rectal invasion direct from the prostate is pretty uncommon.

The benefit of local control in the gland before proving you can get systemic control (not specific to this case) is unclear at best.

My thoughts: try systemic therapy +/- sacral SBRT. If he tolerates systemic therapy well, leave well enough alone until there is a more compelling reason to treat.

I also don’t think biopsies are necessary. If you absolutely must, please use a transperineal approach. Risk of rectal complications at this point with a trans rectal approach is fairly significant.

Why no trans rectal Bx? Done plenty post XRT without any issues. He's clearly higher risk for infection so very reasonable to do TP even if needing anesthesia but TRUS is not wrong (despite RCT data of unchanged infection risk)

 

[ramsesthenice]

Why no trans rectal Bx? Done plenty post XRT without any issues. He's clearly higher risk for infection so very reasonable to do TP even if needing anesthesia but TRUS is not wrong (despite RCT data of unchanged infection risk)

I’ve seen a couple develop non healing rectal wall injuries. It’s certainly not most. But sprinkle in a little DM (and I’m going to take a wild guess that it’s not well controlled) and you have a nice setup for badness.

 

[TheWallnerus]

I’ve seen a couple develop non healing rectal wall injuries. It’s certainly not most. But sprinkle in a little DM (and I’m going to take a wild guess that it’s not well controlled) and you have a nice setup for badness.

Notable “literature history” of association of worse tox outcomes with prostate RT in those with DM

Prostate cancer patients with unmanaged diabetes or on insulin have worse outcomes and toxicities after treatment with radiation therapy

To determine the impact of type 2 diabetes mellitus (T2DM) for men with localized prostate cancer receiving definitive radiation therapy (RT).We perform a retrospective review of 3,217 patients, from 1998-2013, subdivided into 5 subgroups: (I) no T2DM; ...

www.ncbi.nlm.nih.gov

 

[ramsesthenice]

Something else I have done a few times (6-7) for bulky symptomatic recurrences is 45/30 BID. Totally made up and I first tried it about 7 years ago before the SBRT data looked good. Every time, I’ve gotten an excellent and durable palliate response without significant toxicity. It’s not technically ablative but I haven’t seen a local progression yet. When I get to 10, I plan to write it up. It’s still my personal preference for palliation in situations where I am not concerned about being ablative (ie, other metastatic sites, questionable PFS, etc).

 

[rahdonc]

MRI could be helpful to better define the extent of the prostate disease. Should biopsy before offering any kind of reirradiation salvage.