Intact Prostate Cancer Discussion - SBRT, Brachytherapy, EBRT, SpaceOAR, Margins

[medgator]

late RT toxicities don’t plateau. The longer you follow the more you’ll see

Agreed, even 5 years out though, can't remember the last one

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[medgator]

Again - there is no need to do this in your standard patient, for those who are still doing conventional fractionation.

There is rationale for it in SBRT patients as well as patients who are on anti-coagulation, even if nine-weekers, because they are at higher risk of bleeding.

Yes this makes the most sense

 

[BobbyHeenan]

I really appreciate your posts, you have a strong general clinical experience and it shows.

Thank you. I appreciate it. I love this field and am fortunate to have a good job and felt like I had good training.

I had a professor say you should never be the first to do a procedure (or a new technique, etc), but also don't be the last. I want to at least have spaceOAR in my toolkit so to speak (luckily as noted above, we already had ultrasound/stepper equipment...because even with that equipment when you put man hours into the equation the finances are just not good and possibly even detrimental...not to mention the patients costs go up too). Trying to take a pragmatic approach.

 

[Burt Radnolds]

We have a very robust prostate program in conjunction with a large group of urologists, offering the full gamut of everything except hdr brachy. We have used a lot of spaceoar but now after doing it for several years, have had a handful of trainwrecks in line with the above quoted data. We use it less now.

 

[BobbyHeenan]

We have a very robust prostate program in conjunction with a large group of urologists, offering the full gamut of everything except hdr brachy. We have used a lot of spaceoar but now after doing it for several years, have had a handful of trainwrecks in line with the above quoted data. We use it less now.

May want to consider publishing it if you have any inclination at all. That randomized trial data is almost too good. Zero problems and ?improvements in urinary and ED function? not clearly explained by dosimetry.

I understand the reluctance to publish but could reach out to the other centers to combine data so you’re not singled out.

 

[Mandelin Rain]

Of course it improves urinary toxicity/DVH. It shoves the prostate anteriorly into the bladder. Makes complete sense. [green font]

 

[scarbrtj]

We have a very robust prostate program in conjunction with a large group of urologists, offering the full gamut of everything except hdr brachy. We have used a lot of spaceoar but now after doing it for several years, have had a handful of trainwrecks in line with the above quoted data. We use it less now.

As rad oncs we treat patients with the greatest non-invasive therapy in the history of medicine: the beam. Even so there's been a tendency to muck it up with invasive accoutrements like SpaceOAR. (How about when rad oncs were asking ENTs to remove/re-implant salivary glands to prevent xerstomia?) I have not had a significant rectal toxicity in 10+ years over thousands of patients w/ IG-IMRT and being anal about DVHs and rational about margins.

 

[BobbyHeenan]

As rad oncs we treat patients with the greatest non-invasive therapy in the history of medicine: the beam. Even so there's been a tendency to muck it up with invasive accoutrements like SpaceOAR. (How about when rad oncs were asking ENTs to remove/re-implant salivary glands to prevent xerstomia?) I have not had a significant rectal toxicity in 10+ years over thousands of patients w/ IG-IMRT and being anal about DVHs and rational about margins.

You mean you don’t use 10mm margins (allowed on the phase 3 trial)?

 

[SneakyBooger]

As rad oncs we treat patients with the greatest non-invasive therapy in the history of medicine: the beam. Even so there's been a tendency to muck it up with invasive accoutrements like SpaceOAR. (How about when rad oncs were asking ENTs to remove/re-implant salivary glands to prevent xerstomia?) I have not had a significant rectal toxicity in 10+ years over thousands of patients w/ IG-IMRT and being anal about DVHs and rational about margins.

Absolutely agree with scarbrtj.

Looking at the MAUDE data more closely:

5 colostomies in 3 years? No thank you.

 

[PhotonBomb]

You mean you don’t use 10mm margins (allowed on the phase 3 trial)?

lol

this does raise a good discussion point - what are the standard margins (non-posterior and posterior you all use?) I'm a 5 mm/3 mm posterior guy. Daily IGRT, no fiducials. (this is non SBRT I'm talking about, standard hypofrac)

 

[medgator]

lol

this does raise a good discussion point - what are the standard margins (non-posterior and posterior you all use?) I'm a 5 mm/3 mm posterior guy. Daily IGRT, no fiducials. (this is non SBRT I'm talking about, standard hypofrac)

With cbct? Don't think anyone is just doing kv alone without fiducials and those kind of margins.

I do 6/4 with fiducials, kv daily

 

[PhotonBomb]

With cbct? Don't think anyone is just doing kv alone without fiducials and those kind of margins.

I do 6/4 with fiducials, kv daily

Daily CBCT yeah

 

[deleted1002574]

I do fiducials, CBCT, 6/4, bladder volume ~250-350cc

 

[RickyScott]

Absolutely agree with scarbrtj.

Looking at the MAUDE data more closely:

5 colostomies in 3 years? No thank you.

View attachment 286532

Like protons this seems to be a therapy that looks better on paper/dose distribution but is accompanied by small risk of disasterous events that are just not seen or heard of with IGRT based ebrt.

 

[Reaganite]

Heard from someone in the company they are expecting up to a 50% cut in reimbursement for spaceoar..
Factoring in cost of equipment lease I'm not sure its going to be a big financial draw moving forward. I know the reps have been aggressively selling it to my urologists by pointing out the prof reimbursement is about the same as prostatectomy.

 

[medgator]

. I know the reps have been aggressively selling it to my urologists by pointing out the prof reimbursement is about the same as prostatectomy.

I guess RP has taken a big financial hit the last few years..... It certainly is a lot quicker to do than one

 

[SneakyBooger]

Hmmmmm, I totally missed the 2nd half of the toxicity table in the MAUDE study.

As if colostomies weren't bad enough, it gets even worse - deaths.

 

[medgator]

Hmmmmm, I totally missed the 2nd half of the toxicity table in the MAUDE study.

As if colostomies weren't bad enough, it gets even worse - deaths.

View attachment 286610

I have personally not seen it, but a partner who does more has had a few pts with post procedure n/v and syncope

 

[Mandelin Rain]

I wonder if worldwide there have been 2 grade V toxicities from prostate imrt in the past 2 years. Because in the tiny fraction of those who got SpaceOAR, two died directly as a result of it.

Good marketing gimmick. Solution to a non problem.

 

[RickyScott]

Was at academic center that used calypso for prostate 10 yrs ago although I didn’t treat prostate there. 2 pts ended up in icu with sepsis over several years. Thought it was the stupidest thing ever for whatever minor theoretical benefit the product delivered.

 

[medgator]

Was at academic center that used calypso for prostate 10 yrs ago although I didn’t treat prostate there. 2 pts ended up in icu with sepsis over several years. Thought it was the stupidest thing ever for whatever minor theoretical benefit the product delivered.

I've seen urosepsis with plain old trus fiducials as well. One argument for cbct

 

[RickyScott]

I've seen urosepsis with plain old trus fiducials as well. One argument for cbct

I agree. But with calypso needles and trackers are larger so more of an issue. Number of icu admits probably equaled number of times they stopped beam intrafraction due to gas or something during that period.

 

[Mandelin Rain]

#keepnoninvasivetreatmentsnoninvasive

 

[evilbooyaa]

I suggest the moderators move the SpaceOAR discussion to a separate thread. Little to do with the original post.

Agreed. Good discussion, has been moved into a new thread.

 

[PhotonBomb]

is there anyone that actually does a 1 cm expansion? I am sure there are - would love to know their reasons.

 

[medgator]

is there anyone that actually does a 1 cm expansion? I am sure there are - would love to know their reasons.

Pretty sure the only time I ever saw that was in the last practice I worked at (boomer did it).

 

[Mandelin Rain]

No one has done a 1cm ptv in probably 8 years except.... some corporation running a trial trying to have enough events to find a statistically significant difference

 

[PhotonBomb]

No one has done a 1cm ptv in probably 8 years except.... some corporation running a trial trying to have enough events to find a statistically significant difference

one would hope but I am certain some people do it 'because you never know' and 'just to be safe' and 'that's how the trials did it' and other garbage

 

[evilbooyaa]

I will do 7mm around and 5mm posteriorly if covering LNs, otherwise 5mm around and 3mm posteriorly if treating prostate alone (or during boost). I think 5mm posteriorly when treating prostate alone and using CBCT is overkill.

 

[BobbyHeenan]

No one has done a 1cm ptv in probably 8 years except.... some corporation running a trial trying to have enough events to find a statistically significant difference

10 mm was allowed on the trial. But only 5-10 mm was mandated.

I have no clue what % of patients had what margins. Would LOVE to see a breakdown on toxicity based on margins though in a supplement. Suspect that's buried somewhere. I asked the reps and they looked at me like I was special needs when I asked them about these margin issues.

 

[Mandelin Rain]

I’m a 6 and 4 guy.

 

[Aphtalyfe]

There have been a few published results with HDR single fraction... all the way up to 21 Gy. (19, 20, 20.5, 21) Most showing inferior bFFS. There is also data to suggest that DIL boost doesn't help as much as we hoped it would.

The magic number will be somewhere between 21 and 24. The question is what can the urethra tolerate? Also, if doing single fraction SBRT... you would probably need a foley to ensure that the urethra doesn't get toasted.

Dr. Greco in Portugal has a trial looking at 45/5 vs 24/1. (they use a rectal balloon, fiducials, and foley) https://ascopubs.org/doi/abs/10.1200/JCO.2018.36.6_suppl.128

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I think with the changing reimbursement rates for SpaceOAR it will be done a bit more judiciously. I also think that if we're moving towards single fraction SBRT/HDR, that SpaceOAR will become more important.

 

[DoctwoB]

I wonder if worldwide there have been 2 grade V toxicities from prostate imrt in the past 2 years. Because in the tiny fraction of those who got SpaceOAR, two died directly as a result of it.

Good marketing gimmick. Solution to a non problem.

Personally I’ve seen 3 (Urologist here). Story usually goes:

Bad radiation cystitis->refractory hematuria requiring cbi-> CBI clots off -> Bladder perforates-> peritonitis -> ex lap -> death.

Of course these are from GU toxicity. Never seen a death from rectal toxicity.

 

[RickyScott]

Personally I’ve seen 3 (Urologist here). Story usually goes:

Bad radiation cystitis->refractory hematuria requiring cbi-> CBI clots off -> Bladder perforates-> peritonitis -> ex lap -> death.

Of course these are from GU toxicity. Never seen a death from rectal toxicity.

Curious if these could have been prevented with cone beams checking to make sure bladder is full. Possible rare pt with cystitis had empty bladder throughout treatment. I know personally some very large institutional experiences with well followed pts that never had grade v toxicity or rectal fistula.

 

[Burt Radnolds]

Curious if these could have been prevented with cone beams checking to make sure bladder is full. Possible rare pt with cystitis had empty bladder throughout treatment. I know personally some very large institutional experiences with well followed pts that never had grade v toxicity or rectal fistula.

These things can just happen no matter what you do. No matter how great your plan looks and how great the prep is, the prostate closely approximates the rectal and bladder walls, which will see full dose and potentially be at risk. Additionally, some patients cannot maintain a full bladder with all the coaxing and pharmacologic optimization in the world. Some patients will have other risk factors such as anticoagulation or underlying radiosensitivity.

Practice long enough and you will see some bad things happen no matter how perfect you practice. If you don't, you don't see that many patients, don't follow your patients, or are very very lucky.

 

[scarbrtj]

Personally I’ve seen 3 (Urologist here). Story usually goes:

Bad radiation cystitis->refractory hematuria requiring cbi-> CBI clots off -> Bladder perforates-> peritonitis -> ex lap -> death.

Of course these are from GU toxicity. Never seen a death from rectal toxicity.

Are you sure of any of these: 1) IMRT or not, 2) tx (PTV) margins (incl. volumes such as ENI or no), 3) daily imaging/IGRT employed (if at all)... for these three cases...
It's one thing to call these radiation cystitis cases. Quite a different thing to call them IG-IMRT cystitis cases. E.g., in "proper" prostate only IG-IMRT, not much more than the trigonal region will get high dose RT exposure. A urologist would have a long row to hoe with me if he described, or showed me pics of, a bloody mess all along the dome of the bladder and tried to call it radiation cystitis. I'm not saying I've ever personally managed localized hematuria from a small region of the bladder vs "fulminant"whole-bladder hematuria, but I can guess they'd be different clinical scenarios. Prostatectomies done by one-armed, half-blind surgeons are bound to have different clinical outcomes vs able-bodied surgeons. Again... a guess!

 

[Palex80]

We are not doing SpaceOAR, it's not covered by insurance (yet). Furthermore, there are only a few people with experience on it and like everything else in medicine, there certainly is a learning curve in how to use.
DVHs certainly look better with a SpaceOAR and rectal toxicity will be lower, the question is how clinical (not statistical) significant will the benefit be.

Other than that we treat the prostate with a 7mm uniform margin, fiducials, daily CBCT. Standard fractionation is 63/3.

I would love to go lower in terms of fractions and I believe we will in the coming years. Something like 5-10 fractions sounds reasonable to me.
I am not a fan of the ultra-fractionation with 1 x 19 Gy (or whatever else). I do not think it will work in all prostate tumors.

 

[DoctwoB]

Are you sure of any of these: 1) IMRT or not, 2) tx (PTV) margins (incl. volumes such as ENI or no), 3) daily imaging/IGRT employed (if at all)... for these three cases...
It's one thing to call these radiation cystitis cases. Quite a different thing to call them IG-IMRT cystitis cases. E.g., in "proper" prostate only IG-IMRT, not much more than the trigonal region will get high dose RT exposure. A urologist would have a long row to hoe with me if he described, or showed me pics of, a bloody mess all along the dome of the bladder and tried to call it radiation cystitis. I'm not saying I've ever personally managed localized hematuria from a small region of the bladder vs "fulminant"whole-bladder hematuria, but I can guess they'd be different clinical scenarios. Prostatectomies done by one-armed, half-blind surgeons are bound to have different clinical outcomes vs able-bodied surgeons. Again... a guess!

Honestly have no idea about the characteristics of treatment they received. Anecdotally most of the bad hemorrhagic radiation cystitis I see is in men with XRT >5 years ago, but whether that is a factor of the time course of the complication or less modern techniques used I couldn’t tell you.

 

[SneakyBooger]

there certainly is a learning curve in how to use.

P80, the Stuttgart experience didn't find this in their population - paragraph bottom left of page:

 

[medgator]

P80, the Stuttgart experience didn't find this in their population - paragraph bottom left of page:


View attachment 286704

Those were all balloon spacer pts. Not sure anyone is doing that?

 

[scarbrtj]

Honestly have no idea about the characteristics of treatment they received. Anecdotally most of the bad hemorrhagic radiation cystitis I see is in men with XRT >5 years ago, but whether that is a factor of the time course of the complication or less modern techniques used I couldn’t tell you.

I can tell you

 

[scarbrtj]

I will try to quote Patrick Kupelian from 2005 who was using Novalis (kV IGRT w/ fiducials) at that time at MD Anderson Orlando:
"I put 4mm around the prostate. Past 72 Gy, I put 0 posteriorly."

He just recently had another margin-y paper.

I talk about this a lot but what if you used 4mm margins vs 7mm margins on a 4cm prostate:
PTV volume 7mm margins: 82.5 cc
PTV volume 4mm margins: 57.9 cc
Toxicity correlates with treatment volume in radiation therapy. Trimming margins just 3mm from 7 to 4 cuts treatment volume by 30% here! All dose isovolumes will contract/expand accordingly too; i.e., the 50% isovol will maybe go from 300ccs to 210ccs with a 7->4 reduction. As Herman Suit used to say, "There's no clinical indication for one picogray of dose outside the tumor."

 

[RickyScott]

These things can just happen no matter what you do. No matter how great your plan looks and how great the prep is, the prostate closely approximates the rectal and bladder walls, which will see full dose and potentially be at risk. Additionally, some patients cannot maintain a full bladder with all the coaxing and pharmacologic optimization in the world. Some patients will have other risk factors such as anticoagulation or underlying radiosensitivity.

Practice long enough and you will see some bad things happen no matter how perfect you practice. If you don't, you don't see that many patients, don't follow your patients, or are very very lucky.

I have quite a bit of experience, know a lot of people, and several instituitonal experiences. Never ever heard one case fatal cystitis let a lone 3. Only heard - 2nd hand of one rectal fistula after ill advised biopsy. Again, at one time highly involved with very large prostate database. This just didn’t happen. Never Ever

As pointed out, cystitis should be at base of bladder. In few dialysis pts I have treated, very careful about how much I expand into bladder if at all if no disease detected on base at biopsy or mri.

 

[scarbrtj]

I have quite a bit of experience, know a lot of people, and several instituitonal experiences. Never ever heard one case fatal cystitis let a lone 3. Only heard of one fistulas after ill advised biopsy either. Again, at one time highly involved with very large prostate database. This just didn’t happen.

As pointed out, cystitis should be at base of bladder. In few dialysis pts I have treated, very careful about how much I expand into bladder if at all if no disease detected on base at biopsy or mri.

If I had patients with complications like this after prostatectomy, radiation with ~zero risk of life threatening complications would sound pretty good!

 

[evilbooyaa]

I think the truth is somewhere in the middle. Some places don't do margins correctly, don't do proper dose constraints, etc, and will be at higher risk for developing bad late side effects.

I think the people who have had zero side effects need to think about dose escalating. Also I will be on the urologist's side here that frequently these patients are not followed > 5 years out by rad onc, which is where some of these toxicities can and do still develop. If you're not seeing them for follow-up you won't know that they had this toxicity because the urologists aren't going to bother calling you about it.

 

[thecarbonionangle]

What margins are people using for prostate SBRT?

for HDR, are you guys doing 13.5x2?

 

[Aphtalyfe]

What margins are people using for prostate SBRT?

5mm except 3mm posterior (w/ fiducials, CBCT)

for HDR, are you guys doing 13.5x2?

Yes. Either 2 days back to back (single implant) or 1 week apart. (2 implants)
If they have a reason to be sensitive to radiation we might fractionate the HDR a bit more.
If radiorecurrent we do 6Gy x 6
Combo we do 15 Gy x 1 w/ fiducials/SpaceOAR at the time of HDR implant. Followed by EBRT

 

[thecarbonionangle]

5mm except 3mm posterior (w/ fiducials, CBCT)



Yes. Either 2 days back to back (single implant) or 1 week apart. (2 implants)
If they have a reason to be sensitive to radiation we might fractionate the HDR a bit more.
If radiorecurrent we do 6Gy x 6
Combo we do 15 Gy x 1 w/ fiducials/SpaceOAR at the time of HDR implant. Followed by EBRT

Would you ever do 13.5 BID, separated by 6-8 hrs?

i like the idea of a single implant so the back to back, 2 day regimen is appealing as well for my future practice

whenever you do two days, two fractions, do you do a sim and a plan for each fraction or treat with previous day plan?

 

[thecarbonionangle]

For prostate SBRT, say 7.25x5 how many of you sim and treat with a foley vs no foley?

 

[OTN]

For prostate SBRT, say 7.25x5 how many of you sim and treat with a foley vs no foley?

No foley.
3mm margins all around.
Comfortably full bladder.
8 Gy x 5.
Make sure rectum is empty for sim and tx.