Prostate LDR vs HDR vs SBRT Discussion

[RollTideRadOnc]

If we as a field determined that prostate brachytherapy is important and offers QOL or disease control benefits compared to VMAT or SBRT, it should be reflected in the training of radiation oncologists. If only we had some mechanism to ensure that residents got sufficient experience......

This is where you're off. Brachy doesn't offer any improvements in a real disease endpoint. For instance, look at the largest and best known prospective study: ASCENDE-RT. Absolutely no differens in mets at 9 years. Absolutely no difference in OS. Just an improvement in biochemical recurrence rates -- which unless leads to other improved endpoints -- is worthless in and of itself.

The one thing brachy does increase with certainty? Toxicity.

So I would argue it has not been determined "as a field" that this is neccessary. It is merely a niche modality with pluses and minuses.

As SABR develops further, and as local / regional salavage of truly isolated recurrences (as determined by PSMA) is further refined, the so called "advantages" of brachy will be less and less.

In my mind, given all that, it's perfectly reasonable to move it to the realm of fellowship. It's not a bread and butter technique for a reason.

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[yesmaster]

It is merely a niche modality with pluses and minuses.

Biochemical control is disease control in prostate cancer, but whatever, that's fine, your point is well-taken.

In any case, requirements ought to be more specific and rigorous, and arguing that a large % of current residencies or current practitioners don't do X, Y, Z is a lame excuse.

 

[Chartreuse Wombat]

A few points worth noting. First, the toxicity of going from 70 to 78 Gy is peanuts compared to the potential toxicity of adding brachy. For those who have been practicing long enough with these pts, this should be clear.

Second, going from 70 to 78 does actually decrease mets. Unlike best evidence for brachy, which does not show this.

https://www.redjournal.org/article/S0360-3016(19)30289-5/abstract

https://www.redjournal.org/article/S0360-3016(19)30619-4/fulltext

Mets is a real end pont.

Peanuts? Unless it happens to you.

The largest trial of dose escalation found that Grade 2+ GI/GU toxicity increase by 30-50%. (NNH 16-20)

Effect of Standard vs Dose-Escalated Radiation Therapy for Patients With Intermediate-Risk Prostate Cancer: The NRG Oncology RTOG 0126 Randomized Clinical Trial - PubMed

clinicaltrials.gov Identifier: NCT00033631.

www.ncbi.nlm.nih.gov

FWIW 0126 did show fewer DM (Supplemental Figure below) but the reduction was 6% to 4% (NNT=50).

 

[RollTideRadOnc]

Peanuts? Unless it happens to you.

The largest trial of dose escalation found that Grade 2+ GI/GU toxicity increase by 30-50%. (NNH 16-20)

Effect of Standard vs Dose-Escalated Radiation Therapy for Patients With Intermediate-Risk Prostate Cancer: The NRG Oncology RTOG 0126 Randomized Clinical Trial - PubMed

clinicaltrials.gov Identifier: NCT00033631.

www.ncbi.nlm.nih.gov

FWIW 0126 did show fewer DM (Supplemental Figure below) but the reduction was 6% to 4% (NNT=50).

View attachment 306660

Perhaps peanuts was not the best choice of phrase. However, I think we might agree that addition of brachy entails a much higher risk of longterm meaningful urinary toxicity (for instance G3+). I'm hesitant to over weigh how meaningful an increase in toxicity 78 Gy entails, if it being primarily driven by Grade 2 events.

 

[deleted774703]

Yeaaaa not that excited about brachy boost prostate unless urologist believes it and will send over teh patient

 

[Aphtalyfe]

The one thing brachy does increase with certainty? Toxicity.

With HDR boost we see very little Grade 3+ late toxicities. In published series the rate of late Grade 3 GU toxicity is 1-3%. We are in the process of publishing our experience but seems to be <1%.

Food for thought.

 

[seper]

With HDR boost we see very little Grade 3+ late toxicities. In published series the rate of late Grade 3 GU toxicity is 1-3%. We are in the process of publishing our experience but seems to be <1%.

Food for thought.

Are we talking HDR boost for prostate Ca?

 

[Aphtalyfe]

Are we talking HDR boost for prostate Ca?

Yup. There is of course a higher incidence of acute grade 3, but late grade 3+ (strictures, necrosis, fistula, incontinence) is pretty low. Could also be observer bias, but even so... the almost 20% of late grade 3 GU toxicity with LDR boost is much higher than I would expect with HDR.

 

[evilbooyaa]

Yup. There is of course a higher incidence of acute grade 3, but late grade 3+ (strictures, necrosis, fistula, incontinence) is pretty low. Could also be observer bias, but even so... the almost 20% of late grade 3 GU toxicity with LDR boost is much higher than I would expect with HDR.

Always going to be a difference between the pros who report single institution series and when things are done in a multicenter trial setting.

Especially in something like LDR prostate which can be incredibly unforgiving and there's no ability to 'compensate' for it.

HDR prostate much more forgiving for a suboptimal needle placement or two.

 

[Aphtalyfe]

Always going to be a difference between the pros who report single institution series and when things are done in a multicenter trial setting.

Especially in something like LDR prostate which can be incredibly unforgiving and there's no ability to 'compensate' for it.

HDR prostate much more forgiving for a suboptimal needle placement or two.

Well I think ASCENDE-RT was single center in terms of the brachytherapists... and they are very experienced/high volume center. Again, their toxicity was notably high.

My institution is also very high volume but you are right... HDR is much more forgiving. Teaching residents how to do HDR is much less anxiety provoking than LDR. Even for people who used to do both LDR and HDR, many have transitioned to primarily HDR. Granted, some of that might be billing/reimbursement driven.

 

[MegaVoltagePhoton]

Well I think ASCENDE-RT was single center in terms of the brachytherapists... and they are very experienced/high volume center. Again, their toxicity was notably high.

My institution is also very high volume but you are right... HDR is much more forgiving. Teaching residents how to do HDR is much less anxiety provoking than LDR. Even for people who used to do both LDR and HDR, many have transitioned to primarily HDR. Granted, some of that might be billing/reimbursement driven.

I think the ldr was notstandardized.

 

[thecarbonionangle]

Hdr prostate>>>>>LDR prostate

 

[Aphtalyfe]

I think the ldr was notstandardized.

Even if that's true, the average was close to 20% late grade 3+ GU toxicity... If you had to blame the practitioners at a high volume center vs blame the technique itself... which one do you think is the more likely culprit?

Just to add a little more science to the art: We keep the urethra <105% in most cases (especially post-TURP), <110% is acceptable. LDR allows for 125-130%?

 

[medgator]

Hdr prostate>>>>>LDR prostate

Yup.... You don't see these stories with hdr:

Philly VA Gives 92 Wrong Dose of Radiation: Reports

Ninety-two veterans were given incorrect radiation doses in a common surgical procedure to treat prostate cancer during a six-year period at the Veterans Affairs Medical Center in Philadelphia, according to newspaper reports Sunday.

www.nbcphiladelphia.com

 

[MegaVoltagePhoton]

Even if that's true, the average was close to 20% late grade 3+ GU toxicity... If you had to blame the practitioners at a high volume center vs blame the technique itself... which one do you think is the more likely culprit?

Just to add a little more science to the art: We keep the urethra <105% in most cases (especially post-TURP), <110% is acceptable. LDR allows for 125-130%?

not saying ldr is the way to go (I prefer hdr or really just sbrt I think will eventually offer the same) but the high toxicity in ascende should be interpreted correctly.

 

[seper]

Just like women undergoing Syed template HDR, I bet that a fair number of men undergoing prostate HDR get some PTSD. In contrast, LDR is quick in-and-out.

 

[Aphtalyfe]

Just like women undergoing Syed template HDR, I bet that a fair number of men undergoing prostate HDR get some PTSD. In contrast, LDR is quick in-and-out.

What's the average check-in time to discharge? I've actually never observed a high-volume LDR program in person. For monotherapy it's great that it's only 1 implant though!

Usually my patients are in the department for a total of 4.5-5.5 hours. Including check-in time, IV insertion, implant, anesthesia recovery, treatment planning/delivery, and voiding/ambulation.

 

[scarbrtj]

Usually my patients are in the department for a total of 4.5-5.5 hours. Including check-in time, IV insertion, implant, anesthesia recovery, treatment planning/delivery, and voiding/ambulation.

Man, oh Manischewitz, 5 quick EBRT fractions totally beat the tar out of this. And on liability risk. And in an alternate, just universe should (although it doesn't here) beat the tar out of it on cost.

 

[medgator]

Man, oh Manischewitz, 5 quick EBRT fractions totally beat the tar out of this. And on liability risk. And in an alternate, just universe should (although it doesn't here) beat the tar out of it on cost.

It does on that too i bet. . HDR done in a hospital carries high facility/OR fees I'm sure

 

[Aphtalyfe]

Man, oh Manischewitz, 5 quick EBRT fractions totally beat the tar out of this. And on liability risk. And in an alternate, just universe should (although it doesn't here) beat the tar out of it on cost.

I agree time wise SBRT is better. Although our patients usually get SpaceOAR/Fiducials prior to SBRT so ~1.5hr for SpaceOAR/Fiducial/CT sim. You're right though throughput is way higher with EBRT/SBRT for sure.

I also tend to think SBRT for high-risk disease is subpar to something with a brachytherapy boost. Time will tell.

I'd like to see a trial of SBRT w/ HDR boost, 5Gy x 5 to pelvis, 5-6Gy x 5 to prostate and ??? with HDR boost.

It does on that too i bet. . HDR done in a hospital carries high facility/OR fees I'm sure

Reimbursement depends on the insurance but "Cost" which can be calculated using time driven activity based costing (TDABC) is about the same for HDR mono (2 implants, 2 fractions) and SBRT.

The cheapest (cost for hospital to perform/TDABC) is LDR monotherapy.

Will be interesting to see how things play out with APM!

 

[Gfunk6]

Like Aphtalyfe, we use SBRT with SpaceOAR/Fiducials. We also use the "virtual HDR" regimen published by Fuller.

Virtual HDR CyberKnife SBRT for Localized Prostatic Carcinoma: 5-Year Disease-Free Survival and Toxicity Observations - PubMed

Virtual HDR prostate SBRT creates a very low PSA nadir, a high rate of 5-year disease-free survival and an acceptable toxicity incidence, with results closely resembling those reported post-HDR brachytherapy.

pubmed.ncbi.nlm.nih.gov

We can get truly "extreme" doses to the prostate - as much as 60 Gy+ in five fractions. We also do prostate re-irradiation after primary XRT failure.

 

[Aphtalyfe]

Like Aphtalyfe, we use SBRT with SpaceOAR/Fiducials. We also use the "virtual HDR" regimen published by Fuller.

Virtual HDR CyberKnife SBRT for Localized Prostatic Carcinoma: 5-Year Disease-Free Survival and Toxicity Observations - PubMed

Virtual HDR prostate SBRT creates a very low PSA nadir, a high rate of 5-year disease-free survival and an acceptable toxicity incidence, with results closely resembling those reported post-HDR brachytherapy.

pubmed.ncbi.nlm.nih.gov

We can get truly "extreme" doses to the prostate - as much as 60 Gy+ in five fractions. We also do prostate re-irradiation after primary XRT failure.

Interesting.

Do you insert a foley for every fraction? and do you try to shape where to drop the hot spots?

Also, have you seen much urethral toxicity with a Dmax constraint of 120%?

I've never actually used a cyberknife, but for prostate treatments it has the capability to do real-time tracking as well right?

 

[tomhobbes]

Sorry about this non-sequitur to the most current post. I’m replying to some of the content 10+ posts back by this point.

I posted a few months back about my 3-month LDR experience with Dr. Brian Moran at the Chicago Prostate Cancer Center here. I’ll chime in with my twopence on this topic.

Even if that's true, the average was close to 20% late grade 3+ GU toxicity... If you had to blame the practitioners at a high volume center vs blame the technique itself... which one do you think is the more likely culprit?

Just to add a little more science to the art: We keep the urethra <105% in most cases (especially post-TURP), <110% is acceptable. LDR allows for 125-130%?

At the CPCC urethra was kept under 150%. I didn’t see any G3 acute issues in the (many) follow up visits during my time there. Part of that may have been a generous urethra contour during LDR preplan using a broad brush, along with discharge with Medrol pack and Flomax.

What's the average check-in time to discharge? I've actually never observed a high-volume LDR program in person. For monotherapy it's great that it's only 1 implant though!

Usually my patients are in the department for a total of 4.5-5.5 hours. Including check-in time, IV insertion, implant, anesthesia recovery, treatment planning/delivery, and voiding/ambulation.

Similar total time frame to what you described above. Implant time was 20-30 minutes. Total anesthesia time was ~30-40 minutes. OR turnover was hourly, and on OR days there were 4-5 implants a morning (7 or 8 AM to noon). Patient recovering after anesthesia was maybe another 60-90 minutes. Anesthesia was LMA with sevoflurane and nitrous, skip the fentanyl midazolam cocktail. Honestly the LMA was coming out as the last needle went in. So walk-in to walk-out time varied from 3-4 hours.

It does on that too i bet. . HDR done in a hospital carries high facility/OR fees I'm sure

I agree time wise SBRT is better. Although our patients usually get SpaceOAR/Fiducials prior to SBRT so ~1.5hr for SpaceOAR/Fiducial/CT sim. You're right though throughput is way higher with EBRT/SBRT for sure.

I also tend to think SBRT for high-risk disease is subpar to something with a brachytherapy boost. Time will tell.

I'd like to see a trial of SBRT w/ HDR boost, 5Gy x 5 to pelvis, 5-6Gy x 5 to prostate and ??? with HDR boost.



Reimbursement depends on the insurance but "Cost" which can be calculated using time driven activity based costing (TDABC) is about the same for HDR mono (2 implants, 2 fractions) and SBRT.

The cheapest (cost for hospital to perform/TDABC) is LDR monotherapy.

Will be interesting to see how things play out with APM!

Not my numbers to share. But outpatient clinic-based LDR run the way the Chicago Prostate Cancer Center setup did is cost-effective. A fraction of the proposed numbers in Anne Hubbard’s presentation on bundled payment last ASTRO. I’m not surprised @Aphtalyfe that LDR is the cheapest where you are, too.

As far as the ASCENDE-RT GU toxicity rates – no idea. Every GU radiation oncologist on my job interview trail (both private and academic) said that the published G3 toxicity rate is much higher than what they’ve seen. Some suggested that the ASCENDE protocol was inflexible regarding on-the-fly implant adjustments for pre-plans that may otherwise have resulted in implant objectives being met.

 

[Gfunk6]

Interesting.

Do you insert a foley for every fraction? and do you try to shape where to drop the hot spots?

Also, have you seen much urethral toxicity with a Dmax constraint of 120%?

I've never actually used a cyberknife, but for prostate treatments it has the capability to do real-time tracking as well right?

We don’t use a foley. We very deliberately shape the hotspots around the urethra just like HDR. Have not seen more urethral toxicity any more than conventional fractionation - but like brachy usually short lived.

Sometime people like to trash talk CyberKnife on SDN. But when you can track the prostate continually for yaw, pitch, roll and XYZ transition and use 3.75 mm MLCs to deliver 80-100 non-coplanar beams in < 20 minutes - you would be amazed at what can be achieved.

 

[MegaVoltagePhoton]

You definitely do not need a Cyberknife for prostate sbrt though in case that dissuades people