Pelvic nodal SBRT

[Grubbe-a-dub-dub]

About to do a peer review for a case where I want to use SBRT for an isolated pelvic nodal recurrence for a patient with prostate cancer treated with EBRT (did not include pelvis in prior field).

Anyone have strong evidence for this? What does fx would you use?

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[Sheldor]

What about oligomet data? SABR-COMET and Gomez? Additionally, at ASTRO this year didn't they present a prostate oligomet paper?

 

[Grubbe-a-dub-dub]

Actually, I just reviewed the case again. It's an isolated pelvic nodal failure after prostatectomy and salvage RT to the prostate bed alone. Thoughts?

 

[seper]

I would put the patient on ADT instead, especially if he only had short-term ADT in the past.

 

[Sheldor]

Actually, I just reviewed the case again. It's an isolated pelvic nodal failure after prostatectomy and salvage RT to the prostate bed alone. Thoughts?

I've had really good luck doing nodes alone over 28 fractions and boosting the positive node to 70 Gy using SIB. I have a few patients who are still disease free after doing that.

 

[seper]

That's hard to do in a patient previously treated to the prostate fossa.

[/QUOTE]

I've had really good luck doing nodes alone over 28 fractions and boosting the positive node to 70 Gy using SIB. I have a few patients who are still disease free after doing that.

 

[Sheldor]

That's hard to do in a patient previously treated to the prostate fossa.

[/QUOTE]

If they did fossa alone I haven't had any problems. Essentially treat superior to their prior field fossa alone field. Internal/External iliacs up to the commons

 

[scarbrtj]

I have done this. SBRT is a good option as is high dose conventional fractionation. If they deny SBRT, obv choose high dose IG-IMRT, 70+ Gy IMHO. Historically, staging-wise, node-positive equaled M1. A bit of mis-classification as there are clearly more N1 patients who have long-term DFSs after maximal local therapies than M1 patients do. Would not only add AAT but also Zytiga; although unlike the "typical" stage IV patient would not plan on lifelong AAT therapy 'til failure. Would have planned stopping point... I like a year (two is valid too) and then see what the PSA does. But to your original question... if the insurance company will not allow the cheaper, more convenient option of SBRT, simply use the much more expensive but still oncologically efficacious option of IG-IMRT at 1.8-2.5Gy per day. This, of course, will be allowed. My "extratargetorial" percent isodose lines look essentially the same in SBRT or routine IG-IMRT anyways. Which is to say I'm not lackadaisical with SBRT I'm just really fastidious about my prostate IG-IMRT. Either w/ SBRT or IMRT, I'd be very ISRT, no ENI.

 

[MegaVoltagePhoton]

There are data for sbrt. Stomp trial for example. Recent retrospective report from Hopkins in red journal suggests adt plus sbrt may be better than sbrt alone. Other option is pelvic nodal RT with adt. They are investigating both approaches in the storm trial.

 

[evilbooyaa]

This patient is not oligometastatic. He has regionally recurrent disease. He does not have M1 disease if he has a regional LN positive. Yes N1 = Stage IV in prostate (and that's a dumb historical relic of prostate cancer that needs to be eliminated given long-term control and *gasp* cure of N1 patients) but that is not the same as oligometastatic disease, IMO. STOMP and ORIOLE required oligoMetastatic (M1) disease AFAIK.

You can still SBRT it if you want, but I would favor a more comprehensive treatment of the nodes (above the level of the fossa) to 45Gy with a SIB as high as you can go (limited by bowel dosimetry). Shoot for 70Gy if feasible. Overlap with a previous fossa only field is unlikely to limit you, unless the LN is co-planar with the previous fossa treatment. I would give ADT concurrently and adjuvantly for at least 1 year.

Alternatively, you could consider neoadjuvant ADT for 4 months. If the node is no longer visible, then treat all pelvic LNs comprehensively to 45Gy. If there is still residual LN (albeit smaller) may be easier to dose escalate. I think this patient requires comprehensive nodal treatment with proper SIB escalation to the nodal disease.

If you SBRT the LN you see and he recurs in other LNs, you're now in a bit of a pickle.

 

[MegaVoltagePhoton]

This patient is not oligometastatic. He has regionally recurrent disease. He does not have M1 disease if he has a regional LN positive. Yes N1 = Stage IV in prostate (and that's a dumb historical relic of prostate cancer that needs to be eliminated given long-term control and *gasp* cure of N1 patients) but that is not the same as oligometastatic disease, IMO. STOMP and ORIOLE required oligoMetastatic (M1) disease AFAIK.

You can still SBRT it if you want, but I would favor a more comprehensive treatment of the nodes (above the level of the fossa) to 45Gy with a SIB as high as you can go (limited by bowel dosimetry). Shoot for 70Gy if feasible. Overlap with a previous fossa only field is unlikely to limit you, unless the LN is co-planar with the previous fossa treatment. I would give ADT concurrently and adjuvantly for at least 1 year.

Alternatively, you could consider neoadjuvant ADT for 4 months. If the node is no longer visible, then treat all pelvic LNs comprehensively to 45Gy. If there is still residual LN (albeit smaller) may be easier to dose escalate. I think this patient requires comprehensive nodal treatment with proper SIB escalation to the nodal disease.

If you SBRT the LN you see and he recurs in other LNs, you're now in a bit of a pickle.

So that's actually not correct. 42% of patients on STOMP had N1 disease actually...For ORIOLES I don't know the number, but note I said the retrospective series (not ORIOLES) which is in press at Red Journal https://www.redjournal.org/article/S0360-3016(19)33641-7/fulltext

Actually most patients getting SBRT for mets prospectively have had nodal disease if you look at the trials. I think it's something many people miss because when we think metastatic we think of M1a node or bone, but actually, many of these patients have pelvic nodal relapses.

 

[Chartreuse Wombat]

I think that it is a mistake to treat focal LN with SBRT.

I have attached one of the few studies with reasonable followup; most patients develop recurrence in a LN nearby.

Better to treat the regional nodes with SIB.

Of course one cannot be dogmatic given the weak evidence but the natural history of LN metastases is different than bone metastases where SCRT seems to work better.

 

[Burt Radnolds]

I think that it is a mistake to treat focal LN with SBRT.

I have attached one of the few studies with reasonable followup; most patients develop recurrence in a LN nearby.

Better to treat the regional nodes with SIB.

Of course one cannot be dogmatic given the weak evidence but the natural history of LN metastases is different than bone metastases where SCRT seems to work better.

Agree with this. Have been in this dilemma before and my conclusions were the same after reviewing the available data. I also still think that SBRT is acceptable, with appropriate counseling, and have had patients still opt for it given the convenience and lower toxicity profile of SBRT (16 v 5% late toxicity in above provided study). Particularly older patients traveling far.

 

[MegaVoltagePhoton]

Agree with this. Have been in this dilemma before and my conclusions were the same after reviewing the available data. I also still think that SBRT is acceptable, with appropriate counseling, and have had patients still opt for it given the convenience and lower toxicity profile of SBRT (16 v 5% late toxicity in above provided study). Particularly older patients traveling far.

I don’t disagree but it is an open question for sure and there are data to use sbrt here. There is I believe an ongoing Belgian trial (storm) looking at this.

 

[seper]

So why do you guys believe that nodal-only mets have better prognosis than bone disease?

 

[MegaVoltagePhoton]

So why do you guys believe that nodal-only mets have better prognosis than bone disease?

Bone disease also fails, just in bone and not nodes. I don’t think the prognosis of bony disease is better it is just that you can’t do much more than treat the bony lesion, whereas with node lesions as they said you might get something out of treating adjacent nodes

Hopkins is going to run a trial of sbrt plus xofigo given the high rate of distant bone failure after SBRT to bony mets

 

[Chartreuse Wombat]

Just one of many papers that survival for N+ better than M1

Assessment of the prognostic value of the 8th AJCC staging system for patients with clinically staged prostate cancer; A time to sub-classify stage IV?

The American Joint Committee on Cancer (AJCC) staging system (8[th] edition) for prostate cancer has been published. The current study seeks to validate the prognostic performance of the changes in the new system among clinically staged prostate cancer ...

www.ncbi.nlm.nih.gov

 

[scarbrtj]

If you SBRT the LN you see and he recurs in other LNs, you're now in a bit of a pickle.

Sour pickle either way but you can rather easily make the argument that if he recurs out-of-field from the SBRT re-XRT, you can just SBRT that. So you can argue either scenario. In the setting of recurrence I am always more worried about the disease I know is grossly positive vs some lurking microscopic disease which, after a long DFS interval, has been reluctant to show itself.

I think that it is a mistake to treat focal LN with SBRT.

I have attached one of the few studies with reasonable followup; most patients develop recurrence in a LN nearby.

Better to treat the regional nodes with SIB.

Of course one cannot be dogmatic given the weak evidence but the natural history of LN metastases is different than bone metastases where SCRT seems to work better.

Good paper. The only counter/question I would have is what difference, if any, would the abiraterone era have on these patients... could it allow ISRT. If there was much overlap between previous fields and trying to do re-ENI, I would lean real strongly toward XRT to gross dz only.

So why do you guys believe that nodal-only mets have better prognosis than bone disease?

That's why the staging was changed. Used to be, if you were node-pos, you were as good as M1 because either way you were stage IV. Now, you're IV-A instead of M1 (M1 is IV-B). This was a point Swanson made in his plenary presentation to ASTRO last decade on his SWOG study re: N+. He presented actually a fair amount of N+ data from SWOG (wouldn't know it from this abstract) and said, look, it's time to be not nihilistic about N+ disease because I've cured quite a few of these patients. It was the first time that I can recall being disavowed of the notion of N+ being relatively incurable. (Needless to say SBRT wasn't a thing back then, it was early adj RT not recurrent dz, etc etc.) But playing the other side of the coin... a +LN is, technically, a metastasis. And a single one would technically be an oligometastasis!

 

[evilbooyaa]

So that's actually not correct. 42% of patients on STOMP had N1 disease actually...For ORIOLES I don't know the number, but note I said the retrospective series (not ORIOLES) which is in press at Red Journal https://www.redjournal.org/article/S0360-3016(19)33641-7/fulltext

Actually most patients getting SBRT for mets prospectively have had nodal disease if you look at the trials. I think it's something many people miss because when we think metastatic we think of M1a node or bone, but actually, many of these patients have pelvic nodal relapses.

Reviewing STOMP's JCO publication, 21/62 reported patients had N1 (only) disease. So I concede that point with 1/3rd of patients being called 'oligometastatic' in STOMP.

That being said, in STOMP those patients likely had SURGERY, not SBRT to the nodal disease. Remember that STOMP was just metastasis-directed therapy, not solely SBRT (similar to how MDACC Gomez Trial was not RT alone, patients could have surgery). If patients had previously had a PLND, they had removal of only the suspicious lymph nodes.

If they didn't have a PLND then they had a full salvage PLND in addition to removing the suspicious node. To me that sounds a lot more similar with comprehensive nodal RT rather than SBRT.

 

[evilbooyaa]

But playing the other side of the coin... a +LN is, technically, a metastasis. And a single one would technically be an oligometastasis!

By that logic, technically a lung cancer with a positive hilar LN is a metastasis and technically an oligometastatic cancer? Do you see where that side of the coin leads you?

In prostate cancer, it's crap logic and relics of old staging paradigms that N1 prostate cancer is stage IV (and no it does not matter that it is stage IVa and IVb IMO) and not stage III. Also see, Sarcoma staging. Same issue IMO.

 

[Chartreuse Wombat]

The comparison arm in STOMP was nothing. Once can conclude that treatment is better than nothing (at least for the horrible endpoint of bRFS)

 

[evilbooyaa]

So why do you guys believe that nodal-only mets have better prognosis than bone disease?

Because there's a data that says it. Do we need a RCT for this?

Just as an example:

https://www.sciencedirect.com/science/article/pii/S0302283813003400 - 30% no increase in PSA with N+ disease
https://www.sciencedirect.com/science/article/pii/S0302283818306675 - NCDB

 

[seper]

Out of 10,000 men authors found 4 node-positive that were alive and cancer-free at 8 years, but technically this paper does provide the evidence I was asking about. Thanks

Just one of many papers that survival for N+ better than M1

Assessment of the prognostic value of the 8th AJCC staging system for patients with clinically staged prostate cancer; A time to sub-classify stage IV?

The American Joint Committee on Cancer (AJCC) staging system (8[th] edition) for prostate cancer has been published. The current study seeks to validate the prognostic performance of the changes in the new system among clinically staged prostate cancer ...

www.ncbi.nlm.nih.gov

 

[medgator]

Because there's a data that says it. Do we need a RCT for this?

Just as an example:

https://www.sciencedirect.com/science/article/pii/S0302283813003400 - 30% no increase in PSA with N+ disease
https://www.sciencedirect.com/science/article/pii/S0302283818306675 - NCDB

Or just plain logic... You know, T, N, M.....

 

[Grubbe-a-dub-dub]

Fail - they denied the treatment....I tried to use the STOMP trial for justification, but she wasn't impressed by the rationale of avoiding hormone treatment.

I was about to tell her to try some ADT and let me know how you feel on it....if we can avoid it with a safe and minimally toxic treatment why wouldn't we try?

I'll try to put it through for IMRT but I doubt it'll go through.

 

[evilbooyaa]

Fail - they denied the treatment....I tried to use the STOMP trial for justification, but she wasn't impressed by the rationale of avoiding hormone treatment.

I was about to tell her to try some ADT and let me know how you feel on it....if we can avoid it with a safe and minimally toxic treatment why wouldn't we try?

I'll try to put it through for IMRT but I doubt it'll go through.

Tons of data to suggest that RT + ADT is better than ADT alone in node positive prostate. I think in a potentially curative situation I would favor use of ADT, FWIW.

 

[Chartreuse Wombat]

Out of 10,000 men authors found 4 node-positive that were alive and cancer-free at 8 years, but technically this paper does provide the evidence I was asking about. Thanks

You asked why people would think N1 is different than M1. The figure below appears in this paper

IVA (N+) survival is better than IVB (e.g. Bone met)

What am i missing?

 

[Chartreuse Wombat]

Sour pickle either way but you can rather easily make the argument that if he recurs out-of-field from the SBRT re-XRT, you can just SBRT that. So you can argue either scenario. In the setting of recurrence I am always more worried about the disease I know is grossly positive vs some lurking microscopic disease which, after a long DFS interval, has been reluctant to show itself.

Good paper. The only counter/question I would have is what difference, if any, would the abiraterone era have on these patients... could it allow ISRT. If there was much overlap between previous fields and trying to do re-ENI, I would lean real strongly toward XRT to gross dz only.

That's why the staging was changed. Used to be, if you were node-pos, you were as good as M1 because either way you were stage IV. Now, you're IV-A instead of M1 (M1 is IV-B). This was a point Swanson made in his plenary presentation to ASTRO last decade on his SWOG study re: N+. He presented actually a fair amount of N+ data from SWOG (wouldn't know it from this abstract) and said, look, it's time to be not nihilistic about N+ disease because I've cured quite a few of these patients. It was the first time that I can recall being disavowed of the notion of N+ being relatively incurable. (Needless to say SBRT wasn't a thing back then, it was early adj RT not recurrent dz, etc etc.) But playing the other side of the coin... a +LN is, technically, a metastasis. And a single one would technically be an oligometastasis!

The abiraterone question is valid. More evidence (weak as it is) that IFRT is not good for nodes in prostate.

 

[medgator]

I'll try to put it through for IMRT but I doubt it'll go through.

Why not? Previous xrt history

 

[Burt Radnolds]

That's a pretty absurd denial of treatment. If they reject IMRT as well they are criminals.

 

[scarbrtj]

By that logic, technically a lung cancer with a positive hilar LN is a metastasis and technically an oligometastatic cancer? Do you see where that side of the coin leads you?

In prostate cancer, it's crap logic and relics of old staging paradigms that N1 prostate cancer is stage IV (and no it does not matter that it is stage IVa and IVb IMO) and not stage III. Also see, Sarcoma staging. Same issue IMO.

Well I was being mostly facetious. The OP HPV+ stagers listened to you and moved some of what used to be stage IV (IV-A) patients all the way down to stage II. And hows about when we had that whole celiac axis node thing being M1a or M1b in esophageal if the tumor were just an inch cranial or caudal. Or, you can have a single SLN+ in breast cancer and there's good data that just essentially is a marker for metastatic disease in most patients. Staging is a little bit of a reductio ad absurdum. But in the words of Don Rumsfeld: you go to war with the army you have not the army you want. Today's staging systems will also soon themselves be "relics of old staging paradigms."

 

[Mandelin Rain]

Abutting previous XRT is one of the surest ways to get IMRT (and usually SBRT) paid for. If you weren't using that as your primary rational last time, I'd call back.

 

[scarbrtj]

That's a pretty absurd denial of treatment. If they reject IMRT as well they are criminals.

They won't, and this is one of those billing funhouse mirror rooms where the ins. company actually argues against its own self-interest.

 

[deleted205418]

Actually, I just reviewed the case again. It's an isolated pelvic nodal failure after prostatectomy and salvage RT to the prostate bed alone. Thoughts?

Limited data though this is the largest series I'm aware of. Ongoing RCTs in Europe addressing node-only SBRT versus pelvic nodal RT. Until then I think pelvic nodal RT with SIB is probably the right choice though SBRT could be considered for poor PS / life expectancy patients for whom the GI toxicity from pelvic RT may not be worth it.

Metastasis-directed Therapy in Treating Nodal Oligorecurrent Prostate Cancer: A Multi-institutional Analysis Comparing the Outcome and Toxicity of Stereotactic Body Radiotherapy and Elective Nodal Radiotherapy - PubMed

This study investigated the difference between stereotactic and elective nodal radiotherapy in treating limited nodal metastatic prostate cancer. Nodal relapse was less frequent following elective nodal radiotherapy than following stereotactic body radiotherapy, and thus elective nodal...

www.ncbi.nlm.nih.gov

 

[radiation]

Gonna play devil's advocate here and suggest a salvage pelvic node dissection isn't an unreasonable thing to discuss if the surgeon is willing

Long-term outcomes of salvage lymph node dissection for clinically recurrent prostate cancer: results of a single-institution series with a minimum follow-up of 5 years - PubMed

Salvage lymph node dissection may represent a therapeutic option for selected patients with nodal recurrence after radical prostatectomy. Roughly 40% of men did not show any further clinical recurrence at long-term follow-up after surgery.

www.ncbi.nlm.nih.gov

American Urological Association

 

[ramsesthenice]

I think what’s missing here is patient selection. Someone who has a radiographic “isolated” nodal recurrence 3 years after surgery with a PSA of 0.5 and DT of 18 months is far more likely to truly have an oligometastatic recurrence and do well with SBRT than someone with less favorable characteristics.

I have treated 8 such favorable patients over the last 3 years with SBRT. Only 3 are still NED. Two had subsequent PA failures (would not have been covered with comprehensive nodal RT). One developed a thoracic bone met, one had an isolated pelvic met (maybe would have been prevented with pelvic RT), and one has a slowly rising PSA and no radiographic identifiable disease.

In my opinion, for patients with favorable characteristics the ability to delay ADT for 12+ months with nontoxic therapy is clinically meaningful. But don’t fool yourself, your not curing many of these folks.

 

[Ray D. Ayshun]

I have a patient with progression on abi. Axumin scan shows only two para-aortic nodes that are positive. I forget now if this would historically be his only two sites of mets, or if this is more officially a case of oligoprogression. I'm wondering about sbrting the nodes with a scheme more in line with the Oriole trial, which was a bit more conservative than STOMP SBRT. At the same time, I'm wondering about treating the nodes slightly up and downstream electively to like 25 Gy in 5 fx, prioritizing normal tissue, which is conceptually in line with what Wombat posted. There's no precedent for this in 5 fx, but the Durham VA/Duke put out a paper taking this approach in ten fx.

Hypofractionated Image-Guided Radiation Therapy With Simultaneous-Integrated Boost Technique for Limited Metastases: A Multi-Institutional Analysis

Purpose: To perform a multi-institutional analysis following treatment of limited osseous and/or nodal metastases in patients using a novel hypofractionated image-guided radiotherapy with simultaneous-integrated boost (HIGRT-SIB) technique.Methods: Consecutive ...

www.ncbi.nlm.nih.gov

thoughts?

 

[ramsesthenice]

I have a patient with progression on abi. Axumin scan shows only two para-aortic nodes that are positive. I forget now if this would historically be his only two sites of mets, or if this is more officially a case of oligoprogression. I'm wondering about sbrting the nodes with a scheme more in line with the Oriole trial, which was a bit more conservative than STOMP SBRT. At the same time, I'm wondering about treating the nodes slightly up and downstream electively to like 25 Gy in 5 fx, prioritizing normal tissue, which is conceptually in line with what Wombat posted. There's no precedent for this in 5 fx, but the Durham VA/Duke put out a paper taking this approach in ten fx.

Hypofractionated Image-Guided Radiation Therapy With Simultaneous-Integrated Boost Technique for Limited Metastases: A Multi-Institutional Analysis

Purpose: To perform a multi-institutional analysis following treatment of limited osseous and/or nodal metastases in patients using a novel hypofractionated image-guided radiotherapy with simultaneous-integrated boost (HIGRT-SIB) technique.Methods: Consecutive ...

www.ncbi.nlm.nih.gov

thoughts?

Technically you could do it. Not really sure how much it will help though. No matter how big you make it chances are they will progress eventually. Once you get outside the pelvis I typically just treat the involved nodes with the caveat that no one really knows.

 

[Palex80]

I have a patient with progression on abi. Axumin scan shows only two para-aortic nodes that are positive. I forget now if this would historically be his only two sites of mets, or if this is more officially a case of oligoprogression. I'm wondering about sbrting the nodes with a scheme more in line with the Oriole trial, which was a bit more conservative than STOMP SBRT. At the same time, I'm wondering about treating the nodes slightly up and downstream electively to like 25 Gy in 5 fx, prioritizing normal tissue, which is conceptually in line with what Wombat posted. There's no precedent for this in 5 fx, but the Durham VA/Duke put out a paper taking this approach in ten fx.

Hypofractionated Image-Guided Radiation Therapy With Simultaneous-Integrated Boost Technique for Limited Metastases: A Multi-Institutional Analysis

Purpose: To perform a multi-institutional analysis following treatment of limited osseous and/or nodal metastases in patients using a novel hypofractionated image-guided radiotherapy with simultaneous-integrated boost (HIGRT-SIB) technique.Methods: Consecutive ...

www.ncbi.nlm.nih.gov

thoughts?

I'd say it all depends on location of this node and adjacent organs at risk.
We generally give 3 x 10 Gy whenever possible

If there's alot of small bowel in the vicinity any schedule with 5-10 fractions is reasonable.
6 x 6 Gy is a nice schedule with a Dmax small bowel < 6 x 5 Gy (6 x 4.5 Gy if you want to be very careful).
I've also done 10 x 5 Gy with a Dmax small bowel < 10 x 3.8 Gy.

I wouldn't do any sort of ENI. We do not really know if ENI provides any benefit even in the mHSPC situation and this patient actually has mCRPC.
The STORM-trial is currently evaluating ENI for N1-pelvis-recurrence in HSPC.

PEACE V – Salvage Treatment of OligoRecurrent nodal prostate cancer Metastases (STORM): a study protocol for a randomized controlled phase II trial - BMC Cancer

Background Pelvic nodal recurrences are being increasingly diagnosed with the introduction of new molecular imaging techniques, like choline and PSMA PET-CT, in the restaging of recurrent prostate cancer (PCa). At this moment, there are no specific treatment recommendations for patients with...

bmccancer.biomedcentral.com

 

[ramsesthenice]

I'd say it all depends on location of this node and adjacent organs at risk.
We generally give 3 x 10 Gy whenever possible

If there's alot of small bowel in the vicinity any schedule with 5-10 fractions is reasonable.
6 x 6 Gy is a nice schedule with a Dmax small bowel < 6 x 5 Gy (6 x 4.5 Gy if you want to be very careful).
I've also done 10 x 5 Gy with a Dmax small bowel < 10 x 3.8 Gy.

I wouldn't do any sort of ENI. We do not really know if ENI provides any benefit even in the mHSPC situation and this patient actually has mCRPC.
The STORM-trial is currently evaluating ENI for N1-pelvis-recurrence in HSPC.

PEACE V – Salvage Treatment of OligoRecurrent nodal prostate cancer Metastases (STORM): a study protocol for a randomized controlled phase II trial - BMC Cancer

Background Pelvic nodal recurrences are being increasingly diagnosed with the introduction of new molecular imaging techniques, like choline and PSMA PET-CT, in the restaging of recurrent prostate cancer (PCa). At this moment, there are no specific treatment recommendations for patients with...

bmccancer.biomedcentral.com

I also do lower doses for prostate Mets. Anywhere from 10 x3 to 8 x5. Remember 10x5 is used for most diseases because it gives a BED of 100 when a/b = 10. With a low a/b you (should) get a lot more bang for your buck. I don’t think I’ve ever had an in field failure. But, as expected, probably 80% progress distantly within 18 months. Makes me really want to avoid overdoing normal tissue dosing.

 

[Ray D. Ayshun]

I also do lower doses for prostate Mets. Anywhere from 10 x3 to 8 x5. Remember 10x5 is used for most diseases because it gives a BED of 100 when a/b = 10. With a low a/b you (should) get a lot more bang for your buck. I don’t think I’ve ever had an in field failure. But, as expected, probably 80% progress distantly within 18 months. Makes me really want to avoid overdoing normal tissue dosing.

Right. I mean, we do 7ish x 5 for definitive treatment of prostate CA in the nonmetastatic setting. Seems like a good, safe dose.

 

[taserlaser]

Of note, say what you want about the doses used here, but it might be that dose escalation may be worthwhile.

DEFINE_ME

 

[evilbooyaa]

I have a patient with progression on abi. Axumin scan shows only two para-aortic nodes that are positive. I forget now if this would historically be his only two sites of mets, or if this is more officially a case of oligoprogression. I'm wondering about sbrting the nodes with a scheme more in line with the Oriole trial, which was a bit more conservative than STOMP SBRT. At the same time, I'm wondering about treating the nodes slightly up and downstream electively to like 25 Gy in 5 fx, prioritizing normal tissue, which is conceptually in line with what Wombat posted. There's no precedent for this in 5 fx, but the Durham VA/Duke put out a paper taking this approach in ten fx.

Hypofractionated Image-Guided Radiation Therapy With Simultaneous-Integrated Boost Technique for Limited Metastases: A Multi-Institutional Analysis

Purpose: To perform a multi-institutional analysis following treatment of limited osseous and/or nodal metastases in patients using a novel hypofractionated image-guided radiotherapy with simultaneous-integrated boost (HIGRT-SIB) technique.Methods: Consecutive ...

www.ncbi.nlm.nih.gov

thoughts?

Para-aortic in the pelvis (like next step from common iliac LNs) or para-aortic in the abdomen (like definitely M1 disease)? Has patient already had pelvic nodal RT and this is stepwise progression up the chain?

Assuming that the patient has had nodal RT in the past and this is stepwise progression up the nodal chain, without any evidence for distant metastatic disease, my opinion has not changed from what Wombat posted over a year ago (See post #12 in this thread), pending results of ongoing clinical trial looking at this. Treat an elective region and boost lymph nodes. I'm personally not a fan of doing this with 5Gy x 5, personally, so would do 45/25 and SIB lymph node as high as safely possible.

To me, not dissimilar to have a cervical cancer patient who got pelvic RT who recurs in the para-aortics, and you treat 'definitively' with elective nodal volumes 2cm above para-aortic nodal extension with SIB to gross disease.

If this is like an intraabdominal para-aortic LN and not 'stepwise progression' up the vascular/nodal chain, then I'd be more apt to just zap what you see and call it a day.