Lobectomy improved survival over SBRT?

[napoleondynamite]

I haven't read the article yet, but important to be aware of this one. I'll be interested to delve deeper into patient selection & characteristics.

http://www.annalsthoracicsurgery.org/article/S0003-4975(17)31099-8/fulltext

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[Palex80]

Well to me it makes sense, since it's a retrospective analysis.

Fit patients got lobectomy, unfit ones got SBRT or sublobar resection.
You do not know how they were staged, since it's retrospective. Did they all get PET-CT?
SBRT is an excellent modality, but it cannot perform nodal staging like surgical procedures can. Not every stage I NSCLC remains a stage I after surgical staging.

 

[napoleondynamite]

Well to me it makes sense, since it's a retrospective analysis.

Fit patients got lobectomy, unfit ones got SBRT or sublobar resection.
You do not know how they were staged, since it's retrospective. Did they all get PET-CT?
SBRT is an excellent modality, but it cannot perform nodal staging like surgical procedures can. Not every stage I NSCLC remains a stage I after surgical staging.

Exactly


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[Haybrant]

gotta say I used to be much more gung ho about SBRT than I am in practice. If someone can get a surgery and they have central lung im not really there to promote sbrt so much even if patient pushing for it

just curious now, what are your guys central dose/fractionation? What is your strategy in terms of limiting the itv/ptv and the airway, like you only allow one wall of the airway into the ptv? thanks

 

[OTN]

Any retrospective analysis of SBRT vs surgery is going to be so fraught with selection bias I don't think it can tell us anything comparatively. I will say, though, that VATS has come a long way since SBRT was first developed, so it is going to be a tougher hurdle for SBRT to climb to achieve superiority...which is good for patients, obviously.

For central lesions I do 55 Gy in 5 fx or 62.5 Gy in 10 fx if it's abutting the esophagus, and I've been very happy with the results over the last several years. I don't limit the ITV/PTV depending on the airway. I also limit dose to the chest wall according to the Harvard paper, and I've noticed a drop in post-procedural chest wall pain as a result.

 

[seper]

Yes, it is retrospective but well done. For me, this study confirms what I've already known from being busy with lung SBRT for > 5 years: SBRT is not nearly as good as surgery.

 

[Haybrant]

Any retrospective analysis of SBRT vs surgery is going to be so fraught with selection bias I don't think it can tell us anything comparatively. I will say, though, that VATS has come a long way since SBRT was first developed, so it is going to be a tougher hurdle for SBRT to climb to achieve superiority...which is good for patients, obviously.

For central lesions I do 55 Gy in 5 fx or 62.5 Gy in 10 fx if it's abutting the esophagus, and I've been very happy with the results over the last several years. I don't limit the ITV/PTV depending on the airway. I also limit dose to the chest wall according to the Harvard paper, and I've noticed a drop in post-procedural chest wall pain as a result.

i havent followed the debates too closely on central tumors but sbrt billing aside do we have sufficient evidence now for 5 fraction sbrt if tumor abutting lobar/central airways?

 

[seper]

There were some deaths in RTOG 0813, but the final message from the authorities was worded "protocol dose was safe", or something like that.

 

[Haybrant]

There were some deaths in RTOG 0813, but the final message from the authorities was worded "protocol dose was safe", or something like that.

ya wasn't sure what their conclusion was; is it published yet or this was just ASTRO abstract presentation. Is there some astro consensus or any consensus (NCCN) that says what is ok for central tumors right now? Like what do you point to if you cause grade 4/5 toxicity?

 

[Gfunk6]

Like what do you point to if you cause grade 4/5 toxicity?

Your medical malpractice carrier and pray that you documented discussion chance of "fatal or catastrophic" toxicity.

 

[evilbooyaa]

50Gy in 5fx or 60/8fx are both reasonable options for central tumors, IMO, with no published data that I'm familiar with of grade 5 (and maybe grade 4) toxicity. Both remain above BED 100.

And yes, not surprised that patients fit enough for lobectomy survive longer.
In terms of cancer-specific survival, not all clinically stage I NSCLC patients are pathological stage I. Surgery can catch this, SBRT cannot. What was the rate of pathological upstaging in the surgery group? If they were upstaged, were those patients included in the results? Even if they were, those patients could have gotten chemotherapy or RT as necessary. So many questions left unanswered, but it's a thoracic surgery journal, so the reviewers don't really care about that, just to be able to say, "LOBECTOMY IS BETTAH"

Regardless, lobectomy continues to be the standard of care in NSCLC in medically operable patients.

IMO, sublobar resection vs SBRT is the more interesting selling point - if a patient isn't fully medically operable to be able to tolerate a lobectomy, then why do a sublobar resection at all and not just SBRT it, if outcomes are the same?

 

[BobbyHeenan]

Yes, it is retrospective but well done. For me, this study confirms what I've already known from being busy with lung SBRT for > 5 years: SBRT is not nearly as good as surgery.

If by "surgery" you mean a lobectomy and node dissection in patients fit enough for it then I agree.

Where I see the problem is CT surgeons doing narrow margin wedge resections in borderline patients where I think a good PET/EBUS and SBRT is a better option.

 

[BobbyHeenan]

NCCN guidelines now list 50 Gy in 5 as an option for central tumors. Their dose constraint is < 105% of Rx to the proximal bronchial tree. So you at least have that to lean on.

If you're nervous about 5 fractions, I sometimes use 60-70 Gy in 10 (gets you a BED close to 100) though I've seen the same kind of imaging change (focal pneumonitis/consolidation in high to moderate dose area) picture radiographically as I do in SBRT in these cases. This 10 fraction regimen is also in NCCN guidelines.

 

[medgator]

Yes, it is retrospective but well done. For me, this study confirms what I've already known from being busy with lung SBRT for > 5 years: SBRT is not nearly as good as surgery.

Still better than anything else... have to remind the IR guys in town occasionally who are a little sketchy trying to promote rfa/cryo

 

[medgator]

gotta say I used to be much more gung ho about SBRT than I am in practice. If someone can get a surgery and they have central lung im not really there to promote sbrt so much even if patient pushing for it

just curious now, what are your guys central dose/fractionation? What is your strategy in terms of limiting the itv/ptv and the airway, like you only allow one wall of the airway into the ptv? thanks

For central tumors with airway concerns, we did 70/17 with good results in residency which I continue to do, based on the reference below which is also in the nccn index

Phase I study of accelerated conformal radiotherapy for stage I non-small-cell lung cancer in patients with pulmonary dysfunction: CALGB 39904. - PubMed - NCBI

I feel no need to change that, and iirc the current astro sbrt white paper mentions 6-15 fractions for central tumors as an option

There were some deaths in RTOG 0813, but the final message from the authorities was worded "protocol dose was safe", or something like that.

Lol yup...not doing that in pp

 

[seper]

I wonder what "correct answer" would be on 2018 oral boards: SBRT in 5 fx vs. hypofx 10-17 fx for a small central lung nodule?

For central tumors with airway concerns, we did 70/17 with good results in residency which I continue to do, based on the reference below which is also in the nccn index

Phase I study of accelerated conformal radiotherapy for stage I non-small-cell lung cancer in patients with pulmonary dysfunction: CALGB 39904. - PubMed - NCBI

I feel no need to change that, and iirc the current astro sbrt white paper mentions 6-15 fractions for central tumors as an option


Lol yup...not doing that in pp

 

[medgator]

I wonder what "correct answer" would be on 2018 oral boards: SBRT in 5 fx vs. hypofx 10-17 fx for a small central lung nodule?

With boards, I think there isn't always one correct answer, especially in controversial areas. I passed my boards several years ago saying accelerated hypofx for central although my examiner at the time did mention that people were starting to do 5 fractions for central lesions.

Sbrt guidelines from astro

http://www.practicalradonc.org/article/S1879-8500(17)30121-2/fulltext

"For central tumors for which SBRT is deemed too high risk, hypofractionated radiation therapy utilizing 6 to 15 fractions can be considered."

For me, I wonder about doing sbrt on cT3 lesions, which they also endorse...personally I believe in chemo/xrt for those

"SBRT may be utilized in patients with cT3 disease due to chest wall invasion without clear evidence of reduced efficacy or increased toxicity compared to tumors abutting the chest wall."

 

[Palex80]

With boards, I think there isn't always one correct answer, especially in controversial areas. I passed my boards several years ago saying accelerated hypofx for central although my examiner at the time did mention that people were starting to do 5 fractions for central lesions.

Sbrt guidelines from astro

http://www.practicalradonc.org/article/S1879-8500(17)30121-2/fulltext

"For central tumors for which SBRT is deemed too high risk, hypofractionated radiation therapy utilizing 6 to 15 fractions can be considered."

For me, I wonder about doing sbrt on cT3 lesions, which they also endorse...personally I believe in chemo/xrt for those

"SBRT may be utilized in patients with cT3 disease due to chest wall invasion without clear evidence of reduced efficacy or increased toxicity compared to tumors abutting the chest wall."

Indeed, that's a controversial issue.
The point is probably, that they specifically endorse SBRT for cT3 lesions with chest wall invasion and not other cT3 lesions, like very big tumors or invasive centrally located tumors.
In nig or centrally located tumors SBRT is probably not a good option, due to the fact that nodal recurrence may become an issue and you should at least cover the ipsilateral lymphatics in the lung hilus. Furthermore the risk of metastasis is higher, making chemo important.
On the other hand a rather medium sized lesion with chest wall invasion that's let's say 4-5 cm does not harbor a larger risk for lymph node metastasis probably than you "typical" SBRT-eligible T2 tumor somewhere in the middle of the lung. I think that's why they specifically endorse SBRT in these cases.
You may prefer chemo/xrt, but why? You give chemo to enhance systemic control or increase local effect. Yet if the risk of metastasis is not significantly higher than in a medium sized lesion in the middle of the lung that only gets SBRT without chemo and if you can enhance local effect of RT in a chest wall invading lesion by dose escalating with SBRT, you don't need chemo.

In the end you could always do a tailored approach like SBRT + sequential chemotherapy to combar microscopic disease. And of course you should pay attention to the fractionation regime for your SBRT or you may run into toxicity issues on the chest wall. I've seen a couple of rib fractures aber SBRT in lesions near the chest wall.

 

[medgator]

Indeed, that's a controversial issue.
The point is probably, that they specifically endorse SBRT for cT3 lesions with chest wall invasion and not other cT3 lesions, like very big tumors or invasive centrally located tumors.

I would think the chest wall invasion would actually be the more difficult case for SBRT, given concerns for pain/fx/ulceration post-Tx.

In nig or centrally located tumors SBRT is probably not a good option, due to the fact that nodal recurrence may become an issue and you should at least cover the ipsilateral lymphatics in the lung hilus.

Most people have moved away from ENI (elective nodal radiation) in NSCLC, at least in the US in order to facilitate dose escalation.

http://ascopubs.org/doi/full/10.1200/jco.2007.13.2191

Furthermore the risk of metastasis is higher, making chemo important.

Generally though, in the US at least, weekly carbo/taxol is given as a sensitizer during radiation, and would not be expected to have much effect systemically.

You may prefer chemo/xrt, but why? You give chemo to enhance systemic control or increase local effect. Yet if the risk of metastasis is not significantly higher than in a medium sized lesion in the middle of the lung that only gets SBRT without chemo and if you can enhance local effect of RT in a chest wall invading lesion by dose escalating with SBRT, you don't need chemo.

I just checked.... NCCN currently endorses chemo-radiation for T3 tumors with chestwall invasion (NSCL-6) if no surgery is planned. I feel there is quite a bit of syngerism (i.e. more than the "Sum of the parts") in combining chemo and radiation together, while carrying a lower risk of chest wall toxicity as compared to SBRT. Concurrent chemo provides its own "dose escalation".... personally, I think modest hypo-fractionation at 2.5 Gy/day with chemo would be the way to go, but in private practice, I stick to standard fx.

Would be nice to have some data to look at it, but there is nothing supporting either SBRT vs chemo-radiation as the preferred approach in these patients AFAIK.

In the end you could always do a tailored approach like SBRT + sequential chemotherapy to combar microscopic disease. And of course you should pay attention to the fractionation regime for your SBRT or you may run into toxicity issues on the chest wall. I've seen a couple of rib fractures aber SBRT in lesions near the chest wall.

Which is why i'm cautious with SBRT for cT3 chest wall lesions or central lesions, personally. The idea of adjuvant chemo with SBRT is interesting, makes sense as there are indications for chemo after surgery.

 

[evilbooyaa]

If you keep V30 < 30cc for a 5 fraction regimen to the chest wall you will keep yourself out of trouble in regards to SBRT. It's generally not that problematic of a constraint to meet, even with lesions right against the pleura/chest wall, unless it's really coating a huge portion of pleura. Remember to not overdraw your chest wall. Accept a little bit cold PTV as necessary. Keep BED over 100.

 

[napoleondynamite]

If you keep V30 < 30cc for a 5 fraction regimen to the chest wall you will keep yourself out of trouble in regards to SBRT. It's generally not that problematic of a constraint to meet, even with lesions right against the pleura/chest wall, unless it's really coating a huge portion of pleura. Remember to not overdraw your chest wall. Accept a little bit cold PTV as necessary. Keep BED over 100.

What's your source for that constraint? Thanks


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[medgator]

What's your source for that constraint? Thanks


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This is for 3 fraction:

http://ascopubs.org/doi/full/10.1200/JCO.2008.19.6386

"A recent combined analysis of patients treated with thoracic SBRT from the Universities of Virginia and Colorado revealed that the volume of chest wall receiving at least 30 Gy in three fractions (V30) was the best predictor of chest wall toxicity.19 The incidence of severe chest wall toxicity (pain requiring narcotic analgesics or rib fracture) increased with increasing V30, and no chest wall toxicity was observed with V30 less than 10 mL. "

Uva study: http://www.redjournal.org/article/S0360-3016(08)01062-6/fulltext

 

[evilbooyaa]

What's your source for that constraint? Thanks


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I go with the Cleveland Clinic data. Prediction of chest wall toxicity from lung stereotactic body radiotherapy (SBRT). - PubMed - NCBI

What medgator gave (UVA data of V30 < 10cc) is hard to meet in most cases, and with the cut-offs of 10cc, 40cc and 120cc, are huge jumps.

Again, the CC data is for 3 fractions, but at my institution we extrapolate that in a conservative fashion to 5 fractions, as I'd like my chest wall late toxicity to be definitively lower than the 10 to 15% that Stephans et al suggest in their analysis. They also suggest V60 to <=3cc, but we generally change our dose prescription for tumors abutting chest wall to 50Gy/5 to avoid that as an issue.

 

[Haybrant]

aside question: I have a guy who had IIIA 2 years ago I gave CRT to the RUL/Level 4R. Now he has 2 T1a's both in the lower part of the the left upper lobe peripheral about 4-5 cm apart but on the same axial plane. Simulated them planning to SBRT both at the same time. His lung motion was quite high 2.5 cm - what strategies do you use in this setting?

 

[medgator]

aside question: I have a guy who had IIIA 2 years ago I gave CRT to the RUL/Level 4R. Now he has 2 T1a's both in the lower part of the the left upper lobe peripheral about 4-5 cm apart but on the same axial plane. Simulated them planning to SBRT both at the same time. His lung motion was quite high 2.5 cm - what strategies do you use in this setting?

No abdominal compression device?

 

[Haybrant]

No abdominal compression device?

sorry, yes abdominal compression belt was used! I was going to see what a plan looks like with single and dual iso. Not sure if people feel comfortable treating two lesions at the same time in this kind of situation, maybe treat one then wait a month then the next one?

 

[seper]

I personally wouldn't be too aggressive - these are likey mets and further chest progression will follow shortly

 

[medgator]

I personally wouldn't be too aggressive - these are likey mets and further chest progression will follow shortly

Agreed.

Could also be T3 situation with with other nodules in the lobe where chemo rt might be the better way to go....sometimes you don't want to be too conformal in a situation like that.

One option could be a few cycles of chemo and restage

 

[Haybrant]

Agreed.

Could also be T3 situation with with other nodules in the love where chemo rt might be the better way to go....sometimes you don't want to be too conformal in a situation like that.

One option could be a few cycles of chemo and restage

I hear you guys; the two lesions have grown slightly but everything else is stable for 4 months, no new lesions/no new disease.

 

[evilbooyaa]

What's your overlap dose from the previous plan? If you're treating him, I think treating one then the other (with a re-sim) is reasonable, as is treating both. Would do it with 2 separate isos, 4-5cm apart in the axial plane is pretty significant to me. CBCT for each iso probably. Regarding the motion, since you did a 4DCT I would do respiratory gating, 40 to 60, or whatever your preference is to minimize the motion and shrink your volumes - I don't think you should treat a 2.5cm envelope (the tumor is really moving 2.5cm sup inf?), especially for an upper lobe tumor (that's an awful lot of motion for even the lower portion of the upper lobe). I'm assuming these have both been biopsied or are at least strongly PET-avid? What were the histologies of all 3 areas?

However, the age old question - are two nodules in the same lobe T3 or two synchronous T1as? Related questions, are 2 nodules in the same lung T4 or two synchronous T1as?

If he's been re-staged for these lesions and there's no mediastinal LN disease or distant mets I think the likelihood that it's actually M1 from his contralateral lung cancer is low. Assuming he's a smoker.

I don't see any role for few cycles of chemo and restaging here. Is patient a surgical candidate?

 

[seper]

XRT is very reasonable, but what I'm saying it pays to be conservative with dosing and frationation in recently irradiated stage III NSCLC. Lesson hard learned.

 

[nkmiami]

aside question: I have a guy who had IIIA 2 years ago I gave CRT to the RUL/Level 4R. Now he has 2 T1a's both in the lower part of the the left upper lobe peripheral about 4-5 cm apart but on the same axial plane. Simulated them planning to SBRT both at the same time. His lung motion was quite high 2.5 cm - what strategies do you use in this setting?

I have always wanted to uses a cpap machine after seeing paper on it a couple years ago to dampen resp motion, never actually done it.

 

[napoleondynamite]

I have always wanted to uses a cpap machine after seeing paper on it a couple years ago to dampen resp motion, never actually done it.

Or just use breath hold..

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[nkmiami]

well, it is not that simple- breath hold at expiration is not that easy- the patients that can do it often are not the ones being sent for srt, nor are they the ones who really need breath hold.

 

[napoleondynamite]

well, it is not that simple- breath hold at expiration is not that easy- the patients that can do it often are not the ones being sent for srt, nor are they the ones who really need breath hold.

Really? I've honestly never had a problem getting anyone through breath-hold. Sometimes it takes a little coaching and patience, but I've had patience with pretty crappy lung function get through it just fine

Maybe I'm not familiar with the technique you are describing... Do you treat at expiration for some reason?

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[nkmiami]

inspiration in the lung (although very rarely as lung stereo has very little toxiciry), expiration in the abdomen.

 

[napoleondynamite]

inspiration in the lung (although very rarely as lung stereo has very little toxiciry), expiration in the abdomen.

But why expiration in the abdomen instead of just breath hold?

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[nkmiami]

expiration (abdomen) is supposedly more reproducible- there may be different amounts of "inspiration." I mainly use breath hold in the abdomen because on a free breathing cone beam, it can be hard to visualize anything. For example, bowel gas causes a lot of artifact/distortion on a free breathing cone beam.

Recently, in abdominal patients who cant hold their breath, I have been planning and sending over the 50% phase on a 4d scan. In my experience, if you are lining up to a stent, the stent contoured on the 50% will line up to the free breathing stent on a cone beam. I have also found that to be true of the liver outline. A free breathing cone beam probably represents "an average volume"

I would be interested to hear others experience.

 

[Neuronix]

Among academic institutions there is variability about deep inspiratory breath hold vs expiratory breath hold in the abdomen for SBRT. You could almost flip a coin. There are some dosimetric analyses on this topic as well that you can sort of argue either way with.

I am agnostic on this topic and have done it both ways even within the past year. My only advice is that this is a minor point. It's much more important whatever techniques you use are calibrated and performed correctly.

 

[evilbooyaa]

Or just use breath hold..

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There are patients who can't do a consistent breath hold at deep inspiration, or they can only hold it for like 10 seconds due to compromised lung function. There can also be some variability in the magnitude of breath hold, meaning if you're simming your SBRTs with breath hold alone (without doing a 4D) it might be risky. End expiration breath hold is an option but can be difficult as well, which is why respiratory gating is generally done at end expiration, because it's longer time period than end inspiration.

Agree with Neuronix above, that whatever you do, be confident in it.

 

[nkmiami]

Anyone using 50% phase in abdomen for patients who cant hold breath?