Early stage NSCLC SBRT/hypofrac

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Radonky

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Wanted to review how you guys would approach this

Got an elderly guy, GOLD 4 COPD, FVC 1.8L, 45% predicted, FEV1 860cc, 28% predicted, FEV1/FVC ratio 47%, with a peripheral early stage NSCLC, about 1.5cm, close to the chest wall, biopsy proven, PET negative, MRI brain negative. No matter what we did, tumor movement was 2cm+ on 4D, even after re-sim, plate/belt, education, etc. I've heard off hand that if movement >1cm you should not do SBRT, others say it is OK if it is a small target.

What is your go to regimen in this situation? Still do SBRT? I was initially thinking 50/5, its far away from OAR's, other than chest wall, which I would optimize to but would probably not meet. Otherwise was thinking 60/15 or 70/20...thoughts?
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Toughie

Whatever you do, large amounts of non tumor lung volume will be irradiated.

70/17-20 sounds good.

I am in the “60/15 is wimpy” camp
 
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I would stick with 50/5. Sure maybe you could get a bit less fibrosis with something more fractionated, but doubt it'll be a meaningful difference clinically. Do a very heterogenous 50/5 and allow it to get very hot in the middle to allow for sharp dose fall off, even more than your typical sbrt plan. Only other way to save lung is to do gating or DIBH if you have the capability. I think with such a small tumor and heterogenous plan it'll be okay ultimately
 
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Radonky said:
I've heard off hand that if movement >1cm you should not do SBRT
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I've treated routinely in this scenario. 50/5. If you have a posterior/inferior tumor, it's gonna move. I have never had problems with 4D and ITV approach in this setting. I have used gating or breath-hold on occasion (usually when motion means that a more sensitive OAR is at risk (such as bowel or stomach on the left side).

Extent of COPD not typically my main worry. Interstitial lung disease is much more concerning for SBRT IMO.

I think we have some lung attendings on here. Maybe @Lamount or others can weigh in.
 
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Never mind!
I’m a wimp! Haha.
Looking forward to the smart people answers
 
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RealSimulD said:
Toughie

Whatever you do, large amounts of non tumor lung volume will be irradiated.

70/17-20 sounds good.

I am in the “60/15 is wimpy” camp
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70/17 Very close to the 100 BED cutoff, agree I'm in the 60/15 isn't enough camp also.

Still use 17fx for ultra central tumors and have been happy with the results and i sleep well at night in terms of worrying about toxicity
 
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50/5. I don’t really really flinch at these anymore and will Rx 54/3 for some targets if no significant PTV overlap with OARs. Very easy to still meet constraints. Gating (or breath hold) is helpful - we gate in exhale usually and it reduces the size of the PTV (but sometimes not by much).
 
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communitydoc13 said:
I've treated routinely in this scenario. 50/5. If you have a posterior/inferior tumor, it's gonna move. I have never had problems with 4D and ITV approach in this setting. I have used gating or breath-hold on occasion (usually when motion means that a more sensitive OAR is at risk (such as bowel or stomach on the left side).

Extent of COPD not typically my main worry. Interstitial lung disease is much more concerning for SBRT IMO.

I think we have some lung attendings on here. Maybe @Lamount or others can weigh in.
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With a lot of movement, I will sometimes do 70/10 (MDACC) or 60/8 (Hasbeek). Both have excellent control (on par with any SBRT regiment) and (anecdotally) you can afford to treat a bigger volume than 50/5, without causing as big of a scar. MDACC has also shown that they have less chest wall tox with 70/10 vs 50/4. Lastly, you have a little less risk of massive underdosing due to missing with more fractionation. Those are my go-to regimens for larger tumors.

Would def recommend using a more generous PTV expansion on ITV if you don’t feel like your 4D is capturing all of the motion.
 
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Send him to a center with an MRI linac for gated radiotherapy?
 
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Probably fine with 50/5. I sometimes use expiratory breath hold in these situations. I would not worry about the PFTs. It has been shown that sbrt has minimal effect.
 
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Radonky said:
Wanted to review how you guys would approach this

Got an elderly guy, GOLD 4 COPD, FVC 1.8L, 45% predicted, FEV1 860cc, 28% predicted, FEV1/FVC ratio 47%, with a peripheral early stage NSCLC, about 1.5cm, close to the chest wall, biopsy proven, PET negative, MRI brain negative. No matter what we did, tumor movement was 2cm+ on 4D, even after re-sim, plate/belt, education, etc. I've heard off hand that if movement >1cm you should not do SBRT, others say it is OK if it is a small target.

What is your go to regimen in this situation? Still do SBRT? I was initially thinking 50/5, its far away from OAR's, other than chest wall, which I would optimize to but would probably not meet. Otherwise was thinking 60/15 or 70/20...thoughts?
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80.5/35, works great in these situations. Make the proper ITV, marginate it, plan it beautifully, and beam it. Have never had chest wall pain syndrome after 80.5/35. And it cures cancer.
 
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TheWallnerus said:
80.5/35, works great in these situations. Make the proper ITV, marginate it, plan it beautifully, and beam it. Have never had chest wall pain syndrome after 80.5/35. And it cures cancer.
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Iweird that no chest wall pain with 80 gy, but 50/2of protons breaks a rib in breast. Would hate to think of what that is doing to the anterior heart.
 
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Just plan it out and see how it looks. My CW constraints for SBRT are 57-60 max and 40-45 to <5 cc. If it doesn't work, 70/10 should be fine as even 60/10 to a decent volume of the chest wall should be reasonably well-tolerated and certainly more aggressive than 60/15,. I'd probably not waste my dosimetrist's time on SBRT from what it sounds like, but might be able to be met.
 
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60 in 15 works great but I usually reserve that for bulkier or N1 cases where chemo is not offered. Agree with 50 in 5.
 
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60/15 BED is 84
70/17 BED is ~100

I feel 60/15 is halfway between cure and palliation- but that’s not based on data.
 
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RealSimulD said:
60/15 BED is 84
70/17 BED is ~100

I feel 60/15 is halfway between cure and palliation- but that’s not based on data.
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You know what, whenever I use 60/15 the patient is usually in a situation that is between cure and palliation. It's a good dose for those situations.
 
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60/15 fx was not inferior to 60/8 on the Lustre trial. Likely underpowered to show a difference, but numerically not much difference between the two.
 
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madchemist89 said:
60/15 fx was not inferior to 60/8 on the Lustre trial. Likely underpowered to show a difference, but numerically not much difference between the two.
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Yeah, just a feeling I guess. Probably is just fine.
 
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madchemist89 said:
60/15 fx was not inferior to 60/8 on the Lustre trial. Likely underpowered to show a difference, but numerically not much difference between the two.
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I suppose to each his own. I think many would argue that lustre supports not using 60/15 when feasible, particularly in a peripheral tumor.

Edit: I read the results of lustre as #750orGTFO
 
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Ray D. Ayshun said:
I suppose to each his own. I think many would argue that lustre supports not using 60/15 when feasible, particularly in a peripheral tumor.
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Just on the BED argument alone imo better to use 70/17.

Aggressive palliation to me is using something like 40-45/15 against a massive tumor, against the spine etc that you'll never cure, esp if pt isn't getting chemo
 
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I would never advocate for 60/15 for a non ultracentral that meets constraints. I just wanted to illustrate that it is a definitive regimen albeit it does not meet 100 BED. It is a good alternative when constraints cannot be met with more aggressive regimens.
 
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rad oncs again arguing about yet again dose and fractions! I have yet to see the phase 3 randomized trials investigating any of the fractionations we argue for or against!
 
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100.0% of our effort should be on derailing the insanity of MOC, and howling at ASTRO leadership's sheer stupidity on workforce management.

SK has left the arena
 
Radonky said:
Wanted to review how you guys would approach this

Got an elderly guy, GOLD 4 COPD, FVC 1.8L, 45% predicted, FEV1 860cc, 28% predicted, FEV1/FVC ratio 47%, with a peripheral early stage NSCLC, about 1.5cm, close to the chest wall, biopsy proven, PET negative, MRI brain negative. No matter what we did, tumor movement was 2cm+ on 4D, even after re-sim, plate/belt, education, etc. I've heard off hand that if movement >1cm you should not do SBRT, others say it is OK if it is a small target.

What is your go to regimen in this situation? Still do SBRT? I was initially thinking 50/5, its far away from OAR's, other than chest wall, which I would optimize to but would probably not meet. Otherwise was thinking 60/15 or 70/20...thoughts?
Click to expand...
with a 1.5 cm GTV even with 2 cm of tumor motion your ITV should still be a reasonable size. I would plan to 50/5 and see if you can meet constraints.
 
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RadOncDoc21 said:
rad oncs again arguing about yet again dose and fractions! I have yet to see the phase 3 randomized trials investigating any of the fractionations we argue for or against!
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Lustre was phase III (admittedly allocated 2:1 with SBRT and kinda-SBRT), and while it closed early/was underpowered, there's enough there for me to accept that 60/15 is for when you're worried about a G5 toxicity. I hate the dose/fraction debate as well, but there seem to be enough other choices in light of this data to have to get creative to use this schema.
 
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Ray D. Ayshun said:
Lustre was phase III (admittedly allocated 2:1 with SBRT and kinda-SBRT), and while it closed early/was underpowered, there's enough there for me to accept that 60/15 is for when you're worried about a G5 toxicity. I hate the dose/fraction debate as well, but there seem to be enough other choices in light of this data to have to get creative to use this schema.
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This is the best I’ve seen that compares these doses and fractionations… thank you! I guess the problem is that like most all other studies, we’re still left to our own discretion since it was unfortunately underpowered but at least there is data.
 
RadOncDoc21 said:
This is the best I’ve seen that compares these doses and fractionations… thank you! I guess the problem is that like most all other studies, we’re still left to our own discretion since it was unfortunately underpowered but at least there is data.
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yes, and weirdly allocated. At this point, this may be the best radiation trial in years.
 
Who says if movement is > 1cm you shouldn't SBRT, in the era of 4DCT and being able to treat the entire envelope?

50-55/5 assuming you can't meet 3Fx chest wall constraints for 54/3. COPD on O2 is not an issue for a first course of SBRT, only ILD.

Giving BED < 100 is completely unnecessary.

Consider some form of breath-hold (although unlikely to tolerate) and respiratory gating (if you have capability) otherwise, plan it out, meet the CW constriant, and beam on.
 
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RadOncDoc21 said:
This is the best I’ve seen that compares these doses and fractionations… thank you! I guess the problem is that like most all other studies, we’re still left to our own discretion since it was unfortunately underpowered but at least there is data.
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Sunset trial will be helpful for ultracentral lesions.

Here, the question I have is: what is our concern with a peripheral lesion with lots of motion?

I can think of four concerns. In this setting, none seem high priority to me, but wondering about others thoughts.

1. Chest wall dose: We have several chest wall constraints to pick from and going from 3 to 5 fractions probably enough for most cases.

2. Lung dose: Given the very large size of lesions treated in multiple published series, even 4 cm of motion in a small peripheral lesion is unlikely to move you past typical 4-5 fraction lung constraints re V2000, V1350 and V1250.

3. Missing the target: As stated above, 4D and look at individual respiratory phases. I would say standard protocol should be to draw your ITV on MIP and then verify and adjust to include all motion as demonstrated on all phases of your respiratory cycle (there are typically 2-4 phases that encompass all the motion in my experience). It is true that in targets with lots of movement, MIP may not demonstrate total extent of motion.

4. Dosimetry: Seem like we are much less concerned about this now than 15 years ago (I remember when people were avoiding beam modulation through a moving target). Given all the limiting cases (10% difference regarding heterogeneity correction period!) I have a hard time believing that planning on an average scan isn't going to be fine.
 
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communitydoc13 said:
Sunset trial will be helpful for ultracentral lesions.

Here, the question I have is: what is our concern with a peripheral lesion with lots of motion?

I can think of four concerns. In this setting, none seem high priority to me, but wondering about others thoughts.

1. Chest wall dose: We have several chest wall constraints to pick from and going from 3 to 5 fractions probably enough for most cases.

2. Lung dose: Given the very large size of lesions treated in multiple published series, even 4 cm of motion in a small peripheral lesion is unlikely to move you past typical 4-5 fraction lung constraints re V2000, V1350 and V1250.

3. Missing the target: As stated above, 4D and look at individual respiratory phases. I would say standard protocol should be to draw your ITV on MIP and then verify and adjust to include all motion as demonstrated on all phases of your respiratory cycle (there are typically 2-4 phases that encompass all the motion in my experience). It is true that in targets with lots of movement, MIP may not demonstrate total extent of motion.

4. Dosimetry: Seem like we are much less concerned about this now than 15 years ago (I remember when people were avoiding beam modulation through a moving target). Given all the limiting cases (10% difference regarding heterogeneity correction period!) I have a hard time believing that planning on an average scan isn't going to be fine.
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should still look into avoiding IMRT planning (use 3D arcs if physics had them commissioned)
 
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A_DeMichele said:
should still look into avoiding IMRT planning (use 3D arcs if physics had them commissioned)
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I think VMAT with planning to ITV plus expansion is now most common approach? This is still inverse planned. Are you referring to static field planning?

Or are you stating that with large motion, the uncertainty (regarding timing of modulation relative to a moving target) makes VMAT not ideal?
 
communitydoc13 said:
Sunset trial will be helpful for ultracentral lesions.

Here, the question I have is: what is our concern with a peripheral lesion with lots of motion?

I can think of four concerns. In this setting, none seem high priority to me, but wondering about others thoughts.

1. Chest wall dose: We have several chest wall constraints to pick from and going from 3 to 5 fractions probably enough for most cases.

2. Lung dose: Given the very large size of lesions treated in multiple published series, even 4 cm of motion in a small peripheral lesion is unlikely to move you past typical 4-5 fraction lung constraints re V2000, V1350 and V1250.

3. Missing the target: As stated above, 4D and look at individual respiratory phases. I would say standard protocol should be to draw your ITV on MIP and then verify and adjust to include all motion as demonstrated on all phases of your respiratory cycle (there are typically 2-4 phases that encompass all the motion in my experience). It is true that in targets with lots of movement, MIP may not demonstrate total extent of motion.

4. Dosimetry: Seem like we are much less concerned about this now than 15 years ago (I remember when people were avoiding beam modulation through a moving target). Given all the limiting cases (10% difference regarding heterogeneity correction period!) I have a hard time believing that planning on an average scan isn't going to be fine.
Click to expand...
Personally, would be worried about missing which makes me want to do a more generous expansion to PTV expansion. With bigger volume, chest wall is the direct concern but, would also want to avoid making a giant scar (not really an issue for most, but with severe COPD, it doesn’t necessarily take much). Even with the expansion, missing is still a consideration.

With 70/10… it seems like you can have your cake and eat it too.
 
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If the ITV is 2cm sup and 2cm inf from GTV, what're you guys worried about missing? Why bigger PTV margin when the ITV is already yugeeeee?
 
A_DeMichele said:
should still look into avoiding IMRT planning (use 3D arcs if physics had them commissioned)
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Do what now

Even in a single fraction, the (IMRT) dose in a moving area doesn't differ "a lot" from planned. After 10 or 15 fractions, the dose in a moving area is very close to the planned dose.

ixrftSk.jpg



 
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RealSimulD said:
People confusing itv and PTV
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Honestly, I think I've just let go and let God on this. People could call it the MTV for all I care. Just show me the 3D dose distribution and your DVH. If it's tight and good (that's what she said) that's all that counts.
 
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