Post-op lung

[deleted4401]

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56 year year old lady with hx of tobacco use with a a CT scan for another reason, KPS 100. Showed a mass in the LUL of lung. 1.3cm. PET scan - was FDG avid, no other areas of concern, mediastinum/hilum clean. Bx - mucinous adenoCA consistent with lung primary. MRI brain negative, except for asx meningioma.

Lobectomy/mediastinal assessment. 1.3cm primary, no involvement of pleura. 1mm parenchymal margin. No LVSI. LNs from 5, 7, 9, 10, 11, 12, as well as some bronchial LNs. 9L positive, the rest negative. Final stage IIIA. Going to get chemo.

RT? - 9L is low mediastinum. Target would be somewhat strange appearing. How about RT for the close margin?

S

 

[probiotic]

According to DeVita (9th edition) PORT is reasonable in N2 disease or if margins are close despite PORT meta analysis.

 

[Gfunk6]

Tough case, there is a distinct lack of modern, randomized data to answer this question. My gut feeling that any benefit she gets from PORT will be marginal, possibly giving her a LRC advantage rather than OS.

Still with technically N2 disease and close margins, I would do PORT after chemo but I would limit the field size to maximize therapeutic ratio. To justify, I would simply use the retrospective analysis of the ANITA trial.

According to DeVita (9th edition) PORT is reasonable in N2 disease or if margins are close despite PORT meta analysis.

Textbooks in residency are fine, but I would not use Devita to justify treatment IRL or a Tumor Board.

 

[Neuronix]

Can also justify with the SEER analysis showing OS benefit in N2 disease: http://www.ncbi.nlm.nih.gov/pubmed/16769986. I think we would recommend treatment, particularly with KPS 100.

 

[deleted4401]

Only 9L positive. Sorry that wasn't clear. I just listed which were excised.

 

[Neuronix]

Only 9L positive. Sorry that wasn't clear. I just listed which were excised.

Duh. You were perfectly clear. Nevermind on the additional staging scans 🙂

 

[hot sauce]

For those suggesting PORT, what dose and volumes would you recommend?

 

[TarHeelRadOnc]

Tough case, there is a distinct lack of modern, randomized data to answer this question. My gut feeling that any benefit she gets from PORT will be marginal, possibly giving her a LRC advantage rather than OS.

Still with technically N2 disease and close margins, I would do PORT after chemo but I would limit the field size to maximize therapeutic ratio. To justify, I would simply use the retrospective analysis of the ANITA trial.



Textbooks in residency are fine, but I would not use Devita to justify treatment IRL or a Tumor Board.

Tricky case.

Two issues: close margin and occult N2

Regarding the former, parenchymal margins are the worst. Difficult/impossible to localize. For a patient treated with lobectomy, the close parenchymal margin would be adjacent to the fissure, parietal pleura or mediastinal pleura. These could be reasonably viewed as natural barriers to spread (similar to pectoralis fascia in breast). As such, would not try to boost this margin.

Regarding the later, we can quote post-metaanalysis data supporting PORT for N2 all day long (SEER, ANITA, Mayo, Upenn, etc), but none of that data applies to this unique situation. If you look at the POF data for early stage NSCLC from Duke (Kelsey et al), a 9L node is not even on the radar for a LUL primary. Based on the ongoing French PORT trial and the Duke POF study, appropriate elective volumes for a LUL primary would include the LUL bronchial stump, Lt hilum, 2L, 4L, 5, 6, 7 and any other involved mediastinal nodal areas. That volume would be pretty big in this patient due to inferior extent. I try to limit lung V20 <25% and MLD <14Gy in PORT cases due to increase risk of (treatment associated?) cardiopulmonary mortality. Those constraints would be challenging to meet if you are treating the mediastinum from 2L to 9L. I would simulate after chemo and see how well you could do with the DVH, but would have a low threshold to bail out. Hard to PROVE a survival benefit of PORT, even in N2 disease (for the record, SEER analyses have never proven anything).

 

[Seldon1985]

For those suggesting PORT, what dose and volumes would you recommend?

Good question. Bronchial stump + ipsilateral hilum + how much mediastinum? This is the one place I still see my attendings using elective coverage of very limited mediastinal stations (one station above or below, depending on the scenario)...

 

[Cancerdancer]

Having been in the OR on a fair amount of lobectomies, would add two things to the discussion.
1. Often these lymph node samplings are just that...plucking tissue with forceps. The surgeons don't seem to think of them as oncologic in terms of control like they do in the axilla (with good reason, very different territory). High probability of gross disease left behind in my opinion. It has flavored my tendency to give PORT, especially in pts such as this where distant risk isn't terribly high.

2. Likewise, a real possibility that the positive LN is mislabeled when passing from fellow to attending to scrub tech to pathologist. I'd treat 4L, 5, 6, 7, and 9.

 

[Palex80]

I sometimes decide upon yes/no for pN2 Stage IIIA NSCLC according to the characteristics of the involved node(s).
So, some information on size of metastasis, ECE, local L1 around the node would be interesting. I don't know if you have that SimulD.

 

[deleted4401]

Yes - that's the issue, the location, as compared to the primary. It's odd for it to pop up in the pulmonary ligament, and the field gets strange, long, and lots of lung involved. I'm not sure of mislabeling - kind of hard to judge something like that? This guy is an actual thoracic surgeon (not common around these parts), and I think he's pretty comfortable with where it was located, but it's a good thought to keep in mind.

Palex - No ECE mentioned, but gotta call the pathologist, because they didn't specifically say no ECE. What does "local L1" mean?

TarHeelDoc - when you say not to boost the margin, do you mean not go up to >50.4, or do you mean not treat at all? How in the world to locate that? Using preop CT tough, because now that lobe is gone, and it gets filled in with other parenchyma. Can try to get the dx rad or surgeon to help localize, if he left clips or something.

Probiotic - cute comment about DeVita (or NCCN or UpToDate). I know what the book says, but curious to know what real doctors do in odd cases.

-S

 

[Palex80]

Palex - No ECE mentioned, but gotta call the pathologist, because they didn't specifically say no ECE. What does "local L1" mean?

Lymphangiosis carcinomatosa in the tissue around the involved node.

I'd be more inclined to treat the primary tumor site than the pN2-site. You can put a gap between both volumes actually. I would try to avoid to treat excessively lots of lung.
I would probably give 54/2 to the primary tumor site. It's not incomplete resection, so no 60 Gy, but it's still only 1mm safety margin, so I'd like to go a just a bit higher than 50/2.
But, hey, no evidence there, just my gut feeling.

 

[TarHeelRadOnc]

Yes - that's the issue, the location, as compared to the primary. It's odd for it to pop up in the pulmonary ligament, and the field gets strange, long, and lots of lung involved. I'm not sure of mislabeling - kind of hard to judge something like that? This guy is an actual thoracic surgeon (not common around these parts), and I think he's pretty comfortable with where it was located, but it's a good thought to keep in mind.

Palex - No ECE mentioned, but gotta call the pathologist, because they didn't specifically say no ECE. What does "local L1" mean?

TarHeelDoc - when you say not to boost the margin, do you mean not go up to >50.4, or do you mean not treat at all? How in the world to locate that? Using preop CT tough, because now that lobe is gone, and it gets filled in with other parenchyma. Can try to get the dx rad or surgeon to help localize, if he left clips or something.

Probiotic - cute comment about DeVita (or NCCN or UpToDate). I know what the book says, but curious to know what real doctors do in odd cases.

-S

Sorry, I should have been more clear. I would not try to treat the close parenchymal margin at all. I do not feel that it can be reliably localized, and think that the fissure or adjacent pleura act as natural barriers to spread in the setting of lobectomy.