Clinical Case Management - Treatment Planning for MALT Lymphoma of the Duodenum

[dieABRdie]

So I thought coming out to the boonies I would be kicked back treating standard breast/prostate/lung/H&N....
I was wrong. I would say at least 1/3rd of my cases are something weird.

This case is pretty straightforward as far as dose/fractionation, just wanted to get some input on how people would plan this.

60 year old female with MALT lymphoma of the duodenal bulb. Plan for 24Gy in 12 fractions. The patient was simulated on an empty stomach. We don't have 4D CT but I did full inspiration and expiration scans just to be sure there wasn't a lot of motion (there wasn't). Unfortunately she has a history of chronic kidney disease so we couldn't give her contrast (GFR = 20)... but I do have a PET scan done recently to fuse.

These guidelines suggest to treat the whole duodenum... Modern radiation therapy for extranodal lymphomas: field and dose guidelines from the International Lymphoma Radiation Oncology Group. - PubMed - NCBI

But I'm worried about knocking out the rest of her kidney function so I was thinking of just focusing it down to the involved area of duodenum with a reasonable CTV margin and then a PTV.

So what volume and margins might people use here?

And of course the insurance company is fighting me on using IMRT....

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[gmsquid]

I would treat whole duodenum with a 1-1.5 cm PTV margin. You’re running into difficulty staying off kidneys with a four field?

 

[gmsquid]

Also, just wondering why the need for IV contrast?

 

[Mandelin Rain]

I mean, you’re going to 24 Gy. If the volume comes low enough to worry about kidneys , try appa or slightly oblique opposed fields. Duodenum is usually kind of a midline-ish organ.

 

[gmsquid]

And if you are very worried, consider getting a renal scan and see which kidney is doing all the work.

 

[dieABRdie]

I would treat whole duodenum with a 1-1.5 cm PTV margin. You’re running into difficulty staying off kidneys with a four field?

I think we can come up with something. I was just curious what others would use for treatment volumes.
I typically would have liked contrast for any tumors in the intestinal wall.... but it really wasn't necessary in this case.

 

[dieABRdie]

I mean, you’re going to 24 Gy. If the volume comes low enough to worry about kidneys , try appa or slightly oblique opposed fields. Duodenum is usually kind of a midline-ish organ.

Thanks. I was mostly worried because she's technically stage 4 CKD and I didn't know if the typical dose constraints would hold up. I've looked briefly but haven't come up with much.

 

[scarbrtj]

Thanks. I was mostly worried because she's technically stage 4 CKD and I didn't know if the typical dose constraints would hold up. I've looked briefly but haven't come up with much.

get creative, go non-coplanar if nec, spill dose over into everything but kidney
remember a 1.5cm PTV = 2cm block from old days
1.5 is fine

 

[Palex80]

Let‘s be frank...

We have little evidence on „what“ to treat when it comes to GI lymphoma.
“Old“ volumes were gigantic by all means and toxicity high.

But who says you have to treat the entire duodenum? What‘s the logic behind it? Would the lymphoma cells grow till the aboral end of the duodenum and stop when they reach the border to the jejunum („Oh wait, we are duodenal-lymphoma-cells, we don‘t go into the jejunum!“).

24 Gy are probably fine, but let‘s be frank, we do not know if they are safe. We are extrapolating the dose from the nodular-lymphoma-trial. We can probably do that, but we do not really know... Gastric-MALT-data were conflicting on the question of dose.

Also bear in mind that „old“ data are probably biased against RT efficacy and effect of local control depending on dose may not be that well documented, since „old“ patient series certainly underestimated the stage in many patients. We did not have PET and flow-cytometry of bone marrow back then. Those trials probably treated quite a few stage III/IV patients with RT for presumed stage I (including the British trial). No way to see if dose escalation is important, when you are not treating „all“ of the disease.

One could also argue for whole-stomach-bowel-RT with 2x2 Gy and then cone down to 24-30 Gy at the macroscopic lymphoma? I think there‘s a trial that was/is studying that...
FORT-data don’t look that bad for 2x2 Gy.

 

[evilbooyaa]

Has the patient had staging beyond a simple EGD (push enteroscopy or capsule EGD)? These are frequently multifocal per the guidelines you linked:

Primary duodenal follicular lymphoma is increasingly recognized and is often detected incidentally during the endoscopic investigation of abdominal symptoms. It has a very indolent natural history, and many clinicians observe rather than treat this condition. When RT is considered, a detailed staging evaluation is mandatory because pill-camera endoscopy or double balloon/push enteroscopy detects multifocal disease in many patients. Imaging including PET may be insensitive to small-volume multifocal disease. If disease is localized to the duodenum, RT can be confined to this organ (71).

Small bowel indolent lymphoma often presents with pain or obstructive symptoms and is sometimes treated surgically in the first instance. If disease is confined to bowel, RT requires whole abdominal irradiation. The use of whole abdominal irradiation requires due consideration of possible short-term and long-term toxicity.

Is she symptomatic? This suggests you can potentially just observe this until symptomatic progression (the reference for the guidelines you linked): https://www.tandfonline.com/doi/full/10.3109/10428194.2012.698390

The gastrointestinal (GI) tract is the most common extranodal site of non-Hodgkin lymphoma, but primary follicular lymphoma (FL) of the GI tract is rare and accounts for less than 7% of GI lymphomas [1,2]. Recent studies suggest that FL of the GI tract is particularly indolent and may represent a distinct localized variant of FL [3–7]. In a study of 63 patients with stage I FL of the duodenum, Schmatz et al. reported that 38% of patients were observed, with no transformation and only two cases of progressive disease [4]. Therefore, observation was suggested as the most sensible treatment strategy. Other management strategies have included radiation therapy (similar to the approach for stage I nodal FL), chemotherapy (most commonly rituximab) and surgery [4–10].

Obviously no RCT data, just something to consider.

Otherwise 4-field with obliques as necessary to stay off the kidneys to 24Gy in 12 fractions, up to maybe 30Gy in 15-20 fractions would be my preferred. I would personally favor doing the whole duodenum since this is a rare disease and in those situations one should just follow published guidelines as one will not have a clinical gestalt for the disease process.

As Palex mentioned above, doing 2Gy x 2 to whole organ with a cone down to 24/12 would not be unreasonable either. I would not recommend 2Gy x 2 as her whole course in a curative situation.

IMRT would potentially be useful to minimize stomach and other intestinal dose but I'm not surprised it's not authorized by insurance.

 

[seper]

I've treated n=2 like that, and I've radiated the whole organ to 25.5/1.5 Gy followed by conedown of 5 about Gy. Good thing doses involved are so low.

 

[PhotonBomb]

With doses these low you can’t cause much harm!

You almost have to pay to get this kind of RT!