Splenic RT

[Haybrant]

Got referred a guy with Myelofibrosis multiple lines of therapy now with refractory thrombocytopenia in the 30s. He has a huge spleen 24-25 cm. Hes not that symptomatic from it however, no nausea, eating ok, no abd discomfort no TTP, having occasional loose stool. He was referred from med onc for RT. Is thrombocytopenia due to splenomegaly itself an indication for whole spleen RT? I mean the spleen is huge but his symptoms aren’t bad, in the past only given whole spleen RT for symptomatic splenomegaly. Was planning .2Gy x 10 fractions.

---

Members don't see this ad.

 

[thecarbonionangle]

Boom boom that spleen brotha! 20/5

 

[medgator]

Boom boom that spleen brotha! 20/5

hope you're joking....

 

[deleted18755]

I agree a little weird since you’renot palliating symptoms caused by an enlarged spleen but doesn’t seem unreasonable.

There are many acceptable and highly effective regimens involving “ultra low” dose RT in this setting (4Gy x 5 is obviously not one of them). Make sure you alert your dosimetrist and physicist so they don’t think you made a Gy/cGy mistake or something and think they are helping you by “correcting” the dose and triple check your decimal points before signing the plan.

 

[Palex80]

There are three different indications to treat an enlarged spleen in hematologic malignancies:

1. To treat an aggressive lymphoma which was present in the spleen with consolidative radiotherapy after chemotherapy (quite rare scenario) --> usually dose 30/2 (or something else in that range).
The few cases I've seen had bulky nodes in the spleen hilum invading the spleen.

2. To palliate an aggressive or non-aggressive lymphoma in the spleen causing trouble --> usually boom-boom or any other "palliative" regime you prefer
Most common indication I see for this is CLL. It's getting less common now with lots and lots of new lines of treatment becoming available for CLL.

3. To treat hematopoiesis taking place outside of the bone marrow because of a myeloproliferative neoplasia of the bone marrow which itself is causing the spleen to grow --> usually very-low-dose radiotherapy over 1-2 weeks or even longer with doses <0.5 Gy/d usually.
Most common indication I see for this is myelofibrosis. It's getting less common now with JAK2 inhibitors working quite well too.

Now, people often mix up 2 & 3, but these are two distinct situations with unique approaches. However clinical presentation may be similar with cytopenia.
Cytopenia can happen in scenario 2 due to bone marrow infiltration by the NHL and is certain in scenario 3 due to the bone marrow failing because of the disease. However in both cases, cytopenia also happens due to a "mechanical" issue. The enlarged spleen pretty much destroys red cells and consumes platelets.
And this is the paradoxon here in scenario 3. Although the spleen is the place where hematopoiesis is taking place, it would have been irrational to treat that and thus further risk deterioration of blood values. Yet, if you manage to make the spleen shrink, blood values will get better. There is however a "tricky" phase where cytopenia may get a lot worse, hence the low doses prescriped and often checks of blood values recommended.

 

[Mandelin Rain]

And this is the paradoxon here in scenario 3. Although the spleen is the place where hematopoiesis is taking place, it would have been irrational to treat that and thus further risk deterioration of blood values. Yet, if you manage to make the spleen shrink, blood values will get better. There is however a "tricky" phase where cytopenia may get a lot worse, hence the low doses prescribed and often checks of blood values recommended.

This.

Last time I did this, I did 0.5 Gy x 10 and checked CBCs 2-3 x weekly. Worked really well for like 9 months.

 

[evilbooyaa]

Boom boom that spleen brotha! 20/5

What the what?

No, like not at all. Not for myelofibrosis.

Palex is spot on. < 1Gy (0.2-0.5Gy) per fraction x 10.

The patient, while not clinically symptomatic, IS having issues with platelet destruction due to his hyperenlarged spleen. With no evidence for lymphoma in the patient's history, OP, your dosing is reasonable.

 

[PhotonBomb]

Boom boom that spleen brotha! 20/5

Dude, lay low. no.

a) that's not boom boom
b) no

 

[scarbrtj]

Boom boom that spleen brotha! 20/5

BOOMER. /ˈbo͞omər/ noun. 1. A person that booms.

 

[maruchan]

Was referred a patient with TTP refractory to many different therapies for splenic RT in lieu of splenectomy.

Has anyone done splenic RT for TTP? Does that even make sense?

 

[xyz01]

Maybe somebody has some insights...

Patient treated for residual follicular lymphoma in 2022 an recieved 24 Gy to the whole spleen. Treatment was well tolerated.
In the meantime he developed DLBCL with allogenic SCT and is now under consolidation therapy. Recent PET-CT still shows rest lymphoma in the spleen.
Would anybody re-treat the spleen?
To my understanding prior radiation dose should not be a problem for (current) cytopenia nor is there any Max dose I'm aware of...

 

[evilbooyaa]

Spleen is functionally not working already, take it as high as you'd want. Main risk of tox if you go super high would be vascular compromise, but persistent DLBCL I'd feel totally fine taking it for up to another 50Gy @ normal fractionation

 

[Palex80]

Maybe somebody has some insights...

Patient treated for residual follicular lymphoma in 2022 an recieved 24 Gy to the whole spleen. Treatment was well tolerated.
In the meantime he developed DLBCL with allogenic SCT and is now under consolidation therapy. Recent PET-CT still shows rest lymphoma in the spleen.
Would anybody re-treat the spleen?
To my understanding prior radiation dose should not be a problem for (current) cytopenia nor is there any Max dose I'm aware of...

Spleen is functionally not working already, take it as high as you'd want. Main risk of tox if you go super high would be vascular compromise, but persistent DLBCL I'd feel totally fine taking it for up to another 50Gy @ normal fractionation

One issue may be, that we don't really know what is in that spleen.
It could be DLBCL, it could also be FL.
If it's a solitary lesion and the patient is in good shape, one could even think about splenectomy. Both therapeutic and diagnostic.
Knowing he has residual DLBCL despite allogenic transplant, could be informative for further treatment, for example reducing immunosuppresion faster or giving donor lymphocyte infusions.
Did the patient really have allogenic SCT or CAR-Ts? Allogenic SCT is not that common for DLBCL.

 

[xyz01]

Thank you for your repsonses!
Yes, he did recieve allogenic SCT. To my understanding the DLBCL developed out of the follicular lymphoma, so I don't think histology from splenectomy would have any therapeutic consequences..

 

[Palex80]

Yes, he did recieve allogenic SCT. To my understanding the DLBCL developed out of the follicular lymphoma, so I don't think histology from splenectomy would have any therapeutic consequences..

It depends.
Transformation is a clonal event arising from a single cell, meaning that an advanced stage FL may transform only at one site and then spread out from there, while other sites may still keep the FL phenotype.

In your patient:
The FL may have transformed to a DLBLC, but the spleen-involvement may have still kept the FL phenotype (or at least parts of it).
Do you have histology from the spleen (at any point) proving DLBCL there?


I have seen several patients with transformed low-grade lymphoma to a DLBCL who achieved CR with chemo +/- ASCT, and years later recurred with the initial low-grade lymphoma.

 

[xyz01]

Ok, I see what you're getting at.
There has never been a histology from the spleen.
Initially was considered as stage III (IV?) FL with histology taken from paravertebral soft tissue; Patient recieved systemtic therapy and progressed 2 times in the spleen. The second time PET showed no signs of extrasplenic activity, so he was treated with radiotherapy
2 Years later he progressed on multiple signs with new histology taken from (different?) soft tissue, witch showed DLBCL with aditional bone marrow biopsy witch showed MDS transitioning to AML. (hence the allogenic SCT?)..

 

[Palex80]

Ok, I see what you're getting at.
There has never been a histology from the spleen.
Initially was considered as stage III (IV?) FL with histology taken from paravertebral soft tissue; Patient recieved systemtic therapy and progressed 2 times in the spleen. The second time PET showed no signs of extrasplenic activity, so he was treated with radiotherapy
2 Years later he progressed on multiple signs with new histology taken from (different?) soft tissue, witch showed DLBCL with aditional bone marrow biopsy witch showed MDS transitioning to AML. (hence the allogenic SCT?)..

Thank you for elaborating.
I still think there's a chance, it's FL in the spleen.

 

[evilbooyaa]

Thank you for elaborating.
I still think there's a chance, it's FL in the spleen.

And if it is, 50Gy will kill it.
If it is DLBCL, 50Gy will kill it as well.

If you treat it as active FL and give 24Gy and it is FL, then OK
If it is DLBCL, 24Gy will not do anything.

I understand concerns about prognosis with residual disease postSCT of relapsed DLBCL, but I laready imagine a person with that story has a relatively poor prognosis. Not unreasonable to discuss with heme/onc, but I can't imagine someone post alloSCT for relapsed DLBCL is a great candidate for a splenectomy.

 

[xyz01]

Discussed it with the hem/onc. They are not really keen to operate on a post SCT patient. Plan is to reduce/discontinue immunosupressants an redo a PET-scan in 2 month. If there is lymphoma left, we will radiate it..
Last question:
Would anybody just treat the pet positive lesion vs the whole spleen?
Thanks again!

 

[evilbooyaa]

Discussed it with the hem/onc. They are not really keen to operate on a post SCT patient. Plan is to reduce/discontinue immunosupressants an redo a PET-scan in 2 month. If there is lymphoma left, we will radiate it..
Last question:
Would anybody just treat the pet positive lesion vs the whole spleen?
Thanks again!

I don't see the rationale of not treating now. Risk of toxicity is low.

I would treat entire spleen and underdose at edges of OARs as necessary.