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.

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[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?