Understanding PET Scan Results with CLL

[FlaKeys]

Hello! I was diagnosed with CLL (11Q) in 2013. On Ibrutinib since 2015 and have very thankfully done very well with basically zero problems. CT scans have showed some mild increase in nodes over the last several years. Doctor ordered a PET Scan. I have the results. What would indicated Richter's transformation?

As always.....Thank you!

[AussieNeil Partner Administrator]

There should be a brief statement by the radiologist about your scan results, but here's my understanding of why you were recommended for a PET scan and how it will be interpreted.

PET scans or to use the full name, F-fluorodeoxyglucose positron emission tomography (FDG PET) scans rely on Standardized uptake values (SUVs) to identify any tissue which is taking up the injected fluorodeoxyglucose radioactive tracer at a higher rate than normal - indicating fast growing cancer cells. Basically, CLL being a chronic blood cancer and using lipids (fat) for an energy source, rather than glucose, has low SUV uptakes, so the CLL infiltrated nodes, spleen, bone marrow, etc don't show up that well on PET scans. (That's why CT scans are preferentially used to check the CLL tumour burden. healthunlocked.com/cllsuppo... ) Richter's Syndrome/Transformation is when the CLL transforms into an aggressive lymphoma, usually DLBCL and sometimes Hodgkin's Lymphoma. So if any of those new pesky nodes have transformed, they should have a much higher SUV score than other nodes. I expect that the most likely outcome is that your CLL has developed resistance to ibrutinib; you've done very well to get to 9 years of maintenance therapy, given the median time to developing resistance is less than that - about 6 years, depending on past treatments and markers.

This paper found the median SUV in a couple of CLL patients to be around 5, in 55 DLBCL patients 17.1 (range 6.4–52.4) and finally in 21 Hodgkin's Lymphoma patients12.4 (8.7–27.0)

High SUV uptake on FDG–PET/CT predicts for an aggressive B-cell lymphoma in a prospective study of primary FDG–PET/CT staging in lymphoma

annalsofoncology.org/articl...

So if any of those nodes have SUV results putting them potentially into the aggressive lymphoma category, Richter's Transformation needs to be confirmed by excising the node and checking its pathology.

Given your long history on ibrutinib and the "mild increase in nodes over the last several years", I don't think you have anything to worry about - it's just your specialist being thorough. Nodes which have transformed into Richter's grow rapidly and you'd be feeling unwell. A blood test checking your LDH (Lactate dehydrogenase) would also be likely to be several times your baseline level, though that increase isn't always seen.

Neil

[FlaKeys in reply to AussieNeil]

Thank you so much for this explanation!! It helps me understand the results and reason for this different test. The radiologist’s “Impression” is:

“Multiple enlarged hypermetabolic nodes in the neck, chest, abdomen, and pelvis compatible with known lymphomatous process.”

The SUV’s in the report were 1.9-3.5. I am not familiar with the SUV and was concerned this meant Richter’s.

One thing I have learned from this journey is to not panic before I gather and understand all the information!

I am so thankful for the Ibrutinib journey! I still feel wonderful and have no issues after all this time. What a blessing it has been.

Do you have an idea of what is available now post ibrutinib?

thank you!!!!!

[AussieNeil Partner Administrator in reply to FlaKeys]

You should be very relieved that "The SUV’s in the report were 1.9-3.5". That's too low for Richter's

This recent post healthunlocked.com/cllsuppo... by my fellow Aussie co-admin CLLerinOz , with a helpful commentary by Skyshark , reviews options available to you in the bottom row.

Neil

[FlaKeys]

i am so very relieved! And I am especially thankful for this group and for your help! Information is so important!