- FDG PET/CT plays an important role in staging and assessing treatment response for FDG-avid lymphomas according to the Lugano classification criteria. - For FDG-avid lymphomas, FDG PET/CT is the standard for imaging and a 5-point scale should be used for response assessment. A bone marrow biopsy is no longer needed for routine staging of Hodgkin's lymphoma and most diffuse large B-cell lymphomas. - While interim PET-adapted treatment strategies have shown benefit for Hodgkin's lymphoma, the data is less clear for non-Hodgkin's lymphoma and treatment escalation based on an interim positive PET scan is not routinely recommended.

1. Response evaluation criteria for FDG
PET/CT in lymphoma
1 2 J A N U A R Y, 2 0 2 3 .
MIAD ALSULAMI.MD .FRCPC

2. Outlines:
• Background Information And Definitions.
• Patient Preparations.
• Brief review of the Lugano classification and Response evaluation
criteria .
• Role of iPET CT in FDG avid lymphoma .

3. Background Information And
Definitions.

4. • F18 FDG also commonly called fluorodeoxyglucose.
• Radiopharmaceuticalused in the medical imaging modality positron
emission tomography PET CT.
• Chemically, it is a glucose analog, with the positron-emitting
radionuclide fluorine-18 substituted for the normal hydroxyl group at
the C-2 position in the glucose molecule.

5. • FDG is taken up by high-glucose-using cells such as tumor cells where
phosphorylation prevents the glucose from being released again from
the cell.
• FDG is missing this 2-hydroxyl,FDG cannot be further metabolized in
cells.
• The labeled 18F FDG compound has a relatively short shelf life which
is dominated by the physical decay of fluorine-18 with a half-life of
109.8 minutes, or slightly less than two hours.

7. Patient Preparations

8. • Patients should be instructed to fast and not consume beverages,
except for water, for at least 4–6 .
• The patient should remain seated or recumbent for 18F-FDG
administration and the subsequent uptake phase to avoid muscular
uptake.
• The blood glucose level should be checked before 18F-FDG
administration.
• Most institutions reschedule the patient if the blood glucose level is
greater than 150–200 mg/Dl.

10. • Reducing the serum glucose level by administering insulin can be
considered, but the administration of 18F-FDG should be delayed
after insulin administration (with the duration of the delay being
dependent on the type and route of administration of insulin).

11. • Post biopsy : 7 to 10 days
• Post surgery: 4-6 weeks ( minimum 2 weeks)
• Post chemotherapy: 3 months after the end of treatment ( minimum
3 weeks) .
• PET should not be performed earlier than 10 days after
Chemotherapy , to avoid the “stunning” effect of therapy on tumor
cells and nonspecific FDG uptake due to CT-induced inflammation.
• Post radiotherapy: 12 weeks ( 3 months)
• G-CSF: 5 days to 4 weeks.

12. Bone Marrow Hyperplasia
Increased bone marrow cellularity can be due to Decreased
peripheral blood cell counts leading to Marrow expansion:
1. Anemia
2. Leukemia
Induced by pharmacologic agents:
1. Chemotherapy
2. Bone marrow stimulating agents (GCSF, EPO)

13. Brief review of the Lugano
classification and the role of FDG-
PET/CT in Lymphoma

15. • A workshop was held at the 11th International Conference on
Malignant Lymphoma in Lugano, Switzerland, in June 2011.
• The conference included leading hematologists, oncologists, radiation
oncologists, pathologists, radiologists, and nuclear medicine
physicians, representing major international lymphoma clinical trials
groups and cancer centers.

16. • The accurate assessment of initial disease status and therapeutic
responses is critical to the optimal management of patients with
lymphoma.
• Currently, staging and treatment response evaluation for lymphoma
has been standardized into the Lugano classification.
• Lugano classification incorporates positron emission tomography
(PET) into the existing response criteria, and response assessment
using FDG-PET/CT has been proven to predict the prognosis in various
lymphoma subtypes effectively.

17. • As a result, FDG PET CT was formally incorporated into standard
staging for FDG-avid lymphomas.
• A modification of the Ann Arbor descriptive terminology will be used
for anatomic distribution of disease extent.
• The suffixes A or B for symptoms will only be included for HL.
• A bone marrow biopsy is no longer indicated for the routine staging of
HL and most diffuse large B-cell lymphomas.

18. • PET-CT will be used to assess response in FDG-avid histologies using
the 5-point scale.
• Routine surveillance scans are discouraged.

19. https://oncologypro.esmo.org/content/download/75355/1377102/file/ESMO-E-Learning-The-Lugano-Classification-
Recommendations-For-Hodgkins-and-Non-Hodginks-Lymphoma-Staging-Response-Assessment-and-Follow-Up-Zucca-Pavanello.pdf

22.  FDG PET CT is indicated in all types of lymphoma except :
1. Chronic lymphocytic leukaemia/small lymphocytic lymphoma
2. Lymphoplasmacytic lymphoma/Waldenstrom’s macroglobulinemia,
3. Mycosis fungoides,
4. Marginal zone lymphomas
Unless there is a suspicion of aggressive transformation

23. • PET-CT is indicated in all FDG avid lymphoma as a part of staging and
response assessment.
• CECT rarely alters management, and can be reserved for:
1. Measurement of nodal size for trials.
2. Radiation planning.
3. Distinguishing bowel from nodes.
4. Assessing compression/thrombosis of central/mediastinal vessels.

24. • In practice many patients have separate CECT before PET-CT.
• If CECT is required at staging, it should ideally be combined with
PET-CT at a single visit.
• Full dose CECT involves additional radiation, which should be
considered when deciding which examination(s) to perform.

25. • PET-CT is recommended for response assessment using 5-Point Scale
(5-PS).
Staging and response assessment of lymphoma: a brief review of the Lugano classification and the role of FDG-PET/CT

27. Biopsy of residual metabolically active tissue is recommended if
salvage treatment is considered→ interval scan can be considered
where clinical likelihood of disease is low.

28. Role of iPET CT in FDG avid
lymphoma

30. Role of iPET CT in FDG avid lymphoma
• Interim PET-adapted strategies have gained hold in HL.
• The data in NHL are less conclusive.
• Numerous studies have explored escalation of therapy in response to
a positive interim PET in this patient population.
• No consistent improvement in outcomes has been demonstrated
with intensified regimens compared to standard R-CHOP.

31. • The overall predictive value was lower than that of HL.
• No trial has, thus far, demonstrated the superiority of the iPET-driven
strategy over the conventional methodology in DLBCL.
• Therefore, in patients with DLBCL, treatment escalation for interim
PET positivity is not recommended in routine practice.

32. Summary :
• The Deauville scale and Lugano criteria are part of an ongoing
process to improve incorporation of FDG PET/CT in the treatment of
lymphoma.
• The Lugano criteria incorporates the Deauville scale and provides
additional integration with CT, pathology, radiotherapy and clinical
practice.

33. • Changes introduced by the Lugano criteria include:
1. FDG PET/CT is the standard for imaging FDG-avid lymphomas
2. CT is indicated for non-avid histologies.
3. If FDG PET/CT is performed for HL a BMB is no longer indicated.
4. If FDG PET/CT for DLBCL is negative a BMB is only needed if
identifying a discordant histology is important for patient
management.
5. The 5-point scale for FDG PET/CT should be used for response
assessment in FDG-avid lymphomas.

34. THANK YOU !