PET/CT: Clinical role in lymphomas

Area of Science:

• Oncology
• Nuclear Medicine
• Radiology

Background:

• 18F-FDG PET/CT is the preferred imaging modality for staging most lymphomas.
• FDG uptake varies among lymphoma subtypes, with aggressive lymphomas generally showing higher uptake than indolent ones.
• PET/CT enhances detection of nodal and extra-nodal disease compared to CT alone.

Purpose of the Study:

• To evaluate the role of 18F-FDG PET/CT in the initial staging of lymphomas.
• To assess the utility of interim PET/CT in therapeutic evaluation and response assessment.
• To determine the accuracy of PET/CT in post-treatment assessment and predicting survival outcomes.

Main Methods:

• Utilized 18F-FDG PET/CT for initial staging and interim treatment response assessment in Hodgkin's and Non-Hodgkin lymphomas.
• Applied the Deauville 5-score scale for standardized interpretation of PET/CT findings.
• Compared PET/CT accuracy with CT for detecting nodal, extra-nodal, and residual disease.

Main Results:

• PET/CT leads to upstaging in up to 25% of Hodgkin lymphomas and has high sensitivity for nodal and extra-nodal disease.
• Interim PET/CT demonstrates high Negative Predictive Value (NPV) for treatment response and progression-free survival in Hodgkin's.
• PET/CT accurately assesses residual disease post-treatment and predicts outcomes in patients undergoing megatherapy before stem cell transplantation.

Conclusions:

• 18F-FDG PET/CT is an established and essential tool in lymphoma management, influencing therapeutic decisions.
• The Deauville score improves the reliability of PET/CT interpretation for treatment response assessment.
• PET/CT significantly enhances diagnostic accuracy and prognostic value across various stages of lymphoma care.