Observer variation in interpreting 18F-FDG PET/CT findings for lymphoma staging

Area of Science:

• Oncology
• Radiology
• Medical Imaging

Background:

• Positron Emission Tomography (PET) has demonstrated high accuracy in lymphoma staging.
• Limited data exists on observer variation in PET-based lymphoma staging.

Purpose of the Study:

• To quantify observer agreement for lymphoma staging using PET/CT.
• To assess the reliability of PET/CT as a noninvasive staging tool.

Main Methods:

• 100 lymphoma patients' PET/CT images were reviewed by 3 experienced observers.
• Ann Arbor stage, nodal, and extranodal regions were assessed.
• Weighted kappa and intraclass correlation coefficients were used to measure agreement.

Main Results:

• High intra- and interobserver agreement was found for Ann Arbor stage (kappa(w) = 0.79-0.91).
• Agreement was high for nodal regions (intraclass correlation coefficient, 0.83-0.93) and extranodal disease (kappa = 0.74-0.86).
• Lower agreement was noted for hilar and infraclavicular regions, and bowel involvement.

Conclusions:

• Experienced observers demonstrate high agreement in lymphoma staging with PET/CT.
• PET/CT is a robust noninvasive tool for lymphoma staging.
• Further research is needed for restaging variability during and after chemotherapy.