18 F-FDG PET/contrast enhanced CT in the standard follow-up of patients with lymphoma.

AIM: To assess the diagnostic accuracy of 18 F-FDG PET/contrast enhanced computed tomography (ceCT) in the detection of asymptomatic recurrences in patients with lymphoma.

MATERIAL AND METHODS: Patients with lymphoma and clinical complete remission underwent 18 F-FDG PET/ceCT for standard follow-up.18 F-FDG PET and ceCT were evaluated blindly by two independent observers, and classified as positive or negative for recurrence. Additionally a combined evaluation of both techniques was performed. The final diagnosis was established by histopathological analysis or a clinical follow-up longer than 6 months. Statistical diagnostic parameters and concordance levels between both diagnostic techniques were calculated.

RESULTS: A total of 114 explorations on 90 patients were analyzed. Only 4 patients were diagnosed as asymptomatic recurrence during the follow-up. 18 F-FDG PET/ceCT, 18 F-FDG PET and ceCT showed an association with the final diagnosis (p=0.002 and χ2 =11.96; p<0.001 and χ2 =15.60; p=0.001 and χ2 =11.96, respectively). The concordance between 18 F-FDG PET and ceCT was moderate/high and significant (kappa=0.672; p<0.001). A sensitivity and specificity of 50% and 88% was obtained for the 18 F-FDG PET/ceCT civ, 50% and 93% for the 18 F-FDG PET, and 50% and 91% for the ceCT.

CONCLUSION: The combined use of 18 F-FDG PET/ceCT did not offer any advantage compared to any isolated diagnostic technique in the detection of asymptomatic lymphoma recurrence.