Comparison of 18F-FDG Pet/CT and CT: diagnosis performance in lymphoma patient after treatment

Retrospectively comparing 18F-FDG PET/CT and CT findings at the same anatomic locations in patients with lymphoma by using a combined PET/CT scanner and to analyze the lesions on both metabolic and anatomic bases to evaluate their sensitivity specificity positive predictive value (PPV), negative predictive value (NPV), and accuracy. We analyzed all studies, all patients, common cell type in this study such as diffuse large B cell lymphoma (DLBCL) and Hodgkin's lymphoma and indication of the study such as restaging for recurrence post-therapy and evaluate residual disease within two months after chemotherapy.

Sixty-seven lymphoma patients were studied PET/CT between January 2007 and December 2012 in Siriraj Hospital. We excluded six patients due to no medial report in our hospital. Sixty-one patients (29 male, 32 female, mean age 46.6 +/- 17.7 years, range 8-75) with NHL and with HL) were analyzed for the result of dual-modality PET/CT They underwent 77 18F-FDG PET/CT studies for restaging, for recurrence post-therapy based on 41 studies and evaluation of residual disease within two months after chemotherapy in 36 studies.

The statistical parameters of 18F-FDG PET/CT imaging of lymphoma patients after treatment show significantly better specificity than CT and insignificant high accuracy for all studies, all patients, histology of DLBCL, indication of evaluation of active lymphoma within two months after chemotherapy. The 18F-FDG PET/CT parameters of accuracy and PPV are higher than CT without statistical significance. The 18F-FDG PET/CT is not significantly better than CT for histology of Hodgkin's lymphoma and indication of restaging for recurrence post-therapy Nevertheless, the 18F-FDG PET/CT shows slightly improved specificity PPV and accuracy than CT The sensitivity of CT in this study is high and may be from most of our cases selected post-treatment lymphoma that had a residual mass after treatment. Therefore, the sensitivity of PET scan is not significantly higher when compared with CT scan.

The PET/CT is better than CT for post-treatment lymphoma patient particularly for cell type of DLBCL and indication for evaluation of active lymphoma within two months after chemotherapy.