Interim FDG-PET in Diffuse Large B-Cell Non-Hodgkin’s Lymphoma: A Meta-Analysis
Ezzeldin Ibrahim, Mubarak Al-Mansour, Meteb Al-Foheidi and Ghieth Kazkaz
World Journal of Medical Research 2013, 2:4
FDG-PET is increasingly being used in non-Hodgkin’s lymphoma (NHL), however, the value of interim FDG-PET (IFDG-PET) performed during induction chemotherapy is not established. A meta-analysis was designed to define the clinical utility of IFDG-PET.
According to predefined selection criteria, literature search identified 22 studies included in the analyses.
There were 1,957 patients (median age of 55 years, 58% males, 95% diffuse large B-cell, 36% stage I/II, and 64% stage III/IV). Patients with negative IFDG-PET had 62% reduction in the risk of disease progression (hazard ratio [HR] = 0.38; 95% CI, 0.30–0.47; P <0.0001) and 72% mortality reduction (HR = 0.28; 95% CI, 0.21–0.38; P <0.0001) as compared with those with positive IFDG-PET. IFDG-PET predicted survival regardless of the number of chemotherapy (CTX) cycles prior to interim assessment. Meta-regression analysis demonstrated that higher study quality score, increasing median age, increasing number of prior CTX cycles, and longer follow-up were associated with more favorable progression-free survival (PFS). Moreover, visual methods were more related to lower HRs as compared with quantitative/semi-quantitative (Q/SQ) interpretation techniques. IFDG-PET demonstrated moderate sensitivity and specificity for predicting PFS (61.8% and 66.0 %, respectively), and overall survival (62.0% and 63.0%, respectively), with visual image interpretations outperforming Q/SQ methods. The meta-analysis showed several limitations attributed to studies quality and to interpretation methods.
The current meta-analysis demonstrated the predicting utility of IFDG-PET. Future studies should use standardized imaging parameters and examine the effect of using IFDG-PET results on adaptive induction therapy.
Non-Hodgkin’s lymphoma; FDG-PET; Interim; Prediction; Prognosis.