Prognostic value of interim FDG-PET in R-CHOP-treated diffuse large B-cell lymphoma: Systematic review and meta-analysis

- Interim FDG-PET in DLBCL is frequently performed in clinical practice and its use is promoted by current guidelines.
- A systematic review and meta-analysis revealed interim FDG-PET to have some correlation with outcome.
- However, interim FDG-PET has not consistently proven to surpass the prognostic potential of the IPI.
- At present there is no scientific base to support the use of interim FDG-PET in R-CHOP-treated DLBCL.

This study aimed to systematically review and meta-analyze the prognostic value of interim 18F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in diffuse large B-cell lymphoma (DLBCL) patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP). MEDLINE and EMBASE were systematically searched for suitable studies. Included studies were methodologically appraised, and results were summarized both descriptively and meta-analytically. Nine studies, comprising a total of 996 R-CHOP-treated DLBCL patients, were included. Overall, studies were of moderate methodological quality. The area under the summary receiver operating curve (AUC) of interim FDG-PET in predicting treatment failure and death were 0.651 and 0.817, respectively. There was no heterogeneity in diagnostic odds ratios across available studies (I2 = 0.0%). At multivariable analysis, 2 studies reported interim FDG-PET to have independent prognostic value in addition to the International Prognostic Index (IPI) in predicting treatment failure, whereas 3 studies reported that this was not the case. One study reported interim FDG-PET to have independent prognostic value in addition to the IPI in predicting death, whereas 2 studies reported that this was not the case. In conclusion, interim FDG-PET in R-CHOP-treated DLBCL has some correlation with outcome, but its prognostic value is homogeneously suboptimal across studies and it has not consistently proven to surpass the prognostic potential of the IPI. Moreover, there is a lack of studies that compared interim FDG-PET to the recently developed and superior National Comprehensive Cancer Network-IPI. Therefore, at present there is no scientific base to support the clinical use of interim FDG-PET in R-CHOP-treated DLBCL.