Diagnostic Performance of 18F-FDG PET or PET/CT for Detection of Post-Transplant Lymphoproliferative Disorder: A Systematic Review and a Bivariate Meta-Analysis
, Francesco Bertagna 3, Luca Canziani 4, Michele Ghielmini 5,6, Luca Ceriani 7,8 and Giorgio Treglia 5,7,9,*Round 1
Reviewer 1 Report
The presented work "Diagnostic Performance of 18F-FDG PET or PET/CT for Detection of Post-transplant Lymphoproliferative Disorder: A Systematic Review and a Bivariate Meta-Analysis" is nice clear written paper. In which authors have studied the diagnostic power of PET/CT for PTLD.
There are several minor point to address:
Please discuss more the effect of only 6 papers in review.
It is not clear the use of reference 6 in a text " Therefore, we aimed to perform a systematic review and bivariate meta-analysis about the diagnostic performance of 18F-FDG PET or PET/CT for detection PTLD to provide timely evidence-based data in this setting [6]." Please rephrase or remove the reference.
Please provide more " Technical details about 18F-FDG PET or PET/CT in the included studies are summarized in Table2." Table 2 does not contain:
Mean injected activity of 18F-FDG.
Mean Time of PET scan.
What protocol was used for PET/CT ? For example, "2 bed positions over upper body".
Correction: CT is used for PET reconstruction as attenuation map. If Modality is PET/CT , than CT was used for anatomical reference. Please correct the table.
Thank you
Author Response
We thank the Reviewer for having appreciated our article. We have addressed minor points as requested by the reviewer. Changes are marked in red text in the revised manusript and listed below:
- We have better discussed the effect of few papers in the review. We added in the discussion this statement: "A limited number of studies including information on the diagnostic performance of 18F-FDG PET or PET/CT in PTLD were available for this systematic review and meta-analysis, thus influencing the statistical power and hampering the generalization of the results. Therefore, more studies on the diagnostic performance of 18F-FDG PET or PET/CT in PTLD are warranted."
- We have changed the position of previous reference 6, according to the reviewer’s suggestion.
- We have provided more technical details in the revised Table 2 about 18F-FDG PET or PET/CT according to reviewer’s suggestions, including mean injected activity of 18F-FDG, time between 18F-FDG injection and PET acquisition, and some available information on PET protocol from the included articles.
- We have added in the revised manuscript that, when PET/CT was performed, CT was used for PET reconstruction as attenuation map and for anatomical reference. We have also deleted the column about other imaging methods in Table 2.
Reviewer 2 Report
Ballova and colleagues present a systematic review and bivariate meta-analysis on the diagnostic performance of FDG PET or PET/CT for detection of PTLD. To my knowledge, this is the first meta-analysis addressing this topic, and adequately incorporates five retrospective single center studies from the literature. This is an important study as PET can potentially upstage PTLD at diagnosis, particularly among the many with extranodal involvement such as the bone marrow. The study question is clear, literature search comprehensive, bias adequately addressed, and there was no significant heterogeneity found among the included studies. The studies did include all types of PTLD, although most were in the setting solid organ transplant (and a few post-HSCT) and most patients had histologically proven monomorphic PTLD (although a few had polymorphic, early lesions and Hodgkin like PTLD). The authors report a pooled sensitivity and specificity of about 90%, odds ratio of 70.4, high positive LR and low negative LR. The authors acknowledge that PET/CT might have false negative results when PTLD lesions are located in areas with high physiological FDG uptake or in non-destructive or polymorphic PTLD. The authors also acknowledge the limited available data in the literature and need for larger prospective studies. One thing not acknowledged that could be added is that PTLD latency after transplant and EBV status were not assessed, which would be interesting as some consider late, EBV negative monomorphic cases to be more like de novo DLBCL.
Author Response
We thank the Reviewer for having appreciated our article. We have addressed minor points as requested by the reviewer. Changes are marked in red text in the revised manusript and listed below:
- According to the reviewer comment we have added more information on PTLD latency after transplant and EBV status in the included studies. These additional data were reported in the revised Table 1.
