Page 46 - 18F-FDG PET as biomarker in aggressive lymphoma; technical and clinical validation

Chapter 3
heterogeneity in patient populations, therapy regimens, PET scanners, timing of the interim 18F-FDG PET scans, and/or differences in the visual criteria used for interpretation of the interim 18F-FDG PET scans made it hard to clarify the accuracy of interim 18F-FDG PET to predict clinical outcome in DLBCL.
Therefore, we performed a new systematic review and meta-analysis, focusing on DLBCL patients only, assessing both the hazard ratio (HR) and diagnostic parameters (sensitivity, specificity, and predictive values) of interim 18F-FDG PET on PFS or event-free survival (EFS) in patients with DLBCL treated with first-line immuno-chemotherapy regimens. The primary outcome measure was PFS (preferably) or EFS at 2 years, since DLBCL patients who are event- free after 24 months have demonstrated an overall survival (OS) comparable to an age- and sex-matched general population [19]. In order to reduce the previously described heterogeneity we performed several subgroup analyses, for example, by the type of 18F-FDG PET scanner and the type of visual criteria used for interpretation of the interim 18F-FDG PET scans. In this meticulously performed review we contacted the authors for additional information if necessary.
Materials and methods
Search strategy
For this systematic review and meta-analysis we searched in collaboration with a medical librarian Pubmed/MEDLINE, Embase, and the Cochrane Library databases from onset until July 11, 2017 with a language restriction to English, French, Dutch, or German. Our search strategy contained a combination of various indexed terms and free text words for “positron emission tomography” and “non-Hodgkin lymphoma” (full search strategy Supplemental Table 1). We included full-text publications of original prospective and retrospective studies. Excluded were conference abstracts, letters, comments, editorials, review articles, animal studies, and case reports. Reference lists of included articles were checked to identify additional eligible studies.
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