Diagnostic Yield of Extensive Systemic Staging Including Whole-body 18F-fluoro-deoxy-glucose Positron Emission Tomography With or Without Computed Tomography in Patients With Primary Central Nervous System Lymphoma: Systematic Review and Meta-analysis.

The extent of staging required to evaluate for systemic involvement in patients with primary central nervous system lymphoma (PCNSL) remains controversial. Eligible studies reporting on diagnostic yield of extensive systemic staging, including pre-treatment whole-body 18F-fluoro-deoxy-glocose positron emission tomography with or without computed tomography, in immuno-competent adults with PCNSL were identified through systematic literature search. Diagnostic yield was defined as the proportion of patients with abnormal test results outside the neuraxis that led to detection of concordant systemic high-grade lymphoma on an individual patient basis (true positives). Data were pooled using random-effects model to produce summary estimates with 95% confidence intervals (CIs). Weighted-mean pooled analysis involving 1099 patients from 14 primary studies provided an overall diagnostic yield of 6% (95% CI, 4%-8%) for extensive systemic staging in PCNSL with implications for diagnosis, prognosis, and therapy. Summary estimates of false positivity were just marginally lower at 5% (95% CI, 3%-8%) for such systemic staging.