Fig. 4.

Demographic distribution of IPCG survey response. The IPCG imaging subcommittee surveyed members to determine clinical imaging practices for the evaluation of PCNSL at institutions across the world. About 147 institutions were invited to participate in this electronic survey. A 20% response rate was received from institutions delineated on the map from North America (N = 11), Europe (N = 17), and India (N = 1). Abbreviations: IPCG, International PCNSL Collaborative Group; PCNSL, primary central nervous system lymphoma.