Yoshihiro Nishiyama MD, Presenter: Nothing to Disclose

Yuka Yamamoto MD, PhD, Abstract Co-Author: Nothing to Disclose

Nobuyuki Kawai MD, Abstract Co-Author: Nothing to Disclose

Yasuhiro Sasakawa, Abstract Co-Author: Nothing to Disclose

Yukito Maeda, Abstract Co-Author: Nothing to Disclose

F-18 FDG (FDG) PET has been used as a promising tool to diagnose primary central nervous system lymphoma (PCNSL) because the tumor shows very high FDG accumulation. Although C-11 methionine (MET) PET has been reported to be useful for evaluating various brain tumors, the role of MET PET in PCNSL is unclear. We compared the uptake of MET and FDG in patients with PCNSL.

Ten lesions in 8 immunocompetent patients with PCNSL were examined. All patients underwent PET with MET (15 min p.i.) and FDG (60 min p.i.). PET results were evaluated by visual and semi-quantitative analysis. For semi-quantitative analysis, the standardized uptake value (SUV) for tumor and tumor to contralateral normal brain tissue (T/N) ratio were determined by region-of-interest analysis.

All 10 lesions showed focally increased uptake of both MET and FDG. The mean (±SD) MET SUV in the contralateral normal brain tissue (1.3±0.2) was significantly lower than that of FDG SUV (6.0±1.9; p<0.02). The mean (±SD) MET SUV in the PCNSL (3.5±1.6) was significantly lower than that of FDG SUV (14.1±5.7; p<0.006). There was no significant difference between MET T/N ratio (2.6±1.1) and FDG T/N ratio (2.6±1.3).

MET PET showed as high a sensitivity as FDG PET for the detection of PCNSL, although uptake of MET in PCNSL was significantly lower than that of FDG.

MET PET showed as high a sensitivity as FDG PET for the detection of PCNSL, although uptake of MET in PCNSL was significantly lower than that of FDG.

Nishiyama, Y, Yamamoto, Y, Kawai, N, Sasakawa, Y, Maeda, Y, Comparison of C-11 Methionine and F-18 FDG PET in Patients with Primary Central Nervous System Lymphoma.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8007753.html