Annals of Nuclear Medicine

, Volume 24, Issue 5, pp 335–343

Use of PET in the diagnosis of primary CNS lymphoma in patients with atypical MR findings

  • Nobuyuki Kawai
  • Shuichi Okubo
  • Keisuke Miyake
  • Yukito Maeda
  • Yuka Yamamoto
  • Yoshihiro Nishiyama
  • Takashi Tamiya
Original Article

Abstract

Objective

The diagnosis of primary central nervous system lymphoma (PCNSL) in immunocompetent patients with atypical magnetic resonance (MR) findings such as disseminated lesions or no (non-enhancing) lesion is sometimes difficult because of mimicking other tumorous and non-tumorous diseases. Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) and 11C-methionine (MET) can measure the glucose and amino acid metabolism in the lesions and may provide useful information for diagnosing PCNSL in patients with such subtle MR findings.

Methods

We performed PET studies with FDG and MET in 17 histologically proven PCNSL and compared the uptake of FDG and MET qualitatively and quantitatively in the tumors between 12 typical and 5 atypical MR findings.

Results

All typical PCNSL showed strong uptake of FDG and MET; however, visual analysis of FDG and MET uptake in atypical PCNSL was not very useful for finding lesions in the brain. Semiquantitative FDG and MET uptake values (SUVmax) and quantitative FDG influx rate constant (Ki) in the tumors are significantly lower in atypical PCNSL compared with those in typical PCNSL. These values obtained in the lesions with atypical MR findings were also not useful for differentiating PCNSL from other tumorous and non-tumorous diseases. The k3 values evaluated by FDG kinetic analysis in atypical PCNSL were similar to those obtained in typical PCNSL.

Conclusions

Visual analysis of FDG and MET uptake in atypical PCNSL was not useful for finding the lesions in the brain. Semiquantitative and quantitative values obtained in the lesions with atypical MR findings were also not useful for differentiating PCNSL from other tumorous and non-tumorous diseases. The k3 values evaluated by FDG kinetic analysis in atypical PCNSL may provide valuable information in the diagnosis of PCNSL.

Keywords

Fluorodeoxyglucose Kinetic analysis Methionine Primary central nervous system lymphoma Positron emission tomography 

Abbreviations

PET

Positron emission tomography

CNS

Central nervous system

MR

Magnetic resonance

Copyright information

© The Japanese Society of Nuclear Medicine 2010

Authors and Affiliations

  • Nobuyuki Kawai
    • 1
  • Shuichi Okubo
    • 1
  • Keisuke Miyake
    • 1
  • Yukito Maeda
    • 2
  • Yuka Yamamoto
    • 2
  • Yoshihiro Nishiyama
    • 2
  • Takashi Tamiya
    • 1
  1. 1.Department of Neurological SurgeryKagawa University, Faculty of MedicineKagawaJapan
  2. 2.Department of RadiologyKagawa University, Faculty of MedicineKagawaJapan

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