RT Journal Article SR Electronic T1 18F-FDG PET Is an Independent Outcome Predictor in Primary Central Nervous System Lymphoma JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 184 OP 191 DO 10.2967/jnumed.112.108654 VO 54 IS 2 A1 Benjamin Kasenda A1 Vanessa Haug A1 Elisabeth Schorb A1 Kristina Fritsch A1 Jürgen Finke A1 Michael Mix A1 Claudia Hader A1 Wolfgang A. Weber A1 Gerald Illerhaus A1 Philipp T. Meyer YR 2013 UL http://jnm.snmjournals.org/content/54/2/184.abstract AB Primary central nervous system (CNS) lymphoma is an aggressive non-Hodgkin lymphoma with poor prognosis. We evaluated pretreatment 18F-FDG PET as a prognostic marker in primary CNS lymphoma. Methods: Forty-two immunocompetent patients with newly diagnosed primary CNS lymphoma who underwent pretreatment 18F-FDG PET were retrospectively analyzed. Baseline status and response to treatment were evaluated by MR imaging. Tumor maximum standardized uptake values were assessed by volume-of-interest analyses using an automatic isocontour definition. A 10-step semiquantitative visual rating system (metabolic imaging lymphoma aggressiveness scale, or MILAS) was used to assess primary CNS lymphoma metabolism as a marker of clinical aggressiveness. Logistic regression, log-rank testing, and multivariable Cox regression were used to investigate the association between 18F-FDG uptake and tumor response and survival. Results: Mean maximum standardized uptake value correlated linearly with MILAS. The distribution of patients according to MILAS (0–9) was 0%, 28.6%, 23.8%, 21.4%, 11.9%, 4.8%, 7.1%, 0%, 0%, and 2.4%. There was no correlation between MILAS and response to treatment. Respective 2- and 5-y survival rates were 52% and 32% for progression-free survival (PFS) and 64% and 50% for overall survival (OS). A cutoff at MILAS 3 was a good separator for PFS (median: 54.7 mo [≤3], 3.8 mo [>3], P = 0.0272) and OS (median: not reached [≤3], 13.8 mo [>3], P = 0.131). In multivariable analyses, increasing MILAS was significantly associated with shorter PFS (hazard ratio, 1.49, P = 0.006) and OS (hazard ratio, 1.43, P = 0.018). Conclusion: Increased pretreatment 18F-FDG uptake may offer new opportunities for baseline risk evaluation in untreated primary CNS lymphoma.