The purpose of this study is to define a reference population for FDG-PET neurological examinations starting from patients having FDG-PET to supervise a non-complicated lymphoma (tumor in remission, low disabling chronic tumor).

This study will also check normality of cerebral functions in this population and analyse the influence of various variation factors, such as age, sex ratio, education level, professional activity and neuropsychological test results on normal data.

This database could be later used as comparison to patient images defining the gravity and localization of their cerebral functional disorders.

Inclusion Criteria:

• Patient with tumor in remission or low disabling chronic tumor
• No parenteral chemotherapy for at least 1 month
• No glucocorticoid treatment
• No general health modification (asthenia, anorexia, weight reduction)

Exclusion Criteria:

• Patient having a known neurodegenerative disorder, a general disease or physical problems that can interfere with cognitive function
• Patient with cerebral pathology history (epilepsy, vascular event, cerebral vascular malformation, tumor, severe cranial trauma, meningitis or infectious or inflammatory encephalitis, hydrocephalus, mental retardation…)
• Patient not having at least 4 years of education
• Patient having an anxiolytic or anti-depressive treatment
• Patient refusing to participate to the study
• Patient incapable to give informed consent (guardianship)