Management Impact of FDG-PET in a Specialist Memory Disorders Clinic
Objectives : The diagnosis of dementia rests predominantly on clinical assessment with support from anatomical imaging and psychometric tests. However, accuracy is poor for non-Alzheimer’s dementia and when cognitive impairment is mild. FDG-PET has been shown to improve diagnostic accuracy. We aimed to assess the management impact of FDG-PET in a multidisciplinary specialist memory disorders clinic.
Methods : 195 patients (108 male:87 female, average age 73.1 yrs) were prospectively studied over a four year period. Patients were referred to the clinic by a primary care physician for assessment of cognitive impairment and initially seen by a neurologist or geriatrician who determined if a FDG-PET scan was indicated. At a subsequent meeting attended by the treating specialist, a pre-PET diagnosis and management plan was formulated on the basis of clinical assessment, MRI, neuropsychology and blood test results. The FDG-PET was then shown and the diagnosis and management plan revised and compared. Management impact was rated as nil (discordant result ignored), low (PET concordant but no change in management), moderate (PET changed diagnosis or dementia type or medication plan), and high (PET changed diagnosis from dementia to normal or vice versa).
Results : Management impact was nil in 3 patients, low in 115, moderate in 66 and high in 11.
Conclusions : FDG-PET has moderate to high management impact in 39% of patients referred from a specialist memory clinic even after full standard investigation. FDG-PET contributes significantly to patient care, assisting appropriate use of medication and counselling of patients and family.