Commissioning of dementia imaging services in the UK With recent restructuring in the NHS over the time of the last government, the majority of commissioning of PET-CT imaging in England occurred centrally through NHS England. Previous commissioning policy statements for PET-CT have been guided by evidence-based indications for PET-CT in the UK issued by the Royal College of Radiologists and the Royal College of Physicians. Although 18
F-FDG brain PET-CT
imaging is supported in selected patients in these publications, the most recent version is quite clear that amyloid imaging should only be used in very specific cases, ie 'the patient has persistent or progressive unexplained memory impairment confirmed by standard medical tests, an unusual clinical presentation and/or an atypically early age of onset'18
.
Recent consultation with the nuclear medicine community by NHS England, has indicated that this has been interpreted as meaning that amyloid PET-CT imaging should not be funded. The caveat of the 10% rule5
Dementia is a significant and increasing burden on the health economy
, which previously allowed providers to implement low activity services, enabling a body of evidence to be developed to support the wider commissioning of these studies in subsequent financial years, also appears to have been removed from the commissioning policy statement from NHS England. This will mean that providers will have to consider the provision of amyloid imaging either as a cost pressure or as research to enable the evidence to be collected to support future funding of these studies. In the current financial climate, it is unlikely that NHS providers will be in a position to provide this as an unfunded service. At the time of writing, the effect of the new government is not known and NHS England has not published its commissioning policy statement and so it is unknown whether the consultation document will be implemented without change. Currently there are no disease-modifying treatments for dementia patients, especially those with Alzheimer’s disease.
Therefore the argument can be made that it is not cost effective to demonstrate amyloid burden, without the ability to reduce that burden. Therefore commissioning of imaging for this reason could be considered unnecessary until drugs are developed to modify the amyloid burden. However, disease-modifying treatments are being extensively researched and so having a diagnostic service in place should enable a more speedy application of the therapy once available.
18F-FDG PET-CT in the diagnosis of dementia
18F-FDG is the most widely used radiopharmaceutical in clinical practice for PET-CT imaging for malignancies in the UK10 18
.
F-FDG PET-CT scanning can also be used to evaluate glucose metabolism within the brain. Dementia is characterised by areas of hypometabolism relative to the glucose metabolism of normal brain tissue. The glucose metabolism of the cerebellum, thalamus and basal ganglia nuclei is not significantly reduced in dementia and so can be used as a reference for 'normal' uptake11
.
The diagnosis of different types of dementia is based on recognition of characteristic patterns of regional hypometabolism. A review by Bohnen et al11
found that 18 F-FDG PET-CT has a sensitivity of between 78% and 96% and specificity of between
73% and 90% when determining the presence or absence of Alzheimer’s disease. Vascular dementia displays a pattern of hypometabolism similar to Alzheimer’s disease and so differentiating the two with PET-CT scans can be problematic12 Studies have shown sensitivity of 90% and specificity of 80% when using 18 with Lewy bodies from Alzheimer’s disease11
. F-FDG PET-CT scans to differentiate dementia
between healthy, Alzheimer’s disease, dementia with Lewy bodies and fronto-temporal dementia subjects11 More importantly, there is evidence that for MCI patients without characteristic patterns of regional hypometabolism on
. Multicentre studies have demonstrated a 96% accuracy in differentiating .
-28-
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68