A request for an MBS item for PET brain scans to diagnose Alzheimer disease (AD) has been approved by the Medicare Services Advisory Committee.
The committee has made a positive recommendation to the Minister for Health in response to an application for Medicare reimbursement by Austin Health for the use of F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) to establish a diagnosis of Alzheimer disease (AD) where other diagnostic methods are inconclusive.
At its November 2020 meeting MSAC accepted that FDG PET was more sensitive than its comparator, single-photon emission computed tomography (SPECT) imaging, which would largely be replaced by PET scan provided at the same fee of $605.05.
The recommendation was in response to a re-submission after a previous application in 2015 was rejected on the basis of a lack of evidence for cost effectiveness.
In its new decision, MSAC accepted recent evidence from a 2020 study showing that FDG PET was significantly more accurate in differentiating AD from non-AD than SPECT. The Nadebaum et al review found that PET had a sensitivity and specificity of 75.8% and 74.3% for diagnosis of AD compared to 42.9% and 82.9% respectively for SPECT imaging.
In making its recommendation, MSAC also recognised that replacing SPECT with FDG PET would align with international clinical guidelines.
It advised that FDG PET should be limited to three scans per lifetime and not more often than once per year, to ensure that it would be used only for diagnosis and not for monitoring.
However, MSAC noted the recommendation to list FDG PET on the MBS at the same fee as SPECT, rather than the fee of over $900 for PET in other neurological indications such as epilepsy – would mean there may be out-of-pocket consumer costs if providers decide to charge more for the service.
It estimated the new MBS item would cover about 6000 services a year based on modelling that between 5-13% of dementia diagnoses were equivocal.
A recent review of the clinical utility of PET in the diagnosis of dementia by Professor Christopher Rowe of Austin Health noted that changes were less clear in the very elderly, and that hypometabolism reflected clinical deficits, so findings were subtle in mild cognitive impairment.
Recommendations from MSAC have to be approved by the Minister for Health before an MBS item is introduced.