Variation of DaTSCAN quantification between different gamma camera types.

OBJECTIVE

To acquire data from a 123I filled Alderson phantom on different gamma cameras types and compare the relative uptake results from processing using the QuantiSPECT program (GE Healthcare).

METHODS

A DaTSCAN phantom was filled using the standard protocol and imaged on seven different gamma camera types and on two identical cameras of the same type. The standard GE Healthcare protocols for the given cameras were used. Aliquots of the striatum and brain background were counted in a gamma counter to determine variations in filling concentration. All the raw DaTSCAN SPECT data was imported into QuantiSPECT and processed by the three different algorithms (two box, three box and crescent) to determine the relative uptake in the striatum. Inter-operater and intra-operator variation was also determined.

RESULTS

The 10% variation in filling concentration found across the sites was compensated for in the final results. There was a 5-15% variation between cameras depending on the processing algorithm used. There was an intra-operator variation of between 5 and 12% which reflected the proportion of operator intervention within the processing method. There was no statistical variation between operators.

CONCLUSIONS

The transfer of a DaTSCAN database between camera types is feasible, but ideally all data would be acquired on a single camera type and phantom data used to normalize the database accordingly.