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.

Development of a combined audiovisual and extremity dose monitoring software tool for use in nuclear medicine.

OBJECTIVES: Conventional extremity dose monitoring in nuclear medicine, using thermoluminescent dosimeters, provides a convenient method of determining integral doses from a series of procedures. Although semiconductor extremity probes are able to add time information and allow doses from individual procedures to be determined, it can be difficult to relate individual operations to the dose-time curve. Solutions to this problem have been identified and developed. METHODS: A novel software tool (Extremity Dose Information Package, EDIP) has been developed that uniquely combines and synchronizes two audiovisual and extremity probe data-streams. The value of this extra information was assessed by acquiring audiovisual and extremity dose information in nuclear medicine and radiopharmacy settings. RESULTS: The ability of the software tool to synchronize audiovisual and dose data-streams was verified. Preliminary studies of handling techniques in radiopharmacy and radioiodine administrations using this tool showed areas in which techniques could be adapted to reduce extremity doses, which would have been difficult or impossible to identify using the dose-time information alone. CONCLUSIONS: This low-cost multimedia extremity dose monitoring package can be used, for example, to aid staff training and pinpoint issues with current operating procedures within a clinical nuclear medicine department. Its unique ability to combine and synchronize audiovisual and dosimetry data is also likely to be of benefit to other industries handling unsealed radioactive materials.

Comparison of different methods of DatSCAN quantification.

BACKGROUND: The quantification of DaTSCAN images can be used as an adjunct to visual assessment to differentiate between Parkinson's syndrome and essential tremor. Many programs have been written to assess the relative uptake in the striatum. AIM: To compare two of the commercially available programs: QuantiSPECT, which analyses isolated data in two dimensions, and BRASS, which performs three-dimensional processing referencing a normal image template. METHOD: Twenty-two patients (11 with Parkinson's syndrome and 11 with essential tremor) were visually assessed by two nuclear medicine consultants. The patient data were then processed using two commercial programs to determine the relative uptake in the striatum. A comparison of the results from the programs was performed, together with a comparison with the visual assessment. The inter-operator and intra-operator variabilities were also ascertained. RESULTS: All programs and processing methods could distinguish between Parkinson's syndrome and essential tremor. There was also a good correlation between the results from the three- and two-dimensional methods. The intra-operator and inter-operator variabilities were dependent on the amount of operator intervention. CONCLUSION: Both programs allowed statistical differentiation between Parkinson's syndrome and essential tremor. Strict operator protocols are needed with QuantiSPECT to reduce inter- and intra-operator variation. The three-dimensional method (BRASS) gave greater concordance than the two-dimensional method (QuantiSPECT) with the visual assessment, but at a cost of increased operator time.

Delivery and collection of radioactive packages to and from UK hospital nuclear medicine departments.

Under radiation protection legislation in the UK, employers have a duty to maintain appropriate records to account for radioactive materials in their possession and to ensure security of these materials. This applies to radioactive packages, containing items such as technetium generators, which are regularly delivered to hospital nuclear medicine departments. It also applies to the collection of packages, such as those containing used generators for return to the supplier. This article has been written by the professional bodies representing nuclear medicine in the UK in order to provide guidance to hospitals on appropriate procedures that will comply with the legislation. General principles, which should be met by any acceptable protocol, are stated, and practical guidance on how these may be implemented is given. Some example scenarios are outlined.

Dissociation of Tc-99m DTPA in a nebulizer.

An unexpected biodistribution of nebulized Tc-99m diethylene triamine pentaacetic acid was detected after the ventilation of a patient referred for diagnosis of pulmonary embolism. Radiochemical purity testing of the stock vial showed more than 95% labelling. Further investigation indicated that the problem was possibly associated with a cleaning agent used for the nebulizer, leading to the dissociation of the Tc-99m diethylene triamine pentaacetic acid. Manufacturer's instructions for cleaning of the nebulizer specify the use of 70% denatured ethanol solution, but a chlorine-based agent had been used inadvertently.