Nuclear medicine survey statistics
This page contains usage statistics and a summary of the data submitted to the NDRLS nuclear medicine survey.
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The DRLs were derived from two data sources. The first was a survey of Australian nuclear medicine facilities conducted in 2014/15 (the NDRLS survey). We asked participating facility to report every dose (from both radiopharmaceutical and CT sources) delivered within their department over a four week period. The median of the doses delivered at each facility (termed the facility reference level, or FRL) was calculated for each protocol reported. If a facility conducted a procedure four or more times, the FRL was included in the DRL calculation. A DRL was calculated using the NDRLS survey data for all procedures with at least four FRLs. From this data, DRLs for fifteen general nuclear medicine procedures, three PET protocols, three PET/CT scan regions and seven SPECT/CT scan regions were defined.
The second source of data was an extensive survey conducted on behalf of the ANZSNM in 2008 (Diagnostic Reference Activities for Nuclear Medicine Procedures in Australia and New Zealand). Rather than request details of individual administrations, the ANZSNM survey asked participants to enter the doses prescribed for each of their protocols. The ANZSNM then published the most common activity (MCA) reported for over 70 different nuclear medicine and PET protocols.
There were a number of protocols listed in the ANZSNM table that did not receive enough data in the NDRLS survey to derive a DRL. In these cases, the ANZSNM data was reanalysed using the reported activity at each site as the FRL. The ANZSNM data accounted for around 50 of the general nuclear medicine DRLs.
The metric chosen to define the DRLs was the 75th percentile of the FRL distribution, keeping the nuclear medicine DRLs consistent with the CT DRLs already published by ARPANSA. In addition to the DRL, the 50th and 25th percentiles of the distributions were also calculated.
The methodology used to calculate the DRLs is demonstrated using bone scans as an example in Figure 1:
- Top left: A histogram of the age and gender of the patients scanned. Only adult patients were considered (arbitrarily defined as patients over the age of 15).
- Top right: A histogram of the activities administered to individual patients. Each different colour/shading represents patients at a different facility. The green, blue and red lines represent the 25th, 50th and 75th percentiles of the administered activity respectively.
- Bottom left: A scatter plot of the activity administered to individual patients as a function of weight. Each different marker colour/shape represents a different facility. Not all facilities provided the weight of every patient – the scatter plots therefore do not necessarily include every patient. The green, blue and red lines represent the 25th, 50th and 75th percentiles of the administered activity respectively (from the top right figure). This plot was used to determine if weight correction was regularly employed (no in the case of bone scans).
- Bottom right: A histogram of the median dose administered at each facility. This is known as the facility reference level (FRL). The green, blue and red lines represent the 25th, 50th and 75th percentiles of the FRL distribution, and are the basis of the DRLs. The colour of the histogram bins is indicative of the number of individual scans conducted at the facility with the given FRL – the darker the colour, the more scans conducted.
Figure 1: The bone scan data submitted to the NDRLS survey
A similar methodology was used to set the DRLs for PET scans where weight correction wasn’t commonplace and the DRLs for the CT component of SPECT/PET scans.
ARPANSA sent invitations to participate in the NDRLS survey to 175 imaging facilities throughout the ACT, NSW, the NT, SA, Tasmania, and Victoria. The state regulators for Queensland and WA sent invitations to their licensees on behalf of ARPANSA. Seventy-eight facilities participated in the survey, which ARPANSA estimates represents a third of all nuclear medicine facilities within Australia. Figure 2 shows the number of invitations sent, the number of facilities that enrolled in the survey and the number of those facilities that submitted data to the survey.
The two tables below categorise the number of facilities by the facility type and the submission type.
Table 1: The type of facilities that participated in the NDRLS survey
|Facility type||Number of facilities|
|Private in public||26|
Table 2: The number of facilities that submitted data and the number of scans submitted, categorised by modality and age group.
|Number of facilities||Number of scans||Number of facilities||Number of scans|
|General nuclear medicine||76||11815||38||414|
Summaries of the number of surveys submitted are presented in tables 3 and 4. The FRL distribution for all protocols (including those gathered as part of the 2008 ANZSNM survey) can be accessed by clicking the entries in the DRL tables on the Current NM DRLs page.
Table 3: The general nuclear medicine protocols reported by NDRLS survey participants. Only the protocols that were used to develop the DRLs are shown.
|Category||Scan||Radiopharmaceutical||Number of facilities||Number of scans|
|Cardiac||Gated blood pool scan||Tc_99m RBCs||37||443|
|MPI - 1 day rest + stress||Tc_99m MIBI||56||1709|
|MPI - single phase||Tc_99m MIBI||22||583|
|Parathyroid subtraction||Tc_99m Pertechnetate||13||79|
|Gastrointestinal||Gastric emptying||Tc_99m Colloid, DTPA||11||70|
|Genitourinary||Renal scan||Tc_99m DTPA||8||45|
|Nervous system||Brain||Tc_99m HMPAO/ECD||9||110|
|Pulmonary||Lung perfusion||Tc_99m MAA||57||829|
|Skeletal||Bone scan||Tc_99m MDP/HDP||73||5244|
Table 4: The PET protocols reported by NDRLS survey participants. Only the protocols that were used the develop the DRLs are shown.
|Category||Radiopharmaceutical||Number of facilities||Number of scans|
|Body (weight corrected)||F_18 FDG||13||2655|