DRLs for general nuclear medicine, PET and the CT component of SPECT/CT and PET/CT
The DRLs are not recommended doses. They are only a reflection of current practice within Australia. The DRLs should not be used as the basis of calculating paediatric doses or as a starting point for facilities conducting a scan for the first time. Most importantly, if your facility uses a dose lower than the DRL, you should not increase the dose you use to match the DRL.
While it is true that the median dose is also not a recommendation, ARPANSA believes that the median dose is a reasonable starting point for facilities to use when introducing procedures they haven’t performed before. As with the DRL, if your facility uses a dose lower than the median dose, you should not increase your doses to match.
If the activity your facility routinely administers is higher than the DRL then you should review your protocols. When doing so, ensure that any reduction in dose does not degrade the image quality to the point where diagnosis is compromised. Maintaining diagnostic quality is of paramount importance, even if doing so requires a dose higher than the DRL (which might occur if your facility uses older hardware or regularly images patients with clinical indications that are underrepresented within the NDRLS data).
The tables below provide links to images (gif format) showing the data used to derive the DRL. Contact us if an alternate format is required.
General nuclear medicine
The 25th percentile, median and DRL doses are expressed in term of MBq, unless otherwise stated.
Category - cardiac
Procedure name | Nuclide | Chemical form | Route of admin. |
25th percentile |
Median | DRL |
---|---|---|---|---|---|---|
Cardiac first pass | Tc-99m | Pertechnetate, Red cells |
IV | 590 | 875 | 930 |
Cardiac L/R shunt | Tc-99m | Pertechnetate | IV bolus | 400 | 550 | 900 |
Cardiac R/L shunt | Tc-99m | MAA | IV | 100 | 150 | 185 |
Gated blood pool scan | Tc-99m | Red cells | IV | 900 | 990 | 1030 |
Myocardial hot spot | Tc-99m | PYP | IV | 720 | 800 | 800 |
MPI - Rest | Tl-201 | Chloride | IV | 80 | 115 | 120 |
MPI - Stress | Tl-201 | Chloride | IV | 100 | 120 | 120 |
MPI - Reinjection | Tl-201 | Chloride | IV | 30 | 40 | 40 |
MPI - Single phase | Tc-99m | Tetrofosmin, MIBI |
IV | 350 | 475 | 620 |
MPI - 1 day rest + stress | Tc-99m | Tetrofosmin, MIBI |
IV | 1250 | 1400 | 1520 |
Note: dose is for both studies combined | ||||||
MPI - 1 day rest (201Tl) /stress (99mTc) |
Tl-201 | Chloride | IV | 100 | 110 | 130 |
Tc-99m | Tetrofosmin, MIBI |
IV | 900 | 1000 | 1050 |
Category - endocrine
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Parathyroid | Tc-99m | Tetrofosmin, MIBI |
IV | 765 | 820 | 900 |
Parathyroid subtraction | Tc-99m | Pertechnetate | IV | 45 | 75 | 220 |
Thyroid | I-123 | Iodide | IV | 180 | 185 | 345 |
Thyroid | Tc-99m | Pertechnetate | IV | 200 | 210 | 215 |
Category - gastrointestinal
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Blood loss | Tc-99m | Red cells | IV | 800 | 1000 | 1000 |
Colonic transit | Ga-67 | Citrate | Oral | 6 | 10 | 20 |
Gastric emptying | Ga-67 | Citrate | Oral | 10 | 15 | 20 |
Gastric emptying | Tc-99m | Colloid, DTPA |
Oral | 39 | 43 | 44 |
Oesophageal reflux | Tc-99m | Colloid, DPTA |
Oral | 40 | 40 | 40 |
Oesophageal transit | Tc-99m | Colloid, DPTA |
Oral | 20 | 40 | 40 |
Small bowel transit | Tc-99m | Colloid, DPTA |
Oral | 20 | 40 | 40 |
Meckel’s diverticulum | Tc-99m | Pertechnetate | IV | 225 | 400 | 400 |
Salivary glands | Tc-99m | Pertechnetate | IV | 150 | 185 | 200 |
Category - genitourinary
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Renal cystogram | Tc-99m | Pertechnetate | Bladder | 40 | 50 | 94 |
Renal scan | Tc-99m | DMSA | IV | 120 | 150 | 200 |
Renal scan | Tc-99m | DTPA | IV | 380 | 400 | 500 |
Renal scan | Tc-99m | MAG3 | IV | 235 | 270 | 305 |
Renal transplant | Tc-99m | DTPA, MAG3 |
IV | 200 | 300 | 400 |
Testicular scan | Tc-99m | Pertechnetate | IV | 210 | 400 | 600 |
Category - haematological
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Arterial infusion | Tc-99m | MAA | Intra- arterial |
100 | 135 | 190 |
Le Veen shunt | Tc-99m | Colloid | Intra- peritoneal |
95 | 185 | 200 |
Venogram | Tc-99m | Pertechnetate | IV | 700 | 770 | 800 |
Hepatobiliary | Tc-99m | HIDA, DISIDA, DIDA |
IV | 185 | 205 | 210 |
Liver blood flow | Tc-99m | Red cells | IV | 800 | 900 | 1000 |
Liver/spleen | Tc-99m | Colloid | IV | 150 | 200 | 200 |
Liver transplant | Tc-99m | HIDA, DISIDA | IV | 155 | 185 | 200 |
Category - infection
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Infection | Ga-67 | Citrate | IV | 185 | 200 | 220 |
Infection | Tc-99m | WBC-colloid, WBC-HMPAO |
IV | 500 | 700 | 800 |
Category - lacrimal
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Lacrimal drainage | Tc-99m | Pertechnetate | Eye drops | 7 | 10 | 18 |
Note: dose is expressed in terms of drops per eye |
Category - lymphatic
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Lymphoscintigraphy | Tc-99m | Nanocolloid | Perilesional | 33 | 42 | 52 |
Note: dose is for entire procedure, not per injection |
Category - nervous system
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Brain | Tc-99m | DTPA | IV | 800 | 800 | 900 |
Brain | Tc-99m | HMPAO, ECD |
IV | 640 | 720 | 750 |
CSF leak | In-111 | DTPA | Intrathecal | 15 | 21.5 | 38 |
CSF leak | Tc-99m | DTPA | Intrathecal | 77 | 300 | 370 |
CSF shunt patency | Tc-99m | Pertechnetate, DTPA |
Cisternal | 40 | 40 | 80 |
Category - oncology
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Somatostatin receptors | In-111 | Octreotide | IV | 200 | 200 | 240 |
Thyroid - wb scan for Ca | I-123 | Iodide | Oral | 190 | 310 | 400 |
Thyroid - wb scan for Ca | I-131 | Iodide | Oral | 100 | 150 | 185 |
Tumour | Ga-67 | Citrate | IV | 300 | 400 | 400 |
Tumour | I-123 | MIBG | IV infusion | 200 | 290 | 400 |
Tumour | I-131 | MIBG | IV infusion | 24 | 31 | 38 |
Tumour | Tc-99m | MIBI | IV | 740 | 800 | 800 |
Tumour | Tc-99m | [V]-DMSA | IV | 370 | 400 | 440 |
Tumour | Tl-201 | Chloride | IV | 115 | 125 | 185 |
Category - pulmonary
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Lung perfusion | Tc-99m | MAA | IV | 200 | 220 | 240 |
Category - skeletal
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Bone marrow | Tc-99m | Colloid, nanocolloid |
IV | 250 | 400 | 550 |
Bone scan | Tc-99m | MDP, HDP | IV | 810 | 840 | 920 |
Category - splenic
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Liver/spleen - see Hepatobiliary |
||||||
Spleen | Tc-99m | Denatured RBCs |
IV | 200 | 335 | 705 |
Category - non-imaging
Procedure name | Nuclide | Chemical form | Route of admin. | 25th percentile | Median | DRL |
---|---|---|---|---|---|---|
Breath test | C-14 | Urea | Oral | 0.037 | 0.037 | 0.037 |
GIT blood loss | Cr-51 | Red cells | IV | 4 | 4 | 5.5 |
Plasma volume | I-125 | HSA | IV | 0.2 | 0.25 | 0.5 |
Red cell survival | Cr-51 | Red cells | IV | 4 | 6 | 7 |
Red cell volume | Cr-51 | Red cells | IV | 1 | 2 | 4 |
Renal GFR | Tc-99m | DTPA | IV | 60 | 80 | 100 |
Renal GFR | Cr-51 | EDTA | IV | 3 | 4 | 4 |
NM CT
The DRLs below are for CT scans conducted for the purposes of attenuation correction or localisation in conjunction with a SPECT scan. There were numerous submissions for skeletal CTs conducted of the extremities, but no DRL has been issued because the effective dose of such scans is minimal.
If your facility regularly delivers a dose higher than the DRL, you may be using a larger scan region than required for the clinical task or you might be conducting a higher quality scan than required.
Category | Region | 25th percentile (mGy.cm) | Median (mGy.cm) | DRL (mGy.cm) |
---|---|---|---|---|
Cardiac | Chest | 25 | 40 | 45 |
Lymphatic (Breast Ca.) | Chest | 80 | 115 | 170 |
Neurological | Brain | 45 | 225 | 255 |
Parathyroid | Neck/Chest | 140 | 205 | 255 |
Pulmonary | Chest | 70 | 95 | 120 |
Skeletal | Axial | 115 | 170 | 240 |
Axial (2 bed) | 195 | 340 | 415 |
PET
FDG scanning in PET is one of the few nuclear medicine procedures where weight correction is used routinely at the majority of Australian imaging facilities. However, there were a number of the submissions to the NDRL survey from facilities that clearly didn’t conduct weight correction. As a result, two DRLs for whole body FDG scans have been issued.
Category | Pharmaceutical | 25th percentile (MBq) |
Median (MBq) |
DRL (MBq) |
---|---|---|---|---|
Body | F-18 FDG | 225 | 250 | 310 |
Body (weight corrected) | F-18 FDG | 2.5 x kg + 75 | 2.5 x kg + 100 | 2.5 x kg + 125 |
Brain | F-18 FDG | 200 | 220 | 250 |
There were submissions from facilities using Ga-68 dotatate and PSMA, however, the liaison panel suggested that the amount of activity used in Ga-68 scans is largely independent of the pharmaceutical used and the clinical indications of the patient and that issuing a DRL would be inappropriate. For information purposes only, the Ga-68 percentiles are shown below.
Category | Pharmaceutical | 25th percentile (MBq) |
Median (MBq) |
75th percentile (MBq) |
---|---|---|---|---|
Ga-68 | Dotatate/PSMA | 150 | 150 | 190 |
PET CT
The DRLs below are for CT scans conducted for the purposes of attenuation correction or localisation in conjunction with a PET scan.
Region | 25th percentile (mGy.cm) |
50th percentile (mGy.cm) |
DRL (mGy.cm) |
---|---|---|---|
Head/Brain | 75 | 125 | 325 |
Whole body (Eyes - Thighs) | 325 | 430 | 540 |
Whole body (Vertex - Toes) | 495 | 655 | 985 |
Further information on International Best Practice for Radiation Protection of Patients can be found on the International Atomic Energy Agency Radiation Protection of Patients website, which can be accessed via the following link:
IAEA Radiation Protection of Patients (RPOP)
