Nuclear medicine DRL tables

DRLs for general nuclear medicine, PET and the CT component of SPECT/CT and PET/CT

 

PDF iconNuclear medicine diagnostic reference levels
 

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)

IAEA Radiation Protection of Patients (RPOP) Logo, with link to website