Quality Control and Regulation
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Solve questions (25) →Contents
- 27.1 Gamma Camera Quality Control (Daily, Weekly, Annual)
- 27.2 PET/CT Quality Control
- 27.3 Dose Calibrator Quality Control
- 27.4 Radiopharmaceutical Quality Control (TLC, Purity Tests)
- 27.5 Licensing and Regulation (TAEK, IAEA, NRC)
- 27.6 Radioactive Waste Management
- Key Points for the Board
- Current guidelines on this chapter's topics
Learning objectives and modules3 modules · about 2 h 35 min
Learning objectives
After this chapter you will be able to:
- List gamma camera quality control tests with their frequencies and acceptance limits.
- Explain PET/CT quality control tests.
- Apply dose calibrator tests (constancy, linearity, accuracy, geometry).
- Apply radiopharmaceutical quality control (radiochemical purity, Mo-99 breakthrough, aluminium) and interpret the result.
- State the basic rules of licensing, transport and radioactive waste management.
Modules
The chapter is divided into study modules without changing the order of the text: read, watch the animations, then answer the questions linked to those headings.
- Module 127.1–27.2 Gamma Camera Quality Control (Daily, Weekly, Annual) · PET/CT Quality Control1 h · 5 animations · 19 questionsAnswer the questions →
- Module 227.3–27.4 Dose Calibrator Quality Control · Radiopharmaceutical Quality Control (TLC, Purity Tests)50 min · 1 animation · 24 questionsAnswer the questions →
- Module 327.5–27.6 Licensing and Regulation (TAEK, IAEA, NRC) · Radioactive Waste Management · Key Points for the Board45 min · 2 animations · 13 questionsAnswer the questions →
Times are estimates: 130 words per minute, 3 min per animation, 1.5 min per question.
MOST FREQUENTLY ASKED IN THIS CHAPTER
27.1 Gamma Camera Quality Control (Daily, Weekly, Annual)16 questions
General Principles
EANM Concepts:
Daily Quality Control Tests
1. Energy Peak Check (Peaking / Photopeak Check):
→ Energy peak check (peaking). If the photopeak is wrong, all other tests and patient images are affected → it must be done before anything else!
Left: the ±10% window on the energy spectrum and a Tc-99m photopeak sliding with gain drift; a flood image building up as counts accumulate (normal or with a PMT failure); a four-quadrant bar phantom. Right: the share of counts in the window, UFOV and CFOV integral uniformity, and which quadrant is resolved.
Daily energy peak and uniformity checks and the weekly bar phantom ensure the camera gives accurate, uniform and linear images.
Source: test methods and acceptance values from the book (27.1, EANM); uniformity calculated as in NEMA NU 1. Camera size, PMT failure magnitude and counts representative.
How to use: a single click on the drawing pauses and resumes; in the uniformity and bar phantom figures ↑ ↓ or the buttons below switch the state (normal / fault); use the time bar below to go to any moment.
Figure 27.1: Energy peak check: a correctly set Tc-99m photopeak with a ±10% window, and photopeak shift due to PMT gain drift (schematic).
2. Daily Uniformity Test (Flood Field Uniformity):
IU (%) = (Max − Min) / (Max + Min) × 100
→ Intrinsic = without collimator (point source), extrinsic = with collimator (flood source).
→ 3-5 million.
→ Non-uniformity → PMT failure or crystal defect.
Left: the ±10% window on the energy spectrum and a Tc-99m photopeak sliding with gain drift; a flood image building up as counts accumulate (normal or with a PMT failure); a four-quadrant bar phantom. Right: the share of counts in the window, UFOV and CFOV integral uniformity, and which quadrant is resolved.
Daily energy peak and uniformity checks and the weekly bar phantom ensure the camera gives accurate, uniform and linear images.
Source: test methods and acceptance values from the book (27.1, EANM); uniformity calculated as in NEMA NU 1. Camera size, PMT failure magnitude and counts representative.
How to use: a single click on the drawing pauses and resumes; in the uniformity and bar phantom figures ↑ ↓ or the buttons below switch the state (normal / fault); use the time bar below to go to any moment.
Figure 27.2: Set-up for intrinsic and extrinsic uniformity tests, flood image with a PMT failure and the integral uniformity formula (schematic).
3. Daily Background Check:
Weekly Quality Control Tests
1. Spatial Resolution and Linearity:
Left: the ±10% window on the energy spectrum and a Tc-99m photopeak sliding with gain drift; a flood image building up as counts accumulate (normal or with a PMT failure); a four-quadrant bar phantom. Right: the share of counts in the window, UFOV and CFOV integral uniformity, and which quadrant is resolved.
Daily energy peak and uniformity checks and the weekly bar phantom ensure the camera gives accurate, uniform and linear images.
Source: test methods and acceptance values from the book (27.1, EANM); uniformity calculated as in NEMA NU 1. Camera size, PMT failure magnitude and counts representative.
How to use: a single click on the drawing pauses and resumes; in the uniformity and bar phantom figures ↑ ↓ or the buttons below switch the state (normal / fault); use the time bar below to go to any moment.
Figure 27.3: Four-quadrant bar phantom image: normal appearance and non-linearity due to a PMT/electronic problem (schematic).
2. Measurement of Spatial Resolution:
Annual (or Semi-Annual) Quality Control Tests
1. Centre of Rotation (COR):
→ COR error.
→ Every 3-6 months or after a collimator change.
→ ≤0.5 pixel.
Three SPECT artefacts are shown with real projection and filtered back-projection: a sinogram break and double contour with patient motion halfway through acquisition, a sinogram stripe and a ring in the slice with detector non-uniformity, and blurring of a point source that turns into a ring with a centre-of-rotation (COR) error. The size of the error is chosen in each step.
Key point: SPECT assumes all projections are consistent; patient motion gives a break and double contour, a fixed detector defect a ring, and a centre-of-rotation shift a blurred or ring-shaped point source.
Source: book (sinogram break, double contour/streaks; non-uniformity → ring; COR: blurred if small, doughnut if large; COR test every 3-6 months). Calculation: same projector as the tomography animation, 64 × 64 (4 mm pixels), 96 angles / 360°, ramp-filtered FBP with 3 × 3 smoothing, noise-free. Shift, defect and COR values illustrative.
How to use: ↑ ↓ or the buttons below change the size of the fault (shift, sensitivity loss, centre-of-rotation error); the sinogram and the slice are recomputed for each choice; ← → change steps.
Figure 27.4: Centre of rotation (COR) error: mismatch between mechanical and electronic centres, shift in the sinogram and ring/blurring artefact on reconstruction (schematic).
2. Uniformity (High-Count):
3. Energy Resolution:
4. Count Rate Performance:
5. Spatial Resolution (Quantitative):
6. Sensitivity:
7. SPECT Performance – Jaszczak Phantom (EANM):
SPECT/CT-Specific Quality Control
CT Component:
SPECT-CT Co-registration:
CT Daily QC (EANM):
→ SPECT-CT misregistration.
→ 0 ± 5 HU.
→ Uniformity.
27.2 PET/CT Quality Control3 questions
Daily Quality Control
1. Detector Normalisation / Blank Scan:
2. Timing Calibration:
3. Daily QC Phantom:
Weekly/Monthly Quality Control
1. Uniformity:
2. SUV Accuracy (Calibration Verification):
Annual (or Acceptance Test) Quality Control
1. Spatial Resolution:
2. Sensitivity:
3. Scatter Fraction:
4. Count Rate Performance:
Figure 27.5: PET count rate performance: true, scatter and random coincidences with the NECR curve and peak NECR (schematic).
5. Image Quality Phantom (IEC Body Phantom):
→ When the lesion diameter is <2-3 × the spatial resolution (i.e. 10-12 mm).
→ Noise Equivalent Count Rate → a performance measure combining true, scatter and random coincidences.
→ A faulty detector block.
A section through the centre of a uniform sphere, blurred by the system FWHM, is shown side by side for a hot (4:1) and a cold (0) lesion; on the right the profiles are compared with the true values. The second step shows the recovery coefficient (maximum and mean) against lesion diameter / FWHM and where the chosen lesion lies.
Key point: when the lesion is smaller than 2-3 × FWHM a hot lesion is underestimated (spill-out) and a cold lesion overestimated (spill-in); the loss is described by the recovery coefficient and can be corrected.
Source: book (PVE < 2-3 × FWHM, spill-out / spill-in, RC = measured/true, corrected = measured/RC). Calculation: convolution of a uniform sphere with a 3D Gaussian (analytic formula; σ = FWHM/2.355); hot lesion 4:1, cold 0:1; mean RC over the sphere volume. No noise or voxel size effects.
How to use: ↑ ↓ or the buttons below change the lesion diameter; the second row picks the resolution (FWHM); ← → change steps.
Figure 27.6: Hot and cold spheres in the IEC body phantom and contrast recovery by sphere diameter; partial volume effect in small spheres.
PET/CT – CT Component QC
ACR Accreditation Requirements (PET/CT)
27.3 Dose Calibrator Quality Control11 questions
General Principles
Daily Quality Control
1. Constancy Test:
→ Cs-137 (most common) or Co-57.
→ Daily decay is negligible → the reference value stays stable.
→ ±5%.
Tests at Installation and Annually
2. Accuracy Test:
3. Linearity Test:
Figure 27.7: Dose calibrator quality control: daily constancy monitoring with Cs-137 (action ±3%, tolerance ±5%) and linearity test with a decaying Tc-99m source (±10%).
4. Geometry Dependence Test:
EANM Notes on the Dose Calibrator (Activity Meter):
Dose Calibrator QC Summary Table:
| Test | Frequency | Source | Acceptance Criterion |
|---|---|---|---|
| Constancy | Daily | Cs-137 or Co-57 | ±5% |
| Accuracy | Installation + Annual | NIST-traceable (≥2 nuclides) | ±5% |
| Linearity | Installation + every 6 months or annually | Tc-99m (decaying source) | ±10% |
| Geometry | Installation | Same activity, different volumes | Variability recorded |
Probes and Radiation Protection Instruments (EANM)
27.4 Radiopharmaceutical Quality Control (TLC, Purity Tests)13 questions
Quality Control Parameters
Three main purity parameters are assessed in radiopharmaceutical quality control:
1. Radionuclidic Purity:
→ The Tc-99m eluate is placed in a lead container (6 mm Pb) → Tc-99m (140 keV) is absorbed, Mo-99 (740-780 keV) passes through → measured in the dose calibrator.
→ ≤0.15 µCi Mo-99 / mCi Tc-99m.
→ As the generator ages or with excessive elution.
Figure 27.8: Mo-99 breakthrough test: a 6 mm lead container absorbs Tc-99m photons, and the high-energy photons of Mo-99 are measured (schematic).
2. Radiochemical Purity (RCP):
TLC Systems (Tc-99m-Labelled Radiopharmaceuticals)
System 1: ITLC-SG + Acetone
System 2: ITLC-SG + Saline (0.9% NaCl)
RCP Calculation:
RCP (%) = 100 − (%Free TcO₄⁻ + %TcO₂)
→ ITLC-SG + acetone → free TcO₄⁻ migrates to the front, the labelled compound remains at the origin.
→ ITLC-SG + saline → TcO₂ remains at the origin, the others migrate to the front.
→ Thyroid, stomach, salivary glands.
→ Liver, spleen, bone marrow.
An ITLC-SG strip is developed first in acetone, then in saline: as the solvent rises, free pertechnetate (and in saline the Tc complex) moves to the front while the rest stays at the origin; the strip is cut and the halves counted. In the last step radiochemical purity is calculated from both results and compared with the 90% limit; three preparation scenarios can be chosen.
Key point: acetone measures free pertechnetate (moves to the front), saline measures colloidal Tc (stays at the origin); RCP = 100 − free TcO₄⁻ − colloidal Tc, and for most kits it must be at least 90%.
Source: book (ITLC-SG + acetone: TcO₄⁻ Rf 1, complex and colloid Rf 0; ITLC-SG + saline or 85% methanol: TcO₄⁻ and complex Rf 1, colloid Rf 0; RCP = 100 − free − colloid; limit ≥90%; example 4% / 2% → 94%). Percentages of the other two scenarios illustrative. Lipophilic complexes (e.g. MIBI, HMPAO) need different solvent systems.
How to use: a single click on the drawing pauses and resumes; ↑ ↓ or the buttons below change the preparation scenario; ← → change steps.
Figure 27.9: Determination of free pertechnetate and hydrolysed Tc (TcO₂) in Tc-99m radiopharmaceuticals with two ITLC-SG systems, and RCP calculation (schematic).
Radiochemical Purity – Other Radiopharmaceuticals
FDG (F-18 Fluorodeoxyglucose):
Ga-68 DOTATATE:
3. Chemical Purity:
→ When preparing Tc-99m sulphur colloid → Al³⁺ causes the colloid to flocculate → large particles form → risk of embolisation in pulmonary capillaries.
→ ≤10 µg/mL.
→ Colorimetric test (aurintricarboxylic acid).
Other Quality Control Parameters
4. Radionuclide Identity:
5. Sterility and Apyrogenicity:
6. Particle Size (Particulate Radiopharmaceuticals):
→ 10-90 µm.
→ 200,000-700,000.
→ Reduced (down to 100,000) → to reduce the risk of pulmonary and paradoxical embolism.
→ 10,000-50,000 particles are sufficient.
Radiopharmaceutical QC Summary Table:
| Parameter | Test Method | Acceptance Criterion |
|---|---|---|
| Radionuclidic purity | Gamma spectrometry (MCA) | Mo-99: ≤0.15 µCi/mCi Tc-99m |
| Radiochemical purity | TLC (ITLC-SG) | ≥90% (depending on kit) |
| Chemical purity (Al³⁺) | Colorimetric (aurin) | ≤10 µg/mL |
| Chemical purity (Kryptofix) | TLC spot test | ≤50 µg/mL |
| pH | pH paper / pH meter | 4.5-8.5 (FDG) |
| Sterility | Membrane filtration | No growth (14 days) |
| Endotoxin | LAL test | ≤175 EU/V |
| Particle size (MAA) | Haemocytometer / microscope | 10-90 µm |
| Radionuclide identity | Half-life measurement | ±10% |
27.5 Licensing and Regulation (TAEK, IAEA, NRC)3 questions
International Regulatory Bodies
1. IAEA (International Atomic Energy Agency):
2. ICRP (International Commission on Radiological Protection):
→ 20 mSv/year (averaged over 5 years), ≤50 mSv in a single year.
→ 1 mSv/year.
→ ≤1 mSv (whole pregnancy).
→ 20 mSv/year (the old limit was 150 mSv/year → an important change!).
3. NRC (Nuclear Regulatory Commission – USA):
→ Wrong patient, wrong radiopharmaceutical, wrong route of administration, or >20% deviation from the prescribed dose + organ dose >50 rem or effective dose >5 rem.
→ 1 calendar day (telephone) + 15 days (written).
→ 5 rem/year (50 mSv/year) → different from ICRP!
Regulatory Bodies in Türkiye
TAEK (Turkish Atomic Energy Authority) / NDK (Nuclear Regulatory Authority):
ALARA Principle
How many photons from a source reach a worker depends on distance, time and lead shielding; the shielding order and bremsstrahlung for a beta source are shown.
Key point: dose rate falls with the square of distance, dose rises in proportion to time, and each HVL of lead halves the photons passing; a beta source is shielded first with low-Z material.
Source: book (Γ Tc-99m 0.78, I-131 2.17, F-18 5.7 R·cm²/mCi·h; lead HVL 0.3 / 3 / 4 mm); example 20 mCi (740 MBq) point source, body attenuation and scatter not included. Beta step: P-32 Emax 1.711 MeV (ENSDF), range NIST ESTAR, bremsstrahlung fraction Cherry, Sorenson & Phelps (Physics in Nuclear Medicine). Magnifier: Rutherford scattering; bremsstrahlung spectrum and angular distribution after Bethe–Heitler (Attix, Introduction to Radiological Physics and Radiation Dosimetry); atomic radii not to scale.
How to use: press and drag the worker (release and it moves back and forth on its own); hold ← → to change the distance smoothly; one click on the drawing pauses and resumes, double-click enlarges.
Figure 27.10: The three ALARA principles: dose increasing linearly with time, the inverse square law, and shielding with the half-value layer.
Radiation Areas and Signage
Clinical Audit and Department Management
Structured Reporting
→ >5 mrem/hour at 30 cm.
→ >100 mrem/hour at 30 cm.
→ 2 mrem/hour.
→ Magenta (purple) trefoil + yellow background.
27.6 Radioactive Waste Management10 questions
Classification of Radioactive Waste
1. Short-Lived Waste (T½ ≤120 days):
2. Long-Lived Waste (T½ >120 days):
Tc-99m atoms decay at random; the measured stepped curve lies around the theoretical exponential; half-life marks, the 10 half-life rule and the mean life are shown.
Key point: the remaining activity halves with each half-life and falls below one thousandth after 10 half-lives; the mean life is 1.443 × T½.
Source: book; Tc-99m T½ 6.01 h (λ 0.115/h, τ 8.67 h).
How to use: one click on the atom panel pauses and resumes; move over or drag along the curve to read the fraction remaining at that time; ← → change steps.
Figure 27.11: Decay-in-storage: after 10 half-lives the activity falls to about 1/1000.
3. Mixed Waste:
Liquid Radioactive Waste
Gaseous Radioactive Waste
Waste Records and Documentation
Transport of Radioactive Material
→ 10 half-lives (falls to ~1/1000).
→ 80 days.
→ ~60 hours.
→ Dose rate of the package at 1 metre (mrem/hour).
→ TI = 0 and surface dose rate ≤0.5 mrem/hour.
Figure 27.12: Radioactive package labels: White-I, Yellow-II, Yellow-III and exclusive use according to the transport index (TI) and surface dose rate (schematic).
Contamination and Decontamination
Types of Contamination:
Detection of Contamination:
Principles of Decontamination:
Figure 27.13: Management of minor and major radioactive spills and principles of personnel decontamination.
Key Points for the Board
Gamma Camera Quality Control
PET/CT Quality Control
Dose Calibrator Quality Control
Radiopharmaceutical Quality Control
Licensing and Regulation
Radioactive Waste Management
Additional Notes from EANM Guidelines:
Current guidelines on this chapter's topics
The latest guidelines and consensus documents on the procedures covered in this chapter (official EANM index and primary sources, November 2026). Comparison of the text with these versions is in progress; consult the guideline itself for details.
- 2023ESR paper on structured reporting in radiology — update 2023 (opens in a new tab)
- 2022EANM guidelines for PET-CT and PET-MR routine quality control (opens in a new tab)
- 2022EANM guideline on quality risk management for radiopharmaceuticals (opens in a new tab)
- 2021QUANUM 3.0: An Updated Tool for Nuclear Medicine Audits (IAEA) (opens in a new tab)
- 2010Routine Quality Control Recommendations for Nuclear Medicine Instrumentation (opens in a new tab)
- 2010Acceptance Testing for Nuclear Medicine Instrumentation (opens in a new tab)
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