Thallium (Tl-201) Chloride Curium
Diagnostic radiopharmaceutical — solution for intravenous injection, 37 MBq/mL
Quick Facts About Thallium (Tl-201) Chloride
Key Takeaways About Thallium (Tl-201) Chloride
- Diagnostic only: Thallium-201 chloride is a diagnostic imaging agent – it is not used to treat disease but to detect and map it through nuclear medicine scans
- Potassium analogue: Tl-201 enters cells via the sodium-potassium ATPase pump, so its distribution reflects regional blood flow and viable tissue
- Hospital-only administration: Only authorised nuclear medicine staff may prepare and administer this radiopharmaceutical in licensed facilities
- Radiation exposure: A typical study delivers an effective dose of roughly 15–22 mSv, comparable to several years of natural background radiation but clinically justified by the diagnostic information
- Pregnancy is a contraindication: Inform the nuclear medicine team of any confirmed or suspected pregnancy; breastfeeding must be interrupted after injection
What Is Thallium (Tl-201) Chloride and What Is It Used For?
Thallium (Tl-201) chloride is a sterile, isotonic, clear and colourless solution containing the radioactive isotope thallium-201 in the form of thallous chloride. It is used exclusively as a diagnostic tracer in nuclear medicine – most commonly for myocardial perfusion imaging, but also for parathyroid gland localisation and for imaging of certain soft-tissue tumours.
Thallium-201 is a radionuclide produced in a cyclotron by bombarding natural thallium targets with protons. The resulting isotope decays by electron capture to stable mercury-201, emitting characteristic mercury X-rays in the 68–82 keV range (approximately 95% photon abundance) together with smaller contributions of 135 keV and 167 keV gamma radiation. This photon energy is well suited to detection by modern gamma cameras, enabling high-quality planar and single-photon emission computed tomography (SPECT) imaging.
Biologically, the thallous (Tl+) cation behaves as a potassium analogue. After intravenous injection, approximately 85% of the administered activity is extracted from the bloodstream on first pass through the myocardium, mediated by the sodium-potassium ATPase pump present in every living cell. The distribution of activity in the heart muscle therefore reflects both regional coronary blood flow and the integrity of the myocardial cells themselves. This dual dependence is the reason Tl-201 became, and remains, a reference tracer for the assessment of cell viability after myocardial infarction.
Clinically, Thallium (Tl-201) chloride Curium is authorised for several diagnostic indications:
- Myocardial perfusion imaging (MPI): detection of coronary artery disease, quantification of the extent and severity of ischaemia, evaluation of risk before non-cardiac surgery, and assessment of the efficacy of revascularisation procedures such as coronary angioplasty or bypass grafting
- Assessment of myocardial viability: differentiation of hibernating but viable myocardium from irreversible scar tissue, which guides decisions on revascularisation
- Parathyroid scintigraphy: localisation of hyperfunctioning parathyroid adenomas, particularly when technetium-99m sestamibi imaging is non-diagnostic or unavailable
- Tumour imaging: characterisation of certain tumours such as parathyroid carcinoma, selected brain tumours (differentiation of recurrence from radiation necrosis), and osseous or soft-tissue lesions
Tl-201 imaging provides functional information that complements anatomical imaging such as coronary angiography, computed tomography (CT), or magnetic resonance imaging (MRI). A perfusion defect visible on a Tl-201 SPECT scan tells the clinician not only where a coronary stenosis is likely to be haemodynamically significant but also whether the subtended myocardium is still alive and worth revascularising. Although newer tracers such as technetium-99m sestamibi and tetrofosmin have replaced thallium in many departments, Tl-201 remains a valuable tool and is regarded as the most accurate tracer for the detection of viable myocardium.
Thallium (Tl-201) chloride is used to detect disease, not to treat it. The amount of chemical thallium administered is measured in nanograms and has no pharmacological effect. The product is handled, stored, and disposed of under strict radiation protection regulations.
What Should You Know Before Having Thallium (Tl-201) Chloride?
Before your scan, inform the nuclear medicine team about pregnancy, breastfeeding, allergies, heart or kidney conditions, and all medications – including over-the-counter drugs, herbal supplements, and caffeine. Correct preparation is essential for an accurate result and for minimising unnecessary radiation exposure.
Contraindications
Thallium (Tl-201) chloride Curium must not be administered in the following circumstances:
- Confirmed or suspected pregnancy: radiation exposure of the fetus must be avoided whenever possible. Alternative non-radiating imaging (for example stress echocardiography or cardiac MRI) is used instead
- Known hypersensitivity to thallous chloride or to any excipient of the product
There is no absolute age-related contraindication, but paediatric use is rare and is reserved for situations where the clinical benefit clearly outweighs the increased relative radiation sensitivity of children. In patients with severe, unstable cardiac conditions, the stress component of the test (exercise or pharmacological stress) may be contraindicated even when the tracer itself is not.
Warnings and Precautions
Nuclear medicine procedures using ionising radiation must always be clinically justified and optimised in line with the ALARA principle (As Low As Reasonably Achievable) and ICRP (International Commission on Radiological Protection) recommendations. The referring physician and the nuclear medicine specialist jointly decide that the expected diagnostic benefit outweighs the radiation dose for the individual patient.
Particular caution is required in the following patient groups:
- Patients with severe coronary artery disease, unstable angina, or recent myocardial infarction: the stress protocol may need to be modified or a pharmacological stressor substituted for exercise
- Patients with bronchospastic airway disease (asthma, COPD): adenosine, regadenoson, and dipyridamole can provoke bronchospasm and must be used with caution, or avoided entirely in favour of dobutamine
- Patients with second- or third-degree atrioventricular block (without a pacemaker): adenosine and dipyridamole are usually contraindicated
- Patients with severe renal or hepatic impairment: although Tl-201 itself requires no dose reduction, concomitant medications and stress agents may need adjustment
- Patients with congenital or acquired long-QT syndrome or significant electrolyte disturbances, especially hypokalaemia or hypomagnesaemia
- Children and adolescents: activity should be scaled down using the EANM Paediatric Dosage Card. Tissues are more radiosensitive, so scans are only performed when strictly indicated
After the injection, patients are typically asked to drink plenty of fluids and to void the bladder frequently during the following 24–48 hours. This accelerates the elimination of activity through the urine and reduces the radiation dose to the bladder wall. Close physical contact with pregnant women and young children should be limited for approximately 24 hours after injection, according to local radiation protection advice.
Pregnancy and Breastfeeding
Pregnancy is a contraindication to Tl-201 imaging. Every woman of childbearing potential must be asked about possible pregnancy before the scan, and a pregnancy test may be requested when any doubt exists. If an urgent diagnostic question cannot be answered by a non-radiating alternative, the scan is sometimes performed in close consultation between the nuclear medicine physician, the referring cardiologist, and the patient, with the lowest possible administered activity.
Thallium-201 is excreted into breast milk in small but measurable amounts. Current international guidance (EANM, ICRP) recommends interrupting breastfeeding for at least 48 hours after a standard cardiac Tl-201 study, with milk expressed and discarded during that period. For larger administered activities, longer interruption or complete cessation may be advised. Your nuclear medicine department will provide specific instructions based on the exact activity administered and the age of the infant.
Men and women should also be informed that thallium-201 has a physical half-life of about three days, so measurable radioactivity persists for approximately 10–15 days after injection before decaying to background levels. No fertility effects have been reported at diagnostic doses.
Never undergo a Tl-201 scan if you are pregnant, think you may be pregnant, or are trying to become pregnant, unless your doctor has determined that it is absolutely necessary. If you are breastfeeding, inform the nuclear medicine department in advance so that the appropriate interruption period can be planned.
How Does Thallium (Tl-201) Chloride Interact with Other Drugs?
Thallium-201 itself has no classical pharmacokinetic interactions, but many commonly used cardiovascular medications – along with caffeine – can alter myocardial perfusion, mask ischaemia, or interfere with pharmacological stress testing. Always bring a complete list of medications, over-the-counter products, and supplements to your appointment.
Because only trace (nanogram) amounts of chemical thallium are administered, there are no classical drug-metabolism interactions of the kind seen with oral medicines. However, the diagnostic information obtained from a Tl-201 perfusion scan depends critically on the cardiovascular state of the patient at the time of injection. Several classes of drugs modify myocardial blood flow, heart rate, or coronary tone and can therefore blunt or exaggerate perfusion abnormalities.
Major Interactions
The following drug classes are of particular importance and are typically withheld for a defined period before the examination, when safe and in agreement with the prescribing doctor:
| Drug / Drug Class | Type of Interaction | Clinical Significance | Recommendation |
|---|---|---|---|
| Beta-blockers (metoprolol, atenolol, bisoprolol) | Haemodynamic | Blunt heart-rate response; may mask ischaemia | Consider withholding 24–48 h before exercise MPI if clinically safe |
| Calcium-channel blockers (diltiazem, verapamil) | Haemodynamic / vasodilatory | Reduce sensitivity for ischaemia detection | Withhold 24–48 h before exercise testing when possible |
| Nitrates (isosorbide, nitroglycerin) | Vasodilation | May improve perfusion in ischaemic areas and mask defects | Withhold long-acting nitrates ≥12 h before stress study |
| Caffeine & methylxanthines (theophylline, aminophylline) | Adenosine-receptor antagonism | Block the effect of adenosine, regadenoson, and dipyridamole stress agents | Avoid caffeine for at least 24 h; theophylline 48 h before pharmacological stress |
| Dipyridamole (chronic therapy) | Pre-existing adenosine potentiation | Alters response to pharmacological stress | Discontinue 48 h before adenosine/regadenoson MPI |
| Digoxin | Inhibition of Na+/K+-ATPase | Theoretically reduces myocardial Tl-201 uptake | Inform the nuclear medicine team; no routine withdrawal needed at therapeutic doses |
| Insulin & glucose infusions | Shift of Tl-201 into skeletal muscle | May reduce myocardial-to-background contrast | Avoid heavy meals and large glucose loads before injection |
Minor Interactions and Factors That May Affect Image Quality
| Factor | Potential Impact | Recommendation |
|---|---|---|
| Recent barium studies or contrast enhancement | Attenuation artefacts on SPECT | Schedule Tl-201 study before barium examinations |
| Chronic kidney disease | Slower urinary clearance; altered body distribution | Inform the nuclear medicine team; no specific dose adjustment |
| Severe hypokalaemia | Altered cardiac uptake | Correct electrolytes before elective imaging |
| Recent heavy exercise without imaging | Transient redistribution patterns | Avoid strenuous exercise in the 24 h prior to rest imaging |
The tables above are not exhaustive. Because diagnostic accuracy depends on meticulous patient preparation, always provide the nuclear medicine department with a complete list of current medications, supplements, and recent investigations. Never stop a prescribed cardiac medication on your own – the decision to withhold a drug before stress testing is made jointly by your cardiologist and the nuclear medicine team.
Fast for 4–6 hours before the scan. Avoid caffeinated beverages (coffee, tea, cola, energy drinks) and chocolate for at least 24 hours if pharmacological stress is planned. Smoking should also be avoided on the day of the test because nicotine and carbon monoxide influence coronary tone and haemoglobin-oxygen affinity.
What Is the Correct Dosage of Thallium (Tl-201) Chloride?
Thallium (Tl-201) chloride Curium is supplied as a solution containing 37 MBq of Tl-201 per millilitre at the calibration time. Typical adult activities are 37–111 MBq for myocardial perfusion imaging, with paediatric activities calculated per kilogram according to the EANM Paediatric Dosage Card. The dose is always prescribed individually by the nuclear medicine physician.
Dose selection in nuclear medicine is an optimisation between image quality and radiation exposure. Too little activity leads to noisy, non-diagnostic images and potentially a repeat study (with additional radiation); too much activity delivers an unnecessary dose. National diagnostic reference levels (DRLs), the EANM Procedure Guidelines, and local protocols define typical ranges that balance these competing requirements.
Adults
Standard Adult Activities
For myocardial perfusion imaging, the typical administered activity is 74–111 MBq (2–3 mCi) for a single-tracer stress-redistribution protocol. A reinjection dose of 37 MBq (1 mCi) may be given 3–4 hours after the initial scan to improve the detection of viable myocardium. Imaging begins 5–10 minutes after stress injection and is repeated at 3–4 hours to document redistribution.
For parathyroid scintigraphy, the typical activity is 74–111 MBq, often used in combination with technetium-99m pertechnetate for subtraction imaging.
For tumour imaging (including brain and bone/soft-tissue lesions), typical activities range from 74 to 185 MBq (2–5 mCi), determined by the indication and scanner type.
Children and Adolescents
Paediatric Use
Paediatric dosing is calculated per kilogram of body weight according to the European Association of Nuclear Medicine (EANM) Paediatric Dosage Card. For myocardial perfusion imaging, the minimum recommended activity is generally 37 MBq, with body-weight-based adjustment up to typical adult levels. Imaging in children is performed only when clearly indicated and after considering non-radiating alternatives such as stress echocardiography or cardiac MRI.
Elderly Patients
Geriatric Dosage Considerations
No activity reduction is required on the basis of age alone. Dose selection in older patients follows the same principles as in younger adults, but additional attention is given to concomitant medications, renal function, and the safety of the stress protocol. Exercise stress may need to be replaced by pharmacological stress in patients unable to reach the target heart rate.
Missed or Repeated Studies
Unlike oral medicines, Tl-201 is administered as a single intravenous injection by a healthcare professional, so the concept of a “missed dose” does not apply. If a scheduled scan is cancelled, the prepared radioactive dose is either redirected to another eligible patient (when possible) or disposed of through the department’s radioactive waste procedure. Rescheduling should be arranged promptly through the referring physician.
If the images are technically inadequate, a repeat scan may be required. The decision to repeat is taken only when the potential diagnostic benefit justifies the additional radiation exposure. Technical failures are uncommon in experienced departments.
Overdose
Radiopharmaceutical doses are prepared and verified in shielded facilities by trained personnel, so overdose is extremely rare. Should an excess activity be administered, management focuses on reducing the absorbed radiation dose: increased fluid intake, frequent voiding of the bladder, and, in exceptional cases, pharmacological measures such as the use of Prussian blue (ferric hexacyanoferrate) to accelerate faecal elimination. The nuclear medicine physician will document the event and arrange radiation dosimetry follow-up.
| Indication / Patient Group | Typical Activity | Notes |
|---|---|---|
| Adult stress MPI | 74–111 MBq (2–3 mCi) | Injected at peak exercise or during pharmacological stress |
| Viability re-injection | 37 MBq (1 mCi) | Given 3–4 h after initial stress dose to enhance viable myocardium |
| Parathyroid scintigraphy | 74–111 MBq | Often combined with 99mTc subtraction imaging |
| Tumour imaging | 74–185 MBq | Indication-specific; SPECT or SPECT/CT acquisition |
| Paediatric patients | Weight-based, min. 37 MBq | Per EANM Paediatric Dosage Card |
| Renal impairment | Standard activity | No specific reduction; advise extra hydration post-injection |
| Hepatic impairment | Standard activity | No specific reduction required |
What Are the Side Effects of Thallium (Tl-201) Chloride?
Because only trace (nanogram) amounts of thallium are administered, direct side effects are very uncommon. Most symptoms experienced on the day of the scan relate to the stress test (exercise or pharmacological agent) rather than to the tracer itself. Serious hypersensitivity reactions are rare.
Side effects are classified by frequency according to the MedDRA and CIOMS conventions: very common (affects more than 1 in 10 people), common (affects 1 in 10 to 1 in 100 people), uncommon (affects 1 in 100 to 1 in 1,000 people), and rare (affects 1 in 1,000 to 1 in 10,000 people). The table below covers reactions attributed to Tl-201 chloride itself and, separately, the most common effects associated with concurrent stress testing.
It is also important to remember that every diagnostic use of a radiopharmaceutical involves exposure to ionising radiation. The stochastic risk of radiation-induced malignancy is small but not zero; it accumulates with cumulative lifetime exposure. This is why every imaging request must be individually justified and why children and pregnant women receive special consideration.
Very Common Side Effects
May affect more than 1 in 10 people – of the stress procedure, not the tracer itself
- Flushing and warmth (during adenosine, regadenoson, or dipyridamole infusion)
- Chest tightness or a vague chest sensation (pharmacological stress)
- Shortness of breath during stress
- Headache during or shortly after stress
Common Side Effects
May affect up to 1 in 10 people
- Dizziness or light-headedness
- Palpitations or transient rhythm disturbance during stress
- Metallic or unusual taste immediately after injection
- Nausea or mild abdominal discomfort
- Transient hypotension, especially with dipyridamole
Uncommon Side Effects
May affect up to 1 in 100 people
- Mild injection-site reaction (pain, redness, small haematoma)
- Vasovagal syncope after venipuncture or injection
- Bronchospasm, particularly in patients with asthma or COPD
- Atrioventricular block during adenosine or dipyridamole infusion
- Transient ST-segment changes on ECG
Rare Side Effects
May affect up to 1 in 1,000 people
- Hypersensitivity reactions (rash, pruritus, urticaria)
- Anaphylactoid or anaphylactic reactions
- Severe hypotension or bradyarrhythmia
- Myocardial infarction during exercise or pharmacological stress (very rare in properly selected patients)
- Extravasation of the radioactive dose at the injection site
Severe chest pain that does not settle, difficulty breathing or swallowing, swelling of the face, lips, tongue or throat, widespread rash with blistering, fainting, or a feeling of impending collapse. Nuclear medicine departments are equipped and trained to manage these reactions, including the use of aminophylline to reverse adenosine-related symptoms and of emergency resuscitation protocols if required.
Because Tl-201 chloride is administered in a monitored clinical environment, most reactions are recognised and treated immediately. Nevertheless, you should continue to report any delayed symptoms to your doctor in the days following the scan. Suspected adverse reactions to any medicine, including radiopharmaceuticals, can also be reported directly to your national pharmacovigilance authority, which helps improve the safety information available for future patients.
Radiation Safety and Dose
Every Tl-201 administration delivers a calculated radiation dose that depends on the activity injected and on individual patient factors. Published dosimetry models (ICRP Publication 128) estimate an effective dose of approximately 0.14 mSv per MBq administered to adults, which corresponds to roughly 15–22 mSv for a typical 111 MBq cardiac study. For context, this is higher than a technetium-99m sestamibi scan (approximately 7–9 mSv) but similar to a diagnostic coronary CT angiography examination. The organ receiving the largest absorbed dose is usually the kidneys.
Practical measures to reduce unnecessary exposure include drinking 1–2 litres of water after the scan, emptying the bladder frequently for 24–48 hours, and avoiding prolonged close contact with pregnant women and young children for approximately 24 hours. The physical half-life of 73 hours means that residual radioactivity declines by about half every three days and is effectively negligible within two weeks.
How Is Thallium (Tl-201) Chloride Stored?
Thallium (Tl-201) chloride Curium is a radioactive medicinal product. Storage, handling, and disposal are performed exclusively by authorised nuclear medicine personnel in shielded, licensed facilities in accordance with national radiation protection legislation.
The product is supplied in a lead-shielded multidose vial, labelled with the radionuclide identity, activity at reference time, calibration date and time, volume, and a radioactive hazard symbol. Vials are stored upright at controlled room temperature (typically below 25°C) in dedicated radioactive storage cupboards that provide shielding for both stock and used containers. Storage conditions and expiry information are documented in the product’s Summary of Product Characteristics (SmPC) as authorised by the national medicines agency.
The useful shelf-life of a Tl-201 vial is relatively short. Because of the 73-hour physical half-life, activity decreases by roughly 50% every three days, limiting the clinical window during which the product can be used while still delivering an adequate dose for imaging. Nuclear medicine departments therefore order Tl-201 according to their scheduled patient list and dispose of unused activity through radioactive waste management programmes once it has decayed to exempt levels.
Patients do not handle the product at any stage. After the injection, you may be given written information explaining how much radioactivity is now in your body, how long residual radiation will remain, and any short-term precautions (for example, sitting at the back of an aircraft if flying within the next few days, or informing airport security if radiation-monitoring alarms are triggered – Tl-201 injections have occasionally activated such detectors for up to two to three weeks after administration).
If you plan to travel internationally within approximately three weeks of a Tl-201 scan, ask the nuclear medicine department for a written certificate explaining the procedure. This document helps you clear airport radiation monitors without delay.
What Does Thallium (Tl-201) Chloride Contain?
Each millilitre of Thallium (Tl-201) Chloride Curium solution for injection contains 37 MBq of thallium-201 as thallous chloride at the reference date and time, dissolved in a sterile, pyrogen-free, isotonic sodium chloride vehicle.
The active radionuclide is thallium-201 (201Tl), present as the chemically stable thallous cation (Tl+) in the form of thallous chloride. Thallium-201 is produced in a cyclotron, typically by proton bombardment of a natural or enriched thallium target, followed by purification to remove other thallium isotopes and contaminants. The resulting product has a high radionuclidic purity and is supplied at a defined activity concentration and calibration time.
The excipients in the injection vehicle are selected to ensure that the solution is safe for intravenous administration. The typical formulation contains sodium chloride (to provide isotonicity), hydrochloric acid or sodium hydroxide (to adjust the pH to approximately 4.5–7.0), and water for injections. The complete list of excipients is stated in the product’s Summary of Product Characteristics and may vary slightly between batches or formulations.
No pharmacological effect is attributable to the chemical content of the injection: the nanogram-level amount of thallium ion is far below any biologically active threshold, and the small volume of isotonic sodium chloride has no clinical impact on electrolyte balance. The diagnostic information is generated purely by the photon emissions of the decaying radionuclide.
Patients with known hypersensitivity to any excipient should inform the nuclear medicine department in advance. Latex-free equipment is used by default in most modern departments, but if you have severe latex allergy or other specific sensitivities (for example, to certain antiseptics), mention this explicitly during your pre-scan assessment.
Frequently Asked Questions About Thallium (Tl-201) Chloride
A thallium scan is a type of nuclear medicine test that uses a small injection of thallium-201 chloride together with a gamma camera to create pictures of your heart muscle, parathyroid glands, or certain tumours. In cardiology, it is most often used to detect narrowed coronary arteries, assess chest pain, plan revascularisation, and determine whether weakened heart muscle is still alive after a heart attack. The test provides functional information that X-rays and angiograms alone cannot give.
Follow the written instructions given by your nuclear medicine department. In general, you will be asked to: (1) fast for 4–6 hours before the scan; (2) avoid caffeine (coffee, tea, chocolate, cola, energy drinks, decaffeinated products, and many over-the-counter cold remedies) for at least 24 hours; (3) bring a complete list of medications and discuss with your cardiologist whether any should be withheld temporarily; (4) wear comfortable clothing and walking shoes for possible exercise on a treadmill or bicycle; and (5) inform staff if you are or could be pregnant, or if you are breastfeeding.
The intravenous injection itself feels like a standard blood sample – a brief needle prick. Most patients feel nothing from the tracer. If the scan includes pharmacological stress, you may notice flushing, warmth, chest tightness, mild shortness of breath, or a headache that usually passes within a few minutes. Symptoms from adenosine or regadenoson typically resolve rapidly, and staff can give an antidote (aminophylline) if needed. Exercise-based stress feels like a hard workout on a treadmill or bicycle.
A small amount of radioactivity remains in your body for a few days after the scan, but the emissions are of low energy and weak. For routine daily activities, you can normally resume your usual life immediately. Many departments still advise limiting prolonged close contact (for example, holding a child on your lap for many hours) with pregnant women and young children for about 24 hours. Drink plenty of water and void the bladder regularly for 24–48 hours to speed up clearance. Always follow the specific instructions given by your nuclear medicine team.
Thallium-201 is one of several nuclear-medicine tracers for myocardial perfusion imaging; others include technetium-99m sestamibi, technetium-99m tetrofosmin, and rubidium-82. Thallium is particularly sensitive for detecting viable myocardium, while technetium-based agents generally provide higher-quality images at a lower radiation dose. Alternatives without ionising radiation include stress echocardiography and stress cardiac MRI. Anatomical tests such as coronary angiography or coronary CT angiography show the arteries themselves. Your cardiologist chooses the most appropriate test based on your symptoms, risk factors, and local availability.
Most patients can drive themselves home and return to normal activities the same day, provided they feel well. If you received pharmacological stress agents or experienced significant symptoms during testing, the department may ask you to wait until these have fully resolved, or to arrange a lift. Plan a light day after the test, drink plenty of fluids, and follow any specific advice given to you in writing before you leave the department.
In published meta-analyses, stress Tl-201 SPECT has a sensitivity of approximately 85–90% and specificity of approximately 70–80% for the detection of obstructive coronary artery disease. Accuracy depends on imaging technique, patient body habitus, presence of left-bundle-branch block or prior infarction, and reader experience. For viability assessment, Tl-201 with reinjection is among the most sensitive non-invasive methods available. Your cardiologist will interpret the results in the context of your symptoms, other investigations, and overall cardiovascular risk.
References and Sources
This article is based on internationally recognised medical and pharmaceutical guidelines. All information has been reviewed by qualified healthcare professionals and follows evidence-based principles.
- European Medicines Agency (EMA). Summary of Product Characteristics: Thallous [201Tl] Chloride Injection. EMA, 2024. Available at: www.ema.europa.eu
- European Association of Nuclear Medicine (EANM). Procedure Guidelines for Myocardial Perfusion Imaging in Nuclear Cardiology. European Journal of Nuclear Medicine and Molecular Imaging, 2023.
- International Commission on Radiological Protection (ICRP). ICRP Publication 128: Radiation Dose to Patients from Radiopharmaceuticals. Annals of the ICRP, 2015 (most recent update).
- Society of Nuclear Medicine and Molecular Imaging (SNMMI) & American Society of Nuclear Cardiology (ASNC). Joint Procedure Guideline for SPECT/CT Myocardial Perfusion Imaging. Journal of Nuclear Medicine, 2023.
- U.S. Food and Drug Administration (FDA). Prescribing Information: Thallous Chloride Tl-201 Injection. FDA, 2024. Available at: www.fda.gov
- World Health Organization (WHO). Basic Safety Standards for Protection Against Ionizing Radiation and for the Safety of Radiation Sources. Geneva: World Health Organization, 2022.
- British National Formulary (BNF). Prescribing Guidance: Radiopharmaceuticals for Diagnosis. NICE, 2024. Available at: bnf.nice.org.uk
- EANM Dosimetry Committee. Paediatric Dosage Card (Version 5.7.2016). European Association of Nuclear Medicine, 2016. Available at: www.eanm.org
- Verberne HJ, Acampa W, Anagnostopoulos C, et al. EANM procedural guidelines for radionuclide myocardial perfusion imaging with SPECT and SPECT/CT: 2015 revision. European Journal of Nuclear Medicine and Molecular Imaging.
- Goodman & Gilman’s. The Pharmacological Basis of Therapeutics: Diagnostic Agents. 14th Edition. McGraw-Hill Education, 2023.
About the Medical Editorial Team
This article has been written and reviewed by iMedic’s Medical Editorial Team, consisting of licensed physicians and specialists in nuclear medicine, clinical pharmacology, and cardiology with expertise in diagnostic imaging, radiation protection, and evidence-based medicine.
iMedic Medical Editorial Team – specialists in nuclear medicine and clinical pharmacology. All content is researched and written using peer-reviewed sources and international pharmaceutical guidelines (EMA, FDA, EANM, SNMMI, ICRP, WHO).
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