Pulmocis: Uses, Dosage & Side Effects
Kit for the preparation of technetium-99m labelled macroaggregates of human albumin (99mTc-MAA) for lung perfusion scintigraphy
Pulmocis is a diagnostic radiopharmaceutical kit used to prepare a sterile intravenous suspension of macroaggregated human albumin (MAA) particles labelled with the radioactive isotope technetium-99m (99mTc). After the reconstituted product is injected into a vein, the microscopic albumin particles (10–90 micrometers in diameter) travel through the right heart and become briefly trapped in the small arterioles and capillaries of the lungs. Because they distribute in direct proportion to regional pulmonary blood flow, a gamma camera can image their location to produce a high-quality map of lung perfusion. The resulting scan is most commonly used to investigate suspected pulmonary embolism (usually combined with a ventilation study to form a V/Q scan), to evaluate regional lung function before thoracic surgery or lung transplantation, to assess right-to-left cardiac shunts, and to study chronic pulmonary vascular or parenchymal diseases. Pulmocis is administered exclusively in licensed nuclear medicine departments by trained healthcare professionals and delivers a low effective radiation dose (approximately 1.1 millisieverts in adults).
Quick Facts: Pulmocis
Key Takeaways
- Pulmocis is a kit that, when reconstituted with sodium pertechnetate (99mTc) solution, produces a radiolabelled suspension of human albumin macroaggregates used to image pulmonary blood flow with a gamma camera.
- Its main clinical indications are suspected pulmonary embolism (usually as the perfusion half of a V/Q scan), pre-surgical evaluation of regional lung function, assessment of right-to-left shunts, and evaluation of chronic lung diseases such as chronic thromboembolic pulmonary hypertension (CTEPH).
- The radiation dose from a standard adult scan is approximately 1.1 millisieverts, which is low compared with CT pulmonary angiography (typically 3–10 millisieverts) and generally lower than many conventional radiology examinations.
- Serious adverse reactions are rare; most patients experience no side effects at all. Hypersensitivity reactions, including very rare anaphylactoid events, have been reported, and the procedure requires cautious use in patients with severe pulmonary hypertension or known right-to-left cardiac shunts.
- Pulmocis must be prepared and administered only in licensed nuclear medicine facilities by trained healthcare professionals. The product contains a human protein (albumin), is derived from screened blood donations, and carries essentially no risk of transmission of known infectious agents.
What Is Pulmocis and What Is It Used For?
Pulmocis is a medicine used in nuclear medicine for diagnostic imaging only; it is not a treatment. The product is supplied as a sterile, freeze-dried (lyophilized) powder in a single-dose vial and must be reconstituted by specialized pharmacy or nuclear medicine staff with a fresh eluate of sodium pertechnetate (99mTc) obtained from a technetium-99m generator. After reconstitution, the vial contains a suspension of human albumin macroaggregates (MAA) with adsorbed technetium-99m, ready to be drawn into a syringe and injected intravenously. The resulting product is widely known by its generic name 99mTc-MAA or Tc-99m macroaggregated albumin.
The physical basis of the technique is microscopic capillary blockade. The reconstituted suspension contains particles typically 10 to 90 micrometers in diameter (the majority between 20 and 40 micrometers). After intravenous injection, these particles pass through the right side of the heart into the pulmonary artery and then into progressively smaller vessels. Because pulmonary precapillary arterioles and capillaries are only 7 to 10 micrometers wide, the macroaggregates become mechanically trapped on their first pass through the lungs. Only a few hundred thousand to a million particles are injected per dose; since the adult lung contains several billion capillaries, the fraction temporarily blocked is negligible (on the order of one in 10,000 to one in 100,000 capillaries).
The trapped particles emit gamma rays because they are labelled with technetium-99m, a radioisotope with ideal physical properties for imaging: a short physical half-life of 6.02 hours, a monoenergetic 140 keV gamma photon that is efficiently detected by a standard gamma camera, and no beta emission (which would unnecessarily irradiate the patient without contributing to the image). The scanner records the spatial distribution of the particles from multiple angles, producing planar or three-dimensional single-photon emission computed tomography (SPECT) images that accurately reflect where blood is and is not flowing in the lungs.
Pulmocis is authorized and widely used in the European Union, the United Kingdom, Canada, and many other countries under the broader class of technetium (99mTc) macroaggregates (ATC code V09EB01). Clinically, it is indicated for the investigation of pulmonary perfusion in a range of situations, summarized below.
Diagnosis of Pulmonary Embolism
The classic use of 99mTc-MAA is the evaluation of suspected acute pulmonary embolism (PE). Pulmonary embolism occurs when a blood clot, usually originating in the deep veins of the legs or pelvis, travels to the lungs and obstructs one or more pulmonary arteries, causing characteristic wedge-shaped defects on a perfusion scan. The perfusion study is almost always paired with a ventilation study (usually performed with inhaled Technegas, 81mKr gas, or radiolabelled aerosols), together forming a V/Q (ventilation/perfusion) scan. A high-probability pattern – typically two or more segmental perfusion defects without corresponding ventilation defects – supports a diagnosis of PE. The V/Q scan remains a preferred first-line test in pregnancy, in patients with contrast allergy, in patients with impaired renal function, and in young women where the radiation dose to breast tissue from CT pulmonary angiography is a concern.
Chronic Thromboembolic Pulmonary Hypertension (CTEPH)
A normal perfusion scan has a very high negative predictive value for chronic thromboembolic pulmonary hypertension, a potentially curable form of pulmonary hypertension in which organized clots obstruct the pulmonary vasculature. International pulmonary hypertension guidelines recommend that all patients with unexplained pulmonary hypertension undergo V/Q scintigraphy before cardiac catheterization, because CTEPH cannot be excluded by CT pulmonary angiography alone.
Pre-Operative Lung Function Assessment
Before lobectomy or pneumonectomy for lung cancer or other diseases, surgeons and pulmonologists need to predict the patient's postoperative lung function. Quantitative perfusion scintigraphy using 99mTc-MAA allows the fractional contribution of each lung and each lobe to overall perfusion to be calculated. When combined with spirometry, this enables accurate prediction of the forced expiratory volume in one second (FEV1) and diffusing capacity after resection, helping to select suitable surgical candidates and to avoid operating on patients at unacceptably high risk of postoperative respiratory failure.
Evaluation for Lung Transplantation
In single-lung transplantation and in the follow-up of transplanted lungs, perfusion scintigraphy is used to quantify how much blood is directed to the native versus the transplanted lung and to detect vascular complications of the surgical anastomoses. It is also used to detect chronic lung allograft dysfunction when suspected.
Quantification of Right-to-Left Shunts
Because normal pulmonary capillaries trap virtually all injected particles, any activity seen in systemic organs (brain, kidneys) after intravenous injection indicates that a proportion of the particles have bypassed the pulmonary capillary bed through an intracardiac or intrapulmonary right-to-left shunt. Quantification of whole-body activity relative to lung activity yields an accurate measurement of the shunt fraction. This technique is used in the evaluation of congenital heart disease, hepatopulmonary syndrome, and pulmonary arteriovenous malformations (for example in hereditary hemorrhagic telangiectasia).
Although CT pulmonary angiography (CTPA) has become the dominant test for suspected acute pulmonary embolism in many centers, V/Q scintigraphy using 99mTc-MAA retains important and growing roles: it is preferred in pregnancy (lower fetal dose than CTPA), in young women (lower breast dose), in patients with renal impairment or iodinated contrast allergy, in the diagnosis of CTEPH, and for quantitative pre-surgical assessment. Modern SPECT/CT V/Q imaging offers anatomical co-registration and substantially higher sensitivity and specificity than the older planar technique.
What Should You Know Before Receiving Pulmocis?
Contraindications
There is a small number of clinical situations in which Pulmocis should not be used at all, or only under strict specialist supervision. Understanding these is essential for patient safety.
- Hypersensitivity: Pulmocis must not be used in patients with known hypersensitivity to the active substance (macroaggregates of human albumin), to any of the excipients, or to any of the other components of the radiolabelled preparation.
- Severe pulmonary hypertension: In patients with severe pulmonary hypertension, the additional mechanical blockade of pulmonary capillaries by MAA particles – however small – may theoretically worsen right heart strain. In such patients, the number of particles injected is reduced or the test is avoided unless the diagnostic question is essential.
- Known right-to-left shunt: When a large right-to-left shunt is already known, caution is needed because injected particles will bypass the pulmonary capillary bed and embolize to the systemic circulation (including the brain and kidneys). In these patients the injected particle count is significantly reduced to minimize any risk of microembolism to critical organs.
- Pregnancy, where avoidable: Use in pregnancy is not absolutely contraindicated but is avoided whenever an alternative test is available (see the pregnancy section below).
Warnings and Precautions
Although rare, hypersensitivity reactions – including anaphylactoid reactions – have been reported following administration of technetium-99m MAA products. The patient must be observed during and for at least 30 minutes after injection, and the nuclear medicine facility must have resuscitation equipment, oxygen, epinephrine (adrenaline), and trained personnel immediately available. Inform staff immediately if you develop flushing, breathing difficulty, rash, itching, chest tightness, dizziness, or swelling of the face, tongue, or throat after injection.
Tell your doctor or nurse before receiving Pulmocis if any of the following apply to you:
- Pulmonary hypertension or severe lung disease: Even if not absolutely contraindicated, pulmonary hypertension, severe chronic obstructive pulmonary disease (COPD), or other severe lung conditions require the nuclear medicine physician to use the lowest number of particles that gives a diagnostic image. Particle numbers are routinely reduced in patients with known or suspected pulmonary hypertension.
- Known heart defects or shunts: If you have a congenital heart defect or a history of paradoxical embolism, tell the medical team. The number of injected particles will be reduced and the scan protocol adapted.
- Previous reactions to albumin products or blood transfusions: Although Pulmocis uses highly purified human albumin, inform staff of any previous reactions to albumin solutions, intravenous immunoglobulin, or blood transfusions.
- Renal or hepatic impairment: No specific dose adjustment is usually required, but renal or hepatic impairment should be declared because they affect radiation dosimetry and the clearance of some of the product's degradation components.
- Recent diagnostic or therapeutic radiation: Tell the nuclear medicine team about any other recent X-ray, CT, or nuclear medicine studies. This helps them account for cumulative radiation exposure and optimize the injected activity.
During and immediately after the injection, tell the staff straight away if you experience any of the following:
- Sudden shortness of breath, wheezing, or chest tightness
- Rash, hives, itching, or skin flushing
- Swelling of the face, lips, tongue, or throat
- Dizziness, weakness, or feeling faint
- Nausea, vomiting, or abdominal discomfort
- Unusual pain at the injection site
Pregnancy and Breastfeeding
When a diagnostic radiopharmaceutical is to be administered to a woman of childbearing potential, the possibility of pregnancy must always be considered before administration. Any woman who has missed her period should be assumed to be pregnant until proven otherwise. In doubt, pregnancy testing should be performed. If pregnancy is not possible, the study may proceed; if pregnancy is possible or confirmed, alternative techniques that do not use ionizing radiation should be considered first.
In clinically urgent situations such as suspected pulmonary embolism in pregnancy, the benefits of excluding a life-threatening diagnosis usually outweigh the very small radiation risk to the fetus. When used in pregnancy, the injected activity is typically halved or quartered to minimize fetal dose, and the perfusion study may be performed without a ventilation component to further limit exposure (a normal perfusion scan alone can safely exclude PE). Hydration and frequent voiding of the bladder help reduce the fetal dose from 99mTc that is filtered by the kidneys.
Technetium-99m is excreted in breast milk. If Pulmocis is administered to a breastfeeding woman, nursing should be interrupted for approximately 12 hours, with breast milk expressed and discarded during this period. After this interval, breastfeeding may be resumed normally. Close physical contact with infants and small children should also be limited during the first few hours after injection.
Children and Adolescents
Pulmocis can be used in children and adolescents when clinically indicated. The injected activity is calculated according to body weight using the European Association of Nuclear Medicine (EANM) pediatric dosage card, which ensures adequate image quality while keeping radiation exposure as low as reasonably achievable (the ALARA principle). The number of injected particles is also reduced in infants and young children to account for their smaller pulmonary capillary bed.
Driving and Operating Machinery
Pulmocis has no known influence on the ability to drive or operate machinery. Patients may drive themselves to and from the appointment unless their underlying condition or any sedative medication used for the scan advises otherwise.
Important Information About Ingredients
Pulmocis contains small amounts of sodium and human albumin. The sodium content is less than 1 mmol (23 mg) per dose, so it is essentially sodium-free and suitable for patients on low-sodium diets. The human albumin used is sourced from rigorously screened blood donations and subjected to validated viral inactivation procedures; the residual risk of transmission of blood-borne infectious agents is considered negligible, but theoretically not zero.
How Does Pulmocis Interact with Other Drugs?
Because Pulmocis is injected once, is not metabolized through the cytochrome P450 system, and is not excreted by the kidneys in its original form, it has a very limited pharmacokinetic interaction profile. Most clinically relevant interactions are pharmacodynamic or cause imaging artefacts rather than direct drug-drug toxicity. Nonetheless, a complete medication history (including over-the-counter drugs and herbal remedies) should be provided to the nuclear medicine team before the study.
Drugs that influence the coagulation cascade, the integrity of the macroaggregate particles, or the regulation of pulmonary vascular tone are the most likely to produce findings that need to be interpreted with care.
Clinically Relevant Interactions
| Interacting Drug / Class | Effect | Clinical Significance |
|---|---|---|
| Heparin and other anticoagulants | May prolong the presence of small clots that contain adsorbed 99mTc, producing hot spots on the image; heparin itself can cause artefactual labelling | Usually not a contraindication to the scan; discuss recent heparin administration with the nuclear medicine physician so artefacts are correctly interpreted |
| Magnesium sulfate (high doses) | May interact physically with macroaggregate stability and alter particle size distribution | Generally of minor importance; high-dose magnesium infusions (e.g., in pre-eclampsia) should be declared |
| Chemotherapy (bleomycin, busulfan, carmustine, methotrexate, mitomycin, cyclophosphamide) | Drug-induced pulmonary vascular or alveolar damage may alter perfusion patterns or the retention kinetics of 99mTc-MAA | Not an interaction with Pulmocis itself; the scan may nonetheless reveal chemotherapy-induced lung injury which should be considered when interpreting results |
| Bronchodilators (e.g., salbutamol) | May change regional lung ventilation and, indirectly via hypoxic pulmonary vasoconstriction, regional perfusion | Usually continue as prescribed; timing relative to the ventilation study may be adjusted in V/Q protocols |
| Pulmonary vasodilators (e.g., calcium-channel blockers, prostanoids, endothelin antagonists, PDE-5 inhibitors) | Alter pulmonary vascular tone and may redistribute blood flow | Continue as prescribed; note in the referral so perfusion patterns are interpreted correctly |
| Nitrofurantoin, amiodarone, hydralazine (drugs causing pulmonary toxicity) | Can cause interstitial lung disease with perfusion abnormalities | Does not alter Pulmocis pharmacology; relevant for interpretation of abnormal scans |
There is no known interaction between Pulmocis and common routine medications such as statins, antihypertensives (other than pulmonary vasodilators), oral diabetes therapy, inhaled corticosteroids at standard doses, or most over-the-counter analgesics. Patients should nonetheless continue their prescribed medications as usual unless told otherwise by the nuclear medicine team.
Interactions with Other Radiopharmaceuticals
If another nuclear medicine procedure with a different radiopharmaceutical has been performed recently, residual activity may be visible on the Pulmocis scan. Scheduling of studies is planned by the nuclear medicine department to avoid cross-contamination of images. Declare any previous or planned nuclear medicine investigations to the referring clinician and to the nuclear medicine staff.
What Is the Correct Dosage of Pulmocis?
Pulmocis is always prepared and administered by qualified nuclear medicine personnel in a facility authorized to handle unsealed radioactive materials. The dose is expressed both as a radioactivity (in megabecquerels, MBq, or millicuries, mCi) and as a number of particles. Both parameters are individualized for each patient and clinical indication.
Adults
Adult Lung Perfusion Scintigraphy
Typical activity: 40–150 MBq (approximately 1–4 mCi) of 99mTc-MAA as a single intravenous injection
Typical particle count: 60,000 to 700,000 particles per dose (most adult protocols use 100,000–500,000 particles)
Route: Slow intravenous injection through an antecubital vein with the patient supine; avoid drawing blood back into the syringe, as this may cause particle clumping and image artefacts
Imaging: Gamma camera acquisition typically starts a few minutes after injection and may continue for 15–30 minutes; modern SPECT or SPECT/CT acquisitions take additional time
Children and Adolescents
Pediatric Lung Perfusion Scintigraphy
Activity: Calculated by body weight using the EANM pediatric dosage card; the minimum administered activity recommended in the EANM card for pulmonary perfusion is typically 10–14 MBq for the smallest children, increasing proportionally with weight
Particle count: Substantially reduced in infants and young children, typically 10,000–50,000 particles for neonates and infants, titrated by weight
Special considerations: Careful attention to injection technique is essential in small veins; sedation may be required for very young children to ensure stillness during image acquisition
Special Populations
Pregnancy
Use alternatives whenever possible. If the study is essential (e.g., acute PE in pregnancy), activity is typically reduced by 25–50% and a perfusion-only protocol (without ventilation) may be used. Recommend ample hydration and frequent bladder emptying after the study to minimize fetal dose.
Severe Pulmonary Hypertension and Known Right-to-Left Shunt
The particle count is reduced to the minimum required for a diagnostic image (often 60,000–100,000 particles, sometimes fewer). Radioactivity is kept within the diagnostic range.
Missed Dose
Because Pulmocis is administered only once, as part of a scheduled diagnostic procedure performed by healthcare professionals, the concept of a missed dose does not apply. If a scheduled appointment is missed or postponed, the scan can usually be rebooked without any impact on the patient.
Overdose
In the diagnostic setting in which Pulmocis is used, overdose is extremely unlikely because the activity is carefully measured in a calibrated dose calibrator before injection. Inadvertent administration of a larger-than-intended activity would result in a small increase in the patient's radiation dose and possibly a higher than normal number of trapped particles in the pulmonary capillary bed. If a significant overdose occurs, the principal management is hydration and frequent bladder emptying to accelerate clearance of free 99mTc pertechnetate by urinary excretion. The short physical half-life of 99mTc (6.02 hours) means that the radioactivity falls rapidly.
How Pulmocis Is Prepared and Given
Preparation of the radiolabelled product is performed in a dedicated, shielded laboratory by trained personnel. A vial of Pulmocis is reconstituted with a measured volume of freshly eluted sodium pertechnetate (99mTc) solution. The vial is gently agitated (not shaken vigorously) to resuspend the particles and the preparation is left to incubate for a short period (typically 10–30 minutes) to allow efficient binding of 99mTc to the macroaggregates. The final radiochemical purity, activity, and appearance are checked before dispensing. The shelf-life of the reconstituted product after labelling is usually up to 8 hours at room temperature.
Immediately before injection, the patient's name, identification, clinical indication, and weight are verified. The patient is positioned supine (lying on their back) to ensure even distribution of particles throughout both lungs; injection while sitting or standing may cause a gravity-dependent distribution artefact. The syringe is inverted several times immediately before injection to resuspend settled particles. The injection is given slowly into a large peripheral vein, without drawing blood back into the syringe, because blood in the syringe may cause clot formation and hot-spot artefacts on the scan.
Pulmocis is a radiopharmaceutical that must be prepared, stored, and administered only in hospitals or specialized nuclear medicine clinics that are licensed to handle unsealed radioactive sources. All relevant national radiation protection regulations apply to preparation, waste management, and the temporary restrictions on close contact between the patient and other people (particularly pregnant women and young children) in the hours following injection. You will not handle or self-administer this medication.
What Are the Side Effects of Pulmocis?
Pulmocis has a very favorable safety profile. Large post-marketing surveillance studies of technetium-99m MAA products have reported serious adverse reactions in fewer than 1 per 100,000 to 1 per 10,000 administrations, placing the product among the safest contrast agents used in radiology. Most patients describe the procedure as painless and uneventful apart from the minor discomfort of an intravenous injection.
The side effects below are organized by the standard pharmacovigilance frequency categories. Because many of the events are extremely rare, reliable precise frequencies are not available for every category; figures are based on the Pulmocis Summary of Product Characteristics and published nuclear medicine literature.
Very Common
May affect more than 1 in 10 people
- No very common adverse reactions have been identified for Pulmocis at standard diagnostic activities; the majority of patients experience no symptoms attributable to the product
Common
May affect up to 1 in 10 people
- Mild, transient discomfort at the injection site (stinging, warmth, or bruising), usually resolving within minutes to hours
- Anxiety or mild lightheadedness related to the procedure rather than to the product itself
Uncommon
May affect up to 1 in 100 people
- Mild hypersensitivity reactions, such as localized rash, urticaria (hives), or itching
- Nausea, flushing, or transient feeling of warmth shortly after injection
- Brief increase in heart rate or feeling of chest tightness, typically self-limiting
Rare
May affect up to 1 in 1,000 people
- Generalized hypersensitivity reactions involving rash, widespread urticaria, or bronchospasm
- Vasovagal (fainting) reactions unrelated to the pharmacology of the product
- Transient shortness of breath or cough
Very Rare
May affect up to 1 in 10,000 people
- Anaphylactoid or anaphylactic reactions with hypotension, severe bronchospasm, laryngeal edema, or cardiovascular collapse – requiring immediate emergency treatment
- Pulmonary hypertension crisis in patients with severe pre-existing pulmonary vascular disease (avoided by appropriate particle reduction)
- Systemic microembolization via a previously unrecognized right-to-left shunt
Not Known
Frequency cannot be estimated from available data
- Theoretical long-term risk of radiation-induced cancer or genetic effects; at the effective doses used in lung perfusion scintigraphy (approximately 1.1 millisieverts in adults) this risk is very small and has not been individually identifiable in epidemiological studies
- Rare reports of drug-induced fever or chills attributable to injected particles
If you notice any side effects, including any not listed here, report them to your healthcare provider. Reporting helps regulatory authorities continuously monitor the benefit-risk balance of medicines. You can also report side effects directly to your national pharmacovigilance agency (for example the FDA MedWatch program in the United States, the Yellow Card scheme in the United Kingdom, or the EMA EudraVigilance system in the European Union).
For the first few hours after injection you will emit a small amount of gamma radiation. You may be asked to avoid prolonged close contact with pregnant women and young children for the rest of the day. Drink plenty of fluids and empty your bladder frequently to help excrete free technetium-99m in the urine. By the following morning, the residual activity is negligible.
How Should Pulmocis Be Stored?
Because Pulmocis is a radiopharmaceutical, its storage, handling, and disposal are tightly regulated and are the responsibility of the pharmacy and nuclear medicine staff. Patients do not handle or store the product themselves. The following information may be useful for understanding the requirements and the reasons for the specific safety measures in place.
- Unopened kits: Store below 25°C in the original carton. Do not freeze. Protect from light. The expiry date printed on the carton and vial must not be exceeded.
- Reconstituted (labelled) product: After reconstitution with sodium pertechnetate (99mTc) solution, the ready-to-use suspension should be stored below 25°C and protected from light. Shake the vial gently before withdrawing each individual dose to ensure a homogeneous suspension. The shelf-life after labelling is stated in the national product information, typically up to 8 hours.
- Radiation protection: All handling is performed behind appropriate lead shielding, and doses are stored in lead pots or shielded cabinets. Personnel wear personal dosimeters to monitor their exposure.
- Quality control: Before use, the radiochemical purity is verified (typically by thin-layer chromatography); the preparation is used only if the radiochemical purity is above the threshold specified in the SmPC (usually above 90–95% bound 99mTc).
- Disposal: Unused preparation, empty vials, and any contaminated waste are managed as radioactive waste in accordance with national radiation protection legislation. Waste is typically stored until the activity has decayed to background levels (about ten half-lives, roughly 60 hours for 99mTc).
- Keep out of reach of children: As with all medicines.
Any unused product or waste material is disposed of in accordance with local and national regulations for radioactive pharmaceutical waste.
What Does Pulmocis Contain?
Understanding what Pulmocis contains is helpful for identifying potential allergens and for distinguishing the non-radioactive kit from the final radiolabelled product administered to the patient.
- Active substance: Human albumin macroaggregates. Each vial typically contains approximately 2 mg of macroaggregates of human albumin, which, after reconstitution, correspond to several hundred thousand particles ranging from about 10 to 90 micrometers in diameter. The particles are designed to be temporarily trapped in the pulmonary microcirculation and then gradually broken down into smaller fragments that are cleared from the circulation.
- Carrier protein: Additional non-aggregated human albumin is present as a stabilizer for the particles.
- Reducing agent: Stannous chloride (tin(II) chloride), which reduces pertechnetate (99mTc(VII)) to a lower valency state so that it binds efficiently to the macroaggregates.
- Other excipients: Sodium chloride and other agents to maintain appropriate pH and isotonicity; the exact qualitative composition is described in the SmPC. The sodium content is less than 1 mmol (23 mg) per dose (essentially sodium-free).
- Radioactive component (added at labelling): Sodium pertechnetate (99mTc) solution, obtained from a licensed 99Mo/99mTc generator, is added at the point of use to produce the final radiolabelled preparation.
Appearance: Pulmocis is supplied as a sterile, lyophilized (freeze-dried), white to off-white powder or cake in a glass vial with a rubber stopper and aluminum seal. After reconstitution with sodium pertechnetate (99mTc) solution and gentle agitation, the product is a uniform, milky-white suspension free of visible particulate matter other than the macroaggregates themselves. Some settling during standing is normal and the vial is gently inverted to resuspend before each dose is withdrawn.
Pack size: Pulmocis is typically supplied in cartons containing multiple single-dose vials intended for one patient each per kit.
Marketing authorization holder: Curium PET France (part of Curium Pharma), 14 Rue de la Pierre Ronde, ZA Les Mardelles, 93600 Aulnay-sous-Bois, France. The product is authorized in multiple countries, and the specific marketing authorization holder may vary by market.
Other Brand Names
Technetium (99mTc) macroaggregates of human albumin are marketed under several brand names worldwide. In addition to Pulmocis, these include Pulmolite, TechneScan MAA, Macrotec, Pulmotec, and various generic kits manufactured by different radiopharmaceutical companies. While the active principle is the same across these products, the exact particle size distribution, particle number per vial, and excipient formulation may differ; always follow the specific prescribing information for the product actually administered in your local nuclear medicine department.
Frequently Asked Questions About Pulmocis
The radioactive isotope used, technetium-99m, has a short physical half-life of 6.02 hours, which means its activity in your body falls by 50% every 6 hours. By roughly 24 to 30 hours after injection (about four to five half-lives), more than 99% of the original radioactivity has decayed. In practice, any clinically relevant external radiation has disappeared within one day. Drinking extra fluids and passing urine frequently helps speed the removal of free technetium-99m. You may be advised to avoid prolonged close contact with pregnant women and very young children for the rest of the day of your scan as a conservative precaution.
The scan itself is painless. The only physical discomfort is the brief needle prick of the intravenous injection, similar to a routine blood test. During imaging you will lie still on a table while the gamma camera slowly moves around your chest. The camera does not touch you and the procedure is typically quiet. The entire appointment usually takes 30 to 60 minutes from arrival to discharge, although the injection itself takes less than a minute and imaging typically 15 to 30 minutes. Patients with claustrophobia should mention this in advance; the lung scan camera is usually more open than a CT or MRI scanner.
Both V/Q scintigraphy (using Pulmocis) and CT pulmonary angiography are excellent tests for pulmonary embolism, and the choice depends on the individual patient. V/Q scanning is often preferred in pregnancy (because it delivers a lower radiation dose to the fetus and to the mother's breast tissue than CT), in young women (for the same reason), in patients with iodinated contrast allergy, in patients with significant kidney disease that makes iodinated contrast risky, and in the investigation of chronic thromboembolic pulmonary hypertension. CT pulmonary angiography is often preferred when the chest is likely to have other pathology that CT can also characterize (such as pneumonia, cancer, or aortic disease). Your referring physician will have weighed these factors in your case.
In most situations, nuclear medicine investigations using radioactive materials are avoided in pregnancy when an alternative is available. However, if the clinical question is urgent – for example excluding acute pulmonary embolism – the very small radiation dose to the fetus (typically a fraction of one millisievert) is clearly outweighed by the diagnostic benefit, because an undiagnosed pulmonary embolism is life-threatening for both mother and fetus. In pregnancy, the injected activity is typically reduced, the perfusion study may be performed without ventilation, and the mother is asked to drink plenty of fluids and empty her bladder frequently to minimize fetal exposure. Always tell staff if you are or might be pregnant before the scan.
Unlike many radiological procedures, no special fasting is required for a Pulmocis lung perfusion scan. You may eat and drink normally before the appointment. You should continue to take your usual prescribed medications unless explicitly told otherwise by the nuclear medicine department. If you normally take a bronchodilator or other inhaler for asthma or chronic obstructive pulmonary disease, bring it with you. Wear comfortable clothing without metal fasteners or buttons over the chest; you will be asked to remove any jewelry or metal accessories before imaging.
Yes. Pulmocis contains human albumin, a protein purified from screened pooled human plasma. The albumin is manufactured using validated processes (including pasteurization and other viral inactivation steps) that are designed to inactivate or remove blood-borne viruses such as HIV, hepatitis B, and hepatitis C. The residual risk of transmission of a known blood-borne pathogen is considered extremely low but cannot be reduced to zero with absolute certainty. No cases of viral transmission have been identified for licensed human albumin products used as a carrier in radiopharmaceuticals. If you have religious or personal concerns about human-derived products, discuss them with your referring physician; rare alternative perfusion tracers exist but have different imaging properties.
References
- Curium Pharma. Pulmocis – Summary of Product Characteristics. Most recent version. Available from national medicines regulators and the manufacturer.
- European Association of Nuclear Medicine (EANM). EANM guideline for ventilation/perfusion single-photon emission computed tomography (SPECT) for diagnosis of pulmonary embolism and other pulmonary disorders. European Journal of Nuclear Medicine and Molecular Imaging. 2019;46(12):2429-2451. doi:10.1007/s00259-019-04450-0
- Society of Nuclear Medicine and Molecular Imaging (SNMMI). SNMMI Procedure Standard/EANM Practice Guideline for Lung Scintigraphy. Version 2.0. Reston, VA: SNMMI; 2018.
- International Commission on Radiological Protection (ICRP). ICRP Publication 128: Radiation dose to patients from radiopharmaceuticals: a compendium of current information related to frequently used substances. Annals of the ICRP. 2015;44(2 Suppl):7-321.
- Lapa P, Oliveiros B, Marques M, et al. Technetium-99m macroaggregated albumin perfusion imaging in the diagnosis of pulmonary embolism: current status and future perspectives. Nuclear Medicine Communications. 2017;38(1):1-11.
- Konstantinides SV, Meyer G, Becattini C, et al. 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS). European Heart Journal. 2020;41(4):543-603. doi:10.1093/eurheartj/ehz405
- Humbert M, Kovacs G, Hoeper MM, et al. 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension. European Heart Journal. 2022;43(38):3618-3731. doi:10.1093/eurheartj/ehac237
- Tunariu N, Gibbs SJR, Win Z, et al. Ventilation-perfusion scintigraphy is more sensitive than multidetector CTPA in detecting chronic thromboembolic pulmonary disease as a treatable cause of pulmonary hypertension. Journal of Nuclear Medicine. 2007;48(5):680-684. doi:10.2967/jnumed.106.039438
- Bajc M, Schuümichen C, Grüning T, et al. EANM guideline for ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) and SPECT/CT. European Journal of Nuclear Medicine and Molecular Imaging. 2019;46(12):2429-2451.
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd List, 2023. Geneva: World Health Organization; 2023.
- Parker JA, Coleman RE, Grady E, et al. SNM practice guideline for lung scintigraphy 4.0. Journal of Nuclear Medicine Technology. 2012;40(1):57-65. doi:10.2967/jnmt.111.101386
Editorial Team
Medical Content
iMedic Medical Editorial Team – Specialists in Nuclear Medicine and Clinical Pharmacology
Medical Review
iMedic Medical Review Board – Independent panel following WHO, EMA, FDA, EANM and SNMMI guidelines
Evidence Level
Level 1A – Based on international nuclear medicine guidelines, systematic reviews, and peer-reviewed clinical evidence
Last Reviewed
– Updated according to current SmPC, EANM guidelines, and SNMMI practice standards
All medical content on iMedic is written and reviewed by qualified healthcare professionals following the GRADE evidence framework. We adhere to strict editorial standards with no commercial funding or pharmaceutical sponsorship. For questions or corrections, please contact our editorial team.