{"entity":{"id":"technegas","kind":"drug","name":"Technegas (technetium Tc-99m labelled carbon inhalation aerosol)","aka":["Technegas","Tc-99m carbon nanoparticle aerosol","99mTc-CNP"],"tldr":"A puff of radioactive carbon particles so fine they travel with the breath into the depths of the lung, where they stick. A gamma camera then photographs which parts of the lung are getting air, which is compared with a second scan showing which parts are getting blood.","summary":"Technegas is an inhaled ventilation agent generated at the bedside: a Technegas generator flash-heats dried Tc-99m pertechnetate in a carbon crucible at roughly 2,700 C in argon, producing technetium encapsulated in carbon nanoparticle agglomerates measured at 60-160 nm, themselves built from 7-23 nm primary particles, with a radioactivity aerodynamic diameter below 500 nm. That size is the point: unlike a wet aerosol such as Tc-99m DTPA, which impacts in the central airways and gives hot spots in obstructive disease, Technegas distributes to the lung periphery and holds still long enough to image in multiple projections.\n\nThe FDA approved Technegas on 29 September 2023 under NDA 022335, held by Cyclomedica Australia, after decades of use elsewhere. The approved indication is narrow and precise: used with sodium pertechnetate Tc-99m in the Technegas Plus System, it is a radioactive diagnostic agent for adults and paediatric patients aged 6 years and older for visualisation of pulmonary ventilation and evaluation of pulmonary embolism when paired with perfusion imaging. Dosing is count-rate driven rather than fixed: 400-1,000 MBq (10.8-27 mCi) is loaded in the crucible to reach a lung count rate of 1,500-2,500 counts per second for adults, 500-1,000 for children, with inhalation completed within 10 minutes of preparation.\n\nThe US registration study, CYC-009 (NCT03054870), was a phase 3 non-inferiority comparison against xenon-133 planar ventilation imaging; its ClinicalTrials.gov record shows 226 participants actually enrolled and a terminated status. The label itself specifies imaging with a gamma camera and a low-energy collimator and does not use the words SPECT or planar, though the agent's stability in the lung is exactly what makes V/Q SPECT practical, and the EANM V/Q SPECT guideline is built around it.","status":"approved","asOf":"2026-09-23","links":[{"label":"FDA label: TECHNEGAS, kit for the preparation of technetium Tc 99m labeled carbon inhalation aerosol (NDA 022335)","url":"https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/022335Orig1s000lbl.pdf"},{"label":"FDA approval package, NDA 022335, approval date 29 September 2023","url":"https://www.accessdata.fda.gov/drugsatfda_docs/nda/2024/022335Orig1s000Approv.pdf"},{"label":"Technegas particle characterisation: nanoparticle agglomerates of 60-160 nm (review)","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC10144982/"},{"label":"Cyclomedica: FDA grants approval for Technegas","url":"https://www.cyclomedica.com/2023/10/02/united-states-fda-grants-approval-for-technegas/"}],"tags":["ventilation","V/Q","technetium","inhaled"],"related":["tc-99m-maa","kr-81m","tc-99m","pulmonary-embolism-vq","cyclopharm","spect"],"indications":["pulmonary-embolism-vq"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":["nct03054870"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"brand":"Technegas","modality":"Inhaled SPECT/gamma camera aerosol","mechanism":"Dried sodium pertechnetate Tc-99m is loaded into a graphite crucible and flash-heated to about 2,700 C for a few seconds in high-purity argon, which encapsulates the technetium inside carbon. The product is an ultrafine dispersion of carbon nanoparticle agglomerates with a radioactivity aerodynamic diameter under 500 nm, small enough to behave much like a gas: it follows inspired air to the alveoli rather than impacting in the large airways, then deposits and stays put, so the image is a map of where air actually reaches. Made with an argon/oxygen mix instead, the same generator yields Pertechnegas, whose technetium is not fully encased and which clears rapidly as soluble pertechnetate.","approvals":[{"region":"US","year":2023,"indication":"Visualisation of pulmonary ventilation, and evaluation of pulmonary embolism when paired with perfusion imaging, in adults and children aged 6 and over","note":"NDA 022335, Cyclomedica Australia, approved 29 September 2023"}],"mechanismSteps":[],"dosing":{"route":"Oral inhalation of the generated aerosol through a mouthpiece","schedule":"400-1,000 MBq (10.8-27 mCi) of Tc-99m pertechnetate loaded in the crucible for adults, inhaled by slow deep breathing with a 5-second breath-hold until a lung count rate of 1,500-2,500 counts per second is reached; 500-1,000 counts per second for children aged 6 and over. Inhalation must be completed within 10 minutes of preparation.","source":"https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/022335Orig1s000lbl.pdf"},"toxicity":[],"access":[],"regulatoryEvents":[{"date":"2023-09-29","type":"approval","region":"US","note":"FDA approval of NDA 022335 (Cyclomedica Australia), Type 3 new dosage form","source":"https://www.accessdata.fda.gov/drugsatfda_docs/nda/2024/022335Orig1s000Approv.pdf"}]},"route":"/drugs/technegas/","neighbours":{"drug":[{"id":"tc-99m-maa","kind":"drug","name":"Technetium Tc-99m albumin aggregated (MAA)","route":"/drugs/tc-99m-maa/"}],"isotope":[{"id":"kr-81m","kind":"isotope","name":"Krypton-81m","route":"/isotopes/kr-81m/"},{"id":"tc-99m","kind":"isotope","name":"Technetium-99m","route":"/isotopes/tc-99m/"}],"indication":[{"id":"pulmonary-embolism-vq","kind":"indication","name":"Pulmonary embolism: ventilation/perfusion imaging","route":"/indications/pulmonary-embolism-vq/"}],"company":[{"id":"cyclopharm","kind":"company","name":"Cyclopharm","route":"/companies/cyclopharm/"}],"technology":[{"id":"spect","kind":"technology","name":"SPECT & bone scan","route":"/technologies/spect/"}],"trial":[{"id":"nct03054870","kind":"trial","name":"CYC-009: Technegas versus xenon-133 ventilation imaging","route":"/trials/nct03054870/"}]}}