Lipiodol (also known as ethiodized oil) is an oil-based iodinated contrast medium that was historically used for myelography and hysterosalpingography ¹. It was later superseded by newer, less hazardous, agents, and now is used primarily as a therapeutic agent. Guerbet was previously the sole manufacturer of this agent. Vivere imaging has also formulated a similar agent under the name Vividol which has obtained FDA approval.

Structure

Lipiodol comprises a combination of iodine and ethyl esters of poppy seed oil ². The iodine is intercalated into the constituent fatty acids to produce a mixture of iodostearic and stearic-acid derived esters. The precise structure of Lipiodol has never been characterized ².

Uses

Diagnostic

• hysterosalpingography

• lymphography

• dacryocystography (DCG)

Therapeutic

• Lipiodol radiolabeled with I-131/ Re-188

  • Lipiodol has been tagged with radioisotopes for locoregional therapy of primary and secondary liver tumors.

  • I131- Lipiodol was the first intra arterial radio isotope therapy to be developed. Lipiodol was labeled with I-131 using an isotopic ion exchange process. The limitations in its utility as a locoregional therapy agent was a long isolation time of 7-14 days post administration.

  • Rhenium-188 Lipiodol is a radiopharmaceutical that can be used to treat patients with unresectable hepatocellular carcinoma. ¹⁸⁸Re-HDD (4-hexadecyl-4,7-diaza-1,10-decanedithiol)] lipiodol is widely used but unfortunately, the labeling yield with ¹⁸⁸Re-HDD lipiodol is poor. Chelating agent N-DEDC (Nitrido-diethyl-dithicarbamato) is cheaper, easier to tag and more stable. The final lipophilic complex, bis-(diethyldithiocarbamato) nitrido rhenium-188, to be administered through the hepatic artery, is as follows: Re-188 N (DEDC) ₂-Lipiodol ^3-6. O

• conventional transcatheter hepatic arterial chemoembolisation (cTACE) ⁷

  • transcatheter radioembolization was initially developed using Lipiodol, but now non-Lipiodol drug-eluted glass or resin microspheres are preferred ^8,9

• Glue Embolization -

  • Varying concentration ratios of Lipiodol to N- Butyl Cyanoacrylate can be used to vary the polymerization rates within a target vessel or angiosomal bed. Concentrated ratios ~ 50% are used for proximal Embolization and ~ 16/ 33% are used for distal/mid Embolization. A combination of different ratios may be useful when treating complex arterio-venous malformations. A dilute ratio of Lipiodol - NBCA might be utilized for Embolization of a bleeding vessel/ pseudoaneurysm from a proximal catheter position when a distal deeper position might not be possible for coil Embolization.

History and etymology

Lipiodol was discovered by the co-founders of the healthcare company Guerbet, Marcel Guerbet and Laurent Lafay in 1901 ¹⁰. Indeed originally it was marketed as Lipiodol Lafay. Initially it was developed as a therapeutic agent - a way to deliver iodine to tissues.

It was first employed in radiology in 1921 by Jean-Athanase Sicard and Jacques Forestier, French radiologists, who developed positive contrast myelography. This supplanted air myelography which had been used until then. Due to complications (e.g. chemical arachnoiditis) Lipiodol was itself superseded by iophendylate.

It was previously marketed as Ethiodol in the US but is now globally sold as Lipiodol. Vividol - developed in India and being made available globally is emerging as a bio- similar alternative.

An article was published in 2021 to celebrate one hundred years of continuous use of Lipiodol in radiology ¹¹.