Detecting 'Lung Cancer' by Inhaling Contrast Agent

Development of Lung Cancer Differentiation Method Using Contrast Agent Inhalation
Twice as Accurate as Intravenous Administration
Expected to Contribute to Minimizing Lung Resection

▲Lung cancer. [Photo by Asia Economy DB]

[Asia Economy Reporter Junho Hwang] A fluorescence contrast agent inhalation technique to distinguish lung cancer has been developed domestically. Compared to the existing method of injecting a fluorescent contrast agent intravenously to distribute it throughout the body to differentiate lung cancer tissue, this new method reduces the amount of contrast agent to one-twentieth and shortens the diagnostic time from a full day to just 10 minutes. In particular, it can distinguish lung cancer cells about twice as clearly as before, which is expected to greatly improve the efficiency of lung resection surgery.

Inhaling Contrast Agent to Select Lung Cancer

This grip explains the principle of detecting the boundary of lung cancer using a fluorescent contrast agent. The inhaled fluorescent contrast agent ICG distributes to macrophages located in normal alveoli after inhalation, but in the lung cancer area, the alveolar structure is destroyed by cancer cells, significantly reducing the distribution of ICG.

The National Research Foundation of Korea announced on the 21st that Professor Hyung-Koo Kim of Korea University Guro Hospital and Professor Ji-Ho Park of the Department of Bio and Brain Engineering at the Korea Advanced Institute of Science and Technology developed a lung cancer detection technique using inhaled fluorescent contrast agents, which was introduced in the international surgical journal 'JAMA Surgery' published by the American Medical Association.

The research team, while studying inhaled anticancer drugs for lung cancer treatment, confirmed that the inhaled fluorescent contrast agent was distributed only in normal tissues excluding lung cancer tissue. Based on this, they researched a technology that selectively detects only lung cancer. As a result, instead of administering the fluorescent contrast agent indocyanine green intravenously, they developed a method to select lung cancer cells by inhalation.

Indocyanine green is a fluorescent contrast agent approved by the U.S. FDA. When injected intravenously, it distributes throughout the body via the bloodstream, enabling angiography of the fundus vessels, or is absorbed by liver cells and excreted into bile without intestinal circulation, thus used for liver function tests.

The research team confirmed that when indocyanine green is inhaled, it does not adhere to lung cancer where alveolar structures are destroyed but attaches to normal alveoli. This clearly delineates the boundary between lung cancer cells and normal cells, much like the difference between a city with streetlights on during night flights and a dark forest.

When indocyanine green was inhaled by experimental mice and rabbits, the lung cancer boundary could be identified about twice as accurately compared to intravenous administration. Furthermore, the boundary was distinguishable in human lung cancer tissues as well, securing clinical applicability.

Contributing to Minimizing Lung Resection

This graph compares the lung cancer detection efficiency according to the method of fluorescent contrast agent administration (intravenous injection or inhalation). The analysis of the elapsed time from 1 hour to 24 hours after administering the fluorescent contrast agent ICG showed that the inhalation method (yellow graph) had significantly higher lung cancer margin detection efficiency compared to the intravenous injection method (teal graph).

The research team believes this can maximize the efficiency of lung resection surgery caused by lung cancer. As the boundary between lung cancer cells and normal cells becomes clearer, normal cells can be preserved as much as possible without unnecessary resection. Additionally, compared to the existing intravenous injection method that requires administering contrast agents throughout the body, the amount of contrast agent can be reduced to one-twentieth, minimizing side effects caused by the contrast agent. The time to confirm lung cancer lesions can also be drastically shortened from 24 hours to 10 minutes, enhancing surgical convenience.

The research team stated, "Further studies on the toxicity of the inhalation method need to be conducted before clinical use," and added, "We plan to carry out follow-up research on this matter."

This content was produced with the assistance of AI translation services.