<figcaption> Credit: © 2003 Nature Publishing Group</figcaption>
Credit: © 2003 Nature Publishing Group

Sentinel lymph node biopsy, in which lymph nodes that receive direct drainage from a primary tumor site are excised to determine the extent of metastasis, is routinely used to accurately stage melanomas and breast cancers. The technique is time-consuming, difficult to learn, and involves the injection of a potentially hazardous radioactive tracer and a blue detection dye with temporary side effects.

John Frangioni at Beth Israel Deaconess Medical Center in Boston and colleagues harnessed quantum dot technology to map skin sentinel lymph nodes in vivo in mice and pigs using near-infrared fluorescent imaging.


?Using safe and visible light, we could eliminate the radioactivity and blue dye and still perform the procedure ? in a very short period of time,? Frangioni says.

They reduced a procedure that normally takes 20 minutes to something that takes less than a minute by employing a new type...

Since the initial study, Frangioni?s team has published seven additional papers detailing the technique in other tissues, and has several currently in press. But Q-dots still aren?t ready for human use, he says. ?There are regulatory issues and safety issues that are completely unresolved at this point.


1. S. Kim et al., ?Near-infrared fluorescent type II quantum dots for sentinel lymph node mapping,? Nature Biotechnol, 22:93?7, 2004. (Cited in 81 papers)

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