Researchers at Washington University in St. Louis have developed a new imaging technique for melanoma. For melanoma resection it is very important to obtain tumor free margins in order to prevent recurrence. Photoacoustic imaging works by absorption of light by tissue which causes slight heating (a matter of millikelvins) and with that thermoelastic expansion. By using pulsed light, an acoustic signal can be generated using this effect. Photoacoustic tomography detects structures that strongly absorb light such as melanomas which contain melanin. However even melanoma images are still fuzzy using only this method, so the researchers decided to use gold nanocages as a contrast agent. Using nanocages bioconjugated with a certain type of melanocyte-stimulating hormone, they were able to capture high-resolution photoacoustic tomography images where margins are clearly visible. Potential applications of this technique include detection of early stage melanomas and metastatic lymph nodes, treatment using photothermal effects and image-guided surgical resection. Here’s a short video showing the obtained images:
Press release: Seeing melanoma…
Article abstract: In Vivo Molecular Photoacoustic Tomography of Melanomas Targeted by Bioconjugated Gold Nanocages…