This recent article by Lavaud et al. uses high-frequency ultrasound and spectroscopic photoacoustic imaging (PAI), along with commercially available contrast agents to non-invasively examine metastatic liver lesions.
- A mouse model of liver metastasis originating from colon cancer was used for the study.
- PAI and fluorescence (fDOT) imaging, along with commercially available dyes, AngiostampTM800 and ICG were used to monitor liver metastasis development.
- Contrast agent-free PAI showed overall increase in liver HbT signal relating to tumor angiogenesis, and contrasting decrease in oxygen saturation (sO2) reflecting hypoxia development during metastasis.
- Multispectral imaging of ICG showed a decrease in signal during metastasis development, correlating with liver function decrease.
- ICG imaging along was unable to differentiate between liver metastasis stages.
- PA imaging of tumor targeting AngiostampTM800 allowed differentiation between healthy, early and advanced stages of liver metastasis.
- PAI provided higher significance in the metastatic stages discrimination than fDOT.
- Fluorescence imaging, although more sensitive, provides limited depth information and do not allow tissue differentiation, which are both achievable with PA.
Angiostamp800 was introduced for the first time as a new commercially available PA contrast agent with tumor targeting specificity. It allowed for non-invasive photoacoustic and florescence detection of liver metastases, and showed discernible signal changes between early and advance stages of the disease. This presents a potential tool for cancer development and therapeutic monitoring.
- Lavaud, J. et al. Noninvasive monitoring of liver metastasis development via combined multispectral photoacoustic imaging and fluorescence diffuse optical tomography. Int. J. Biol. Sci. 16, 1616–1628 (2020).