Nature Medicine (2011), doi:10.1038/nm.2472.
van Dam, G. M. et al.
“Intraoperative tumor-specific fluorescence imaging in ovarian cancer by folate receptor-α targeting: first in-human results”.
Thanks to fluorescent labels that help them to spot cancerous tissue, surgeons have removed ovarian tumour cells that might otherwise have been left behind.
Most malignant ovarian tumours express high numbers of receptors for the molecule folate (also known as vitamin B9), so by attaching the fluorescent molecule fluorescein iso-thiocyanate to folate, researchers created a cancer-cell probe. After injecting this into patients, labelled cells were made to glow white with a special camera and light, allowing surgeons to spot cancerous tissue even when cells were otherwise indistinguishable from their healthy counterparts.
“This provides more accuracy and more certainty for clinicians to remove cancerous cells in real time during surgery,” says study leader Vasilis Ntziachristos of the Technical University of Munich in Germany. The results are published in Nature Medicine.
Of all the gynaecological cancers — ovarian, vaginal and uterine — ovarian is the greatest killer of women in both theUnited StatesandEurope. Removing as much cancerous tissue as possible during surgery is crucial to giving post-operative chemotherapy the best possible chance to kill the remaining cancer cells.
“This advance represents a real paradigm shift in surgical imaging,” says Ntziachristos. “Until now we could only rely on the human eye to find carcinogenic tissue, or non-specific dyes that would colour the vascular tissue as well as particular cancer cells. Now we are going after precise molecular signals and not simply physiology.”
As a result, in this preliminary study, surgeons were able to remove tumours less than one millimetre in size. In principle, Ntziachristos says, the technique could locate spots of carcinogenic tissue as small as 50 micrometres.
