For a large proportion of those diagnosed with cancer, surgery is often the first line of treatment. The idea is to remove as much of the diseased tissue as possible, then use pharmaceuticals to remove any diseased tissue that remains. However, cancer cells are notoriously difficult to visibly differentiate from our non-diseased cells, making it very hard to precisely remove the diseased mass without taking too much healthy tissue with it. To make sure that all of the cancer has been removed by the operation, surgeons take tissue biopsies from around the tumour site which are then analysed under a microscope to see if there are any remaining cancerous cells. If there are, there is often need for a follow-up operation to remove the remaining affected areas.

Samuel Achilefu and his team at Washington University have addressed this problem by labelling molecules on the cell surfaces of cancerous cells, and highlighting them with visible green light in real time during surgery. Initially, this process involved using a dye to specifically label cancerous cells in the area of interest. The detection of these fluorescently labelled cancer cells worked via a camera mounted above the operating table.

The image was processed to enhance the contrast and reduce background staining. Green light was then projected back onto the patient (a rat in this case) in the areas with cancer cells, lighting up diseased areas which would otherwise be difficult or impossible to see with the naked eye and helping to define the edges of tumours. The system was dubbed Optical Projection of Acquired Luminescence (OPAL).

OPAL, however, evolved before its first trial in a human on February the 10th 2014. It now incorporates the use of ‘smart glasses’ to visualize the image (the highlighted location of cancer cell masses), instead of projecting it directly onto the patient. Dr Julie Margenthaler, who performed the first operation on a patient with breast cancer using the smart glasses, said “the glasses may eliminate the need for follow-up procedures”. She also acknowledges that the technique and technology are still very much in their infancy.

Samuel Achilefu states that there are still a number of hurdles to overcome in order for this imaging method to reach its full potential, getting a more appropriate chemical label approved for medical use being one of them.

With improved treatment options and the potential this imaging technique brings to the table, cancer is certainly no longer a death sentence. It has become survivable, and as we slowly step forward in the field of medical science, it is becoming curable.

 

Oli Purnell