So many people ask us – how does PDT actually treat cancers below the skin’s surface. Well, as the video clip here shows, it really is a very simple process.

So often, medics will tell patients that PDT can only treat surface cancers. You are about to find out how PDT does it.

The procedure is called ‘interstitial’. Fine, hollow fibers are inserted through the skin using modern image guidance techniques to target the cancer.

The light will only travel a circumference of about 2 cm from the source of the light, so in the clip you will see there are three fibres down which the light filaments will be passed. The aim is get the light exposure to the full area to destroy the whole target area.

This technique is used now in the PDT treatment of prostate cancer, with a matrix of light filaments being used. A cancer is three-dimensional, so the light sources need to reach the whole area: top, bottom, left, right and centre.

It is exactly the same process being used now in the pancreatic cancer trial.

With the treatment you will see, the cancer area is quite ‘flat’, so only three fibres are being used. But in the prostate and pancreas you might use three, four or even more light filaments.

The lights are green when they are inserted – not activating the drug or dong any other damage. It is only when the light is switched to the red wavelength is the treatment active.

With this drug treatment, we need just 200-seconds of light.

While you watch this clip, you are actually watching a cancer being destroyed with PDT.

It really is that simple.