Light Beams Reach Deeper to Kill Cancer

Advances in photodynamic therapy have enabled researchers to potentially treat cancer by simply beaming light at tumors deep inside the body.

No, we're not talking about something from science fiction here. A spread of green light doesn't just pass over a patient's body and they're cured, but this may be the closest we've ever come to such fantastical technology.

Photodynamic therapy - the use of lasers to activate cancer-killing drugs called photosensitizing agents - has actually been around for some time now. As things stand, it can only be used to treat surface tumors, such as oral and skin cancers, largely because the activating light simply cannot pass through solid tissue to activate cancer-fighting drugs deeper in the body.

However, that may all change soon. According to a study published in the journal Nature Photonics, researchers from the University of Buffalo have developed a way to create drug-activating light that can penetrate deep within a patient's body. According to co-author Tymish Ohulchanskyy of the University of Buffalo' Institute for Lasers, Photonics and Biophotonics (ILPB), his team was able to make near-infrared beams that convert into visible light as they penetrate deeper into a human body.

"We expect this will vastly expand the applications for an effective cancer phototherapy that's already in use," he said in a university news release.

According to the study, it is simply a matter of the frequency and angle of the light projected. Depending on what the beam passes through, components in the human body such as collagen and other proteins can naturally convert near-infrared light into visible light through professes called "second harmonic generation" and "four-wave mixing."

Of course, according to the study, careful calculations must be made to ensure the proper conversion of the light, but there are no adverse effects from the near-infrared light in the event of a failure.

The University of Boston is reportedly applying for a patent to protect the team's discovery, which may arguably be superior to other solutions to photodynamic therapy's limitations, such as making the drugs themselves sensitive to infrared light rather than visible light.

The study was published in Nature Photonics on May 11.