From the March 2011 issue of HealthCare Business News magazine
“Photodynamic therapy classically means using a laser device to excite a drug or some substance within a cell or tumor to cause fluorescence, so it gives off light to be able to detect something, or to destroy the tissue or lesion by various mechanisms, one of which is causing the compound in the tissue of interest to retain oxygen radicals, among other things,” says Dr. Raymond Lanzafame, a general surgeon in private practice in Rochester, N.Y. Lanzafame is also editor of Photomedicine and Laser Surgery and director of education for ASLMS.
This technique is already being used in ophthalmology to treat macular degeneration and in urology to treat bladder cancers.
“Success of photodynamic therapy has been mostly outside of the U.S.,” says Jansen. “From a regulatory standpoint it’s been a real nightmare getting this into the broader arena in the commercial sector.”
Light nanomedicine
In the research lab, photodynamic therapy is now moving into the realm of nanomedicine. Scientists are uniting gold and other metal particles and therapeutic antibodies and using light energy to heat up the tissues containing the nanoparticles for a highly targeted cancer therapy. If approved, this form of nanomedicine could be introduced into clinical use in as little as five to 10 years.
“The appeal of these kinds of technologies is that you can get to things you might not otherwise get to easily in a classical surgical paradigm,” says Lanzafame.
Photobiomodulation
Low-intensity light therapies are also being used to manipulate cell biology for a range of ameliorative effects from pain relief and wound healing to the promotion of spinal cord tissue regeneration.
“What that discipline is most centered on is the interaction of tissues with light so that one can turn on or off various cellular processes,” says Lanzafame. “There’s a whole cadre of science and research being done in that discipline.”
Preventing resurgeries
Optical diagnostics are becoming a focus in the operating room and may end up saving patient’s lives and a great deal of money. No matter how experienced a surgeon is, statistics show that about 40 percent of cancer surgeries fail to eliminate all traces of the cancer, requiring additional surgeries, says Jansen. “We have the laser sources and we have these fantastic tools to do microsurgery on all sorts of tissues with almost cellular precision, but right now, unless you know what to cut and what not to cut, it doesn’t do you any good.”
New imaging and spectroscopy devices are enabling real-time optical diagnostics during surgery. Surgeons can shine white light on tissues or use fluorescence and analyze the returning spectrum of light to make diagnoses about tissues.
