New optical sources for interstitial and metronomic photodynamic therapy

Multiple clinical studies have shown that interstitial photodynamic therapy (iPDT) is a promising modality in the treatment of several cancers. Laser fibers are usually inserted into the target tissue via needles, or placed in catheters. However, they must be removed from the body soon after use. Innovative implantable and biodegradable light sources could offer interesting alternatives since they not need to be removed as they are gradually resorbed by the tissue. Bioabsorbable polymer optical waveguide are relatively easy to manufacture and can deliver substantial light intensities. Near-infrared rechargeable "optical battery" can be easily optimized in size and shape aiming at different nidus sites. Further studies should evaluate the safety of the biodegradation process which will be required in order to approve these light sources on humans.