Fiber Bragg Gratings For Cancer Treatment

Hyperthermia is a therapeutic approach that is used to treat or limit the growth of certain types of cancer. This process involves heating the cancerous tissue up to temperatures in excess of 40 °C in order to achieve cell death.  Ideally, this temperature increase would be local to an applicator in order to reduce the amount of surrounding healthy cells that would be destroyed.  In the past, temperature monitoring was achieved external to the applicator with the use of a thermal couple or similar temperature sensor.  Our group has recently investigated the use of a tilted fiber Bragg grating (TFBG) as a means of killing cancer cells while simultaneously monitoring the local temperature.  The grating planes in a TFBG act to couple radiation to the cladding or radiation modes of the fiber.  While the magnitude of the spectral peak at the Bragg resonance is reduced it is still possible to monitor it to measure the local temperature of the fiber.  When the fiber surface surrounding a TFBG is coated with an absorbing material such as a dye or metal the light coupled out of the core heats the coating and the surrounding environment.  The TFBG based device is simple to fabricate, robust and does not require an external temperature measurement.