BACKGROUND: Photobiomodulation therapy (PBMT) is recommended for the prevention of oral mucositis (OM) in cancer patients. Transcutaneous, extraoral delivery of PBMT with LED arrays, versus intraoral delivery with laser, may be more effective for treatment of at-risk sites and better tolerated by patients. The objective was to develop an evidence-based extraoral PBMT treatment protocol.
METHODS: We previously demonstrated that Monte Carlo modeling accurately simulates in vivo transmittance measurements. Archival MRI studies (n=18) were used to determine anatomical structures along the trajectories of 850 nm light through the cheek, lip, mandible angle and neck. Optical properties of skin, fat, muscle, cartilage, and blood were obtained from literature, and Monte Carlo modeling was performed for skin types I and VI. Simulation results were used to determine the treatment time needed to deliver a median dose between 1 and 6 J/cm2 to the mucosa.
RESULTS: Cheek had greatest variability in thickness (13-29 mm) corresponding to a 25-fold difference in the mucosal fluence rate. Despite tissue differences, fluence attenuation is primarily determined by the overall thickness of all tissue
|