Optical Dosimetry by Monte Carlo Simulation in Biological Tissue in Optical Treatment of Rheumatoid Arthritis

Aim This study aims to perform optical dosimetry in the patient's chest using Monte Carlo simulation, quantifying absorbed optical energy and photon fluence as a function of depth in biological tissue during arthritis rheumatoid photo‐treatment. Method The MCLTmx code was employed to simulate light transport. A 532, 630, 660, and 850 nm external monoenergetic light source was simulated. The optical energy deposited and photon fluence as a function of depth were calculated under the structural arrangement: source‐air‐skin‐fat‐muscle . Results Experimental validation was successful. The results indicate that the skin receives, on average, three orders of magnitude more optical energy than fat and muscle for all wavelengths. Conclusion The dosimetry developed in this manuscript will serve as a valuable tool to correlate the power of the light source with dosimetric quantities, such as absorbed optical energy and photon fluence, and subsequently with the response to phototreatment. Once this correlation is established, the required irradiation time and power to produce favorable effects in patients suffering from RA can be calculated.