Effect of skin color and other skin properties on the delivered light dose in phototherapy for neonatal hyperbilirubinemia

Significance: Hyperbilirubinemia is a common and potentially harmful condition in newborn infants. Phototherapy is the primary treatment for critically high bilirubin levels. Yet, the impact of patient skin properties and the wavelength of the phototherapy light on the delivered light dose remains unclear. Aim: We investigate the impact of patient skin properties, i.e., skin color, hemoglobin concentration, bilirubin concentration, light scattering, epidermal thickness, and subdermal tissue layer type as well as phototherapy wavelength on the delivered light dose and efficacy of phototherapy using a Monte Carlo model. Approach: The model simulates light transport through the skin to predict the delivered dose and its effect on the reduction in total serum bilirubin concentration after 24 h of treatment (Δ TSB _{0 − 24 h}). Results: Skin color, bilirubin concentration, and epidermal thickness significantly influenced the delivered light dose and predicted Δ TSB _{0 − 24 h.} Light dose varied by a factor of 5.7 between light and dark skin, with respective predicted Δ TSB _{0 − 24 h} reductions of 40.8% and 25.6%. The optimal wavelength for phototherapy shifts from 460 nm for light skin to 470 nm for dark skin. Conclusions: These findings highlight the need for further research into personalized phototherapy protocols to enhance treatment efficacy, particularly for hyperbilirubinemic newborn infants with darker skin.