Noninvasive diffuse optical measurement of blood flow and blood oxygenation for monitoring radiation therapy in patients with head and neck tumors: a pilot study

This pilot study explores the potential of noninvasive diffuse correlation spectroscopy (DCS) and diffuse reflectance spectroscopy (DRS) for monitoring early relative blood flow $(rBF)$, tissue oxygen saturation $(StO2)$, and total hemoglobin concentration $(THC)$ responses to chemo-radiation therapy in patients with head and neck tumors. $rBF$, $StO2$, and $THC$ in superficial neck tumor nodes of eight patients are measured before and during the chemo-radiation therapy period. The weekly $rBF$, $StO2$, and $THC$ kinetics exhibit different patterns for different individuals, including significant early blood flow changes during the first two weeks. Averaged blood flow increases $(52.7±9.7)%$ in the first week and decreases $(42.4±7.0)%$ in the second week. Averaged $StO2$ increases from $(62.9±3.4)%$ baseline value to $(70.4±3.2)%$ at the end of the second week, and averaged $THC$ exhibits a continuous decrease from pretreatment value of $(80.7±7.0)$$[μM]$ to $(73.3±8.3)$$[μM]$ at the end of the second week and to $(63.0±8.1)$$[μM]$ at the end of the fourth week of therapy. These preliminary results suggest daily diffuse-optics-based therapy monitoring is feasible during the first two weeks and may have clinical promise.