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, St O₂, 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.