title: Effect of photothermal therapy on breast tumor vascular contents: noninvasive monitoring by near-infrared spectroscopy.
abstract: The goal of this study was to investigate the effect of photothermal laser irradiation on rat breast tumor (DMBA-4) vascular contents. An 805-nm diode laser was used in our experiment with a power density ranging from 0.32 to 1.27 W/cm2. The dynamic changes of oxygenated hemoglobin and total hemoglobin concentrations, delta[HbO2] and delta[Hb]total, in rat tumors during photothermal irradiation were noninvasively monitored by a near-infrared spectroscopy system. A multichannel thermal detection system was also used simultaneously to record temperatures at different locations within the tumors. Our experimental results showed that: (1) photoirradiation did have the ability to induce hyperthermic effects inside the rat breast tumors in a single exponential trend; (2) the significant changes (P < 0.005) of delta[HbO2] and delta[Hb]total in response to a low dosage of laser irradiation (0.32 W/cm2) have a single exponential increasing trend, similar to that seen in the tumor interior temperature; and (3) the increase in magnitude of delta[HbO2] is nearly two times greater than that of delta[Hb]total, suggesting that photoirradiation may enhance tumor vascular oxygenation. The last observation may be important to reveal the hidden mechanism of photoirradiation on tumors, leading to improvement of tumor treatment efficiency.
authors.affiliation: Biomedical Engineering Program, University of Texas at Arlington, Arlington, TX 76019, USA.
authors.forename: Yueqing
authors.initials: Y
authors.lastname: Gu
authors.forename: Wei R
authors.initials: WR
authors.lastname: Chen
authors.forename: Mengna
authors.initials: M
authors.lastname: Xia
authors.forename: Sang W
authors.initials: SW
authors.lastname: Jeong
authors.forename: Hanli
authors.initials: H
authors.lastname: Liu
mesh_terms: D000818:Animals; D001831:Body Temperature; D005260:Female; D006454:Hemoglobins / Q000528:radiation effects; D006979:Hyperthermia, Induced; D015674:Mammary Neoplasms, Animal / Q000628:therapy*; D010108:Oxyhemoglobins / Q000528:radiation effects; D010789:Phototherapy; D051381:Rats; D013055:Spectrophotometry, Infrared
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins